This webpage provides information about the activities of the Working Group DAT of Division V (WG V-DAT) of the International Association of Geomagnetism and Aeronomy (IAGA Div. V). At the XXIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) held at Sapporo, Japan from 30 June to 11 July, 2003, the Division V of IAGA was re-organized, and the current WG V-DAT, dealing with Geomagnetic data and indices, represents the former Working Group V-2. This working group defines formats for data exchange and sets quality standards for indices of magnetic activity. WG V-DAT encourages free exchange of scientific information. Your comments are welcome.

Data Exchange Format

IAGA2002 is the latest format for observatory ASCII data dissemination. This format was originally released in August 2001, followed by modification in December 2001, July 2003, and August 2011. Detailed description of the IAGA2002 format is found here.

Access to data from geomagnetic observatories

• Kyoto, Japan
• Edinburgh, UK
• Mumbai, India

The International Real Time Magnetic Observatory Network (INTERMAGNET) programme exists to establish a global network of cooperating digital magnetic observatories, adopting modern standard specifications for measuring and recording equipment, in order to facilitate data exchanges and the production of geomagnetic products in near real time. WG V-OBS coordinates issues related to the operation of geomagnetic observatories.

Information on ground, marine and airborne magnetic data and indices are available from the National Centers for Environmental Information (NCEI). The Space Physics Interactive Data Resource (SPIDR) offers geomagnetic data and indices and the ground based magnetometers service. Ground-based magnetometer data from stations providing absolute measurements as well as stations providing variation mesurements are available from SuperMAG.

Geomagnetic data is also available from the World Data Centers for Solar Terrestrial Physics in Russia and China

Old magnetograms that are converted to digital images, as part of ICSU supported project "Rescue of old Analogue Magnetograms by converting to Digital Images", are available for download from Kyoto, Japan or Moscow, Russia. Additionally, scanned magnetograms going back to the 1840s are available from Edinburgh, UK.

Geomagnetic Indices and Event Lists

There are numerous indices of geomagnetic activity. The International Association of Geomagnetism and Aeronomy (IAGA) officially recognizes magnetic indices: aa, am, Kp, Dst, AE, and PC. IAGA also endorses lists of remarkable geomagnetic events such as SSC, SFE, and international quietest (Q-Days) and most disturbed days (D-Days). Criteria for IAGA endorsement of indices became effective in 2009. More information about the IAGA indices and geomagnetic event lists is available from International Services for Geomagnetic Indices (ISGI).

Following lists provide access to the geomagnetic indices and event lists.

• aa Index
• am Index
• Kp Index
• Disturbance storm-time Index (Dst)
• Auroral Electrojet Index (AE)
• Polar Cap (PC) Index
• SSC (storm sudden commencement) and SFE (solar flare effect)
• Q-Days and D-Days

Locations of stations for derivation of the geomagnetic indices are displayed here.

Task Force

Task Force is sometimes formed for critical focus areas of the Working Group.

• Indices, Forecasting, Data Servises, Effects (closed)
• ASCII based data exchange format (closed)
• Criteria for index endorsement (closed)
• Endorsement of PC as an IAGA index (closed)
• Endorsement of the classification of rapid variations as SC (closed)
• Data DOI

Geomagnetism,
Earth Hazards and Observatories,
British Geological Survey, United Kingdom
E-mail:ecla@bgs.ac.uk

DTU Space
National Space Institute
Geomagnetism
Denmark
E-mail:anna@space.dtu.dk