IAGA Division V Working Group V-OBS

IAGA Working Group V-OBS coordinates all issues related to the operation of geomagnetic observatories and, in collaboration with V-MOD, repeat stations around the world. The WG sets quality standards for measurements and for data processing, and supports observatories in need of modern instrumentation or those in danger of closure. It cooperates with INTERMAGNET and is responsible for the organisation of a workshop on geomagnetic observatory instruments, data acquisition and processing every two years. The WG maintains a list of observatories operating worldwide now and in the past, and allocates IAGA codes.

NEW: The XVIIIth IAGA Workshop will be held at the Conrad Observatory near Vienna, Austria on 24-29 June 2018 and will be organised by the Zentralanstalt für Meteorologie und Geodynamik (ZAMG).

NEW: The XIXth IAGA Workshop with be held in Kazan, Russia in June 2020 and will be organised by the Kazan Federal University.

What is an observatory?

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.

Observatory standards

  • 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 γp=2.675153362 ⋅ 108 T-1 s-11 (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.

Observatory workshops

  • The XVIIth IAGA Workshop was held in Dourbes, Belgium in September 2016, organized by the Royal Meteorological Institute of Belgium.
  • The XVIth 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 XIVth 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 XIIIth 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 XIIth 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 XIth 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 Xth Workshop on Geomagnetic Observatory Instruments, Data Acquisition and Processing, Hermanus, South Africa, 15-24 April 2002 available here (39MB).
  • Proceedings of the IXth 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 VIIIth Workshop on Geomagnetic Observatory Data Acquisition and Processing was held at Vassouras, Brazil, 7-17 September 1998.
  • Proceedings of the VIIth 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 VIth 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.

WG business meeting minutes

  • 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.

List of observatories

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 Fusion table. 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 Susan Macmillan.

Map of observatories

Map of observatories from data held as a Google Fusion table. Green pin = "Open", red circle = "Closed", blue circle = "Uncertain", yellow circle = "Provisional" (first annual mean still to be delivered to a WDC). Click on symbol to get more information.

Obtaining an IAGA code

  • 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.

Support for observatories

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.

WG V-OBS CHAIR: WG V-OBS CO-CHAIR:
Dr. Arnaud Chulliat
NOAA National Geophysical Data Center and CIRES
University of Colorado Boulder
325 Broadway, E/GC3
Boulder, CO 80305-3328
USA
arnaud.chulliat@noaa.gov
Dr. Jürgen Matzka
Section 2.3, Earth's Magnetic Field
Helmholtz Centre Potsdam
GFZ German Research Centre For Geosciences
Public Law Foundation State of Brandenburg
Telegrafenberg,
14473 Potsdam Germany
E-Mail: jmat@gfz-potsdam.de