RHESSI/SOHO/TRACE Workshop

Working Group 6 – Imaging Spectroscopy of Thermal Plasma

 

 Objectives

This group will concentrate on the thermal plasmas produced during flares and what they tell us about the energy release process. We will cover the spatial and temporal evolution of the thermal plasma over a broad temperature range, concentrating on those aspects that reveal how energy stored in the coronal magnetic field is transformed during the flare into the thermal energy of the plasma. All available observations and theoretical modeling will be used to address these issues.

Questions

  1. How do we cleanly separate the thermal and nonthermal emissions, particularly in the X‑ray spectrum from 1 – 100 keV?
  2. What is the differential emission measure distribution with temperature and how does it vary in space and time during a flare?
  3. What fraction of the thermal plasma energy comes from direct heating and what fraction comes from heating via accelerated particles?
  4. When and where does the Neupert Effect apply and what does it tell us about the relation between the thermal and nonthermal components of the flare?
  5. What is the total energy that goes into the thermal plasma for any given flare? This question will be addressed in conjunction with Group 8 on Global Energetics.
  6. What does the location of the heated plasma at different temperatures tell us about the location of the energy release site?

Observations

We will use all available observations including those from the following space-based instruments:

  • RHESSI
  • TRACE
  • CDS, EIT, MDI, SUMER, UVCS, and LASCO on SOHO
  • SXI on GOES
  • RESIK and other instruments on Coronas F
  • Solar X-ray Spectrometer (SOXS) on the Indian spacecraft GSAT-2

Extensive use will also be made of ground-based observations as available, including BBSO, La Palma, Nobeyama, Zurich, etc.

Events for Study

We will concentrate on several specific flares that were well observed by the different instruments and that provide a range of different flare types. The suggested flares for analysis are as follows:

 

Date

GOES Peak
UT

GOES
Class

Location

RHESSI

SOHO

TRACE

SXI

RESIK

CME
km s‑1

1

21 April 2002

01:51

X1.5

S14W84

Y

Y

Y

N

N

2500

2

01-Jun-2002 

03:57

M1.5

S19E29

Y

Y

Y

N

?

?

3

23 July 2002

00:35

X4.8

S13E72

Y

Y

Y

N

N

2180

4

26 April 2003

03:06

M2.1

N20W69

Y

?

?

?

Y

?

5

2 Nov. 2003

17:25

X8.3

S14W56

Y

Y

Y

Y

?

?

 

Group Leaders

Brian R. Dennis

NASA Goddard Space Flight Center

Code 682

Greenbelt, MD 20771

Telephone: 301-286-7983

FAX: 301-286-1617

Brian.R.Dennis@nasa.gov

http://hesperia.gsfc.nasa.gov/~dennis/

Harry P. Warren

Naval Research Laboratory

Code 7673HW

Washington, DC 20375

Telephone : 202-404-1453

FAX: 202-404-7997

hwarren@nrl.navy.mil

http://tcrb.nrl.navy.mil/~hwarren