Accession Number : ADA139287

Title :   Very Large Array Observations of Solar Active Regions.

Descriptive Note : Interim scientific rept. 1 Jan-30 Dec 83,


Personal Author(s) : Lang,K R

PDF Url : ADA139287

Report Date : 30 Jan 1984

Pagination or Media Count : 77

Abstract : Observations of solar active regions with the Very Large Array have led to a new understanding of the origin and prediction of the solar bursts which disrupt communication systems and interfere with high-flying aircraft. The detailed temperature, density and magnetic structure of coronal loops have been investigated by using observations at 20 cm wavelength. By studying loop evolution on time scales as short as 10 seconds and as long as days, we have obtained new information about preburst temperature enhancements and changes in the magnetic field topology which account for the release and source of burst energy. Multiple wavelength observations were carried out and combined to specify the three dimensional structure of the temperature, density and magnetic field in the solar atmosphere above active regions. This has helped resolve uncertainties in the coronal magnetic field strength, the temperature of the solar atmosphere above sunspots, the physical nature of the coronal loops, and the dominant radiation mechanisms at different levels in the solar atmosphere. We have also specified the positions, size evolution and magnetic structure of solar bursts, thereby obtaining new information about preburst heating, changing magnetic field configurations, and thes nearly simultaneous excitation of bursts at widely separated areas on the solar surface.

Descriptors :   *Solar activity, Solar disturbances, Arrays, Solar flares, Magnetic fields, Plasma diagnostics

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE