1. The effects of canopy expansion on chromospheric evaporation driven by thermal conduction fronts Authors: F. Rozpedek, S. R. Brannon, D. W. Longcope Credit: M. Aschwanden et al. (LMSAL), TRACE, NASALMSALTRACENASA

2. RD GDS RD accels plasma GDS heats plasma to flare temp. @ loop top Simulation region Chromosphere Reconnection frees loop to contract ~90% free mag. energy => bulk plasma motion (Longcope et al. 2009) Flare loop dynamics

3. 1-D “shocktube” model Model details: Static non-uniform grid: <1 km (chromosphere), ~10 km (corona), scales up in TR Include viscosity & Spitzer conductivity Neglect gravity & explicit radiative effects Simplified model atmosphere: temp. grad. @ const. pressure Classical piston shock (tanh func. w/ Rankine-Hugoniot) MpMp MsMs Chromosphere T=0.01 Corona T=1 Uniform pressure in TR Trans. Reg. (TR) GDS Post-shock Fluid input

4. Model loop atmosphere ChromosphereTRCorona

5. Time Evolution for the uniform tube

10. Question: Is there some observational quantity that would enable us to determine where the nozzle is located relative to the Transition Region? The canopy expansion

11. Varying Area Profile Nozzle below the TR Nozzle at the centre of the TR Nozzle above the TR The area profile has a form of a piecewise linear function. ThermalConductionFrontThermalConductionFrontThermalConductionFront

15. Transsonic points (lower) (upper)

16. Transsonic points (lower) (upper)