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The full SuperMAG magnetometer data set is available for download  here.

Rules of the Road

SuperMAG is made possible by the generous contribution of data by numerous collaborators. To ensure their continued operation the user must follow the below rules-of-the-road. Data, plots or derived data products are provided under the limitations of "fair use" and cannot be redistributed. Contact the individual instrument PI and the SuperMAG PI for requests that are in conflict with these restrictions.

The user is requested to acknowledge individual collaborators and SuperMAG when original data, derived data, movies, or data products are used in publications and/or presentations.

When Using Data

In all cases:

  • Include acknowledgement as listed on the SuperMAG website.
  • Include references to a technical papers for stations used (see list below).
  • Include SuperMAG reference: Gjerloev, J. W. (2012), The SuperMAG data processing technique, J. Geophys. Res., 117, A09213, doi:10.1029/2012JA017683.

In cases that only a few stations play a key role and their data are central to the scientific conclusion of the paper:

  • Offer of co-authorship to the PI (or PIs) of those stations and reference the appropriate paper (see list below).
When Using Indices
  • Include the text: “We gratefully acknowledge the SuperMAG collaborators (”
  • Include appropriate reference for indices used (see list below).
  • Include SuperMAG reference: Gjerloev, J. W. (2012), The SuperMAG data processing technique, J. Geophys. Res., 117, A09213, doi:10.1029/2012JA017683.
When Using Substorm Lists
  • If the substorm onset list is central to your study please offer co-authorship to the authors of the technique you use.
  • When using substorm lists please include acknowledgements found here.
  • Include appropriate reference (see list below)
  • For details please see
When Using OMNI When Using Imaging When using INTERMAGNET Data


Collaborator EMMA

Lichtenberger J., M. Clilverd, B. Heilig, M. Vellante, J. Manninen, C. Rodger, A. Collier, A. Jørgensen, J. Reda, R. Holzworth, and R. Friedel (2013), The plasmasphere during a space weather event: first results from the PLASMON project, J. Space Weather Space Clim., 3, A23 (

Collaborator IMAGE Chain

Tanskanen, E.I. (2009), A comprehensive high-throughput analysis of substorms observed by IMAGE magnetometer network: Years 1993-2003 examined, 114, A05204, doi:10.1029/2008JA013682.

Collaborator MACCS

Engebretson, M. J., W. J. Hughes, J. L. Alford, E. Zesta, L. J. Cahill, Jr., R. L. Arnoldy, and G. D. Reeves (1995), Magnetometer array for cusp and cleft studies observations of the spatial extent of broadband ULF magnetic pulsations at cusp/cleft latitudes , J. Geophys. Res., 100, 19371-19386, doi:10.1029/95JA00768.

Collaborator McMAC Chain

Chi, P. J., M. J. Engebretson, M. B. Moldwin, C. T. Russell, I. R. Mann, M. R. Hairston, M. Reno, J. Goldstein, L. I. Winkler, J. L. Cruz-Abeyro, D.-H. Lee, K.Yumoto, R. Dalrymple, B. Chen, and J. P. Gibson (2013), Sounding of the plasmasphere by Mid-continent MAgnetoseismic Chain magnetometers, J. Geophys. Res. Space Physics, 118, doi:10.1002/jgra.50274.

Collaborator MAGDAS / 210 Chain

Yumoto, K,. and the CPMN Group (2001), Characteristics of Pi 2 magnetic pulsations observed at the CPMN stations: A review of the STEP results, Earth Planets Space, 53, 981-992.

Collaborator CARISMA

Mann, I. R., et al. (2008), The upgraded CARISMA magnetometer array in the THEMIS era, Space Sci. Rev., 141, 413–451, doi:10.1007/s11214-008-9457-6.

Collaborator AALPIP

Clauer, C. R., et al. (2014), An autonomous adaptive low-power instrument platform (AAL-PIP) for remote high-latitude geospace data collection, Geosci. Instrum. Methods Data Syst., 3, 211–227, doi:10.5194/gi-3-211-2014

Collaborator INTERMAGNET

Love, J. J., Chulliat, A., (2013), An international network of magnetic observatories, Eos, 94(42), 373-374, doi:10.1002/2013EO420001


Gjerloev, J. W. (2012), The SuperMAG data processing technique, J. Geophys. Res., 117 , A09213, doi:10.1029/2012JA017683.

Indices SML, SMU, SME

Newell, P. T., and J. W. Gjerloev (2011), Evaluation of SuperMAG auroral electrojet indices as indicators of substorms and auroral power, J. Geophys. Res., 116, A12211, doi:10.1029/2011JA016779.

