Aa Indices.
Dataset description
The aa index is a simple global geomagnetic activity index, with units of 1 nT (nanotesla), which is produced from the K indices from two approximately antipodal observatories. At present these are Hartland observatory in the UK and Canberra observatory in Australia. The main advantage in using aa indices for research purposes is that the time series spans further back (to 1868) than any of the other planetary indices time series.Also, up to date values are produced and made available weekly, giving nearer to real time availability than any other planetary index. In between the weekly updates, BGS calculates estimated aa indices, providing real time "nowcasts" which are updated on an hourly basis. These estimates are clearly marked with the letters "Est". Although calculated by the same method, the aa indices available on this service are not the definitive values. These are published by the International Service for Geomagnetic Indices, CRPE/CNET - CNRS, 4 Avenue de Neptune, F-94107 Saint Maur, Cedex, France.
Constraints
In its role as World Data Centre for Geomagnetism (Edinburgh) we make available the data for scientific research. If the data are used in publications and presentations, the data suppliers and this WDC should be acknowledged. For commercial applications of these data, please contact the relevant institute directly.
Further information
For more information please contact:
Enquiries
British Geological Survey
Environmental Science Centre, Nicker Hill,
Keyworth
Nottingham
NG12 5GG
Tel : +44 (0)115 936 3143
Fax :+44 (0)115 936 3276
Email :enquiries@bgs.ac.uk
Further details
Dataset details
| Language | English |
|---|---|
| Curator | British Geological Survey |
| Supply media/format | DELIMITED ASCII - ASCII Year Files or user defined. |
| Storage format | Digital:Other than Excel etc |
| Frequency of update | weekly |
| Start of capture | 1st January 1868 |
| End of capture | Not applicable |
| Contact details | |
| Department | Enquiries |
| Organisation | British Geological Survey |
| Address | Environmental Science Centre, Nicker Hill, Keyworth |
| City | Nottingham |
| County | Nottinghamshire |
| Country | United Kingdom |
| Postcode | NG12 5GG |
| enquiries@bgs.ac.uk | |
| Telephone | +44 (0)115 936 3143 |
| Fax | +44 (0)115 936 3276 |
| Keywords | |
| Topic category | geoscientificInformation (information pertaining to earth sciences) |
| Keywords and Keyphrases | GEOMAGNETISM |
| Keyword source | BGS Keyphrases |
| Spatial details | |
| Spatial Reference System | Not available |
| Dataset extent | |
| Coverage (Lat/Long) | North boundary : 90 East boundary : 180 South boundary : -90 West boundary : -180 |
| Metadata | |
| Metadata language | English |
| Metadata last updated | 7th September 2006 |
| Metadata standard | ISO standard 19115:2003 |
| Copyright and IPR | |
| The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused. | |
| W -180 | 90 N |
 |
|
| S -90 | 180 E |
