- Space weather
Movie of spectacular aurora over Saskatoon:
Sofko, G.J., K.A. McWilliams and C.R. Bryant, (2013), The substorm current wedge and midnight sector partial ring current: A synthesis based on a magnetotail magnetic field geometry, Adv. Polar Sci., doi:10.3724/SP.J.1085.2013.00032.
Bryant, C.R., K.A. McWilliams, and H.U. Frey (2013), Localized dayside proton aurora at high latitudes, J. Geophys. Res. Space Physics, 118, 3157–3164, doi:10.1002/jgra.50311.
Harrison, R.G., K.A. Nicoll, K.A. McWilliams, Space weather driven changes in lower atmosphere phenomena, J. Atm. Solar-Terr. Phys., Volume 98, Pages 22-30, http://dx.doi.org/10.1016/j.jastp.2013.03.008.
Zhang, Q., B. Zhang, M. Lockwood, H. Hu, J. Moen, J.M. Ruohoniemi, E.G. Thomas, S. Zhang, H. Yang, R. Liu, K.A. McWilliams, J.B.H. Baker, Direct Observations of the Evolution of Polar Cap Ionization Patches, Science 29 March 2013, 339:6127 pp. 1597-1600, DOI: 10.1126/science.1231487
Gillies, D. M., J.-P. St. Maurice, K.A McWilliams, and S. E. Milan (2012), Global Scale Observations of Ionospheric Convection Variation in Response to Sudden Increases in the Solar Wind Dynamic Pressure, J. Geophys. Res., doi:10.1029/2011JA017255
Gillies, D. M., K. A. McWilliams, J.-P. St. Maurice, and S. E. Milan (2011), Global-scale observations of ionospheric convection during geomagnetic storms, J. Geophys. Res., 116, A12238, doi:10.1029/2011JA017086.
R.G. Gillies, G.C. Hussey, G.J. Sofko, P.V. Ponomarenko, K.A. McWilliams (2011), Improvement of HF coherent radar line-of-sight velocities by estimating the refractive index in the scattering volume using radar frequency shifting, Journal of Geophysical Research, 116, A01302, doi:10.1029/2010JA016043.
M. Watanabe, G. J. Sofko, X. Yan, K. A. McWilliams, J.-P. St. Maurice, A. V. Koustov, G. C. Hussey, and M. Hairston (2010), Ionospheric convection signatures of the interchange cycle at small IMF clock angles, Journal of Geophysical Research, doi:10.1029/2009JA015041.
N. Partamies, T.I. Pulkinen, R.L. McPherron, K.A. McWilliams, C.R. Bryant, E. Tanskanen, H.J. Singer, G.D. Reeves, M.F. Thomsen, Different magnetospheric modes: Solar wind driving and coupling efficiency, Annales Geophysicae, 27, pp. 4281—4291, 2009.
N. Partamies, T.I. Pulkinen, R.L. McPherron, K.A. McWilliams, C.R. Bryant, E. Tanskanen, H.J. Singer, G.D. Reeves, M.F. Thomsen, Statistical survey on sawtooth events, SMCs and isolated substorms, Advances in Space Research, 44, pp. 376—384, 2009
R.G. Gillies, G.C. Hussey, G.J. Sofko, K.A. McWilliams, R.A D. Fiori, P. Ponomarenko, and J.-P. St.-Maurice (2009), Improvement of SuperDARN velocity measurements by estimating the index of refraction in the scattering region using interferometry, J. Geophys. Res., 114, A07305, doi:10.1029/2008JA013967
K.A. McWilliams, J.B. Pfeifer, and R.L. McPherron, Steady magnetospheric convection selection criteria: Implications of global SuperDARN convection measurements, Geophysical Research Letters, 35, L09102, doi:10.1029/2008GL033671, 2008
L.J. Baddeley, T.K. Yeoman, K.A. McWilliams, and D.M. Wright, Global Pc5 wave activity observed using SuperDARN radars and ground magnetometers during an extended period of northward IMF, Planetary and Space Science, 55:6, pp. 792-808, 2007
G. Chisham, M. Lester, S.E. Milan, M.P. Freeman, W.A. Bristow, A. Grocott, K.A. McWilliams, J.M. Ruohoniemi, T.K. Yeoman, P.L. Dyson, R.A. Greenwald, T. Kikuchi, M. Pinnock, J.P.S. Rash, N. Sato, G.J. Sofko, J.-P. Villain, and A.D.M. Walker, A decade of Super Dual Auroral Radar Network (SuperDARN): Scientific achievements, new techniques and future directions, Surveys in Geophysics, 28, pp. 33-109, 2007.
George Sofko, Robert Schwab, Masakazu Watanabe, Chaosong Huang, John Foster, and Kathryn McWilliams, Auroral post-secondary ions from the nightside ionosphere in the inner magnetosphere, Journal of Atmospheric and Solar-Terrestrial Physics, 69, pp. 1213-1232, 2007.
A.V. Koustov, R.A. Drayton, R.A. Makarevich, K.A. McWilliams, J.-P. St-Maurice, T. Kikuchi, and H.U. Frey, Observations of high-velocity SAPS-like flows with the King Salmon SuperDARN radar, Annales Geophysicae, 24, pp. 1591–1608, 2006.
J.-C. Cerisier, A. Marchaudon, J.-M. Bosqued, K.A. McWilliams, H.U. Frey, M. Bouhram, H. Laakso, M. Dunlop, M. Förster, A. Fazakerley, Ionospheric signatures of plasma injections in the cusp triggered by solar wind pressure pulses, Journal of Geophysical Research, 110, A08204, doi:10.1029/2004JA010962, 2005.
I.J. Rae, F.R. Fenrich, M. Lester, K.A. McWilliams, and J.D. Scudder, Solar wind modulation of cusp particle signatures and their associated ionospheric flows, Journal of Geophysysical Research, 109, A03223, doi:10.1029/2003JA010188, 2004
K.A. McWilliams, T.K. Yeoman, D.G. Sibeck, S.E. Milan, G.J. Sofko, T. Nagai, T. Mukai, I.J. Coleman, T. Hori, and F.J. Rich, Simultaneous observations of magnetopause flux transfer events and of their associated signatures at ionospheric altitudes, Annales Geophysicae, 22, pp. 2181–2199, 2004.
M. Lester, P.J. Chapman, S.W.H. Cowley, S. Crooks, J.A. Davies, P. Hamadyk, K.A. McWilliams, S.E. Milan, M. Parsons, D. Payne, E.C. Thomas, J. Thornhill, N.M. Wade, T.K. Yeoman, and R.J. Barnes, Stereo CUTLASS - A new capability for the SuperDARN HF radars, Annales Geophysicae, 22, pp. 459–473, 2004.
S.W.H. Cowley, J.A. Davies, A. Grocott, H. Kahn, M. Lester, K.A. McWilliams, S.E. Milan, G. Provan, P.E. Sandholt, J.A. Wild, and T.K. Yeoman, Solar wind-magnetosphere-ionosphere interactions in the Earth's plasma environment, Philosophical Transactions of the Royal Society A, 361, pp. 113–126, 2003.
T.K. Yeoman, P.G. Hanlon, and K.A. McWilliams, A statistical study of the location and motion of the HF radar cusp, Annales Geophysicae, 20, pp. 275–280, 2002.
J.A. Davies, T.K. Yeoman, I.J. Rae, S.E. Milan, M. Lester, K.A. McWilliams and M. Lockwood, Joint CUTLASS Finland and EISCAT VHF radar observations of the ionospheric signatures of dayside transient reconnection, Annales Geophysicae, 20, pp. 781–794, 2002.
P. Prikryl, G. Provan, K.A. McWilliams, and T.K. Yeoman, Ionospheric cusp flows pulsed by solar wind Alfven waves, Annales Geophysicae, 20, pp. 161–174, 2002.
K.A. McWilliams, S.E. Milan, T.K. Yeoman, J.B. Sigwarth, L.A. Frank, and M. Brittnacher, IMF By dependence of the relative position of the dayside ultraviolet auroral oval and the HF radar cusp, Journal of Geophysical Research, 106:A12, pp. 29027–29036, 2001.
K.A. McWilliams, T.K. Yeoman, J.B. Sigwarth, L.A. Frank, and M. Brittnacher, The dayside ultraviolet aurora and convection responses to a southward turning of the interplanetary magnetic field, Annales Geophysicae, 17, pp. 707–721, 2001.
K.A. McWilliams, T.K. Yeoman, and S.W.H. Cowley, Two-dimensional electric field measurements in the ionospheric footprint of a flux transfer event, Annales Geophysicae, 18, pp. 1584–1598, 2001.
D.A. Neudegg, S.W.H. Cowley, K.A. McWilliams, M. Lester, T.K. Yeoman, J. Sigwarth, G. Haerendel, W. Baumjohann, U. Auster, K.-H. Fornacon, and E. Georgescu, The UV aurora and ionospheric flows during flux transfer events, Annales Geophysicae, 19, pp. 179–188, 2001.
K.A. McWilliams, T.K. Yeoman, and G. Provan, A statistical survey of dayside pulsed ionospheric flows as seen by the CUTLASS Finland HF radar, Annales Geophysicae, 18, pp. 445–453, 2000.
C.-S. Huang, G.J. Sofko, K.A. McWilliams, W.A. Bristow, R.A. Greenwald, and M.C. Kelley, SuperDARN observations of quasi-stationary mesoscale convection vortices in the dayside high-latitude ionosphere, Journal of Geophysical Research, 103:A12, pp. 29,239–29,252, 1998
G.J. Sofko, A.V. Koustov, K.A. McWilliams, D. Andre, G.C. Hussey, J. MacDougall, J.- P. St. Maurice, D.R. Moorcroft, J.C. Samson, A. Hamza, and P. Prikryl, The Super Dual Auroral Radar Network (SuperDARN): An international system for space weather determination, Physics in Canada, 54:6, pp. 371-379, 1998
Teaching & Supervision
- PHYS 111.6, General Physics
- GE 124.3, Engineering Mechanics I
- GE 125.3, Engineering Mechanics II
- PHYS 115.3, Physics And The Universe
- PHYS 356.3, Intermediate Electromagnetism
- EP 271.3, Heat Kinetic Theory and Thermodynamics
- PHYS 391.3, CaNoRock Canada Norway Student Sounding Rocket Course
Outreach and Curriculum Development
- CaNoRock - Canada Norway Student Sounding Rocket Program
- CaNoRock STEP
- member of First Year Review Steering Committee, College of Arts & Science
- Science Leadership Fellow, University of Toronto (2013-4)
Atmospheric & Space Physics SuperDARN aurora ionosphere radars space weather
Dr. McWilliams, who works at the Institute of Space and Atmospheric Studies, is a member of the Canadian SuperDARN (Super Dual Auroral Radar Network) team. SuperDARN is an international network of HF radars, nine of which are located at high northern latitudes and 6 of which are located in the Antarctic. 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. Her M.Sc. work at the U of S involved estimations of field-aligned currents from SuperDARN velocity maps. Field-aligned currents are the primary means by which the magnetosphere and the ionosphere are linked. During the course of her M.Sc. work, Dr. McWilliams spent several months at Imperial College, London, analysing magnetic field data from Saturn from the Voyager 1, Voyager 2, and Pioneer 11 spacecraft. She also worked for several months at the British Antarctic Survey, which is home to the group that operates the Antarctic SuperDARN radar located at Halley Station. After her M.Sc. work, Dr. McWilliams received a Commonwealth Scholarship and went to the University of Leicester in England, where she worked with the Radio and Space Plasma Physics Group, who operate the CUTLASS pair of SuperDARN radars in Fenno-Scandia. 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.
Education & Training
NSERC University Faculty Award (2007-2012)
NSERC Postdoctoral Fellow (2002-2004)
Ph.D. (U Leicester) 2001
Commonwealth Scholar (1998-2001)
M.Sc. (U Sask) 1997
B.Sc. (U Sask) 1994