Indices SMLs, SMLd, SMUs, SMUd

Gjerloev, J. W., R. A. Hoffman, S. Ohtani, J. Weygand, and R. Barnes, Response of the Auroral Electrojet Indices to Abrupt Southward IMF Turnings (2010), Annales Geophysicae, 28, 1167-1182.


Newell, P. T., and J. W. Gjerloev (2014), Local geomagnetic indices and the prediction of auroral power, J. Geophys. Res. Space Physics, 119, doi:10.1002/2014JA020524.

Indices SMR, SMR-LT

Newell, P. T. and J. W. Gjerloev (2012), SuperMAG-Based Partial Ring Current Indices, J. Geophys. Res., 117, doi:10.1029/2012JA017586.

Substorm List

Forsyth, C., Rae, I. J., Coxon, J. C., Freeman, M. P., Jackman, C. M., Gjerloev, J., and Fazakerley, A. N. ( 2015), A new technique for determining Substorm Onsets and Phases from Indices of the Electrojet (SOPHIE), J. Geophys. Res. Space Physics, 120, 10,592– 10,606, doi:10.1002/2015JA021343.

Frey, H. U., Mende, S. B., Angelopoulos, V., and Donovan, E. F. (2004), Substorm onset observations by IMAGE‐FUV, J. Geophys. Res., 109, A10304, doi:10.1029/2004JA010607.

Gjerloev, J. W. (2012), The SuperMAG data processing technique, J. Geophys. Res., 117, A09213,  doi:10.1029/2012JA017683.

Liou, K. (2010),  Polar Ultraviolet Imager observation of auroral breakup, J. Geophys. Res.,  115, A12219, doi:10.1029/2010JA015578.

Newell, P. T., and J. W. Gjerloev (2011), Evaluation of SuperMAG auroral electrojet indices as indicators of substorms and auroral power, J. Geophys. Res., 116, A12211, doi:10.1029/2011JA016779.

Newell, P. T., and J. W. Gjerloev (2011), Substorm and magnetosphere characteristic scales inferred from the SuperMAG auroral electrojet indices, J. Geophys. Res., 116, A12232, doi:10.1029/2011JA016936.

Ohtani, S., and J. Gjerloev, Is the Substorm Current Wedge an Ensemble of Wedgelets?: Revisit to Midlatitude Positive Bays, accepted, J. Geophys. Res, 2020.

Station Information

Station name, geographic location and IAGA code can be downloaded as an ASCII file. The file includes a description of variables and other information.

When using this file please acknowledge the SuperMAG collaboration by including the reference below.

Some of the three letter codes are not official IAGA codes but are designated by SuperMAG.

Bxx indicate BAS operated stations
Txx indicate THEMIS project stations
Mxx indicate McMac operated stations
Cxx indicate CARISMA operated stations
Exx indicate ENIGMA operated stations
Pxx indicate EMMA operated stations
Sxx indicate SAMNET operated stations
Axx indicate AMBER operated stations
Gxx indicate MAGDAS operated stations
PGx indicate MIST operated stations


Gjerloev, J. W. (2012), The SuperMAG data processing technique, J. Geophys. Res., 117, A09213, doi:10.1029/2012JA017683.

Gjerloev, J. W. (2009), A Global Ground-Based Magnetometer Initiative, EOS, 90, 230-231, doi:10.1029/2009EO270002.


SuperMAG 1-sec data have been rotated into a local magnetic coordinate system (see below) and the main field has been removed using the baseline technique described in the first reference below (e.g. Gjerloev, J. W., 2012).

Data Cadence

The SuperMAG 1-sec data have been derived from measurements with a 0.5 Hz or higher sampling rate (see ULF Parameters for details)

Coordinate System

Global studies require all data to be rotated into a common known coordinate system. Data provided to SuperMAG from the collaborators are typically in either:

  • Geographic coordinates (north (X), east (Y), vertical down (Z))
  • Geographic coordinates (horizontal intensity (H), declination (D) and vertical down (Z))
  • Geomagnetic coordinates> (magnetic north (H), magnetic east (D) and vertical down (Z))
with or without baselines subtracted. During intitial setup the sensor axes are oriented in either the geographic or local magnetic coordinate system. The Earth main field, however, is constantly changing so the geomagnetic coordinate system is time dependent. The various uncertainties in mind SuperMAG decided to make no assumptions as to the initial setup of the magnetometer other than the Z-axis being vertical. Using the two horizontal components SuperMAG determines a slowly varying time dependent declination angle and subsequently rotates the horizontal components into a local magnetic coordinate system for which the magnetic east component (E) is minimized and the magnetic north component (N) is maximized. Note that geomagnetic coordinates are routinely labeled HDZ although the units of the D-component can be nT or an angle. Likewise, the D-component is often found to have a significant offset. As a consequence SuperMAG decided to denote the components:


  • N-direction is local magnetic north
  • E-direction is local magnetic east
  • Z-direction is vertically down

By definition the typical value (offset) of the E-component is zero. This reference system is independent of the actual orientation of the two horizontal magnetometer axes and the data can be rotated to any desired coordinate system using the appropriate IGRF model.

