Accession Number : ADA292859

Title :   Environmental Conditions Responsible for Solar Activity.

Descriptive Note : Final technical rept. 1 Oct 91-30 Sep 94,

Corporate Author : STANFORD UNIV CA CENTER FOR SPACE SCIENCE AND ASTROPHYSICS

Personal Author(s) : Sturrock, Peter A.

PDF Url : ADA292859

Report Date : 28 FEB 1995

Pagination or Media Count : 18

Abstract : Solar coronal activity is of concern to the Air Force primarily because of the terrestrial effects of coronal mass ejections and solar flares. Coronal mass ejections can lead to geomagnetic disturbances that in turn cause magnetospheric substorms. This geomagnetic activity disturbs the ionosphere, especially in the polar regions, interfering with radio propagation. Ionizing radiation (UV and X-ray) and particle events from solar flares can also lead to ionospheric disturbances. Furthermore, major flares pose serious hazards to astronauts. During the past three years, the Stanford group has obtained significant theoretical insights into the driving mechanism of eruptive events in the solar corona. The question of what causes coronal eruptions inevitably leads to questions concerning the plasma conditions and magnetic field configurations in which eruptions occur. In particular, we have grappled with the long-standing issue of how the coronal plasma is maintained at a temperature of several million degrees, while the underlying surface of the sun that is visible in white light has a temperature of only a few thousand degrees. Our work over the past three years has taken us closer to the goal of being able to predict the imminent onset of solar flares and coronal mass ejections. (AN)

Descriptors :   *MAGNETIC FIELDS, *SOLAR CORONA, *SOLAR FLARES, GEOMAGNETISM, POLAR REGIONS, EXPERIMENTAL DATA, PLASMAS(PHYSICS), ELECTROMAGNETIC WAVE PROPAGATION, RADIO TRANSMISSION, IONIZING RADIATION, MAGNETOSPHERE, MAGNETIC STORMS, SOLAR X RAYS, PHOTOSPHERE, IONOSPHERIC DISTURBANCES, MAGNETOHYDRODYNAMIC WAVES, MAGNETIC DISTURBANCES, SOLAR ULTRAVIOLET RADIATION.

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE