EarthRef.org Reference Database (ERR)
Development and Maintenance by the EarthRef.org Database Team

Detailed Reference Information
Russell et al. 1975
Russell, C.T., Burton, R.K. and McPherron, R.L. (1975). Some properties of the Svalgaard A/C index. Journal of Geophysical Research 80: doi: 10.1029/JA080i010p01349. issn: 0148-0227.

Several properties of the A/C index of polar cap variations introduced by L. Svalgaard in 1972 have been found to vary with time. In the presatellite era, C days, as measured by the Ap index, are almost twice as geomagnetically active as A days, while in the modern epoch they have essentially identical activity. Prior to 1962 there were over 40% more A days than C days per year, while during the modern epoch there are essentially equal numbers of A days and C days. In view of this strong bias to assigning a ''toward'' classification on geomagnetically active days we recommend against using the Svalgaard A/C classication in studies of geomagnetic activity. We further recommend that a full and thorough documentation of the index be prepared and/or that others undertake to compile such a classification separately.

BACKGROUND DATA FILES

Abstract

Journal
Journal of Geophysical Research
http://www.agu.org/journals/jb/
Publisher
American Geophysical Union
2000 Florida Avenue N.W.
Washington, D.C. 20009-1277
USA
1-202-462-6900
1-202-328-0566
service@agu.org
Click to clear formClick to return to previous pageClick to submit