Skip to main content
Dataset Overview | National Centers for Environmental Information (NCEI)

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

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.
Cite this dataset when used as a source.
  • ID not available.
gov.noaa.ngdc.stp.indices:G00584
Download Data
Other Access
Distribution Formats
  • ASCII
Ordering Instructions Ordering Instructions: Data may be downloaded for no cost
Distributor Justin Mabie
Space and Terrestrial Weather Specialist
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
(303) 497-6135
Justin.Mabie@noaa.gov
Dataset Point of Contact Justin Mabie
Space and Terrestrial Weather Specialist
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
(303) 497-6135
Justin.Mabie@noaa.gov
Time Period 1957-01-01 to Present
Spatial Bounding Box Coordinates
West: -180.00
East: 180.00
South: -90.00
North: 90.00
Spatial Coverage Map
General Documentation
Publication Dates
  • publication: 1976-01-01
Edition First
Dataset Progress Status Under development - data is currently in the process of being created
Data Update Frequency As needed
Purpose Geomagnetic 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.
Originators
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Publishers
  • NOAA National Centers for Environmental Information
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Theme keywords NASA/GCMD Earth Science Keywords
  • Earth Science > Solid Earth > Geomagnetism > Geomagnetic Indices
  • Earth Science > Sun-Earth Interactions > Ionosphere/Magnetosphere Dynamics > Aurorae
  • Earth Science > Sun-Earth Interactions > Ionosphere/Magnetosphere Dynamics > Geomagnetic Indices
Data Center keywords Global Change Master Directory (GCMD) Data Center Keywords
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Place keywords NASA/GCMD Earth Science Keywords
  • High Latitude Magnetosphere
  • Magnetosphere (Other)
Project keywords Global Change Master Directory (GCMD) Project Keywords
  • ICSU-WDS > International Council for Science - World Data System
Use Constraints
  • Use Constraints: None
Access Constraints
  • Access Constraints: No Constraints
Fees
  • None
Lineage information for: repository
Processing Steps
  • 2015-04-22T00:00:00 - NOAA created the National Centers for Environmental Information (NCEI) by merging NOAA's National Climatic Data Center (NCDC), National Geophysical Data Center (NGDC), and National Oceanographic Data Center (NODC), including the National Coastal Data Development Center (NCDDC), per the Consolidated and Further Continuing Appropriations Act, 2015, Public Law 113-235. NCEI launched publicly on April 22, 2015.
Last Modified: 2015-09-18
For questions about the information on this page, please email: Justin.Mabie@noaa.gov