**Previous
abstract** **Next
abstract**

**Session 1 - Chromosphere, Corona, Flares.**

*Display session, Friday, June 27*

*Ballroom B, Chair: Charles Kankelborg*

## [1.59] Reconstructing a Flare's Thermodynamic-Spatial Form from Scaling Laws and Soft X-ray Measurements

*H. Garcia (Space Environment Center)*
This analysis of a solar flare's macro thermodynamic-spatial
structure is based on the RTV model of the dynamics of quies
cent solar coronal forms (Rosner,Tucker and Vaiana,1978) and
full disk soft X-ray measurements by the GOES two-channel
soft X-ray sensor. The RTV model provides a relationship
between maximum (loop top) temperature, T_m, and the semi-
loop length, L. In order to reconstruct the flare's thermo-
dynamic macro structure utilizing the RTV law one must know
or be able to solve for T_m and the internal pressure, p (the
latter assumed spatially constant at fixed times). From the
GOES dual X-ray measurement one can derive the spatially
averaged temperature, T_av, and the emission measure, EM, at
any point during the flare. Treating these two derived
parameters as measurements one can solve for the unknowns p
and T_m if the loop length L can be independently specified.
The constant crossection A can be deduced from L utilizing
the theoretical relationship of the ratio L/A to T_m and EM
(Sylwester,1988). Once the flare's L and A are specified
one can numerically integrate over the full semi-length to
compute density, X-ray emission, and the differentials of
of volume, thermal energy and emission measure for equal
increments of temperature; compare the computed T_av and EM
with their observed (derived) values; and recover T_m and p
by linearized iterative solutions. As noted everything
depends on the availability of an independently obtained L.
Fortunately L bears a robust physical relationship with the
flare's rise and decay times and peak temperature. Metcalf
and Fisher (1996) and predecessors (Fisher and Hawley, 1990;
Hawley et al.,1995) have developed algorithms which permit
the loop length to be estimated from X-ray light curves.
These data are used to initiate a solution which not
only yields T_m and p but collaterally determines L as well.
Fourteen cases are discussed comparing thermodynamic results
with Yohkoh SXT measured loop data.

Fisher, G.H. amp; Hawley, S.L. 1990, ApJ, 357, 243
Hawley, S.L., et al. 1995, ApJ, 453, 464
Metcalf, T.R. amp; Fisher, G.H. 1996, ApJ, 462, 977
Rosner, R., Tucker, W.H. amp; Vaiana, G.S. 1978, ApJ, 220, 643
Sylwester, J. 1988, Adv. Space Res. Vol.8, No.11, 55

**Program
listing for Friday**