Space and Atmospheric Studies
Focus of Studies at ISAS
|On almost any night, the aurora dances across the northern sky and is a manifestation of one of the more subtle connections the Earth has with its celestial guardian, the Sun.|
|Human activities as well as solar terrestrial processes are modifying our "atmospheric environment". Longterm variations in solar output, the depletion of ozone, changes in volcanic dust aerosols, and the increases in Green House Gases all contribute to "Climate Change" and influence the ability of the Earth to protect and provide for its inhabitants. The 'space environment' near the Earth is increasingly used for satellites to enhance communications, navigations, earth remote-sensing and to provide a unique habitat for Humans. It is a hazardous environment and requires knowledge of "Space Weather". We explore the climate and storms of space, and are developing the ability to forecast the weather of space. The two themes of 'Climate Change' and 'Space Weather' are major activities of the members of ISAS.|
The Past and Present
The Institute of Space and Atmospheric Studies (ISAS) was formed in 1956 to study the aurora (northern lights), the related 'disturbances' in the upper atmosphere and ionosphere, and the effects of solar activity upon climate. Since that time members of the Institute have expanded the world's knowledge and understanding of how the sun and the earth interact; and trained more than 200 scientists and engineers in a wide range of technical and scientific areas. ISAS developed observing systems for space and atmospheric sciences, ground based optical and radar instruments, and satellite systems, remote sensing technology, and knowledge of STP processes are a vital resource for "Canadian Space Science" and couples powerfully into high-technology industries.
Currently the Institute consists of approximately 40 persons: 6 Physics and Engineering Physics professors who are also Principal Investigators of ISAS programs (plus 3 Emeriti), 2 Adjunct Professors, 3 Research Associates, 6 Research Assistants and Engineers, 1 Technician and 1 Clerical Admininstrative staff and 19 Grad Students. It is the largest and most comprehensive Solar-Terrestrial Physics (STP) and Atmospheric Science Institute in Canada. The members of ISAS work in conjunction with other Canadians and with international teams of scientists, engineers, and technologists. Out colleagues are in Eruope, Scandanavia, Russia, China, India, Australia, Africa, South America, the United States, and Japan.
It is the largest and most comprehensive STP Institute in Canada. The members of ISAS work in conjunction with other Canadians and with international teams of scientists, engineers, and technologists. Our colleagues are in Europe, Scandanavia, Russia, China, India, Australia, Africa, South America, the United States, and Japan.
ISAS's research activities are supported by the University of Saskatchewan, the Canadian Space Agency (CSA), the Natural Science and Engineering Research Council (NSERC) through grants to individual professors, and the Meteorological Service of Canada (MSC).
Auroral Processes, and the related magnetospheric changes, are areas of high priority for research by the Solar Terrestrial Physics community in Canada and internationally (Jean-Pierre St-Maurice, Sasha Koustov, Glenn Hussey. Kathryn McWilliams and George Sofko(Emeritus)). The term "space weather" has been developed to describe the periods of calm and storm in "geospace" near the earth (above 100 km), due to processes that occur on the sun. Understanding and eventual prediction of these storms is desirable, as their effects upon space vehicles and ground based energy distribution systems are serious. A number of communications satellites have been lost (two $100 million Canadian ANIK satellites in one day in January, 1994) due to "geospace" storms, and lost economic activity totalling billions of dollars was suffered by Quebec and the northeastern US during the power blackout of March, 1989.
In ISAS, these processes have been studied for many years, using ground-based optical and radar systems and satellites which sample the magnetospheric space or "geospace" in addition to observing the aurora from above and below.
The major project of these scientists is the highly successful international Super Dual Auroral Radar Network (SuperDARN)(George Sofko (Emeritus) et al), in which pairs of HF (high-frequency) Doppler radars are used to measure, for both hemispheres, the ionospheric velocity and electric field patterns, and also the voltage map. In principle, each radar pair can measure a region of the ionosphere over 3 million square kilometers in size, and can do this for 24 hours each day. These fields-of-view (FOVs) are so large that the radars are ideal instruments for joint studies with satellites which are at very high altitudes but sample along the same magnetic field lines. These stretch from the distant magneto-sphere to the ionosphere. Large and small-scale tornado-like vortex motions, located in the ionospheric flow patterns, are correlated with solar wind fluctuations obtained by satellites located about 1.5 million kilometers from the earth. In January 2002, there were 15 operating radars, 9 in the northern and 6 in the southern hemisphere. Substantial funding has been provided for SuperDARN by Canada, the United States, France, Great Britain, Japan, South Africa, Australia, and Italy. The ISAS team controls the Saskatoon, Prince George, Rankin Inlet, Inuvik and Clyde River radars, whose partners are the US-run radars at Kapuskasing, Ontario, and Kodiak, Alaska, respectively.
To find out more about SuperDARN, go to superdarn.usask.ca
Ionospheric MotionJean-Pierre St-Maurice, Sasha Koustov, Glenn Hussey, and Kathryn McWilliams use radars to study motions in the earth's ionosphere, the region above 100 km in which auroras occur. These motions are caused by electric fields generated far above the ionosphere when the solar wind blows against the earth's magnetosphere. As a result, by studying the ionospheric motions, we can learn a great deal about the transfer of energy to the earth's magnetosphere from the sun via the solar wind.
VHF RadarsThe group also uses VHF (very high frequency) radars for studies of the lower ionospheric E-region, located about 100-120 km above the surface (Glenn Hussey, Alan Manson(Emeritus)). These radars are used to study the very complex plasma physics in this region and are also very useful for auroral substorm studies. During substorms, currents of over 10 million Amperes, driven by voltages of 100,000 Volts or more, can flow in the ionosphere, generating power equivalent to that from ten thousand 100 MegaWatt electrical power stations on the earth!
Ozone DepletionAtomic oxygen, which is essential to the formation of ozone, is formed in the upper atmosphere, from the photodissociation of molecular oxygen, and then transported downward, where it is eventually converted to ozone. Control over the quantity of ozone in the atmosphere occurs in both the region of maximum concentration, where it is attacked by chemicals resulting from human activity, and in the high atmosphere (>100 km) far removed from the `biological shield'. It is the significant reduction in the ozone column that occurs In late winter (related to "Sudden Stratospheric Warmings" (SSW) and in early spring that has provided direct evidence for the impact of human activities on the atmosphere. However, the full details of the processes for ozone-loss, and those which control global warming are still not adequately understood.
Infra Red Aeronomy and Atmospheric Remote SensingOne way to improve our measurement database and understanding of those processes responsible for ozone deletion and global change is through the development of new and improved satellite-borne remote sensing instrumentation. The OSIRIS instrument onboard the Odin spacecraft measures vertical profiles of spectrally dispersed, limb scattered sunlight from the upper troposphere into the lower mesosphere. OSIRIS has been in standard operation since November 2001 and routinely produces height profiles of O3, NO2 and stratospheric aerosols. These products have been used to investigate the effects of volcanic eruptions on climate, the long term trends in changes in the ozone layer, and the physics and chemistry of the mesosphere. The OSIRIS instrument concept (and the related atmospheric science) was developed by the ISAS "Infra Red Aeronomy Group" led by Ted Llewellyn.
Atmospheric DynamicsThe wind and weather systems that transport ozone and other GHG (Green House Gases) into the High Arctic, while determining the annual Polar Vortex structures, provide the isolated northern polar environments for the late winter (SSW) and spring-time destruction of ozone. These are observed and studied with ISAS's ground based radars and the highly sophisticated spectrograph and IR imager of OSIRIS. The three MF radars of Alan Manson's "Atmospheric Dynamics Group" at Saskatoon, Platteville and Tromso, as well as the Meteor Winds Radar at Eureka 80N, Ellesmere Island, measure atmospheric motions from 60-100 km and provide data for the background winds and atmospheric tidal, planetary, and gravity waves. Such waves re-distribute solar energy, and energy associated with weather systems, throughout the entire earth's atmosphere, which stretches from the ground to over 100 km and includes equatorial structures and the "Polar Vortex" of the winter's northern latitudes. These ISAS radars are part of a growing global network of wind sensors, and tell us much about the controlling processes for climate change. Satellite optical interferometers (eg. WINDII, TIDI) measure wind speed and direction by looking at the change in the colour of light (Doppler effect). The combination of high resolution spatial and temporal observations, provided by satellite and ground-based systems, is very synergistic. Already we know that equatorial processes modify the "Polar Vortex", which is the dominant thermal and wind system for middle to polar latitudes during winter and adjacent equinoctial months.
Global Studies of Climate ChangeCollaborations within programs such as the new 2014 international VarSITI program (Variablilty of the Sun and Its Terrestrial Impact) within SCOSTEP (Scientific Committee on Solar Terrestrial Physics) and SPARC (a project of the "World Climate Research Program") allow processes of 'Climate Change' to be studied globally. The new "Probing the Atmosphere of the High Arctic" (PAHA) Program (2013-2017 within NSERC's new "Climate Change and Atmospheric Science" Program, is centred on PEARL [Eureka 80N], and includes an ISAS-led project on the "Polar Vortex". Led by Alan Manson, studies already show that disturbances in the structure of the Polar Vortex during the winters of 2012/13 and 2013/14 are leading to strong outflows of frigid Arctic air over Canada, USA and Europe, throughtout the winter season (November-March)...causing dangerous and "unseasonable" wind, snow and ice conditions, with human and livestock deaths and injuries along with interference in travel and commercial activity. Collaborations with Environment Canada's Meteorological Service are focused upon incorporating these proecesses into Weather Forecasts of expanded duration using their GEM numberical model. Many of these dynamical processes have dimensions which are hemispheric or global. It is also vital to investigate trends in ozone concentration, temperature, and atmospheric dynamics which are occurring over time scales longer than solar cycles (about 11 years), and which also contribute to "Global Climate Change".
Careers & Grad Studies
The Institute of Space and Atmospheric Studies (ISAS) is a research unit of the University of Saskatchewan offering career opportunities for:
- Post Doctoral Fellows
- Research Associates
- Research Engineers
- Visiting Research Scientists
- Graduate Students
Degrees may be awarded in the disciplines of:
- Engineering Physics
- Environmental Engineering
National and International Programmes
- CAWSES (2004-2009) global programmes for 'Space Weather' and 'Climate Change' of SCOSTEP (Scientific Committee on Solar-Terrestrial Physics)
- CEDAR (Coupling Energetics and Dynamics of Atmospheric Regions - U.S.)
- Satellites such as UARS (WINDII, HRDI), MOPITT, ISO-LWS, Odin-OSIRIS, TIMED, ACE
- Canadian CANOPUS and International-SuperDARN programmes
- SPARC (Stratospheric Processes And their Role in Climate), a project of the World Climate Research Programme
Global Change and Space Weather
- The chemistry and physics of the troposphere and middle atmosphere, including production and loss mechanisms for environmentally important molecules e.g. ozone, using ground-based and satellite observing-systems
- Atmospheres of other planets in the solar system to study planetary formation and evolution, using infrared spectrometers on telescopes and satellites (planetary astronomy)
- The dynamics of the middle atmosphere (55-110 km), including measurements of atmospheric waves, turbulence, and related airglow parameters, using MF radars, optical- and satellite-systems
- The auroral E and F regions (100-300 km), focusing upon plasma instabilities, waves and convection patterns, using local VHF/MF radars, and the HF SuperDARN global network
- The magnetosphere, including solar wind interactions, and coupling with the ionosphere and thermosphere, using SuperDARN, satellites and numerical modelling
For well qualified graduate students:
Dr. A.H. Manson, Executive Secretary
Institute of Space and Atmospheric Studies
University of Saskatchewan
116 Science Place
Saskatoon SK S7N 5E2 Canada
The OSIRIS instrument onboard the Odin spacecraft measures vertical profiles of spectrally dispersed, limb scattered sunlight from the upper troposphere into the lower mesosphere. On these pages you will find the user registration, documentation and browse imagery for Odin-OSIRIS Level 2 data products. OSIRIS has been in standard operation since November 2001 and routinely produces height profiles of O3, NO2 and stratospheric aerosols. The Odin satellite also runs a sub-millimeter radiometer (SMR) that measures profiles of many other atmospheric species.
Professor Alan Manson (Physics and Engineering Physics, Emeritus), Dr. Chris Meek (Research Associate, Emeritus), Dr. Zhenhua Li (CANDAC-PAHA PDF)
Our group studies the Dynamics of the Mesosphere, Stratosphere and Tropopause, or Middle Atmosphere (circa 10 - 100km) … below us is the obscure ‘boundary layer’ or biosphere, while 100 km is near the seasonally height-varying Turbopause. We avoid chaos! The observing instrument is mainly the “Medium Frequency Radar” (MFR, or MF 2.2Mhz at Saskatoon, 52N 107W) which has operated continuously since 1979, or for 3.5 solar cycles, SC; the second MFR is located (since 1987 and so 3 SC) at Tromso, Norway on the EISCAT site (70N, 19E). We have also operated MFRs at triangles of unique size: 40km using three receiving sites (GRAVNET) near Saskatoon (circa 1988); a 500km-sided triangle, with two additional MF radars (Robsart, Sask., 49N 109W; Sylvan Lake, Alberta, 52N 114W), which were developed for the Canadian Network for Space Research (CNSR 1992-97); and another MF (forming a NS pair) located at Platteville (Colorado, 40N 105W) as part of the CEDAR program (2002-2015). The addition of international colleagues with an MF at London (1997-2005; Canada 43N, 81W), and two MFRs in Japan (Wakkanai, 45N, 142E; Yamagawa, 31N, 131E), along with our Platteville and Saskatoon MFRs, formed the CUJO Network (Canadian-USA-Japan Opportunity] 81W to 142E, years 2000-2007); and finally the ‘Scandinavian Triangle’ (sides 125 to 270km) with other colleagues for Andenes, (69N, 16E), Tromso (70N 19E) and Esrange (Meteor radar, 68N, 21E) for 1999-2008. Despite the words thus far on “techniques”, we do not allow the radar technique to dominate our research interests, which have always been atmospheric: top of boundary layer (5km) to turbopause (circa 100km), coupling between regions of the planet, tropical to polar, southern and northern hemispheres. Data from the above triangles are archived and would be willingly provided to those with collaborative ideas-papers beyond ours
The development of CANDAC-PEARL at Eureka, Ellesmere Island (80N) www.candac.ca has more recently provided a VHF meteor-scatter radar for winds and temperatures; this SKiYMET system was purchased from MARDOC Inc. Prof Manson is a Co-I for CANDAC [member of the Scientific Steering Committee], and along with Dr Meek “mentors” of the Eureka radar. We provide data to the CANDAC-PEARL Archive for international scientific community-collaborations; time sequences of preliminary data are available for perusal elsewhere at this ISAS web site. Our data archive runs from mid-February 2006, (with gap Sept.2013 to Sept.2015) and continues to this time (May 17, 2017).
