Description
The NOAA National Centers for Environmental Information (formerly National Geophysical Data Center) receives, on a monthly basis, indices that are based on the data from two approximately antipodal observatories in England and Australia. The AA-indices are available from 1868 to present.
Resources
| Name | Format | Description | Link |
|---|---|---|---|
| AA index | Unknown | FTP site for the aa index from 1868 through present day | |
| Web Resource | Unknown | ||
| Major Magnetic Storms 1868 - 2007 according to the AA* Criteria | Unknown | Home page | |
| Global Change Master Directory (GCMD) Keywords | Unknown | The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. | Open resource |