Auroral Electrojet (AE, AL, AO, AU) - A Global Measure of Auroral Zone Magnetic Activity

Description

The AE index is derived from geomagnetic variations in the horizontal component observed at selected (10-13) observatories along the auroral zone in the northern hemisphere. To normalize the data a base value for each station is first calculated for each month by averaging all the data from the station on the five international quietest days. This base value is subtracted from each value of one-minute data obtained at the station during that month. Then among the data from all the stations at each given time (UT), the largest and smallest values are selected. The AU and AL indices are respectively defined by the largest and the smallest values so selected. The symbols, AU and AL, derive from the fact that these values form the upper and lower envelopes of the superposed plots of all the data from these stations as functions of UT. The difference, AU minus AL, defines the AE index, and the mean value of the AU and AL, i.e. (AU+AL)/2, defines the AO index. The term "AE indices" is usually used to represent these four indices (AU, AL, AE and AO). The AU and AL indices are intended to express the strongest current intensity of the eastward and westward auroral electrojets, respectively. The AE index represents the overall activity of the electrojets, and the AO index provides a measure of the equivalent zonal current.

Resources

Name Format Description Link
21 Home page for the World Data Center for Geomagnetism with links to the data http://swdcwww.kugi.kyoto-u.ac.jp/aedir/index.html
0 Home page https://www.ngdc.noaa.gov/geomag
0 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. https://www.earthdata.nasa.gov/learn/find-data/idn/gcmd-keywords
0 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. https://www.earthdata.nasa.gov/learn/find-data/idn/gcmd-keywords
0 ftp site ftp://ftp.ngdc.noaa.gov/STP/GEOMAGNETIC_DATA/INDICES/AURORAL_ELECTROJET
0 ftp://ftp.ngdc.noaa.gov/STP/GEOMAGNETIC_DATA/INDICES/AURORAL_ELECTROJET
21 index.html http://swdcwww.kugi.kyoto-u.ac.jp/aedir/index.html
21 Home page for the World Data Center for Geomagnetism with links to the data http://swdcwww.kugi.kyoto-u.ac.jp/aedir/index.html

Tags

  • international council for science - world data system
  • geomagnetic indices
  • nesdis
  • ionosphere/magnetosphere dynamics
  • icsu-wds
  • national geophysical data center
  • noaa
  • sun-earth interactions
  • magnetosphere (other)
  • u.s. department of commerce
  • high latitude magnetosphere
  • earth science
  • doc/noaa/nesdis/ngdc
  • solid earth
  • aurorae
  • doc/noaa/nesdis/ncei
  • geomagnetism
  • national centers for environmental information

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