Equivalent Ionospheric Currents over North America and Greenland

Curator: James Weygand
Institute of Geophysics and Planetary Physics, UCLA
Phone: (310) 825-3547
E-mail: jweygand(at)igpp.ucla.edu

James Weygand's Office Hours:

Monday through Friday from 07:00 to 18:00 (PST).


Matlab programs are available to combine the spherical elementary currents
with total electron content measurements, SuperDARN flows, THEMIS
all sky images, and AMPERE data.

Data Access:

Contact James Weygand. E-mail above.
Validated data can be found at the Virtual Magnetospheric Observatory:
Equivalent Currents and Current Amplitudes.
Data not yet at the VMO has not been validated and is available upon request.

Key References:

•Amm, O., and A. Viljanen, Ionospheric disturbance magnetic field continuation
from the ground to the ionosphere using spherical elementary current systems,
Earth Planets Space, 51,431-440, 1999.

•Weygand et al., Application and Validation of the Spherical Elementary Currents
Systems Technique for Deriving Ionospheric Equivalent Currents with the North
American and Greenland Ground Magnetometer Arrays, J. Geophys. Res.,
115 doi:10.1029/2010JA016177, 2011.

The Code:

The original Matlab code was provide by Dr. Olaf Amm [Amm and Viljanen, 1999].
James Weygand has adapted the code to include ground magnetometer data from CANMOS,

The Data

Inputs: Nearly all the data was obtained from: CANMOS, CARISMA, GIMA, DTU (Greenland), MACCS,
McMAC, THEMIS, STEP, and USGS. Some data was obtained directly from the PIs.

Outputs: Equivalent ionospheric currents over most parts of Canada, Alaska,
until the Greenland coast (roughly corresponding to an area of about 40 degrees
latitude and 120 degrees longitude)"

Equivalent Ionospheric Current Data Availability

Arrays Involved Interval (YYYY/MM/DD to YYYY/MM/DD)
and STEP
2007/01/01 to 2014/06/30

Example Event

Equivalent Ionospheric Currents
Scaling factors of spherical elementary currents systems (proportional to FAC for uniform conductances)


April 5, 2010 Storms and Substorms


CANMOS and CARISMA: These data were obtained rom the Canadaian Space Science Data Portal.
The Canadian Space Science Data Portal is funded in part by the Canadian Space Agency (CSA),
the Alberta Science and Research Authority (ASRA), and the University of Alberta (UofA).
Also see CARISMA rules of the road.

CANMOS data were obtained by the Canadian Magnetic Observatory Network (CANMON),
maintained and operated by the Geological Survey of Canada, provided the data used in this study -

GIMA: acknowledge the Geophysical Institute, University of Alaska Fairbanks.

Greenland: acknowledge the Technical University of Denmark (DTU).

MACCS: Magnetometer Array for Cusp and Cleft Studies (MACCS) array is
supported by US National Science Foundation grant ATM-0827903 to Augsburg College.
We would like to would like to thank the following:
M. J. Engebretson, D. Murr, and E.S. Steinmetz at Augsburg College and the MACCS team.

THEMIS: see THEMIS rules of the road.

STEP: STEP magnetometer file storage is at Department of Earth and Planetary Physics,
The University of Tokyo and maintained by Dr. Kanji Hayashi (hayashi.AT.grl.s.u-tokyo.ac.jp)

McMAC: The McMAC Project is sponsored by the Magnetospheric Physics Program of
National Science Foundation and maintained by Dr. Peter Chi (pchi AT igpp.ucla.edu)

USGS: The USGS Geomagnetism Program


•Keiling, A., V. Angelopoulos, A. Runov, J. Weygand, S.V. Apatenkov, S. Mende, J. McFadden, D. Larson, O. Amm, K.-H. Glassmeier, and H.U. Auster, Substorm current wedge driven by plasma flow vortices: THEMIS observations, J. Geophys. Res., 114, A00C22, doi:10.1029/2009JA014114, 2009.

•Frey, H.U., O. Amm, C.C. Chaston, S. Fu, G. Haerendel, L. Juusola, T. Karlsson, B. Lanchester, R. Nakamura, N. Ostgaard, T. Sakanoi, E. Seran , D. Whiter, J. Weygand, K. Asamura, and M. Hirahara, Small and meso-scale properties of a substorm onset auroral arc, J. Geophys. Res., 115, A10209, doi:10.1029/ 2010JA015537, 2010.

•Weygand et al., Application and Validation of the Spherical Elementary Currents Systems Technique for Deriving Ionospheric Equivalent Currents with the North American and Greenland Ground Magnetometer Arrays, J. Geophys. Res., 115 doi:10.1029/2010JA016177, 2011.

•Keiling, A., V. Angelopoulos, J.M. Weygand, O. Amm, E. Spanswick, E. Donovan, S. Mende, J. McFadden, D. Larson, K.-H. Glassmeier, and H.U. Auster, THEMIS ground-space observations during the development of auroral spirals, Ann. Geophys., 27, 4317-4332, 2009.

•Nakamura, R. W. Baumjohann, E. Panov, A. A. Petrukovich, V. Angelopoulos, M. Volwerk, W. Magnes, Y. Nishimura, A. Runov, C.T. Russell, J.M. Weygand, O. Amm, H.-U. Auster, J. Bonnell, H. Frey, D. Larson, and J. McFadden, Flux transport, dipolarization and current sheet evolution during a doubleonset substorm, J. Geophys. Res., 116, A00136, doi:10.1029/2010JA015865, 2011.

•Partamies, N., L. Juusola, E. Tanskanen, K. Kauristie, and J.M. Weygand, Substorms during different storm phases, Ann. Geophys., 29, 2031-2043, 2011.

•Yang, J., F. Toffoletto, R. Wolf, S. Sazykin, P. Ontiveros, and J.M. Weygand, Large-scale current systems and ground magnetic disturbance during deep substorm injections, J. Geophys. Res., 117, A4, doi:10.1029/2011JA017415, 2012.

•Jiang, F., R.J. Strangeway, M.G. Kivelson, J.M. Weygand, R.J. Walker, K.K. Khurana, Y. Nishimura, V. Angelopoulos, E. Donovan, In-situ observations of the preexisting auroral arc by THEMIS All Sky Imagers and the FAST spacecraft, J. Geophys. Res., 117, A05211, doi:10.1029/ 2011JA017128, 2011.

•Weygand, J.M., O. Amm, V. Angelopoulos, S.E. Milan, A. Grocott, H. Gleisner, C. Stolle, Comparison Between SuperDARN Flow Vectors and Equivalent Ionospheric Currents from Ground Magnetometer Arrays, J. Geophys. Res., 117, A05325, doi:10.1029/2011JA017407, 2012.

•Haerendel, G., H. U. Frey, C. C. Chaston, O. Amm, L. Juusola, R. Nakamura, E. Seran, and J.M. Weygand, Birth and Life of Auroral Arcs Embedded in the Evening Auroral Oval Convection: A Critical Comparison of Observations with Theory, J. Geophys. Res., 117, A12220, doi:10.1029/2012JA018128, 2012.

•Nakamura, R., W. Baumjohann, E. Panov, M. Volwerk, J. Birn, A. Artemyev, A.A. Petrukovich, O. Amm, L. Juusola, M.G. Kubyshkina, V.A. Sergeev, S. Apatenkov, E. Kronberg, P. Daly, A. Fazakerley, Y. Khotyaintsev, M. Fillingim, J. M. Weygand, Flow bouncing and electron injection observed by Cluster, J. Geophys. Res., 118, 2055-2072, doi:10.1002/jgra.50134, 2013.

•Shi, Q., M. Hartinger, V. Angelopoulos, Q.-G. Zong, X.-Z. Zhou, X. Zhou, A. Kellerman, A. Tian, J.M. Weygand, S. Fu, Zuyin Pu, J. Raeder, Y. Ge, Y. Wang, H. Zhang, Z. Yao, THEMIS observations of ULF wave excitation in the nightside plasma sheet during sudden impulse events, J. Geophys. Res., 118, 284-298, doi:10.1029/2012JA017984, 2012.

•Archer, M. O., T. S. Horbury, J. P. Eastwood, J. M. Weygand, and T. K. Yeoman, Magnetospheric response to magnetosheath pressure pulses: A low-pass filter effect, J. Geophys. Res., 118, doi:10.1002/jgra.50519, 2013.

•Panov E. V., W. Baumjohann, R. Nakamura, O. Amm, M. V. Kubyshkina, K.-H. Glassmeier, J. M. Weygand, V. Angelopoulos, A. A. Petrukovich, and V. A. Sergeev, Ionospheric response to oscillatory flow braking in the magnetotail, J. Geophys. Res., 118, 1529-1544, doi:10.1002/jgra.50190, 2013.

Questions or Corrections can be directed to : jweygand$at$igpp.ucla.edu
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