The MFRs provide echoes from 55/75 to 110 km during day/night hours, and are analyzed by ‘spaced- antenna’ and interferometric techniques to provide winds and wave characterization with periods from 10 min. to 10 years (solar cycle intervals). For SKiYMET, neutral winds data are available from 82-97km. Atmospheric waves involve gravity waves (GW, 10 min to 15 h), tides that are migrating and ‘non-migrating with the sun’ (6-, 8-, 12- and 24-h), planetary waves (PW) (2 - 30d) and seasonal oscillations (12-, 6-, and 3-mths). The minimum period GWs from SKiYMET are 2 hrs; 10 min from the MFR. The three radars provide unique information on the spectral characteristics and wavelengths of these waves; the temporal variability and climatologies of the tides, GW and PW; latitudinal and longitudinal variabilities, structures and modes; and the physical coupling mechanisms between these various scales of motion. Tidal observations have been very successful in providing comprehensive knowledge of the seasonal variations of the 12- and 24-h migrating tides: 65-100km. Tides within the best GCMs, e.g. CMAM, are in useful agreement, but observed tides from Eureka (80N) and Svalbard (78N) are larger than modeled…also, their variability, which is due to non-migrating tides and specifically to Planetary Waves interactions, is larger than modelled.
Our research at Saskatoon has been and is coordinated with national and global-projects of SCOSTEP: “Scientific Committee on Solar Terrestrial Physics”, which match the interests of ISAS very well [Physics and Engineering Physics Dept, University of Saskatchewan], 1957 to present (May, 2017). SCOSTEP provides international collaborative programs and campaigns: VarSITI 2014-18 [Variability of the Sun and Its Terrestrial Impact], with our theme of interest, ROSMIC [Role Of the Sun and the Middle atmosphere / thermosphere / ionosphere In Climate).
During CAWSES (Climate and Weather of Sun-Earth System), 2004-08, Alan Manson led the ’Polar Vortex’ theme within CAWSES. We continue studies of the variabilities of the Polar Vortex within the ‘Polar Night’ Theme of CANDAC-PAHA: ‘Probing the Atmosphere of the High Arctic’, 2014-18. www.candac.ca Earlier completed SCOSTEP programs, for which archived data are also available include: Middle Atmosphere Program (MAP: 1982-85); Solar-Terrestrial Energy Program (STEP: 1990-97); STEP-Results, Applications, and Modeling Phase (SRAMP: 1998-2002); PSMOS (2002-2004. Satellite data are used from a variety of Missions: UARS-WINDII, UARS-HRDI, TIMED-SABER, -TIDI, Odin-OSIRIS, Aura-MLS, ACE-FTS. We are engaged/collaborate with the strong theoretical/observational activity within SPARC (Stratosphere-troposphere Processes and their Role in Climate) and MLT (Mesosphere Lower Thermosphere) communities. These involve tidal and PW studies; time-dependent gravity wave-, tide-, mean wind-structures within GCMs, whose results are usually consistent: Canadian GCM (GEM); CMAM-DAS, with integrated chemistry and ‘data assimilation’, DA; CMAM-30; UKMO-DA [UK Met Office] (used mainly), GEOS-DAS-5-MERRA. The US-based CEDAR programme (‘Polar Workshop’ e.g. Neutral Dynamics, 2017) also provides a regional North American framework for Middle Atmosphere (circa 10 to 100 km) research.
The nature of our CANDAC-PEARL (2005-17+) research [see nearby in this site for thematic research and papers] was collaboratively linked with CAWSES (2004-2008) and related continuations within ROSMIC, especially with the area of ‘waves and coupling processes’ at Eureka. Collaborations with other high latitude radars are engaged/essential e.g. Svalbard, Norway. Briefly: The Polar Regions are unique in the dynamics of the terrestrial atmosphere as they are in the vicinity of the Earth’s rotational axis. In the middle atmosphere they are seasonally and globally the site of large scale ascent and descent, summer/winter in the Arctic/Antarctic. Through our studies and models, also SCOSTEP programs, the consensus of atmospheric science communities is that global dynamics are driven by wave-breaking and dissipation [GW and PW], are either dominant or essential to understanding, knowledge and improved prediction capabilities of operational forecasting GCMs. On this latter, the MSC-EEEC has modest interest in what we are doing…lack of $- support appears to be a problem. Further, various oscillations within oceans and atmosphere [ENSO, AO (NAO), PDO and NPM, PNA] within which waves are imbedded, are jointly involved in rich explanations of large scale coupling processes in the various regions of the atmosphere. The Polar Winter Vortex [PV] is a dominant system for Canadian weather and climate. The purpose of our PAHA-CCAR [“Probing the Atmosphere of the High Arctic” (2014-2018) [Canadian Climate and Atmospheric Research-NSERC]) studies is, for the polar middle atmosphere [circa 10-100km], to identify large scale motions and constituent changes, and to link wave phenomena to the Earth’s large scale circulation and to scales of Canadian provinces. The primary objectives include:
- Investigation of wave signatures (gravity waves, tides and planetary waves) in the polar region, especially during disturbed conditions.
- Identification and characterization of the processes which couple the polar region to other regions of the global atmosphere and also the various altitude regions (troposphere, stratosphere, mesosphere/lower thermosphere) with each other … also longitudinal and hemispheric entities, since symmetry is not assumed.
- Unique phenomena that occur as a result of this coupling and the wave-types themselves: ‘sudden mid-winter stratospheric warmings’, SSW; global constituent and aerosol mixing; extreme variability of wind and temperature-systems; disturbed non-climatological polar latitude airglow signatures [used by GB optical systems without height-ranging]; noctilucent clouds, and systematic and abnormal changes in cloud occurrences associated with Climate Change and Solar Activity.)
A focus upon the ‘radiationally unexpected’ phenomena in the atmosphere, circa 10 to 100 km (middle atmosphere, MA) continues to engage and stimulate us. They offer enormous observational advantages. These events are so unique that they require extreme combinations of dynamics, chemistry and radiation to bring them into existence: phenomena such as SSW (SUDDEN stratospheric warmings) that suggest instabilities; mesospheric inversion layers [MIL]; equinoctial transitions…‘Final Stratospheric Warmings’ (of spring) as compared with mid-winter warmings (and are they really ‘Sudden’?); Stratospheric Warmings in the Arctic and Antarctica, with implications for “Ozone Anomalies”, and the “Winter Anomaly” (of D-region ionization )…all await deeper understanding. As example, is not clear that the polar stratospheres of the annual ‘two polar nights’, are comprehensively understood. Why there? No UV radiation! Also, the SSW studies focus upon 10hPa or 30 km, while the maximum energy and minimization occurs at 50-55 km! We have engaged in global studies throughout our careers and continue this essential dynamic … collaborations with colleagues at lower and tropical locations are welcomed.
The hemispheric differences in all of these phenomena must be considered…we are fortunate to live on ‘two-planets’. The studies must also be inclusive of all latitudes of the planet earth, as the equatorial regions have strong effects upon such phenomena, directly or indirectly, through dynamical processes. Their possible influences of Climate Change upon processes must be strongly in our thinking and strategies.
Optional! Thoughts on Research in Academe, 2017: the group at Saskatoon includes an emeritus senior scientist and research associate (Prof Alan Manson, Dr. Chris Meek), with PDF as PAHA funding allows (Zhenhua Li has been with us for three years [Feb 2014-May 2017]). We now look after the cost, maintenance and operation of the Saskatoon radar ourselves, as ‘Discovery Grant’-funding [expected base-line $ for well-behaved and productive academics on Nationally- and University-approved themes] from NSERC for senior scientists, such as we, is often not awarded. It seems that professors approved by Universities at Emeritus level, who were performing well and above average, for significant career-durations, should be awarded some reasonable subsistence level for ‘a few years’ [publications, attendance at conferences]. E.g. $10-15K pa. Otherwise, prominent Canadians suddenly vanish from the International scene, never to be seen again! This at a time when some Canadian Research Chairs remark that they have too many $, and that the demands placed upon them by the ‘system’ are then beyond reasonable human expectations. I also remark, for the interest of those reading this paragraph, that typical Discovery Grants are now less than half what this modest man received annually for most of his career [unadjusted $]. Further, we seniors have trouble supervising the ‘essential graduate students’ [to some, the main role of Academic-research is as a Grad-MSc/PhD factory for national-wealth], as another younger Professor is required as co-supervisor-colleague.
There is more to ‘say’: The Description of ‘methodologies’ for natural science research, within the NSERC Discovery Grant document, is somewhat unique [developed politically over the last decade] and fixated upon goals and deliverables [we are not all Engineers who design and build beautiful and useful things]. Certainly, quite unlike excellent writings by Professors of Philosophy on the ‘scientific method’ [realistic to we scientists], this Description reads as if directed toward students in an undergraduate Physics or Engineering Lab. [maybe not a splendid lab], where success is almost assured, and goals sensibly never in doubt. Dramatic occurrences testify to this, from conversations with groups of mature ‘grad-students’: They, who were well mentored in the methodology and practices of research (by their supervisors) and who then explain their [now understood /appreciated] approaches and methods in Applications for NSERC Grad Schols, have received rejections and criticism based upon their proposed ‘methods’. (As has Manson, in the second rejection [of my entire career, 49 years] of a Discovery Grant Application in 2012 (after fixing the problems noted in 2011 [reviewing systems have no memory]). Upon reflection, and discussions with Uni-staff who ‘trouble-shoot such issues’, they later submitted grad-applications with the ‘methods provided or inherent in the NSERC application material’, and were generally very successful. They did not believe what they had written was GOOD, or correct, but they had to ‘play the game…the only game in town’. They realized their use of deception. Profs also may have Uni-advisors with skills in writing a successful application…further potential deceit. But, again, when the philosophy espoused in Discovery Grant literature is strongly evident in their applications, success rates are high. Members of committees have bought into this dogma, recognize it easily, award/’reward’ the writers, and have made ‘appeals’ close to impossible, based upon written materials in the Guide…even when aspects of that process may lack ethical stance/actions and even logic. Evidence of ‘innovation’ is also required, explicitly, as if it were not usually there for Profs who write excellent and numerous papers in “good” journals. Such demands lead to exceptional claims by some applicants, although there is no indication that actual deliverables are being later assessed by ‘the system’. It is with great relief that we note another word has been added to ‘Innovative’ in major headings surrounding the ‘Science Review’…the writer cannot find that excellent word…I think it was “Discovery”! Of course…
A commonly heard remark is that if Einstein were a junior Professor in Canada today, he would have trouble in being awarded a Discovery Grant…mathematical theoretical physics? Methodology…? Experience informs me, as Scientist/Professor and Academic/Research Administrator of 50yrs in Canada, that when an Admin-program such as NSERC’s Discovery Grant is so much out of tune with the needs of Professors across the nation, the designers of the system/program are not listening to, or talking with, the Professors in the front line of activity…and maybe there are not enough active Academic Professors involved in the design of the program. ‘Canada’s Fundamental Science Review’, April 10, 2017, contains much fine detail and wisdom…but really nothing of the above has been perceived, and therefore is not addressed. The contamination of the Grant Applications literature is clever, subtle, almost invisible, yet dogmatic and powerful…a strong philosophical cleanser is needed, urgently.
We appreciate the support, collaborations with Prof Chris Hall at Tromso [1987-present], who operates the MF radar there.
Fortunately, opportunities do exist [my pension] for us to interact and network with other scientists in Canada, through CANDAC-PEARL, and in the international SCOSTEP community. The ground-based systems and their associated research in Canada are well integrated with CSA-Space Science involving satellite prototypes /missions or data-archiving, so that opportunities for collaborations also exist.
We welcome contacts from Atmospheric Scientists who find our research, publications and data interesting. The dates and International Programs for which data are archived and available are provided above. We are likely to be interested in joining with you on topics of mutual interest.
This group studies the Dynamics of the Mesosphere and Lower Thermosphere (MLT), or upper Middle Atmosphere (5 - 110 km). The observing instruments are a “Medium Frequency Radar” (MFR) at Saskatoon, which has operated continuously since 1979; and two MF radars, which were developed for the Canadian Network for Space Research (CNSR 1990-95). One is now located at Tromso, Norway on the EISCAT site (70N); the other is located at Platteville (near Boulder) as part of the CEDAR programme (40N). These provide data since 1987 and 2001 respectively. The development of CANDAC-PEARL at Eureka, Ellesmere Island (80N) www.candac.ca has provided a VHF meteor-scatter radar for winds and temperatures; this SKiYMET system was purchased from MARDOC Inc. Prof Manson is a Co-I for CANDAC [member of the Scientific Steering Committee], and along with Dr Meek “mentors” of the Eureka radar. We provide data to the CANDAC-PEARL Archive for international scientific community- collaborations; time sequences of preliminary data are available for perusal elsewhere at this web site. Our data archive runs from mid February 2006.
1. SIGNIFICANT RESEARCH CONTRIBUTIONS (2002-11) with Commentary (selected to demonstrate range of activity)
X. Xu, A. H. Manson, C. E. Meek, and J. R. Drummond, 2011. Quasi-biennial modulation of the wintertime Arctic temperature as revealed by Aura-MLS measurements. Geophysical Research Letters, accepted (2011GL047075) In Press.
This study investigates the interannual variability of zonal mean temperature in the wintertime Northern Hemisphere stratosphere and mesosphere measured by Aura-MLS (Microwave Limb Sounder). Results show that the wintertime Arctic temperature is modulated by the phase of the equatorial quasi-biennial oscillation (QBO) wind. On the whole, the 40-hPa QBO easterly phase corresponds to a warmer (colder) northern polar stratosphere (mesosphere) and vice versa. Accordingly, composite differences show that the planetary waves in the winter Arctic stratosphere and lower mesosphere are stronger when the equatorial 40-hPa QBO in its easterly phase. The presented findings are consistent with the established relationship between the QBO phase and the northern winter polar vortex.
X. Xu, A. H. Manson, C. E. Meek, et al., 2009a. Vertical and inter-hemispheric links in the stratosphere-mesosphere as revealed by the day-to-day variability of Aura-MLS temperature data. Annales Geophysicae, 27, 3387-3409.
Relevance/Why does this exist?
The equivalent paragraph in paper two [SDT. PW global coupling] is also useful to read, before or after this. Although the need for an atmos refrigerator was apparent in ~ 1965 from the magnificent global contours of winds and temps pole to pole and 0-100km of Richard Reed…it was not until Murgatroyd 1970s and Lindzen 1981 did the GW link-work [not together or simultaneously] was it realized that hemispheric meridional winds, temps, and GW fluxes were all involved, linked and essential. Early GCMs used friction, but then GW params did the job [too easily!]. Until this paper, no one had shown, using a global data set, and one measured parameter, the linkages between height-regions in both SH and NH. We used short and long time scales, the best statistics/sig tests, and the Coup d’Grace the need to consider the longitudinal asymmetry of the polar vortex/winds/temps in the NH [SH is OK as a zonal mean…one day we will split it too]. The time to get this paper together was why Xu said to me 12 months after arriving…”But I have not written a paper this 1st year!” Once this was done papers 2 and 3 flowed fast…and he is now like a mighty river flowing through a gorge, or a duck heading for its nest at 50 feet altitude! This is a very good paper…
The coupling processes in the middle atmosphere have been a subject of intense research activity because of their effects on atmospheric circulation, structure, variability, and the distribution of chemical constituents. In this study, the day-to-day variability of Aura-MLS (Microwave Limb Sounder) temperature data are used to reveal the vertical and inter-hemispheric coupling processes in the stratosphere-mesosphere during four northern hemisphere winters (2004/5-2007/8). The UKMO (United Kingdom Meteorological Office) assimilated data and mesospheric winds from MF (medium frequency) radars are also applied to help highlight the coupling processes.
In this study, a clear vertical link can be seen between the stratosphere and mesosphere during winter months. The coolings and reversals of northward meridional winds in the polar winter mesosphere are often observed in relation to warming events (Sudden Stratospheric Warming, SSW for short) and the associated changes in zonal winds in the polar winter stratosphere. An upper-mesospheric cooling usually precedes the beginning of the warming in the stratosphere by 1-2 days. Compared with previous studies, this work systematically reveals these vertical connections based upon a larger observational dataset (multiple years; more parameters; higher vertical resolution; and combination with the vortex characteristics).
The characterization of the vortex for each winter is presented to provide perspective for the statistical analyses later within the paper. The vortices shown and discussed demonstrated strong and variable distortion and displacement, usually into the Scandinavian-Russian sector, which were most extreme during temperature disturbances (SSW or regional warmings). There were 3-4 disturbances each winter, and the three last winters (2005/6-2007/8) experienced major SSW. Given that vertical motions within the vortex and the anticyclone are opposite (downward and upward), and that zonal means are mainly used for inter-hemispheric coupling studies, it is clear that great caution has to be used in statistical analyses of these winters, and possible hemispheric coupling.
Inter-hemispheric coupling has been identified initially by a correlation analysis using the year-to-year monthly zonal mean temperature, although averages over a month [December, January and February are each used] may lose information associated with SSWs. December provides the clearest correlation. Then the correlation analyses are performed based upon the daily zonal mean temperature. From these original time sequences, positive (negative) correlations are generally found between zonal mean temperatures at the Antarctic summer mesopause and in the Arctic winter stratosphere (mesosphere) during northern mid-winters, although these correlations are dominated by the low frequency variability (i.e. the seasonal trend). Using the short-term oscillations, the statistical result, by looking for the largest magnitude of correlation within a range of time-lags (0 to 10 days; positive lags mean that the Antarctic summer mesopause is lagging), indicates that the temporal variability of zonal mean temperature at the Antarctic summer mesopause is also positively (negatively) correlated with the polar winter stratosphere (mesosphere) during three out of the four winters. The remaining winter (2006/7) has more complex correlations structures; correspondingly the polar vortex was distinguished this winter. The correlations are also provided using temperatures in northern longitudinal sectors in a comparison with the Antarctic-mesopause zonal mean temperature. For northern mid-high latitudes (~50-70ºN), temperatures in Scandinavia-Eastern Europe and in the Pacific-Western Canada longitudinal sectors often have opposite signs of correlations with zonal mean temperatures near the Antarctic summer mesopause during northern mid-winters. The statistical results are shown to be associated with the northern hemisphere’s polar vortex characteristics.
Figure 5 Correlation coefficient for daily zonal mean temperature at each latitude/pressure with respect to the same parameter at the Antarctic summer polar mesopause (~0.002 hPa, 80-85ºS, position marked with a ‘×’). The correlations are based on the day-to-day variability over 2004/5 winter (January 24 to March 5), 2005/6 winter (December 26 to February 4), 2006/7 winter (December 26 to March 5) and 2007/8 winter (December 26 to March 5), respectively. The white lines indicate the 95% level of significance.
Comments on Figure 5: Inter-hemispheric coupling in the stratosphere-mesosphere using sequences of daily zonal mean temperature
Now we turn to the correlation analysis with the daily temperatures (3-day means, centered on the middle day). Figure 5 shows the correlation coefficients between zonal mean temperatures near the Antarctic summer polar mesopause (0.002hPa, ~90km, 80-85ºN) and zonal mean temperatures at each global latitude band and pressure level during four winters. The correlations are for the following time intervals: 2004/5 winter (January 24 to March 5), 2005/6 winter (December 26 to February 4), 2006/7 winter (December 26 to March 5) and 2007/8 winter (December 26 to March 5), respectively…they cover most of the stratospheric disturbances in the respective mid-winter. Hence we can expect to be able to identify the influence on the summer mesosphere of the winter disturbances. In this paper, a Monte-Carlo shuffling method is applied to estimate the significance of correlation (e.g. Ebisuzaki, 1997; Usoskin et al., 2006). This spectral method ensures that the significances are appropriate to the degrees of freedom existing in each of the time sequences and hence correlations.
Inspection of Fig. 5 indicates that positive (negative) correlation coefficient values are generally observed in (above) the lower-middle stratosphere (~16-40 km) over high northern latitudes during these winters. Compared to other winters, the 2006/7 winter shows weak positive correlation in the middle mesosphere (~75 km) and a smaller area of positive (negative) correlation in (above) the lower-middle stratosphere (~16-40 km) for high northern latitudes. No significant correlation is found in the middle-upper mesosphere (80-97 km) over high northern latitudes in winters 2005/6 and 2007/8. Other clear features are the negative and significant correlations in the stratosphere and lower mesosphere of the SH summer, in comparison with the middle-upper mesosphere. Both of these areas of significant correlation extend out to low-middle latitudes (circa 30ºS). This is interesting, as anti-correlations between temperature variations in stratosphere and mesosphere are usually not the subject of discussion in the summer hemisphere. Presumably the summer stratosphere is generally warmer due to long hours of insolation, and the mesosphere cooler due to the GW-driven northward flow toward the Arctic (Lindzen, 1981). The correlations in figure 5 are showing variations about those mean states. Finally, in the winter hemisphere, at latitudes outside the polar vortex (circa 50ºN) and extending to the equator, there are areas of significant anti-correlation with height-regions within the vortex. These will be associated with variations in the strength of the Brewer-Dobson Circulation (Salby, 1996; Shepherd, 2000).
The significant positive correlation coefficients in the polar winter stratosphere indicate that when the polar winter stratosphere gets warmer, the polar summer mesosphere gets warmer too. This link matches with the inter-hemispheric connection suggested on the basis of model studies or the year-to-year variability of monthly averaged observations (e.g. Becker and Fritts, 2006; Karlsson et al., 2007, 2009). The intermediary phenomenon is the variable meridional flow, which is initially forced by GW, such that air-flows into the winter mesosphere are weakened or reversed, leading to winter mesospheric cooling. However, we must be careful in the interpretation of such a connection because these correlations in Fig. 4 are dominated by the low frequency variability (i.e. the seasonal trend) in the sequences. We find similar correlation patterns (not shown) if only low frequency variability in zonal mean temperature sequence is used. Because of this, these correlations are not sensitive to the time lag between the sequences, i.e. the correlation coefficient varies little over a wide range of time lags. Hence, for the original sequences of zonal mean temperature (Fig. 5), correlations have been calculated with simultaneous time series.
Fig. 6 Correlation coefficient for temperature over 60-65ºN at each longitude/pressure with respect to zonal mean temperature at the Antarctic summer mesopause (~0.002 hPa, 80-85ºS, position cannot be marked in this figure). The white line indicates the 95% level of significance. Time lags are applied based upon the results from Fig. 12. See text for details.
Comments on Fig 6: Longitudinal variability
The aforementioned correlations are based on the temporal variability of zonal mean temperature. However, we know the temperatures in the winter hemisphere have longitudinal dependence. In particular, the zonal asymmetry of temperature over the winter mid-high latitudes is most obvious during the disturbed days…above figures. Compared to previous correlations with zonal mean temperatures, the correlation with temperatures in different longitudinal sectors in the NH might give more details of the inter-hemispheric connection. Figure 6 shows the correlation between zonal mean temperature at the Antarctic summer mesopause and temperature over 60-65ºN at each longitude sector and pressure level. The SH zonal mean temperature was used because the longitudinal variations were very small in the local summers. Time sequences of temperatures were detrended before calculating correlations for figure 6. To keep consistent with lags giving maximum correlation for theses higher frequency variations (15days and less) in temperature time lags of 0, 6, 2, and 6 days between the summer mesopause and the winter stratosphere-lower mesosphere (~16-80 km), and of 1, 8, 3, and 8 days between the summer mesopause and the winter upper mesosphere (~80-97 km) were respectively applied to the correlations for the 2004/5, 2005/6, 2006/7, and 2007/8 winters in figure 6.. On the whole, the correlations show opposite signs for Scandinavia-Eastern Europe and the Pacific-Western Canada longitudinal quadrants in these four winters (Fig. 6). This is an indicative of temperature asymmetries. As shown in the vortices of figures 1 and 3, Scandinavia-Eastern Europe (the Pacific Western-Canada) is usually occupied by the polar vortex or cyclone (anti-cyclone) near the disturbance dates.
In winter 2004/5, the longitude sector dominated by positive (negative) correlations in the stratosphere (mesosphere) is only slightly larger than that with negative (positive) in the stratosphere (mesosphere). This year did not experience a major SSW, meaning that the zonal asymmetries were not as large as during the other years. [So the correlations using zonal mean temperatures show very weak positive (negative) values in the stratosphere (mesosphere) over 60-65ºN]. During the 2005/6 and 2007/8 winters, stratospheric (mesospheric) positive (negative) correlations appeared at most of mid-latitude longitudes. In contrast, negative (positive) correlations in the stratosphere (mesosphere) occupied the majority of mid-latitude longitudes in the 2006/7 winter. [Correspondingly, the negative (positive) correlations at the stratosphere (mesosphere) are found for the correlations using the zonal mean temperature]. All these indicate a statistical consistency between the correlations for the height versus latitude plots using zonal mean temperatures [not provided here] and for the height versus longitude plots using temperatures in different longitudinal sectors (Fig.6). This analysis also illustrates the inadequacies associated with the use of zonal mean data when dealing with time intervals and winters for which the vortex was significantly distorted and/or displaced from the pole.
A. H. Manson, C. E. Meek, T. Chshyolkova, T. Aso, J. R. Drummond, C. M. Hall, W. K. Hocking, Ch. Jacobi, M. Tsutsumi, W. E. Ward and X. Xu, 2009. Arctic Tidal Characteristics at Eureka (80ºN, 86ºW) and Svalbard (78ºN, 16ºE) for 2006/7: Seasonal and Longitudinal Variations, Migrating and Non-Migrating Tides. Ann. Geophys., 27, 1153-1173.
Operation of a Meteor Radar at Eureka, Ellesmere Island (80ºN, 86ºW) began in February, 2006. The first 12 months of wind data (82-97 km) are combined with winds from the Adventdalen, Svalbard Island (78ºN, 16ºE) Meteor Radar to provide the first contemporaneous longitudinally spaced observations of mean winds, tides and planetary waves at such high polar latitudes. Unique polar information on diurnal non-migrating tides (NMT) is provided, as well as complementary information to that existing for the Antarctic on the semidiurnal NMT.
Zonal and meridional monthly mean winds differed significantly between Canada and Norway, indicating the influence of stationary planetary waves (SPW) in the Arctic mesopause region. Both diurnal (D) and semi-diurnal (SD) winds also demonstrated significantly different magnitudes at Eureka and Svalbard. Typically the D tide was larger at Eureka and the SD tide was larger at Svalbard. Tidal amplitudes in the Arctic were also generally larger than expected from extrapolation of high mid-latitude data. For example time-sequences from ~90 km showed D wind oscillations at Eureka of 30 m/s in February-March, and four day bursts of SD tidal winds at Svalbard reached 40 m/s in June, 2006.
Fitting of wave numbers for the migrating and non-migrating tides (MT, NMT) successfully determines dominant tides for each month and height. For the diurnal tide, NMT with s = 0, +2 (westward) dominate in non-summer months, while for the semi-diurnal tide NMT with s = +1, +3 occur most often during equinoctial or early summer months. These wave numbers are consistent with stationary planetary wave (SPW)-tidal interactions.
Assessment of the global topographic forcing and atmospheric propagation of the SPW (S=1, 2) suggests these winter waves of the northern hemisphere are associated with the 78-80ºN diurnal NMT, but that the SPW of the southern hemisphere winter have little influence on the summer Arctic tidal fields. In contrast the large SPW and NMT of the Arctic winter may be associated, consistent with Antarctic observations, with the observed occurrence of the semidiurnal NMT in the Antarctic summer.
