Aa Indices.
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.
Licence
- Either: (i) the dataset is made freely available, e.g. via the Internet, for a restricted category of use (e.g. educational use only); or (ii) the dataset has not been formally approved by BGS for access and use by external clients under licence, but its use may be permitted under alternative formal arrangements; or (iii) the dataset contains 3rd party data or information obtained by BGS under terms and conditions that must be consulted in order to determine the permitted usage of the dataset. Refer to the BGS staff member responsible for the creation of the dataset if further advice is required. He / she should be familiar with the composition of the dataset, particularly with regard to 3rd party IPR contained in it, and any resultant use restrictions. This staff member should revert to the IPR Section (ipr@bgs.ac.uk) for advice, should the position not be clear.
Data Resources 1
| Dataset Extent: | |
|---|---|
Latitude: |
90.0000° to -90.000° |
Longitude: |
-180.00° to 180.000° |
Additional Links 2
XML
HTML
Additional Information
| Openness score |
|
| Temporal coverage | 1868 |
| Harvest URL | http://metadata.bgs.ac.uk/geonetwork/srv/en/csw? |
| Harvest Date | 17/01/2013 11:50 |
| Harvest GUID | 9df8df51-63b9-37a8-e044-0003ba9b0d98 |
| Extent | Latitude: 90.0000° to -90.0000° Longitude: -180.0000° to 180.0000° |
| Spatial reference system | urn:ogc:def:crs:EPSG::4326 |
| Metadata date | 16/1/2013 |
| Dataset reference date | 1/1/1868 (publication) |
| Frequency of update | weekly |
| Responsible party | British Geological Survey (distributor) |
| Access 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. |
| Metadata language | English |
| Gemini2 resource type | dataset |
| Date added computed | No value |
| Date updated computed | No value |
Developer Tools
The information on this page (the dataset metadata) is also
available in JSON format:
/api/2/rest/package/aa-indices
Read more about this site's CKAN API: About the API
This dataset has a permanent URI:
http://data.gov.uk//dataset/aa-indices
