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DOIs and Licensing for Geomagnetic Data & Products: Current Status

Aude ChambodutA Blog post by Aude Chambodut (WDS Scientific Committee Member)

The longest time series of geomagnetic data are certainly the ones acquired by magnetic observatories (Fig. 1), some of which reach a century of uninterrupted measurements.

There are currently about 200 open magnetic observatories worldwide. In each of them, absolute vector observations of the Earth's magnetic field are recorded accurately and continuously, with a time resolution of one minute or less, over a long period of time. Magnetic observatory data are 'primary data' that are extensively used in the derivation of data products ('secondary data') such as: International Geomagnetic Reference Field models, geomagnetic indices, space weather applications…

Figure 1: Paris declination series: annual means of declination corrected and adjusted to actual French National Magnetic Observatory - CLF (Mandea and LeMouël, 2016).

Figure 1. Paris declination series: annual means of declination corrected and adjusted to actual French National Magnetic Observatory - CLF (Mandea and LeMouël, 2016).

The whole community of geomagnetic observatories is particularly well organized and federated under the auspices of the International Association of Geomagnetism and Aeronomy (IAGA) one of the associations of the International Union of Geodesy and Geophysics [WDS Partner Member].

Since the beginning of the 1960’s (the birth of the World Data Centre system established in 1957 provided archives for the observational data resulting from the 'International Geophysical Year'), magnetic observatories data have been mostly publicly available (Fig. 2). Getting access to a network of stations is much more interesting than having access to just one isolated observatory.

Figure 2: Location of Magnetic Observatories (all periods) which are having at least one data ingested into the Geomagnetism Data Portal of WDC for Geomagnetism (Edinburgh, UK - ).

Figure 2. Location of magnetic observatories (all periods) having at least one datum ingested into the Geomagnetism Data Portal of WDC – Geomagnetism, Edinburgh [WDS Regular Member].

The cooperative spirit within the geomagnetic community thus knows a fairly long-standing history that has had to cope with the successive technological revolutions regarding data recording (e.g., analogic to numeric; Fig. 3), but also regarding the way data are made available (from yearly books, via isolated recording supports, up to connected data repositories). In this regard, the community had practices based on fair-play and goodwill recognition of data sources/providers. Such practices worked, and would have worked for many more decades without new challenges to meet the changing requirements of users and stakeholders.

Indeed, in our increasingly connected world, it is evermore important to closely follow evolution regarding data management. Some aspects were previously not sufficiently taken into account, such as the discovery, citation, and reuse of the geomagnetic data. Nowadays, it appears no longer possible to keep sources of data for only 'informed people', and the existing licensing conditions for distribution of geomagnetic data and data products are (in part) not adequately elaborated to address this change and need to be improved.

Figure 3: Analog magnetogram of Vladivostok (VLA) 24th September 1934 (with ICSU grant-2003 at WDC for Solar-Terrestrial Physics, Moscow, Russia -

Figure 3. Analogue magnetogram from Vladivostok; 24 September 1934 (through ICSU grant-2003 by WDC – Solar–Terrestrial Physics, Moscow [WDS Regular Member]).

IAGA has thus agreed to set up Task Forces on the abovementioned aspects, with a consensus already found when it comes to the aims of data/ data-product licensing and Digital Object Identifier (DOI) minting to:

 – Provide recognition and acknowledgement.
 – Enable creation of new data products from primary data (e.g., geomagnetic indices) or in combination with other data sources (e.g., global models of geomagnetic field).
 – Prevent the change and/or appropriation of data by a third party.
 – Enable reuse of data in a reproducible way.
 – Supply metadata that enable unique identification of a dataset, as well as providing relevant information to the user.
 – Use machine-readable and widely used licenses. 
 – Enable easy online access to research data for discovery.

The work is in progress such that it meets the state-of-art when it comes to applying licenses and minting DOI for geomagnetic data and data products, with the goal to ensure the availability into the 21st century of the tremendous efforts achieved by generations of observers in geomagnetism throughout the world.