Fig. 9 Two tide fits, using the wave numbers of the MT plus one of a range of NMT, were used to find the biggest: either the MT, which is shown here in black, or the NMT wave number in the ranges shown. The latter are appropriate to non-linear interaction with the SPW S=1 or 2.
T. Chshyolkova, A.H. Manson, C.E. Meek, T. Aso, S.K. Avery, C.M. Hall, W. Hocking, K. Igarashi, C. Jacobi, N. Makarov, N. Mitchell, Y. Murayama, W. Singer, D. Thorsen, M. Tsutsumi, 2007. Polar Vortex Evolution during Northern Hemispheric Winter 2004/05. Ann. Geophys., June 29 Volume 25 No. 6.
As a part of the project “Atmospheric Wave Influences upon the Winter Polar Vortices (0-100 km)” of the CAWSES program, data from meteor and medium frequency radars at 12 locations and MetO (UK Meteorological Office) global assimilated fields were analyzed for the first campaign during the Northern Hemispheric winter [2004/05]. The stratospheric state [15-55km] has been described using the Q-diagnostic, which distinguishes regions of rotation [cyclonic and anti-cyclonic] and strain. The stratosphere was cold during winter 2004/05, and the polar vortex strong during most of the winter. Weak disturbances occurred near Dec 31 and Feb1 [stratospheric stationary wave with zonal wave number 1 enhanced]. The strongest deformation was near Feb 25th, a “Canadian Warming”, with an off-centred and elongated vortex .The part of the vortex over Europe was stronger and eastward winds continued to be observed at 52N Collm. In contrast, over Canada winds were westward, and the eastward jet was shifted upward and equatorward. Generaly, compared to previous years, the winter of 2004/05 was characterized by weak planetary wave activity 20-90km. But, the amplitudes of the westward propagating “normal” waves increased by the end of winter and were reaching Southern Hemispheric latitudes in March. Combinations of winds from MetO, thermal winds calculated from temperatures [MLS on Aura satellite], and radar winds provided consistent data from 0- 97km. During days when the vortex [MetO-derived up to 55km] was undisturbed and strong, the radar winds from 82 km and above were consistent with vortex extension to mesopause heights; while during the days when the stratospheric vortex was deformed strong vertical wind gradients existed in the mesosphere, consistent with large thermal winds, and there were wind reversals. A continuation of this study including chemicals (O3, N2O, HCl, and ClO) from Aura is completed and discussed in Form 101. The development of the Q-diagnostic by T.C. has provided us with a powerful tool for her PDF research.
A.H. Manson, C. Meek, T. Chshyolkova, C. McLandress, S.K. Avery, D.C. Fritts, C.M. Hall, W.K. Hocking, K. Igarashi, J.W. MacDougall, Y. Murayama, D.C. Riggin, D. Thorsen, R.A. Vincent, 2006. Winter warmings, tides and planetary waves: comparisons between CMAM (with interactive chemistry) and MFR-MetO observations and data. Ann. Geophys., (10): 2493-2518.
Manson designed this study, and McLandress provided the Canadian Middle Atmosphere Model [CMAM] data, now with interactive chemistry activated. Following the earlier radar-satellite comparisons with CMAM the dynamical characteristics of the model were reassessed. Time sequences of temperatures and winds at Tromso (70N) show that the model has more frequent and earlier stratospheric winter warmings than typically observed. Related…the planetary waves [PW] in CMAM are larger then observed before the winter solstice. Wavelets at two mesospheric heights (76, 85 km) and from equator to polar regions show that CMAM tides are generally larger, but planetary waves (PW) smaller, than medium frequency (MF) radar-derived values. CMAM tides for eight geographic locations and all months of the four seasons are not strikingly different from the earlier CMAM experiment; but local combinations of migrating and non-migrating tides [NMT] components within the mesosphere (circa 50-80km) were demonstrated for the first time. The dominant semi-diurnal tide of middle latitudes is again well realized in CMAM, but with little improvement. The main characteristics of the diurnal tide at low latitudes (S (1, 1) mode) are still well captured by the model, but with unobserved features: a low latitude amplitude maximum; different phases at mid-latitudes, and longitudinal differences [different mix of NMT]. The paper’s significance is due to the sensitivity of tides to background winds, temperatures, chemicals and gravity wave [GW] forcing: for the latter, model-tides are now used as diagnostic for the GW parameterizations. Further collaborations with T. Shepherd-CMAM are proposed, with the view to explore differences/chemistry diagnostically.
T. Chshyolkova, A.H. Manson, C.E. Meek, S.K. Avery, D. Thorsen, J.W. MacDougall, W. Hocking, Y. Murayama, and K. Igarashi, 2006. Planetary wave coupling processes in the middle atmosphere (30-90 km): a study involving MetO and MF radar data. J. Atmos. Solar-Terr. Phys., 68, 353-368.
The focus of the PhD for the first author was to characterize the planetary waves [PW] and coupling of the middle atmosphere. MetO assimilated data [<50km] and mesospheric winds from five Medium Frequency Radars (MFR) from the CUJO (Canada U.S. Japan Opportunity) network were used [2000-2002]. Strong vertical coupling, especially during winter months, was demonstrated. In addition there is also weaker horizontal “inter-hemispheric” coupling during equinoxes. The time interval included austral winters and springs of two years: the unusual year 2002, during which a major stratospheric warming involving a split vortex and wind reversals occurred in the Southern Hemisphere, and a more typical year 2001. In contrast to the usually weak PW activity dominated by eastward motions, strong eastward and westward propagating waves existed during the 2002 winter. Wavelet spectra of MetO winds show strong peaks near 14 days that match similar signals MFR-winds from Antarctica during the warming. This oscillation was generated at low atmospheric heights and propagated upward and northward. The longer duration of the winter vortex (7 months) compared to that of the summer jet in the Northern Hemisphere provide global equinox eastward winds. Analyses show that planetary waves with 10, 16 and 25 day periods penetrated to the opposite hemisphere and were detected by the CUJO systems. This important global theme is part of the Program 2008-13.
Manson A.H., C.E. Meek, M. Hagan, X. Zhang and Y. Luo, 2004. Global Distributions of Diurnal and Semi-Diurnal Tides: Observations from HRDI-UARS of the MLT Region and Comparisons with GSWM-02 (Migrating, Non-migrating Components). Ann. Geophys., 22, 1529-1548.
In the earlier paper (Manson et al., 2002, Ann. Geophys., p877) the emphasis was solely upon the longitudinal and latitudinal structures of the tidal amplitudes and phases from HRDI winds. These are very distinctive for the 24 h tide, with typically four maxima (associated with the major oceans) around the latitude circle. Here spatial complex spectral analysis was used to obtain the zonal wave numbers of the 12 and 24 h tides (migrating and nonmigrating tides, NMT). For the 24 h tide dominant NM tides s= -3,-2, 0, 2 and for the 12 h tide s= -2, 0, 4 were identified. These were related to the wave numbers (S) of the structures by [s (migrating) +-S]; topographic and planetary wave processes provide the forcing at the S wave numbers. Comparisons were made with the GSWM-02, which now has NM tides associated with tropospheric latent heat. While there are useful similarities, the model shows stronger longitudinal structures for both tides than observed; and the total tidal fields differ significantly at times and locations from those observed by HRDI or the MFR systems. There is strong community interest in longitudinal structures, which couple PW and GW processes. Manson designed and wrote it; Hagan provided early access to the model.
Manson A.H., C.E. Meek, S.D. Avery, D. Thorsen, 2003. Ionospheric and dynamical characteristics of the MLT region over Platteville (40N, 105W) and comparisons with the region over Saskatoon (52N, 107W). J. Geophys. Res., 108, No.D13, 4398, doi:10.1029/2002JD002835.
This is the first paper using data from the new Platteville MFR (planned in 2000 Grant Award). Its location due south of Saskatoon is very attractive. Many radars have been placed without strong regard for longitude, but these 2 MFRs allow pure latitudinal effects to be perceived. Together with London, Wakkanai and Yamagawa they form the new CUJO (Canada US Japan Opportunity) network of a 40N chain with 31-52N extensions. Annual contour plots of mean winds, tides (12, 24h), and planetary waves (2, 16day) demonstrate trends over 12° of latitude (1100 km), but many structural similarities. However, very significantly, the wave characteristics have now (Manson et al., 2004, Ann. Geophys., 347) been found to often vary more with longitude (81W-142E) than with latitude (40-52N). Spatial frequency analysis is providing wave numbers consistent with the above. Manson designed and wrote the paper.
Manson AH, Meek C, Hagan M, Koshyk J, Franke S, Fritts D, Hall C, Hocking W, Igarashi K, MacDougall J, Riggin D, Vincent R, 2002. Seasonal variations of the semi-diurnal and diurnal tides in the MLT (Mesosphere- Lower Thermosphere): multi-year MF radar observations from 2-70 degrees N, modelled tides (GSWM, CMAM). Ann. Geophysicae, 20, 661-677.
Motivation for this paper included the availability of data from SCOSTEP's STEP (1991-97) programs, its S-RAMP analysis activity (1998-2002), and the need to characterize tides and planetary waves (1.2 below) globally. Here, tidal data (1990-1997) from 8 Medium Frequency Radars (MFR) were compared with the Global Scale Wave Models (GSWM; 1995, 2000). The radars are at Christmas Island (2N), Hawaii (22N), Yamagawa (31N), Urbana (40N), London (43N), Wakkanai (45N,) Saskatoon (52N) and Tromso (70N). The GSWM2000 model has an improved gravity wave (GW) stress parameterization and background winds from UARS. For the 24h tide, observations and models have short/long wavelengths at low/high latitudes, and low latitude equinoctial maxima. However the 2000 model has much shorter wavelengths at high latitudes than observed. For the 12h tide the 2000 model has become more realistic; but transitions between solstitial states are still not strong and the amplitudes are still small from spring to fall. Our studies are the most comprehensive in height (70-100km) and global coverage, provide very wide graphics presentations, and so represent the most stringent test of the models. The community is presented with a clear indication of strengths and weaknesses of modeled tidal data. Here we considered that longitudinally varying structures associated with non-migrating tides could be an issue in the comparisons. For future observations more emphasis upon longitudinal networks was suggested. Manson devised the study and prepared the paper, Meek and Hagan had the next largest involvement.
Luo Y, Manson AH, Meek CE, Meyer CK, Burrage MD, Fritts DC, Hall CM, Hocking WK, MacDougall J, Riggin DM, Vincent RA, 2002. The 16-day planetary waves (PW): multi-MF radar observations from the arctic to equator and comparisons with the HRDI measurements and the GSWM modeling results. Ann. Geophysicae 20, 691-709.
Motivation for this study was addressed above; physically, interactions of PW, tides and Gravity Waves play crucial roles in energetics and constituent distribution e.g. McLandress, 2002, J.Atmos.Sci., 893. The same MF radars as in 1.1 above were used for this MLT (60-100 km) study, led by Luo (Grad. student); with 2 other papers, 2. below, using Saskatoon and London data, they give a comprehensive assessment of this PW. Beyond low-latitudes the 16d PW (periods 12-24d) dominates from fall to spring, with the amplitudes decreasing with height. At lower latitudes the summer waves become strong where inter-hemisphere wave ducts allow for the leakage from the other hemisphere. The 16d PW in GSWM has similar seasonal tendencies, but the discrepancies are considerable, partly due to differences in the back-ground winds. The observed wave is highly intermittent in time and space as revealed by the radars and satellite (UARS-HRDI) observations. Again these studies provided the most comprehensive study of the 16d PW in height, global coverage and season for the community, contrasting the very limited studies pre-existing. The results are encouraging assessments of longitudinal/latitudinal variations in propagation conditions, intermittency, and to improvements in modeling strategies e.g. the use of General Circulation Models (below).
Manson AH, Meek CE, Koshyk J, Franke S, Fritts DC, Riggin D, Hall CM, Hocking WK, MacDougall J Igarashi K, Vincent RA, 2002. Gravity wave activity and dynamical effects in the middle atmosphere (60-90km): observations from an MF/MLT radar network, and results from the Canadian Middle Atmosphere Model (CMAM). J.Atmos. Solar-Terr. Phys., 64, 65-90.
Motivation here was to critically assess the effects of different GW parameterization schemes upon the global distribution of MLT GW and tides in a Global Circulation Model. GW have an often dominant role in the dynamics, thermal structure and the distribution of atmospheric constituents. With regard to models, usually no seasonal or latitudinal variation in the subgrid-scale GW-drag parameterization scheme is included, and varieties of parameterization schemes have been used. Although these often make conflicting assumptions e.g. Medvedev and Klaassen, 2000, JASTP, 1015, they generally produce similar zonal wind fields. In this paper we used observations from the network of MF radars (1.1, 1.2 above) and data from the Canadian Middle Atmosphere Model (CMAM). GW and tidal wave fields were characterized and compared. There are useful similarities, with CMAM producing quite realistic tides, especially the 12h, and the 24h at low latitudes. However there are strong indications that the two GW-drag parameterization schemes (Hines; Medvedev-Klaassen) have significant and differing effects upon the MLT GW and tides, and that the latter scheme is preferred, with fewer tidal phase discontinuities. This paper has shown the value of such detailed evaluations and assists with optimization and choice of the GW scheme. Other colleagues, e.g. Miyahara, are inserting the MK scheme in their GCMs. Further collaborations with the CMAM community (T. Shepherd, PI) are ongoing, with richer diagnostics. Manson designed the study, and Koshyk provided the CMAM data.
Manson AH, Luo Y, Meek C, 2002. Global distributions of diurnal and semi-diurnal tides: observations from HRDI-UARS of the MLT region. Ann.Geophysicae, 20, 1877-1890.
Motivation here was to demonstrate the global structure of tidal amplitudes and phases; existing work on non-migrating tides and their effects had focused more on the sources and the spectral modes e.g. Forbes et al., 1997, Ann. Geophysicae, 1165. HRDI (High Resolution Doppler Interferometer-UARS) winds data were analyzed in small cells at 96 km for the tides and winds. Two solstices and one equinox were used. The 24h tide that maximizes near the 20-25N/S has significant seasonal changes with equinoctial maxima, and very strong longitudinal variability. Maxima are extraordinarily clear over the oceans. In contrast, the 12h tides that maximize near the 40-55degrees latitude have very strong seasonal changes with winter maxima, and more modest longitudinal changes. Comparisons with MLT radar observations (90 km) and the GSWM were very satisfactory. Solstitial meridional winds are from summer to winter hemispheres. These powerful graphics were well received by the community. Collaborations with Hagan have ensued, with a submitted paper comparing spectral modes in the HRDI data and new GSWM-02 (with non-migrating tides). There is much community interest in such longitudinal structures, which couple into PW and GW processes. Manson designed and wrote this.
Manson AH, Meek CE, Avery SD, Thorsen D, 2003. Ionospheric and dynamical characteristics of the MLT region over Platteville (40N, 105W) and comparisons with the region over Saskatoon (52N,107W). J.Geophys.Res., 108, No.D13, 4398, doi:10.1029/2002JD002835.
This is the first paper using data from the new Platteville MFR (planned in 2000 Grant Award). Its location due south of Saskatoon is very attractive. Many radars have been placed without strong regard for longitude, but these 2 MFRs allow pure latitudinal effects to be perceived. Together with London, Wakkanai and Yamagawa they form the new CUJO (Canada US Japan Opportunity) network of a 40N chain with 31-52N extensions. Annual contour plots of mean winds, tides (12, 24h), and planetary waves (2, 16day) demonstrate trends over 12° of latitude (1100 km), but many structural similarities. However, very significantly, the wave characteristics have now (second paper) been found to often vary more with longitude (81W-142E) than with latitude (40-52N). Spatial frequency analysis is providing wave numbers consistent with 1.4 above. This is an important theme in the Community. Manson designed the paper.
2. PUBLICATIONS (1995-2011) (Refereed journals)
· X. Xu, A. H. Manson, C. E. Meek, C. Jacobi, C. M. Hall, and J. R. Drummond, 2011. The impact of tropospheric and stratospheric observations on the mesospheric winds in a middle atmosphere data assimilation system, J. Geophys. Res., submitted (2011JD015589).
· X. Xu, A. H. Manson, C. E. Meek, D. M. Riggin, C. Jacobi, and J. R. Drummond, 2011. Mesospheric wind diurnal tides within the Canadian Middle Atmosphere Model Data Assimilation System, J. Atmos. Solar-Terr. Phys., submitted (ATP2694).
· X. Xu, A. H. Manson, C. E. Meek, C. Jacobi, C. M. Hall, and J. R. Drummond, 2011. Mesospheric wind semidiurnal tides within the Canadian Middle Atmosphere Model Data Assimilation System, J. Geophys. Res., submitted (2011JD015966).
· A. H. Manson, C. E. Meek, X. Xu, et al., 2011. Arctic tidal characteristics at CANDAC-PEARL (80N, 86W) and Svalbard (78N, 16E) for 2006-2009: observations and comparisons with the model CMAM-DAS. Ann Geophys., submitted.
· A. H. Manson, C. E. Meek, and X. Xu, 2010. Comment on “Global structure, seasonal and interannual variability of the migrating semidiurnal tide seen in the SABER/TIMED temperatures (2002-2007)” by Pancheva et al. Annales Geophysicae, 28, 665-676.
· X. Xu, A. H. Manson, C. E. Meek, et al., 2009c. Asymmetry in the inter-hemispheric planetary-wave link between the two hemispheres. Journal of Atmospheric and Solar-Terrestrial Physics, 71(17-18), 1899-1903, doi: 10.1016/j.jastp.2009.07.011
· X. Xu, A. H. Manson, C. E. Meek, et al., 2009b. Relationship between variability of the semidiurnal tide in the Northern Hemisphere mesosphere and quasi-stationary planetary waves throughout the global middle atmosphere. Annales Geophysicae, 27, 4239-4256.
· A. H. Manson,, C.E. Meek and T. Chshyolkova, 2008. “Regional Stratospheric Warmings in the Pacific-Western Canada (PWC) Sector during Winter 2004/5: Implications for Temperatures, Winds, Chemical Constituents and the Characterization of the Polar Vortex.” Ann. Geophys.., 26, 3597-3622.
· C.M. Hall, C.E. Meek, A.H. Manson and S. Nozawa, 2008. Turbopause determination, climatology and climatic trends, using medium frequency radars at 52N and 70N. J. Geophys. Res., 113, D13, July 2, 2008.
· D. Pancheva, P. Mukhtarov, N.J. Mitchell, E. Merzlyakov, A.K. Smith, B. Andonov, W. Singer, W. Hocking, C. Meek, A. Manson, 2008. Planetary waves in coupling the stratosphere and mesosphere during the major stratospheric warming in 2003/2004. J. Geophys. Res., 113, D12105, doi:10.1029/ 2007JD009011.
· K.F. Tapping, D. Boteler, P. Charbonneau, A. Crouch, A. Manson, H. Paquette, 2007. Solar Magnetic Activity and total Irradiance Since the Maunder Minimum. Solar Physics, In Press 2007.
· C.M. Hall, A. Brekke, A.H. Manson, C.E. Meek and S. Nozawa, 2007. Trends in mesospheric turbulence at 70 N. Atmos. Sci.Let., 8, 80-84.
· P. Mukhtarov, D. Pancheva, B. Andonov, N.J. Mitchell, E. Merzlyakov, W. Singer, W. Hocking, C. Meek, A. Manson, Y. Murayama, 2007. Large-scale thermo-dynamics of the stratosphere and mesosphere during the major stratospheric warming in 2003/2004. J. Atmos. Solar-Terr. Phys., 69, 2338-2354.
· T. Chshyolkova, A.H. Manson, C.E. Meek, T. Aso, S.K. Avery, C.M. Hall, W. Hocking, K. Igarashi, C. Jacobi, N. Makarov, N. Mitchell, Y. Murayama, W. Singer, D. Thorsen, M. Tsutsumi, 2007. Polar Vortex Evolution during Northern Hemispheric Winter 2004/05 Ann. Geophys., 25, 1279-1298.
· A.H. Manson, C. Meek, T. Chshyolkova, C. McLandress, S.K. Avery, D.C. Fritts, C.M. Hall, W.K. Hocking, K. Igarashi, J.W. MacDougall, Y. Murayama, D.C. Riggin, D. Thorsen, R.A. Vincent, 2006. Winter warmings, tides and planetary waves: comparisons between CMAM (with interactive chemistry) and MFR-MetO observations and data. Ann. Geophys., 10, 2493-2518.
· C.M. Hall, S. Nozawa, A.H. Manson, and C.E. Meek, 2006. Tidal signatures in mesospheric turbulence Ann Geophys., 24 (2), 453-465.
· T. Chshyolkova, A.H. Manson, C.E. Meek, S.K. Avery, D. Thorsen, J.W. MacDougall, W. Hocking, Y. Murayama, and K. Igarashi, 2006. Planetary wave coupling processes in the middle atmosphere (30-90 km): a study involving MetO and MF radar data. J. Atmos. Solar-Terr. Phys., 68, 353-368.
· D.M. Riggin, H-L Liu, R.S. Lieberman, R.G. Roble, J.M. Russell III, C.J. Mertens, M.G. Mlynczak, D. Pancheva, S.J., Franke, Y. Murayama, A.H. Manson, C.E. Meek, and R.A. Vincent, 2006. Observations of the 5-day wave in the mesosphere and lower thermosphere J. Atmos. Solar-Terr. Phys., 68, 323-339.
· C.M. Hall, T. Aso, M. Tsutsumi, S. Nozawa, C.E. Meek, and A.H. Manson, 2006. Comparison of meteor and medium frequency radar kilometer scale MLT dynamics at 700N. J. Atmos. Solar-Terr. Phys., 68, 309-316.
· T. Chshyolkova, A.H. Manson, and C.E. Meek, 2005. Climatology of the quasi two-day wave over Saskatoon (520N, 1070W): 14 years of MF radar observations. Advances in Space Res., 35 (11), 2011-2016.
· T. Chshyolkova, A.H. Manson, C.E. Meek, S.K. Avery, D. Thorsen, J.W. MacDougall, W. Hocking, Y. Murayama, and K. Igarashi, 2005. Planetary wave coupling in the middle atmosphere (20-90 km): a CUJO study involving TOMS, MetO and MF radar data. Ann Geophys., 23 (4): 1103-1121, SRef-ID: 1432-0576/ag/2005-23-1103.
· C.M. Hall, T. Aso, M .Tsutsumi, S. Nozawa, A.H. Manson, and C.E. Meek, 2005. A comparison of mesosphere and lower thermosphere neutral winds as determined by meteor and medium-frequency radar at 70ºN. Radio Science Vol. 40, RS4001, doe: 10.1029/2004RS003102.
· S.I. Martynenko, V.T. Rozumenko, O.F. Tyrnov, A.H. Manson, C.E. Meek, 2005. Statistical parameters of nonisothermal lower ionospheric plasma in the electrically active mesosphere. Advances in Space Research 35, 1467-1471.
· C.M. Hall, T. Aso, M .Tsutsumi, et al., 2005. Testing the hypothesis of the influence of neutral turbulence on the deduction of ambipolar diffusivities from meteor trail expansion. Annales Geophysicae 23, 1071-1073.
· E.G. Merzlyakov, Y.I. Portnyagin, C. Jacobi, et al., 2005. On the day-to-day wind and semidiurnal tide variations at heights of the mid-latitude summer mesopause: Zonal wavenumber estimations and its consequences, case-study in 1998. Journal of Atmospheric and Solar-Terrestrial Physics 67,535-551.
· A.H. Manson, C.E. Meek, T. Chshyolkova, et al., 2005. Wave activity (planetary, tidal) throughout the middle atmosphere (20-100 km) over the CUJO network: Satellite (TOMS) and Medium Frequency (MF) radar observations. Annales Geophysicae 23, 305-323.
· Y. Portnyagin, T. Solovjova, E. Merzlyakov, J. Forbes, S. Palo, D. Ortland, W. Hocking, J. MacDougall, T. Thayaparan, A. Manson, C. Meek, et al. 2004. Mesosphere/lower thermosphere prevailing wind model. Advances in Space Research 34, 1755-1762.
· Y.I. Portnyagin, T.V. Solovjova, N.A. Makarov, et al. 2004. Monthly mean climatology of the prevailing winds and tides in the Arctic mesosphere/lower thermosphere. Annales Geophysicae 22, 3395-3410.
· C.E. Meek, A.H. Manson, S.I. Martynenko, V.T. Rozumenko, O.F. Tyrnov, 2004. Remote sensing of mesospheric electric fields using MF radars. Journal of Atmospheric and Solar-Terrestrial Physics 66, 881-890.
· D.M. Riggin, R.S. Lieberman, R.A. Vincent, A.H. Manson, C.E. Meek, et al., 2004. The 2-day wave during the boreal summer of 1994. Journal of Geophysical Research 109, D08110, doi:10.1029/2003JD004493.
· D. Pancheva, N.J. Mitchell, A.H. Manson, C.E. Meek, et al. 2004. Variability of the quasi-2-day wave observed in the MLT region during the PSMOS campaign of June–August 1999. Journal of Atmospheric and Solar-Terrestrial Physics 66, 539-565.
· A.H. Manson, C.E. Meek, M. Hagan, X. Zhang and Y. Luo, 2004. Global Distributions of Diurnal and Semi-Diurnal Tides: Observations from HRDI-UARS of the MLT Region and Comparisons with GSWM-02 (Migrating, Non-migrating Components). Annales Geophysicae 22, 1529-1548.
· A.H. Manson, C.E. Meek, C.M. Hall, S. Nozawa, N.J. Mitchell, D. Pancheva, W. Singer, and P. Hoffmann, 2004. Mesopause Dynamics from the Scandinavian Triangle of Radars within the PSMOS-DATAR Project. Annales Geophysicae 22, 367-386.
· A.H. Manson, C.E. Meek, T. Chshyolkova, S.K. Avery, D. Thorsen, J.W. MacDougall, W. Hocking, Y. Murayama, K. Igarashi, S.P. Namboothiri, and P. Kishore, 2004. Longitudinal and Latitudinal Variations in Dynamic Characteristics of the MLT (70-95km): A Study Involving the CUJO network. Annales Geophysicae 22, 347-365.
· A.H. Manson, C.E. Meek, S.K. Avery, and D. Thorsen, 2003. Ionospheric and dynamical characteristics of the mesosphere-lower thermosphere region over Platteville (40ºN, 105ºW) and comparisons with the region over Saskatoon (52ºN, 107ºW). Journal of Geophysical Research 108, (D13), 4398, doi:10.1029/2002JD002835, 2003.
· K.M. Cierpik, J.M. Forbes, S. Miyahara, Y. Miyoshi, A. Fahrutdinova, C. Jacobi, A.H. Manson, C. Meek, N.J. Mitchell and Y. Portnyagin, 2003. Longitide variability of the solar semidiurnal tide in the lower thermosphere through assimilation of ground-and space-based wind measurements. Journal of Geophysical Research 108, No. A5, doi: 10.1029/2002JA009349.
· D. Pancheva, C. Haldoupis, C.E. Meek, A.H. Manson, and N.J. Mitchell, 2003. Evidence of a role for modulated atmospheric tides in the dependence of sporadic E layers on planetary waves. Journal of Geophysical Research 108, No. A5, doi: 10.1029/2002JA009788.
· C.M. Hall, S. Nozawa, C.E. Meek, A.H. Manson, and Y. Luo, 2003. Periodicities in energy dissipation rates in the auroral mesosphere/lower thermosphere. Annales Geophysicae 21, 787-796.
· A.H. Manson, C.E. Meek, Y. Luo, W.K. Hocking, J. MacDougall, D. Riggin, D.C. Fritts, R.A. Vincent, 2003. Modulation of gravity waves by planetary waves (2 and 16d): observations with the North American-Pacific MLT-MFR radar network. Journal of Atmospheric and Solar-Terrestrial Physics 65, 85-104.
· S. Nozawa, S. Imaida, A. Brekke, C.M. Hall, A. Manson, C. Meek, S. Oyama, K. Dobashi, and R. Fujii, 2002. The quasi 2-day wave observed in the polar mesosphere. Journal of Geophysical Research 108, No. D2, doi: 10.1029/2002JD002440.
· S. Nozawa, A. Brekke, A. Manson, C.M. Hall, C. Meek, K. Morise, S. Oyama, K. Dobashi, and R. Fujii, 2002. A comparison study of the auroral lower thermospheric neutral winds derived by the EISCAT UHF radar and the Tromso medium frequency radar. Journal of Geophysical Research 107, No. A8, doi: 10.1029/2000 JA007581.
· D. Pancheva, E. Merzlyakov, N.J. Mitchell, Yu. Portnyagin, A.H. Manson, Ch. Jacobi, C.E. Meek, Yi Luo, R.R. Clark, W.K. Hocking, J. MacDougall, H.G. Muller, D. Kurschner, G.O.L. Jones, R.A. Vincent, I.M. Reid, W. Singer, K. Igarashi, G.I. Fraser, A.N. Fahrutdinova, A.M. Stepanov, L.M.G. Poole, S.B. Malinga, B.L. Kashcheyev, A.N. Oleynikov, 2002. Global-scale tidal variability during the PSMOS campaign of June-August 1999: interaction with planetary waves. Journal of Atmospheric and Solar-Terrestrial Physics 64, 1865-1896.
· A. H. Manson, Y. Luo, C. Meek, 2002. Global Distributions of Diurnal and Semi-Diurnal Tides: Observations from HRDI-UARS of the MLT Region. Annales Geophysicae 20, 1877-1890.
· J. Oberheide, G.A. Lehmacher, D. Offermann, K.U. Grossmann, A.H. Manson, C.E. Meek, F.J. Schmidlin, W. Singer, P. Hoffmann, and R.A. Vincent, 2002. Geostrophic wind fields in the stratosphere and mesosphere from satellite data. Journal of Geophysical Research 107, No. D23, doi: 10.1029/2001JD000655.
· A.H. Manson, C.E. Meek, J. Koshyk, S. Franke, D.C. Fritts, D. Riggin, C.M. Hall, W.K. Hocking, J. MacDougall, K. Igarashi, R.A. Vincent, 2002. Gravity wave activity and dynamical effects in the middle atmosphere (60-90km): observations from an MF/MLT radar network, and results from the Canadian Middle Atmosphere Model (CMAM). Journal of Atmospheric and Solar-Terrestrial Physics 64, 65-90.
· C.M. Hall, S. Nozawa, C.E. Meek, and A.H. Manson, 2002. On the response of fading times of upper homosphere radar echoes to solar and geomagnetic disturbances. Earth Planets Space 54, 699-705.
· A.H. Manson, C. Meek, M. Hagan, J. Koshyk, S. Franke, D. Fritts, C. Hall, W. Hocking, K. Igarashi, J. MacDougall, D. Riggin and R. Vincent, 2002. Seasonal variations of the semi-diurnal and diurnal tides in the MLT: multi-year MF radar observations from 2-70° N, modelled tides (GSWM, CMAM). Annales Geophysicae 20, 661-677.
· Y. Luo, A.H. Manson, C.E. Meek, C.K. Meyer, M.D Burrage, D.C. Fritts, C.M. Hall, W.K. Hocking, J. MacDougall, D.M. Riggin, and R.A. Vincent, 2002. The 16-day planetary waves: multi-MF radar observations from the arctic to equator and comparisons with the HRDI measurements and the GSWM modelling results. Annales Geophysicae 20, 691-709.
· Norbert Grieger, Evgeny M. Volodin, Gerhard Schmitz, Peter Hoffmann, Alan H. Manson, David C. Fritts, Kiyoshi Igarashi, Werner Singer, 2002. General circulation model results on migrating and nonmigrating tides in the mesosphere and lower thermosphere. Part I: comparison with observations. Journal of Atmospheric and Solar-Terrestrial Physics 64, 897-911.
· Nikolai M. Gavrilov, Shoichiro Fukao, Takuji Nakamura, Christoph Jacobi, Dierk Kurschner, Alan H. Manson, Chris E. Meek, 2002. Comparative study of interannual changes of the mean winds and gravity wave activity in the middle atmosphere over Japan, Central Europe and Canada. Journal of Atmospheric and Solar-Terrestrial Physics 64, 1003-1010.
· D. Pancheva, N.J. Mitchell, M.E. Hagan, A.H. Manson, C.E. Meek, Yi Luo, Ch. Jacobi, D. Kurschner, R.R. Clark, W.K. Hocking, J. MacDougall, G.O.L. Jones, R.A. Vincent, I.M. Reid, W. Singer, K. Igarashi, G.I. Fraser, T. Nakamura, T. Tsuda, Yu. Portnyagin, E. Merzlyakov, A.N. Fahrutdinova, A.M. Stepanov, L.M.G. Poole, S.B. Malinga, B.L. Kashcheyev, A.N. Oleynikov, D.M. Riggin, 2002. Global-scale tidal structure in the mesosphere and lower thermosphere during the PSMOS campaign of June-August 1999 and comparisons with the global-scale wave model. Journal of Atmospheric and Solar-Terrestrial Physics 64, 1011-1035.
· A.H. Manson, C.E. Meek, J. Stegman, P.J. Espy, R.G. Roble, C.M. Hall, P. Hoffmann, Ch. Jacobi, 2002. Springtime transitions in mesopause airglow and dynamics: photometer and MF radar observations in the Scandinavian and Canadian sectors. Journal of Atmospheric and Solar-Terrestrial Physics 64, 1131-1146.
· R.R. Clark, M.D. Burrage, S.J. Franke, A.H. Manson, C.E. Meek, N.J. Mitchell, H.G, Muller, 2002. Observations of 7-d planetary waves with MLT radars and the UARS-HRDI instrument. Journal of Atmospheric and Solar-Terrestrial Physics 64, 1217-1228.
· Y. Luo, A.H. Manson, C.E. Meek, T. Thayaparan, J. MacDougall, W.K. Hocking, 2002. The 16-day wave in the mesosphere and lower thermosphere: simultaneous observations at Saskatoon (52°N, 107°W) and London (43°N, 81°W), Canada. Journal of Atmospheric and Solar-Terrestrial Physics 64, 1287-1307.
· Y. Luo, A.H. Manson, C.E. Meek, K. Igarashi, Ch. Jacobi, 2001. Extra long period (20-40 day) oscillations in the mesospheric and lower thermospheric winds: observations in Canada, Europe and Japan, and considerations of possible solar influences. Journal of Atmospheric and Solar-Terrestrial Physics, 63, 835-852.
· E.G. Merzlyokov, Yu.I. Portnyagin, C. Jacobi, N.J. Mitchell, H.G. Muller, A.H. Manson, A.N. Fachrutdinova, W. Singer, and P. Hoffmann, 2001. On the longitudinal structure of the transient day-to-day variation of the semidiurnal tide in the mid-latitude lower thermosphere – I. Winter season. Annales Geophysicae, 19, 545-562.
· Ch. Jacobi, M. Lange, D. Kürschner, A.H. Manson, and C.E. Meek, 2001. A Long-Term Comparison of Saskatoon MF Radar and Collm LF D1 Mesosphere-Lower Thermosphere Wind Measurements. Phys. Chem. Earth (C), 26, No. 6, 419-424.
· Chris Meek and Alan Manson, 2001. MF radar spaced antenna experiment: wind variance vs. record length. Journal of Atmospheric and Solar-Terrestrial Physics, 63, 181-191.
· R.S. Lieberman, A.K. Smith, S.J. Franke, R.A. Vincent, J.R. Isler, A.H. Manson, C.E. Meek, G.J. Fraser, A. Fahrutdinova, T. Thayaparan, W. Hocking, J. MacDougall, T. Nakamura, and T. Tsuda, 2000. Comparison of mesospheric and lower thermospheric residual wind with High Resolution Doppler Imager, medium frequency, and meteor radar winds. Journal of Geophysical Research, 105, 27,023-27,035.
· G.C. Hussey, C.E. Meek, D. André, A.H. Manson, and G.J. Sofko, 2000. A comparison of Northern Hemisphere winds using SuperDARN meteor trail and MF radar wind measurements. Journal of Geophysical Research, 105, 18,053-18,066.
· Y. Luo, A.H. Manson, C.E. Meek, C.K. Meyer, and J.M. Forbes, January 2000. The quasi 16-day oscillations in the mesosphere and lower thermosphere at Saskatoon (52°N, 107°W), 1980-1996. Journal of Geophysical Research, 105, No. D2, 2125-2138.
· C.M. Hall, S. Nozawa, A.H. Manson, and C.E. Meek, December 1999. Determination of turbulent energy dissipation rate directly from MF-radar determined velocity. Earth Planets Space, 52, 137-141.
· E. Yizengaw, C.M. Hall, A.H. Manson, and C.E. Meek November 1999. Nonvalidation of mesospheric horizontal wind fluctuations derived from temperature data via comparison with MF radar wind measurements. Journal of Geophysical Research, 104, No. D22, 27,565-27,572.
· C.M. Hall, U.-P Hoppe, T.A. Blix, E.V. Thrane, A.H. Manson and C.E. Meek, 1999. Seasonal variation of turbulent energy dissipation rates in the polar mesosphere: a comparison of methods. Earth Planets Space, 51, 515-524.
· Ch. Jacobi, Yu.I. Portnyagin, T.V. Solovjova, P. Hoffmann, W. Singer, A.N. Fahrutdinova, R.A. Ishmuratov, A.G. Beard, N.J. Mitchell, H.G. Muller, R. Schminder, D. Kurschner, A.H. Manson and C.E. Meek, August 1999. Climatology of the semidiurnal tide at 52-56°N from ground-based radar wind measurements 1985-1995. Journal of Atmospheric and Solar-Terrestrial Physics, 61, 975-991.
· A.H. Manson, C.E. Meek, C. Hall, W.K. Hocking, J. MacDougall, S. Franke, K. Igarashi, D. Riggin, D.C. Fritts and R.A. Vincent, July 1999. Gravity wave spectra, directions and wave interactions: Global MLT-MFR network. Earth Planets Space, 51, 543-562.
· A.H. Manson, C.E. Meek, M. Hagan, C. Hall, W. Hocking, J. MacDougall, S. Franke, D. Riggin, D. Fritts, R. Vincent, M. Burrage, 1999. Seasonal variations of the semi-diurnal and diurnal tides in the MLT: multi-year MF radar observations from 2 to 70°N, and the GSWM tidal model. Journal of Atmospheric and Solar-Terrestrial Physics, 61, 809-828.
· R.P. Kane, C.E. Meek and A.H. Manson, February 1999. Quasi-biennial and higher-period oscillations in the mean winds in the mesosphere and lower thermosphere over Saskatoon, 52°N, 107°W. Journal of Geophysical Research, 104, No. A2, 2645-2652.
· C.M. Hall, A.H. Manson and C.E. Meek, November 1998. Seasonal variation of the turbopause: One year of turbulence investigation at 69°N by the joint University of Tromso/University of Saskatchewan MF radar. Journal of Geophysical Research, 103, No. D22, 28,769-28,773.
· C.M. Hall, A.H. Manson, C.E. Meek 1998. Spectral characteristics of spring arctic mesosphere dynamics. Ann. Geophysicae, 16 1607-1618.
· A.H. Manson, C.E. Meek and G.E. Hall 1998. Correlations of gravity waves and tides in the mesosphere over Saskatoon. Journal of Atmospheric and Solar-Terrestrial Physics, 60, 1089-1107.
· A.H. Manson, C.E. Meek, J. Qian and C.S. Gardner, March 1998. Spectra of gravity wave density and wind perturbations observed during Arctic Noctilucent Cloud (ANLC-93) campaign over the Canadian Prairies: Synergistic airborne Na lidar and MF radar observations. Journal of Geophysical Research, 103, No. D6, 6455-6465.
· C.M. Hall, C.E. Meek and A.H. Manson, 1998. Rapid Communication: Turbulent Energy Dissipation Rates from the University of Tromso/University of Saskatchewan MF Radar. Journal of Atmospheric and Solar Terrestrial Physics, 60, No. 4, 437-440.
· C.M. Hall, A.H. Manson and C.E. Meek, 1998. Measurements of the Arctic Turbopause, Annales Geophysicae. 16, 342-345.
· A. Kohsiek, M. Kiefer, C.E. Meek and A.H. Manson, 1998. Fluctuations in Tides and Geomagnetic Variations. Geophysical Research Letters, 25, No. 6, 889-892.
· R.S. Lieberman, W.A. Robinson, S.J. Franke, R.A. Vincent, J.R. Isler, D.C. Fritts, A.H. Manson, C.E. Meek, G.J. Fraser, A. Fahrutdinova, W. Hocking, T. Thayaparan, J. MacDougall, K. Igarashi, T. Nakamura, T. Tsuda, 1998. HRDI Observations of Mean Meridional Winds at Solstice. American Meteor. Soc., 1887-1896.
· A.H. Manson, C.E. Meek, J. Qian, and C.S. Gardner, 1998. Spectra of gravity wave density and wind perturbations observed during Arctic Noctilucent Cloud (ANCL-93) campaign over the Canadian Prairies: Synergistic airborne Na lidar and MF radar observations. J. Geophys. Res., 103, No. D6, 6455-6465.
· C.M. Hall, A.H. Manson, C.E. Meek, 1998. Measurements of the arctic turbopause. Ann. Geophysicae, 16, 342-345.
· C.M. Hall, C.E. Meek, A.H. Manson, 1998. Turbulent energy dissipation rates from the University of Tromsø University of Saskatchewan MF radar. J. of Atmos. Solar-Terr. Phys., 60, 437-440.
· J.M. Forbes, M. Kilpatrick, D. Fritts, A.H. Manson, R.A. Vincent, 1997. Zonal mean and tidal dynamics from space: an empirical examination of aliasing and sampling issues. Ann. Geophysicae, 15, 1158-1164.
· W. Deng et al (19 authors), 1997. Coordinated global radar observations of tidal and planetary waves in the mesophere and lower thermosphere during January 20-30, 1993. J. Geophys. Res., 102, 7307-7318.
· J.M. Forbes, et al (8 authors), 1997. Quasi 2-day oscillation of the ionosphere during summer 1992. J. Geophys. Res., 102, 7301-7305.
· G.E. Hall, J.W. MacDougall, D.R. Moorcroft, and J.-P. St.-Maurice, A.H. Manson, C.E. Meek, 1997. Super Dual Auroral Radar Network observations of meteor echoes. J. Geophys. Res., 102, 14,603-14,614.
· C.E. Meek, A.H. Manson, M.D. Burrage, G. Garbe, L.L. Cogger, 1997. Comparisons between Canadian prairie MF radars, FPI (green and OH lines) and UARS HRDI systems. Ann. Geophysicae, 15, 1099-1110.
· S.E. Palo, et al (23 authors), 1997. An intercomparison between the GSWM, UARS, and ground based radar observations: a case-study in January 1993. Ann. Geophysicae, 15, 1123-1141.
· T. Thayaparan, W.K. Hocking, J. MacDougall, A.H. Manson, C.E. Meek, 1997. Simultaneous observations of the 2-day wave at London (43° N, 81° W) and Saskatoon (52° N, 107° W) near 91 km altitude during the two years of 1993 and 1994. Ann. Geophysicae, 15, 1324-1339.
· Manson, F. Yi, G. Hall, C. Meek, 1996. Comparisons between instantaneous wind measurements made at Saskatoon (52N, 107W) using the colocated medium frequency radars and Fabry-Perot interferometer instruments: Climatologies (1988-1992) and case studies. J. Geophys. Res., 101, 29,553-29,563 .
· J. Bremer, P. Hoffmann, A.H. Manson, C.E. Meek, R. Ruster, W. Singer, 1996. PMSE observations at three different frequencies in northern Europe during summer 1994. Ann. Geophysicae, 14, 1317-1327.
· C.E. Meek, A.H. Manson, S.J. Franke, W. Singer, P. Hoffmann, R.R. Clark, T. Tsuda, T. Nakamura, M. Tsutsumi, M. Hagan, D.C. Fritts, J. Isler and Y.I. Portnyagin, 1996. Global study of northern hemisphere quasi 2-day wave events in the summers of 1992 and 1991. J. Atmos. Terr. Phys., 58, 1401-1411.
· A.E. Hedin, E.L. Fleming, A.H. Manson, F.J. Schmidlin, S.K. Avery, R.R. Clark, S.J. Franke, G.J. Fraser, T. Tsuda, F. Vial and R.A. Vincent, 1996. Empirical wind model for the upper, middle and lower atmosphere. J. Atmos. Terr. Phys., 58, 1421-1447.
· T. Nakamura, T. Tsuda, S. Fukao, A.H. Manson, C.E. Meek, R.A. Vincent and I.M. Reid, 1996. Mesospheric gravity waves at Saskatoon (52° N), Kyoto (35° N), and Adelaide (35° S). J. Geophys. Res., 101, 7005-7012.
· Q. Zhan, A.H. Manson and C.E. Meek, 1996. The impact of gaps and spectral methods on the spectral slope of the middle atmospheric wind. J. Atmos. Terr. Phys., 58, 1329-1336.
· M.D. Burrage, W.R. Skinner, D.A. Gell, P.B. Hays, A.R. Marshall, D.A. Ortland, A.H. Manson, S.J. Franke, D.C. Fritts, P. Hoffmann, C. McLandress, R. Niciejewski, F.J. Schmidlin, G.G. Shepherd, W. Singer, T. Tsuda and R.A. Vincent, 1996. Validation of mesosphere and lower thermosphere winds from the high resolution Doppler imager on UARS. J. Geophys. Res., 101, 10,365-10,392.
· B. Khattatov, M. Geller, V. Yudin, P. Hays, W. Skinner, S. Franke, D. Fritts, J. Isler, A. Manson, C. Meek, R. McMurray, S. Singer. P. Hoffmann and R. Vincent, 1996. Dynamics of the mesosphere and lower thermosphere as seen by MF radars and by HRDI/UARS. J. Geophys. Res., 101, 10,393-10,404.
· W.A. Gault, G. Thuillier, G.G. Shepherd, S.P. Zhang, R.H. Wiens, W.E. Ward, C. Tai, B.H. Solheim, Y.J. Rochon, C. McLandress, C. Lathuillere, V. Fauliot, M. Hersé, C.H. Hersom, R. Gattinger, L. Bourg, M.D. Burrage, S.J. Franke, G. Hernandez, A. Manson, R. Niciejewski and R.A. Vincent, 1996. Validation of O(1S) wind measurements by WINDII: the WIND Imaging Interferometer on UARS. J. Geophys. Res., 101, 10,405-10,430.
· P.J. Espy, R. Huppi and A. Manson, 1995. Large-scale, persistent latitude structures in the mesospheric temperature during ANLC-93. Geophys. Res. Lett., 22, 2801-2804.
· R.H. Wiens, W.F.J. Evans, M.S. Zalcik, A.H. Manson and G.G. Shepherd, 1995. WINDII observation of a PMC breakup event during ANLC-93. Geophys. Res. Lett., 22, 2797-2800.
· L. Zhong, L.J. Sonmor, A.H. Manson and C.E. Meek, 1995. The influence of time-dependent wind on gravity-wave propagation in the middle atmosphere. Ann. Geophysicae, 13, 375-394.
· J.M. Forbes, M.E. Hagan, S. Miyahara, F. Vial, A. Manson, C.E. Meek and Yu. I. Portnyagin, 1995. Quasi 16-d oscillation in the mesosphere and lower thermosphere. J. Geophys. Res., 100, 9149-9163.
· G.E. Hall, C.E. Meek and A.H. Manson, 1995. Hodograph analysis of mesopause region winds observed by three MF radars in the Canadian Prairies. J. Geophys. Res., 100, 7411-7421.
· N.M. Gavrilov, A.H. Manson and C.E. Meek, 1995. Climatological monthly characteristics of middle atmosphere gravity waves (10 min - 10h) during 1979-1993 at Saskatoon. Ann. Geophysicae, 13, 285-295.
4. COMMUNICATIONS AT CONFERENCES
2001-2008 These include 21 (10 first-author) papers at International meetings:
COSPAR (US) 2002; PSMOS (Brazil) 2002; IUGG (Sapporo) 2003; COSPAR (Paris) 2004; IAGA (Toulouse) 2005; SCOSTEP STP-11 (Brazil) 2006; CAWSES (Kyoto) 2007; COSPAR (Montreal) 2008.
Travel to some meetings, and acceptance of invitations for Invited papers (e.g. AGU, COSPAR in 2002, STP-11 2006, CAWSES-Kyoto 2007), have been limited/refused due to wife’s dementia-illness. Both Grads (Luo and Chshyolkova) have attended most of above and presented my/‘group’ papers. All Conference-papers have been published in JGR/ JASTP/ Ann. Geophys.
ADG MF Radar Plots
ISAS Professor Bio
Professor and Canadian Research Chair,
Department of Physics and Engineering Physics
Chair, Institute of Space and Atmospheric Studies
B.A. (College of Valleyfield, PQ, Canada.) 1967
B.Sc. (Universite de Montreal, Canada) 1971
Ph.D. (Yale University, US) 1975
Research and Academic Interests:
The focal point of the research undertaken by Professor St-Maurice and his collaborators is the ionosphere. In the grand scheme of things, this region is the interface where the neutral atmosphere meets the upper ionized regions called magnetosphere and plasmasphere. The ionospheric region is rich with electrical currents triggered either by neutral winds and atmospheric tides generators at lower altitudes and latitudes or by the interaction of the solar wind with the magnetosphere at much higher altitudes and latitudes. In the latter case the electrical currents trigger the spectacular aurora borealis. Some of the research is devoted to the small scale processes responsible for the redistribution of energy and momentum inside a particular constituent like the plasma itself. Or they can involve the exchange of energy and momentum between constituents like the plasma and the fsbackground neutral gas. These studies involve the study of the evolution of structures and, ultimately, turbulence. They also involve the study of ion velocity distributions, which can be very different from the Maxwellian (Gaussian) shape associated with thermal equilibrium. The exchange of momentum and energy between species also triggers larger scale phenomena, for instance, large scale winds and internal gravity waves in the neutral atmosphere. Finally, on larger scales still, the solar wind deposits a lot of its energy and momentum to the magnetosphere and ionosphere, creating a large scale circulation pattern that covers the polar cap and the auroral regions, and sometimes extends to equatorial regions! The research group is particularly interested nowadays in the circulation that takes place over the polar cap itself, outside the auroral regions proper. Prof St-Maurice uses theoretical tools like kinetic and plasma theory to study small scale processes, numerical and theoretical tools to study the neutral wind circulation, Joule heating, and the generation of internal gravity waves in the atmosphere, and experimental tools like radar and satellite data to study large scale processes and plasma turbulence in the radar case, and to study more local kinetic processes in the satellite case. He is currently a co-PI on the US funded AMISR incoherent scatter radar at Resolute Bay and an international PI on the SuperDARN radar network, which currently comprises of the order of 20 radars used to study the plasma circulation on a global scale.
For short vignettes on Prof. St-Maurice's research interests, click here (for u of S production) or here (for Nortel production where you'll need Real Player 8 or higher). For more details go to Prof. St-Maurice's personal web page.
Professor Emeritus, Department of Physics and Engineering Physics
Executive Secretary, Institute of Space and Atmospheric Studies
B.Sc. (University of Canterbury, N.Z.) 1962
Ph.D. (University of Canterbury, N.Z.) 1965
Research and Academic Interests:
Dr. Manson's research interests lie in the area of the Earth's middle atmosphere and thermosphere (20-150 km): dynamics, chemistry, aeronomy and coupling processes. Three main categories are provided:
1. Remote Sensing of the Atmosphere using Radars
Dr. Manson and his colleague, Dr. Chris Meek (Research Associate), have been contributing for over 30 years to the development and operation of radars (Medium Frequency, MF, 2-3 MHz) for the sensing of winds, waves [atmospheric gravity, planetary and tidal] and electron densities in the middle atmosphere (50-110 km). Their research group has developed technologies, e.g. high sensitivity, rapid gain-response receivers and sophisticated analysis methods and software, for the efficient production of winds profiles (3 km, 5 min sampling), using interferometry and spaced-antenna methods. These advances have been applied to the main MF radar near Saskatoon, which has a 4x4 element, crossed- antenna transmission array and several large receiving arrays, and to the two smaller MF radars. One of these is at Ramfjordmoen (70N, Norway) beside the EISCAT facility, near ALOMAR/Andenes, and the other near Boulder (40N, USA), part of the CEDAR program. Drs Manson and Meek are also the “mentors” [principle investigators] of a Meteor Wind/Temperature Radar at Eureka (80N, Canada).
2. Dynamic of the Middle Atmosphere/ Thermosphere
The "Atmospheric Dynamics Group" has now archived almost three solar cycles of winds data. These data are analyzed by advanced spectral techniques to allow process-studies and to obtain climatologies of tidal, planetary and gravity waves. They have spatial scales of 10-10,000 km, and periods of minutes to many days. They interact with the atmosphere and each other in complex, non-linear fashions. Such waves have sources in the lower atmosphere or troposphere, associated with the ozone layer, water vapour, the jet-stream and thunderstorms. Together they redistribute energy, momentum and gaseous-minor constituents and pollutants throughout the entire 100 km-thick atmosphere of the planet. Radar and satellite data (Odin-OSIRIS, Aura-MLS, SCISAT-ACE and TIMED) are archived and used to study regional and global Atmospheric Processes Of Climate and its Change (APOCC).
3. Canadian Network for the Detection of Atmospheric Change (CANDAC), Global Programs
Dr Manson is active within SCOSTEP's CAWSES (Climate And Weather of the Sun Earth System), as convener of the “Coupling Processes” project: “Atmospheric Wave Interactions with the Winter Polar Vortices (0-100 km)”. Global arrays of radars (MF/meteor), opticals (e.g. Fabry-Perot Interferometers) and satellite systems are used. He is a Co-Investigator within the CANDAC Polar Environment Atmospheric Laboratory (PEARL) located on Ellesmere Island at Eureka, and “mentor” of its Meteor Radar (80N). This is the highest latitude Arctic observatory on Earth www.CANDAC.ca .
Department of Physics and Engineering Physics
Institute of Space and Atmospheric Studies
B.Sc. (Exon) 1960
Ph.D. (Exon) 1963
D.Sc. (Sask) 1987
Distinguished University Researcher 2002
Research and Academic Interests:
Dr. Llewellyn was head of the InfraRed Group in the Institute of Space and Atmospheric Studies at the University of Saskatchewan. He also served as the Principal Investigator for the OSIRIS instrument on the Odin satellite from its inception, in 1994, through to 2008. Dr. Llewellyn's research specialization and expertise is optical aeronomy, with particular emphasis on the use of airglow emissions to derive atmospheric state parameters, and on the interaction of spacecraft in low Earth orbit with the atmosphere. He is a co-Investigator for the WINDII instrument on the UARS spacecraft and for the ACE instrument on the Canadian SciSat-I satellite. He was a co-discoverer (with Drs. W.F.J. Evans FRSC, D.M. Hunten FRSC and A. Vallance Jones FRSC) of the upper ozone layer; an together with Drs. R.G.H. Greer, G. Witt, J. Stegman and B.H. Solheim he developed the idea that both the oxygen green line and the low energy molecular oxygen states are excited by energy transfer. Together with Dr. I.C. McDade he developed a set of mechanistic rate constants that can describe the airglow excitation of oxygen. He has also developed, with Dr. McDade, a new description of the processes controlling the collisional relaxation of vibrationally excited OH Another aspect of that collaboration has been the development of a tomographic analysis system that can improve our understanding of airglow distributions. This work is currently being extended by Drs. Bourassa and Degenstein.
While Dr. Llewellyn has been extensively involved with research intended to improve our understanding of the excitation mechanisms for the various airglow emissions most of the current research efforts are directed toward Odin and in particular the OSIRIS instrument, an optical spectrograph and infrared imager, on that satellite. The infrared imager makes observations that allow the application of tomographic techniques to the measurement of the oxygen infrared atmospheric bands and the Meinel OH emissions. In this work he is supported by the efforts of Dr. Richard Gattinger an adjunct faculty member. He has also developed a close collaboration with Professor John Burrows at the University of Bremen. Other related work is involved with the design of new instrumentation that can be used to make spectral tomographic measurements that provide improved knowledge of the atmospheric state parameters both for the Earth and for Mars.
