Transcript Recent changes at World Data Centre for Geomagnetism (Edinburgh)

Recent changes at World Data Centre
for Geomagnetism (Edinburgh)
Susan Macmillan, Tom Shanahan and Sarah Reay
European Repeat Station Workshop Bucharest May 2007
The World Data Centres
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started 50 years ago by ICSU as part of IGY to ensure open access to
global data for academic use and long-term stewardship for future
scientists
originally focussed on physical sciences e.g. solar-terrestrial,
geomagnetism, oceanography, meteorology
centres today more broadly environmental e.g. soils, climate,
biodiversity, ecology
WDC Conference last week in Bremen, Germany. Discussions on:
 relationships with other umbrella organisations e.g. GEOSS, FAGS
 metadata standards – more for geospatial data and not ideal for time
series data e.g. ISO
 data publication and need for persistent identifiers e.g. DOI
assignation
European Repeat Station Workshop Bucharest May 2007
New Journal, to be published by
Copernicus Publications
European Repeat Station Workshop Bucharest May 2007
credit: H. Pfeiffenberger/A. Richter
Recent changes at WDC (Edinburgh)
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Operation of online Geomagnetic Data Master Catalogue for
observatory minute and hourly values passed from DMI to
BGS in May 2007
Address is www.wdc.bgs.ac.uk
See poster!
European Repeat Station Workshop Bucharest May 2007
Data holdings in WDC Edinburgh
200
175
Minute means
Hourly means
Number of observatories
150
Annual means
125
100
75
50
25
0
1810
1830
1850
1870
European Repeat Station Workshop Bucharest May 2007
1890
1910
Year
1930
1950
1970
1990
2010
Repeat data collection
what we do....
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Letters sent every year to organisations operating
observatories requesting repeat station data (this
misses out countries which have repeat station
networks but no observatories)
Data received in wide variety of formats and
reformatted into common format
Data compared with previous data and IGRF for
gross errors
European Repeat Station Workshop Bucharest May 2007
Global magnetic survey data
holdings 1900 onwards
Feb 2003 Mar 2005 May 2007
One-off land vector data
126172
Aeromagnetic vector and scalar data
13512
Marine vector data
13087
Marine scalar data
24515
Repeat vector data
20589
Total
European Repeat Station Workshop Bucharest May 2007
197875
20790
20937
Number of repeat vector data in world and in Europe
TOTAL = 20937
European Repeat Station Workshop Bucharest May 2007
Locations of repeat vector data 1975-2007
TOTAL = 8407 (8260)
European Repeat Station Workshop Bucharest May 2007
Locations of repeat vector data added since Mar 2005
European Repeat Station Workshop Bucharest May 2007
These stations provide data for global modelling
e.g. the new GUFM model by Jackson and Finlay where
differences are used to remove the crustal bias
Issue 1: some stations have
reoccupation intervals of up to 15
years (and more!)
European Repeat Station Workshop Bucharest May 2007
Issue 2: number of repeat station SV
estimates/year not even in time
European Repeat Station Workshop Bucharest May 2007
Issue 3: difficult to assign
meaningful errors
...but still useful!
European Repeat Station Workshop Bucharest May 2007
credit: Chris Finlay
Locations of
repeat vector data
in Europe
1975 - 2007
TOTAL = 4244 (4125)
European Repeat Station Workshop Bucharest May 2007
Example of data available from www.geomag.bgs.ac.uk/gifs/surveydata.html
260 external requests/year
European Repeat Station Workshop Bucharest May 2007
Summary
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WDC Edinburgh actively maintaining Geomagnetic
Data Master Catalogue for observatory data and
global magnetic survey dataset
Several global models incorporate repeat station data
However, main purpose of collecting repeat station
data should remain the derivation of regional models
Would welcome help checking that data held are
complete and correct
Data reformatted by Gerald Duma’s RS-ENTER
particularly welcome!
European Repeat Station Workshop Bucharest May 2007