Conduction-driven chromospheric evaporation in a solar flare

Journal Article · Wed Jun 01 00:00:00 EDT 1988 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/166391· OSTI ID:6969468

Zarro, D M; Lemen, J R

Observations of gentle chromospheric evaporation during the cooling phase of a solar flare are presented. Line profiles of the low-temperature (T of about 6 x 10 to the 6th K) coronal Mg XI line, observed with the X-Ray Polychromator on the Solar Maximum Mission, show a blueshift that persisted for several minutes after the impulsive heating phase. This result represents the first detection of an evaporation signature in a soft X-ray line formed at this low temperature. By combining the Mg XI blueshift velocity data with simultaneous measurements of the flare temperature derived from Ca XIX observations, it is demonstrated that the upward flux of enthalpy transported by this gently evaporating plasma varies linearly with the downward flux of thermal energy conducted from the corona. This relationship is consistent with models of solar flares in which thermal conduction drives chromospheric evaporation during the early part of the cooling phase. 22 references.

• Research Organization: National Aeronautics and Space Administration, Greenbelt, MD (USA). Goddard Space Flight Center; Applied Research Corp., Greenbelt, MD (USA); University College, London (England)
• OSTI ID: 6969468
• Journal Information: Astrophys. J.; (United States), Vol. 329
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHROMOSPHERE
EVAPORATION
SOLAR FLARES
COOLING
CALCIUM
DOPPLER EFFECT
HEAT TRANSFER
MAGNESIUM
SOLAR CORONA
ALKALINE EARTH METALS
ATMOSPHERES
ELEMENTS
ENERGY TRANSFER
METALS
PHASE TRANSFORMATIONS
SOLAR ACTIVITY
SOLAR ATMOSPHERE
STELLAR ATMOSPHERES
STELLAR CORONAE
640104* - Astrophysics & Cosmology- Solar Phenomena