skip to main content

Title: Observation and numerical modeling of chromospheric evaporation during the impulsive phase of a solar flare

We have studied the chromospheric evaporation flow during the impulsive phase of the flare by using the Hinode/EUV Imaging Spectrometer observation and 1D hydrodynamic numerical simulation coupled to the time-dependent ionization. The observation clearly shows that the strong redshift can be observed at the base of the flaring loop only during the impulsive phase. We performed two different numerical simulations to reproduce the strong downflows in FeXII and FeXV during the impulsive phase. By changing the thermal conduction coefficient, we carried out the numerical calculation of chromospheric evaporation in the thermal conduction dominant regime (conductivity coefficient κ{sub 0} = classical value) and the enthalpy flux dominant regime (κ{sub 0} = 0.1 × classical value). The chromospheric evaporation calculation in the enthalpy flux dominant regime could reproduce the strong redshift at the base of the flare during the impulsive phase. This result might indicate that the thermal conduction can be strongly suppressed in some cases of flare. We also find that time-dependent ionization effect is important to reproduce the strong downflows in Fe XII and Fe XV.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. Institute for Space-Earth Environmental Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601 (Japan)
  2. National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292 (Japan)
  3. (The Graduate University of Advanced Studies), Toki, Gifu 509-5292 (Japan)
  4. National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan)
  5. (The Graduate University of Advanced Studies), Mitaka, Tokyo 181-8588 (Japan)
Publication Date:
OSTI Identifier:
22486410
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 10; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CHROMOSPHERE; COMPUTERIZED SIMULATION; ENTHALPY; EVAPORATION; EXTREME ULTRAVIOLET SPECTRA; FLARING; IONIZATION; RED SHIFT; SOLAR FLARES; SPECTROMETERS; THERMAL CONDUCTION; TIME DEPENDENCE