DIVISION V: Geomagnetic observatories, surveys and analyses

Globally, geomagnetic observatories form a network of ground-based stations that continually monitor the natural magnetic field over long periods of time. The aim of each observatory is to capture the absolute magnetic field vector at a fixed location, typically for many years, and to publish data to the wider community. Due to the wide amplitude and frequency ranges of the field sources monitored by observatories, highly sensitive and stable instruments are operated in an environment free from artificial magnetic disturbance and measurements are made to documented metrological standards, such as those defined by INTERMAGNET under the V-OBS Working Group. In addition to derived data products (e.g. activity indices), observatory data are published at a range of sample rates, from annual means to filtered one-minute data and higher, with the absolute magnetic vector referenced to the Earth's geographic co-ordinate system.

• An IAGA guide for observatories is available from the IAGA web site

• Value for the gyromagnetic constant

  The International Council for Science: Committee on Data for Science and Technology  adopted a new value for the gyromagnetic constant in 2006. The new value is γ_p^′=2.675153362 ⋅ 10⁸ T^-1 s^-1 (Mohr et al, 2008). In order to comply with international standards IAGA adopts the new value to replace the value adopted in 1991 for geomagnetic measurements from 2010 on. Observatories and instrument manufacturers should implement the new value as soon as possible. The difference between the old and new constants, however, amounts to only 15 pT in 50 000 nT and thus is within the noise level of most of the present day observatory measurements, therefore it can be safely adopted without problem even if immediate implementation by all observatories at the same time cannot be guaranteed.

  Mohr, P. J., Taylor, B. N. and Newell, D. B., 2008. CODATA recommended values of the fundamental physical constants: 2006. Rev. Mod. Phys. Vol 80, 633-730, DOI: 10.1103/RevModPhys.80.633.

• The XIXth IAGA Workshop was held in Tihany and Sopron, Hungary on 22-26 May 2023, organised by Institute of Earth Physics and Space Science (EPSS).
• Proceedings of the XVIIIth IAGA Workshop held at the Conrad Observatory near Vienna, Austria, in June 2018 are published in Conrad Observatory Journal Nr 5.
• The XVIIIth IAGA Workshop was held at the Conrad Observatory near Vienna, Austria on 24-29 June 2018. It was organised by the Zentralanstalt für Meteorologie und Geodynamik (ZAMG).
• Proceedings of the XVIIth IAGA Workshop held at Dourbes, Belgium, 4–10 September 2016, are published in special joint issue of Annales Geophysicae and Geoscientific Instrumentation, Methods and Data Systems.
• The XVI^th IAGA Workshop was held in Hyderabad, India, in October 2014, organized by the Indian Institute of Geomagnetism (IIG) and the National Geophysical Research Institute.
• Proceedings of the XVth IAGA Workshop on Geomagnetic Observatory Instruments, Data Acquisition and Processing held in San Fernando, Cadiz, Spain, 4-14 June 2012 published in BOLETÍN ROA No. 03/13, available here (16.3 Mb).
• Proceedings of the XIV^th IAGA Workshop On Geomagnetic Observatory Instruments, Data Acquisition and Processing, held in Changchun, Jilin Province, China, September 13 - 23, 2010 published in Data Science Journal Vol. 10, 2011.
• Proceedings of the XIII^th IAGA Workshop On Geomagnetic Observatory Instruments, Data Acquisition and Processing, 9-18 June 2008, Golden and Boulder, Colorado, USA published in USGS Open File Report 2009-1226, 2009.
• Proceedings of XII^th IAGA Workshop on Geomagnetic Observatory Instruments, Data Acquisition and Processing, 19-24 June 2006, Belsk, Poland published in Publications of the Institute of Geophysics, Polish Academy of Science, C-99 (398) (go to C-Geomagnetism, issue C-99 (398)).
• Proceedings of the XI^th Workshop on Geomagnetic Observatory Instruments, Data Acquisition and Processing held in Kakioka, Japan November 2004 published in Earth, Planets and Space Vol. 58 (No. 6), pp. 697-794, 2006.
• Proceedings of the X^th Workshop on Geomagnetic Observatory Instruments, Data Acquisition and Processing, Hermanus, South Africa, 15-24 April 2002 available here (39MB).
• Proceedings of the IX^th Workshop on Geomagnetic Observatory Instruments, Data Acquisition and Processing, Hurbanovo, Slovakia, 2000 published in Geophysical Institute, Slovak Academy of Sciences Contributions to Geophysics & Geodesy, 30 (2), 2000.
• The VIII^th Workshop on Geomagnetic Observatory Data Acquisition and Processing was held at Vassouras, Brazil, 7-17 September 1998.
• Proceedings of the VII^th Workshop on Geomagnetic Observatory Instruments, Data Acquisition and Processing held at Niemegk, Germany, 8-15 September 1996 published in Scientific Technical Report; 98/21, 1998.
• Proceedings of the VI^th Workshop on Geomagnetic Observatory Instruments, Data Acquisition and Processing held at Dourbes, Belgium, 18-24 September 1994 published in J. L. Rasson (ed), Publication scientifique et technique No 003, 1996.
• (V?) Workshop on Geomagnetic Observatory Instruments, Data Acquisition and Processing was held at Chambon la Foret, France, 1992.
• Proceedings of the (IV?) International Workshop on Geomagnetic Observatory Data Acquisition and Processing held at Tihany, Hungary, 3-14 September 1990 publishing in Eotvos Lorand Geophysical Institute of Hungary Geophysical Transactions, Vol. 36, No 3-4, 1991.
• Proceedings of the (III?) International Workshop on Geomagnetic Observatory Data Acquisition and Processing held at Nurmijarvi, Finland, May 15-25, 1989 published in Finnish Meteorological Institute Geophysical Publications, No 15, 1990.
• (From INTERMAGNET history page - Nordic Comparison Meeting at Chambon La Foret, France, May 1987)
• Proceedings of the (I) International Workshop on Magnetic Observatory Instruments held in Ottawa, Canada, 30 July-9 August 1986 published in R.L. Coles (Ed) Geological Survey of Canada, Paper 88-17, Geomagnetic Series, 32, 1988.

• Minutes of the Business Meeting of IAGA WG V-OBS, Berlin, Germany, 13 July 2023.
• Minutes of the Business Meeting of IAGA WG V-OBS, Hyderabad/virtual conference, 22 August 2021.
• Minutes of the Business Meeting of IAGA WG V-OBS, Montreal, Canada, 13 July 2019.
• Minutes of the Business Meeting of IAGA WG V-OBS, Cape Town, South Africa, 29 August 2017.
• Minutes of the Business Meeting of IAGA WG V-OBS, Prague, 23 June 2015.
• Minutes of the Business Meeting of IAGA WG V-OBS, Mérida, August 26th 2013.
• Minutes of the Business Meeting of IAGA Working Group V-OBS, Melbourne, July 2nd, 2011.
• Minutes of the IAGA WG V-OBS business meeting, Tuesday 25 August 2009.

When an observatory does not send data to at least one ICSU World Data System centre (WDC) for several years and does not contribute to an officially recognised IAGA geomagnetic index, it may lose its "open" status in this table. The WG V–OBS chair and co–chair will attempt to contact the observatory before the downgrade is made.

List of observatories held as a Google sheet. The presence of annual means at a WDC is used to determine observatory status. Observatories marked as "Uncertain" may be variometer stations, or their status is genuinely not known by IAGA. Input data came from IAGA catalogue at Boulder and WDC catalogues at Edinburgh, Kyoto and Moscow and from list at previous V-OBS website. Please send updates to Christopher Turbitt.

Map of observatories from data held as a Google sheet. Click on symbol to get more information.

• Before or soon after the observatory becomes operational, the contact person at the operating institute should suggest a suitable 3-letter code that is not already in use and send a request to WG V-OBS chair and co-chair that it be reserved. See this table for a list of codes already in use.
• The contact person should also provide full name and location of the observatory.
• The WG V-OBS chair and/or co-chair should check this table, add the code on a provisional basis and inform the observatory contact person and the WDCs.
• This code becomes official only after data meeting the requirements of an observatory as established by IAGA have been delivered to at least one ICSU World Data System centres (WDC) for the first full year. The requirements are sets of hourly and annual means and ideally also a set of filtered 1-minute means that have all been produced from magnetic field measurements which have baseline control by means of regular absolute measurements. The status of the observatory is then upgraded from "provisional" to "open" in this table.
• When an observatory moves within the same area (precedents on what constitutes this are varied) the operating institute can opt to keep the existing code provided simultaneous measurements are made at both sites in order to establish jump values. In such cases a numeric suffix is added to the database to separate the location/time of the first observatory from the second, third, etc.

The V-OBS Working Group is concerned with helping to maintain a globally diverse network of geomagnetic observatories that operate and publish data to a common standard. As well as encouraging the establishment of new observatories, the WG welcomes offers of assistance in the form of instrumentation, partnership or training aimed at preserving or improving the operation of geomagnetic observatories. The WG also invites communication from observatories or operating institutes that are facing closure or require assistance in publishing data or meeting modern operational standards. Contact can be made through the WG chair or the chair of INTERMAGNET Operations Committee.

Dourbes Observatory maintains a geomagnetic instrument pool to provide for observatories in need of renewed instrumentation (contact: Instrument Pool, IRM-CPG, B-5670 Dourbes, Belgium). The pool constitutes transformed, reconditioned and calibrated magnetometers donated by third-party Institutions. To replenish the rapidly decreasing available pool, we urge the geomagnetic community to continue supply Dourbes with non-magnetic theodolites, fluxgate sensors, digital variometers and proton magnetometers for which they have no use.