Low altitude spacecraft and rockets are frequently enveloped in a vehicle induced glow and, following the discovery that the glow brightness is both species and temperature dependent, Dr. Llewellyn is involved in an on-going program to use the glow signals as an indicator of the atomic oxygen content of the mesosphere and lower thermosphere. This work has a particular importance for low Earth orbit spacecraft.
Department of Physics and Engineering Physics
B.A.Sc. (UBC) 1960
Woodrow Wilson Fellow (1960-63)
Ph.D. (U. of Sask.) 1969
Research and Academic Interests:
- Dr. Sofko became the leader of the Canadian SuperDARN (Super Dual Auroral Radar Network) team in 1993, and remains as one of the international Principal Investigators. As of January, 2009, the SuperDARN network encompasses 21 radars in total, 14 in the northern hemisphere and 7 in the southern hemisphere, and funding is in place to expand the network to 30 radars. The Canadian SuperDARN team, funded by NSERC grants and CSA contracts, includes collaborators at the Universities of Alberta, Calgary, Western Ontario and New Brunswick. The Canadian SuperDARN radar component includes four radars, the two original radars at Saskatoon (1993) and Prince George (2000), and a new pair of radars called the PolarDARN pair at Rankin Inlet (2006) and Inuvik (2007). Each pair of these Doppler radars is capable of measuring a large-scale map (about 4 million square kilometers in size) of the convection, electric fields and field-aligned currents (FACs) in the ionospheric F-region. These fields and FACs are generated in the Earth's magnetosphere as a result of the transfer of energy from the solar wind to the Earth. The SuperDARN project includes direct internaional participation from scientists in Canada, US, Britain, France, Italy, Japan, South Africa, and Australia, and associates in many other nations. The project has been one of the most successful international collaborations in space science, and has led to a total of over 600 published papers.
- Dr. Sofko was the Head of the Auroral Processes Team of the Canadian Network for Space Research (CNSR), one of the Networks of Centers of Excellence established by the Government of Canada in 1990. During the 5- year span of the CNSR, a set of sophistocated multiple-beam phased-array radars called SAPPHIRE NORTH and SAPPHIRE SOUTH were built by the University of Saskatchewan team (Dr. J. A. Koehler and Dr. Sofko).
- Dr. Sofko (Principal Investigator), Dr. Koehler and Dr. Art Wacker of Electrical Engineering were leaders in the application of microwave radars to agriculture via a contract with the Canada Center for Remote Sensing during the period 1985-89. Three microwave radars were used to measure the microwave signature of crops in various stages of development, as part of the RADARSAT program. Measurements by RADARSAT, Canada's remote sensing satellite launched in 1995, and later followed by RADARSAT II. The satellite data are used to assess the status of Canada's crops relative to those in the rest of the world and to plan the most effective approach to their marketing.
- Dr. Sofko came to the U of S for Ph.D. work under a Woodrow Wilson Fellowship awarded in 1960, one of the few WWFs ever awarded to an engineering student. Before completion of his Ph.D. work under the direction of Dr. Alex Kavadas, the founder and first president of SED Systems, Dr. Sofko was hired by the Physics Department in 1963, and was an active member of the Engineering Physics group within the Department, which became the Department of Physics and Engineering Physics in 1982. Dr. Sofko became a Professor Emeritus in 2007, and has remained an active teacher, researcher and grants/contracts administrator since that time.
Department of Physics and Engineering Physics
University Diploma (equiv. M.Sc.),
U of St-Petersburg, Dept. of Radio Physics, Russia, 1977
Candidate of Physical-Mathematical Sciences (equiv. Ph.D.), Moscow Institute of the Physics of the Earth, Russia, 1986
Research and Academic Interests:
Dr. Koustov is interested in studying Sun's influences on the Earth's upper atmosphere and ionosphere via electrodynamical processes by involving data from a variety of instruments on the ground and in space. Among targets of investigation are mechanisms of the solar wind energy entry into the upper atmosphere and establishing of plasma circulation at various ionospheric heights. Research is based on data collected by various ground-based radars such powerful incoherent scatter radars, coherent HF SuperDARN radars and other radio systems. Another significant area of research is plasma physics of small-scale irregularity formation in the ionosphere at various heights and latitudes. Such irregularities are responsible for the onset of coherent echoes and thus ultimately determine the capabilities of coherent radars in studying the plasma flows in the ionosphere and above.
Department of Physics and Engineering Physics
B.E., M.Sc., Ph.D. (Sask.)
Research and Academic Interests
Dr. Hussey's research interests centre around the ionospheric E-region, both at the high- and mid-latitudes as well as the high-latitude ionospheric F-region. His E-region research focuses on a better understanding of the physics of the excitation process of naturally occurring plasma wave instabilities which occur in this region of the ionosphere. The E-region is the transition region between the neutral atmosphere below and the ionised near-Earth space environment above. The dynamics in the neutral atmosphere is dominated by winds and motions of the neutral atmosphere and the weakly ionised region above the E-region is dominated by electrodynamic motions of the charged particles, while the E-region is a combination of neutral and electrodynamics to varying degrees.
In the mid-latitude E-region the contribution of bulk neutral motions on the excitation of plasma instabilities dominate; whereas, the high-latitude E-region is much more dominated by coupling with the upper ionosphere (F-region) and magnetosphere where neutral affects are much more difficult to detect and/or less significant compared to electrodynamical ones. My research focuses on better understanding these plasma processes in the E-region by probing them using coherent backscatter radars both at VHF and HF frequencies. Analysis of the received coherent radar echoes are compare to currently proposed theories and models. Part of my research has involved developing and implementing a novel VHF radar system with unprecedented high spatial and temporal resolution for probing the very dynamical coherent radar backscatter associated with the E-region.
I am also associated with the SuperDARN radar group situated here at the University of Saskatchewan. A SuperDARN radar is an HF coherent backscatter radar used to probe the ionosphere. It is optimised to study the F-region of the ionosphere, for magnetospheric studies, but also can study other regions such as the E-region. SuperDARN is a very versatile experiment and can be used for many types of near-Earth space science, either ground-based, satellite-based, or both. The ePOP satellite, to be launched in 2009, has one experiment where SuperDARN supplies the radio signal to be received by a radio receiver instrument on the satellite. This experiment will allow for trans-ionospheric studies of radio waves as they propagate through the terrestrial ionosphere. In anticipation of the satellite launch, modelling of the expected signal is currently in progress.
Department of Physics and Engineering Physics
Ph.D. (U Sask) 1999
B.Eng. (U Sask) 1993
B.Sc. (U Sask) 1988
Research and Academic Interests:
Dr. Degenstein is an Associate Professor of Engineering Physics at the University of Saskatchewan and has been a member of the U of S faculty since the autumn of 1999. Dr. Degenstein specializes in the remote sensing of the atmosphere through optical means with a primary focus on satellite based optical instrumentation. Dr. Degenstein is an executive member of the Institute of Space and Atmospheric Studies (ISAS) and the head of the Atmospheric Remote sensing Group (ARG) within ISAS. At this time Dr. Degenstein is the Principal Investigator (PI) of OSIRIS, the Optical Spectrograph and InfraRed Imager System. OSIRIS is the Canadian Space Agency (CSA) contribution to the multi-national, Swedish led, Odin mission where the fundamental goal of Odin is to better understand the photochemistry and dynamics associated with arctic ozone and its depletion. Dr. Degenstein is also the PI of the Stratosphere Troposphere Exchange Processes (STEP) mission concept study funded by the CSA. This mission is designed to study the processes that occur in the region know as the Upper Troposphere Lower Stratosphere (UTLS). Dr. Degenstein is currently an executive member of the Space and Atmospheric Environments Advisory Committee (SAEAC), a committee with a mandate to advise the CSA with respect to atmospheric science. He is also the past chair of the Division of Aeronomy and Space Physics (DASP) within the Canadian Association of Physicists.
Dr. Degenstein has been part of the OSIRIS project since the summer of 1993. As a Ph.D. graduate student working with Dr. E.J. (Ted) Llewellyn, the original OSIRIS PI, Dr. Degenstein was involved in almost every aspect of OSIRIS including: design; construction; calibration; characterization; commissioning; validation and analysis of the scientific data stream. As faculty at the University of Saskatchewan Dr. Degenstein has primarily been involved with the analysis of OSIRIS data for the purpose of studying the dynamics and photo-chemistry of the upper troposphere, the stratosphere and the mesosphere. During this time Dr. Degenstein has supervised nine graduate student theses including those written by: Kirk Lamont (M.Sc. 2007), Adam Bourassa (Ph.D. 2007 and M.Sc. 2004); Chris Roth (M.Sc. 2007), Mike Stoicescu (M.Sc. 2006); Reid MacDonald (M.Sc. 2006); Truitt Wiensz (M.Sc. 2005); Paul Loewen (M.Sc. 2004) and Brad Wilcox (M.Sc. 2002).
. . . 2
At this time Dr. Degenstein has two graduate students: Truitt Wiensz (Ph.D.); and Tony Bathgate (M.Sc.). The focus of study for the current members of the ARG is the retrieval of atmospheric aerosol parameters through the investigation of their light scattering properties. These aerosols include: ash and sulphates originating within volcanic eruptions; forest fire particulates; stratospheric sulphate aerosols; cirrus and subvisual cirrus clouds and polar mesospheric and stratospheric clouds. Research funding for most of the work performed by members of the ARG is primarily provided by the CSA and the Natural Sciences and Engineering Research Council (NSERC).
Department of Physics and Engineering Physics
NSERC University Faculty Award (2007-present)
NSERC Postdoctoral Fellow (2002-2004)
Ph.D. (U Leicester) 2001
Commonwealth Scholar (1998-2001)
M.Sc. (U Sask) 1997
B.Sc. (U Sask) 1994
Research and Academic Interests:
Dr. McWilliams research into the interaction of the solar wind and the Earth's space environment relies heavily on data from the Super Dual Auroral Radar Network. She is a member of the Canadian SuperDARN (Super Dual Auroral Radar Network) team. SuperDARN is an international consortium of research groups who operate high-frequency radars in and around the Earth's northern and southern auroral zones. These paired Doppler radars measure the convection velocity (or equivalently the convection electric field) over vast portions of the Earth's polar ionospheres. SuperDARN measurements are largely made in the regions where the aurora borealis and the aurora australis (the northern and southern lights) are most active - the auroral zones. These regions are very important to the Earth's space environment as they are the regions where huge amounts of energy can be transferred to the upper atmosphere from the solar wind via the Earth's magnetosphere. For example, during a typical substorm 50 gigawatts of power can be dumped into the Earth's ionosphere; this produces the beautiful aurora that we can see at night in Saskatoon.
Dr. McWilliams is primarily involved with assimilative studies of the Earth's magnetosphere-ionosphere system. She combines SuperDARN measurements of the Earth's ionosphere, images of the ultraviolet aurora seen from space, images of the visible aurora seen from the ground, magnetic fluctuations observed on the ground and in space, and particles detected in the upper atmosphere, the magnetosphere, and the solar wind. This multi-instrument approach has the advantage of being able to reveal information about both the particles and the fields which exist in the Earth's space environment.
Dr. McWilliams was first involved with SuperDARN as an NSERC summer student, when she was part of the team that built the radar located just outside of Saskatoon. This led to her joining ISAS as a M.Sc. student. Following her Masters' degree, Dr. McWilliams was awarded a Commonwealth Scholarship went to the University of Leicester, which is one of the SuperDARN research groups in England, to do Ph.D studies. Her Ph.D. work was an examination of the direct coupling of the solar wind to the magnetosphere-ionosphere system, primarily by means of transient magnetic reconnection, or 'flux transfer events.' Dr. McWilliams returned to the University of Saskatchewan in 2002 as an NSERC postdoctoral fellow, where she rejoined the Canadian SuperDARN team.
Department of Physics and Engineering Physics
Ph.D. (U Sask) 2007
USSU Teaching Excellence Award (2006)
NSERC Doctoral Scholarship
M.Sc. (U Sask) 2003
B.Eng. (U Sask) 2001
B.Sc. (U Sask) 2001
- Engineering Physics 311: Electronics I
- Engineering Physics 271: Heat, Kinetic Theory and Thermodynamics
- The OSIRIS Satellite Instrument (osirus.usask.ca)
- The Ozone Mapping and Profiler Suite (http://www.npoess.noaa.gov/index.php?pg=omps)
- Atmospheric Optics (http://www.atoptics.co.uk/)
- The Institute of Space and Atmospheric Studies
Research and Academic Interests:
Dr. Bourassa, a member of the Institute of Space and Atmospheric Studies, is actively involved in the development of satellite based remote sensing measurement and inversion techniques that are able to probe the atmosphere globally, frequently and repetitively. The data that these techniques can provide are invaluable to the understanding and monitoring of atmospheric processes. Primarily, his work has been as a member of science team for the Canadian Optical Spectrograph and InfraRed Imaging System (OSIRIS), a satellite instrument designed and built in Canada and currently deployed on the Swedish Odin satellite, and with the Ozone Mapping and Profiling Suite Limb Profiler that is under development at the NASA Langley Research Center. These instruments observe the side, or limb, view of sunlight scattered from the atmosphere. The spectrum of light from the sun, in the process of traveling through the atmosphere and scattering off molecules and particles, possibly several times, is imprinted with the signatures of the atmospheric composition. The great benefit of this relatively new technique is the ability to globally measure the vertical structure of the atmosphere.
Dr. Bourassa is particularly interested in measurements and impacts of aerosols in the upper troposphere and stratosphere. Stratospheric sulphate aerosols are an important type of aerosol due to their effects on climate and ozone and are generally quite difficult to measure at background levels. This thin, fine mist of particles exists naturally, but is highly variable as volcanic eruptions and anthropogenic pollution can strongly modify the concentration of stratospheric aerosol on a global level. The development of radiative transfer modeling and inversion methods for these and other aerosols, including clouds, smoke and dust are a focus of Dr. Bourassa’s current work. Understanding the radiative and chemical effects of these aerosols is a key component in the study of long term atmospheric trends required for further understanding of the Earth’s climate system. These studies are also leading to the development of designs for future optical instrumentation for sub-orbital and space-based remote sensing missions.
Institute of Space and Atmospheric Studies
University of Saskatchewan
116 Science Place - Room 260