Magnetic Local Time (MLT) is calculated using the solar local time (Jean Meeus, Astronomical Algorithms, 2nd edition, ISBN-13: 978-0943396613) and the AACGM system. For more info and a cautionary note see:

Baseline Determination

SuperMAG provides four options for the user:

  1. Subtract the daily variations and yearly trend (using Gjerloev, 2012)
  2. Subtract only the yearly trend (using Gjerloev, 2012)
  3. Do not subtract any baseline
  4. Subtract the start value from thee remaining of the interval.

SuperMAG thus provides 3 different solutions. The user should use the appropriate dataset for the study. As an example a study of the Sq current or the equatorial electrojet should not subtract the daily variations since this will remove part of this signal.

The purpose of determining the baseline is to perform a separation of sources. The measured field on the surface of the Earth is due to a list of sources:

Bmeasured = Bmain + BSq + BFAC + BRC + BEJ + BMP + ...

where the right side terms indicate the contribution due to: The Earth main field; the Sq current system; the field-aligned currents; the ring current; the auroral electrojets; and the magnetopause currents.

The focus of SuperMAG is ionosphere-magnetosphere research so perturbations produced by currents flowing in and between the ionosphere and the magnetosphere should be maintained while all other sources to the measured field should be removed. According to Ampere’s law it is impossible to determine a single unique current solution from the measured field. It is, however, possible to make a separation of sources if reasonable assumptions are made. For example, that the Earth main field is slowly varying compared to all other sources.

The question as to how the baseline should be determined is still under debate as evident from the stream of new papers being published (e.g. Mayaud, 1980; Menvielle et al., 1995; Takahashi et al., 2001; Janzhura and Troshichev, 2008). The fundamental problem is that there is no objective way to evaluate the quality of each technique. In validating any result or technique it is required that a set of ground-truth observations exists. Agreeing with another set of results does not provide an argument of validity, as both could be erroneous. This is particularly true for baseline determination as just about any data provider and as many scientists have developed their own technique.

As mentioned above the purpose of the baseline determination is fundamentally to perform a separation of sources. As there is no objective way to separate the sources neither is there a way to perform an objective evaluation. We therefore conclude that the user of the data must keep in mind the assumptions used in the baseline determination and draw conclusions accordingly.

The above discussion (see Gjerloev, 2012 for an extensive discussion) is why SuperMAG provides four options for the user.

Main Field or Baseline

For SuperMAG 1-sec data the main field, or baseline, has been removed using the technique described in Gjerloev, J. W., 2012 to subtract the daily variations and yearly trend (see description of 1 minute resolution Mmagnetometer data for details).

ULF Parameters

All ULF data products are derived from the 1-sec SuperMAG data (see ULF Parameters for a description of the details).


Gjerloev, J. W., 2012. The SuperMAG data processing technique, J. Geophys. Res., 117, A09213, doi:10.1029/2012JA017683.

Janzhura, A. S. and O. A. Troshichev, 2008. Determination of the running daily geomagnetic variation, J.Atmos.Solar-Terr.Phys. 70, 962-972, doi:10.1016/j.jastp.2007.11.004.

Mayaud, P. N., Derivation, 1980. Meaning and use of geomagnetic indices, Geophys.Monographs,Ser., 22, 154, AGU, Washington D.C.

Menvielle, M., N. Papitashvili, L. Hakkinen, and C. Suckdorff, 1995. Computer production of K indices: Review and comparison of methods, Geophys.J.Int., 123, 866-886, doi:10.1111/j.1365-246X.1995.tb06895.x

Takahashi, K., B. toth, and J. V. Olson, 2001. An automated procedure for near-real-time Kp estimates, J. Geophys. Res., 106, 21,017-21,032, doi:10.1029/2000JA000218.

To Plot Data

To Plot Data

  1. Select the time range of interest
  2. Select the stations of interest
    This can be done three ways:
    • Use the various Lat/Lon options below
    • Select individual stations using the station checklist
    • Use the select options on the map
  3. Select various plotting options:
    The following plot options are available:
    • U/L envelope (upper/lower envelope of N-component for selected stations
    • Subtract start (subtract the value at the start of the time interval for each component)
    • Do Not Remove Daily Baseline (remove yearly trend but includes daily variations)
    • Do Not Remove Any Baseline (validated and rotated data without any baseline removal)
    • IMF GSM and IMF GSE - Propagated IMF in GSM/GSE coordinates

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  1. Login
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