National Geophysical Data Center (NGDC), NOAA Satellite and Information Service

Back to Collection NOAA/NESDIS/NGDC/STP/Indices
View Metadata As: Get Data, FAQ, HTML, 19139 XML
Assess Metadata For: Completeness, DOI Readiness, CSW Readiness, Components

AA Geomagnetic Activity Indices From Two Antipodal Observatories in Australia and England

browse graphicAnnual Sunspot and aa Numbers
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.

Cite this dataset when used as a source.

Search and Download
  • AA index (download)
    FTP site for the aa index from 1868 through present day
Distribution Formats
Distributor Distributor information not available
No point of contact available for this dataset
Documentation links not available.
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
  • publication: 1968-01-01
Edition: First
Dataset Progress Status Complete
Data Update Frequency:
Purpose: Geomagnetic Activity Research
Use Limitations
  • While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.
Time Period: 1868-01-01  to  Present
Spatial Bounding Box Coordinates:
N: 90.000000
S: -90.000000
E: 180.000000
W: -180.000000
Spatial Coverage Map:
  • Earth Science > Land
  • EARTH SCIENCE > SOLID EARTH > Geomagnetism > Geomagnetic Indices
  • Earth Science > Interior & Crust
  • Geomagnetism
  • Global
Use Constraints
  • Use Constraints: None
Access Constraints
  • Access Constraints: No Constraints
  • Free Depends on the Data Set
Lineage Statement Lineage statement not available.

Metadata Last Modified: 2015-09-18

For questions about the information on this page, please email: