Accession Number : ADA138645

Title :   A Catalog of Solar White-Light Flares (1859-1982), Including Their Statistical Properties and Associated Emissions.

Descriptive Note : Environmental research papers,

Corporate Author : AIR FORCE GEOPHYSICS LAB HANSCOM AFB MA

Personal Author(s) : Neidig,D F ; Cliver,E W

PDF Url : ADA138645

Report Date : 20 Sep 1983

Pagination or Media Count : 54

Abstract : This catalog of 57 solar white-light flares reported between 1859 and 1982 includes H-alpha, soft X-ray, and radio emissions associated with the white-light flares. The following are among the conclusions resulting from statistical examination of the listed flares and the active regions in which they occurred: (1) The active regions that produce white-light flares tend to have the following characteristics: (a) magnetic class = Delta; (b) classification of the penumbra of the largest spot = K; and (c) sunspot group area 500 millionths of the solar hemisphere. (2) Northern hemisphere white-light flare activity begins abruptly about 1 or 2 years before solar maximum, and declines slowly thereafter. Southern hemisphere white-light flare activity follows the same pattern, but begins approximately 1 year after solar maximum. (3) White light flares have a mean latitude of 13 + or - 2 deg in the southern hemisphere but a mean latitude of 18 + or - 1 deg in the northern hemisphere. (4) White-light flares exhibit a north-south asymmetry with 70% more events having been observed in the northern hemisphere as compared to the southern (the current solar cycle is a possible exception with southern hemisphere activity dominating) as of December 1982. (5) There is no compelling evidence of preferred solar longitudes for white-light flare active regions. Southern hemisphere activity during the current cycle is a possible exception.

Descriptors :   *SOLAR FLARES, WHITE LIGHT, CATALOGS, SOFT X RAYS, HYDROGEN, SOLAR ACTIVITY, RADIOFREQUENCY, MAGNETIC FIELDS, SUNSPOTS, NORTHERN HEMISPHERE, SOUTHERN HEMISPHERE

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE