Date ( Creation )

1868

Identifier

http://data.bgs.ac.uk/id/dataHolding/13480365

Maintenance and update frequency

weekly Weekly

GEMET - INSPIRE themes

• Geology

BGS Thesaurus of Geosciences

• Geomagnetism

Keywords

• NERC_DDC

Access constraints

otherRestrictions Other restrictions

Use constraints

otherRestrictions Other restrictions

Other constraints

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.

Other constraints

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.

Metadata language

English English

Topic category

• Geoscientific information

Geographic identifier

WORLD [id=100000]

 

Date ( Creation )

1979

N

S

E

W

Supplemental Information

Complete time Series. Global: Derived from 2 Antipodal Locations.

Distribution format

• DELIMITED ASCII - ASCII Year Files or user defined. ()

OnLine resource

http://www.geomag.bgs.ac.uk/data_service/data/magnetic_indices/aaindex.html  

Hierarchy level

dataset Dataset

Other

dataset

Statement

The aa indices are derived using data from two nearly antipodal observatories, where magnetograms were available since 1868. For each three hour interval, K indices are measured at the two stations and converted back into amplitude; an individual aa index is the average of the northern and southern values, weighted to account for the small difference in latitude of the two stations, or for the slight changes in the very place of the observatory. The definitive values are published by the International Service for Geomagnetic Indices.

gmd:MD_Metadata

File identifier

9df8df51-63b9-37a8-e044-0003ba9b0d98   XML

Metadata language

English English

Hierarchy level

dataset Dataset

Date stamp

2021-09-17

Metadata standard version

2.3

Dataset URI

http://data.bgs.ac.uk/id/dataHolding/13480365