Solar flare model atmospheres

Journal Article · Wed Jan 01 04:00:00 EST 1992 · American Astronomical Society, Bulletin; (United States)

OSTI ID:6991213

Fisher, G H ^[1]; Hawley, S L ^[2]

---

1. Univ. of Hawaii (United States)
2. California Univ., Riverside, CA (United States) Lawrence Livermore National Laboratory, CA (United States)

The authors present 3 sets of solar flare atmospheric models, computed in 3 different limits. In all of the models, energy balance is assumed, with radiative losses from the optically thick transitions of HI, CaII, and MgII balancing flare heating from nonthermal electrons and X-rays form the flaring corona. In the 'Hydrostatic' models, they have assumed that flare heating by Coulomb collisions from a flux of nonthermal electrons has been occurring for an infinitely long time, and the corona and chromosphere have achieved both energetic and hydrostatic equilibrium. In the 'Impulsive' models, they have assumed that the atmospheric density remains frozen in its preflare state, but that the atmosphere rapidly achieves a temperature structure consistence with energy balance. In the 'Evolving' models, they have assumed a temporal variation of the nonthermal electron heating rate consistent with flare heating for time scales of 5-10 minutes, corresponding to a long lived and intense flare, continually undergoing chromospheric evaporation. In this case, the chromospheric model is in hydrostatic equilibrium, but the flare transition region is at depths that are much less than those in the 'Hydrostatic' models. They present temperature and density structures in these models atmospheres, line and continuum fluxes from each model, and a few selected line profiles.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6991213
• Journal Information: American Astronomical Society, Bulletin; (United States), Journal Name: American Astronomical Society, Bulletin; (United States) Vol. 24:2; ISSN 0002-7537; ISSN AASBAR
• Country of Publication: United States
• Language: English

Related Subjects

661300* -- Other Aspects of Physical Science-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
CHROMOSPHERE
COLLISIONS
ELECTRONS
ELEMENTARY PARTICLES
ENERGY BALANCE
ENERGY LOSSES
FERMIONS
HEATING
LEPTONS
LOSSES
MAIN SEQUENCE STARS
MATHEMATICAL MODELS
PLASMA DENSITY
PLASMA HEATING
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR CORONA
SOLAR FLARES
STAR MODELS
STARS
STELLAR ATMOSPHERES
STELLAR CORONAE
SUN
TEMPERATURE MEASUREMENT
VARIATIONS