Accession Number:

ADA113084

Title:

Interferometric Microwave Polarimetry as a Tool for Short-Term Solar Flare Prediction.

Descriptive Note:

Rept. for 19 Feb 80-31 Mar 81,

Corporate Author:

CALIFORNIA INST OF TECH PASADENA

Personal Author(s):

Report Date:

1981-08-01

Pagination or Media Count:

29.0

Abstract:

The purpose of this study is to look at a data base of interferometric solar microwave data in order to identify, evaluate and interpret preflare microwave signatures, with reference to their possible role in the short-term prediction of solar flares. Reserving the second half of this data base for verification of tentative results, 27 major flares were selected using optical, soft x-ray OR microwave flux criteria for which good quality interferometric data was available. These events were analysed in detail and very similar preflare signatures noted in four 15 of the cases. The most common signature was a step-like increase in signal amplitude, accompanied by a decrease or reversal in the degree of polarization. Such a signature occurred between a few minutes to a few tens of minutes before the start of the impulsive phase. Optical data, available in three cases, showed the microwave changes were simultaneous with either small brightenings or small-scale filament disruptions. Preliminary results show that such microwave behavior occurs far too seldom for such an association with major flares to be a chance occurrence.

Subject Categories:

  • Astrophysics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE