HR: 08:30h
AN: SH11C-01 INVITED     [Abstracts]
TI: Chromospheric Heating, Transport Processes, and Small Scale Magnetic Fields
AU: * Goodman, M L
EM: mgoodman@isr.us
AF: Institute for Scientific Research, Inc., 2500 Fairmont Avenue - Suite 734, Fairmont, WV 26555-2720 United States
AB: There are two basic categories of theories of chromospheric heating: hydrodynamic heating, and magnetohydrodynamic (MHD) heating. Hydrodynamic heating by shock wave dissipation appears to explain the origin of internetwork CaII bright points, but the associated heating rate appears to be at least one order of magnitude smaller than what is required to balance the chromospheric net radiative loss. Heating by high frequency acoustic waves is a proposed mechanism for chromospheric heating, at least in the internetwork, but so far there is no observational evidence that the energy in such waves is sufficient to heat the chromosphere. Increasing observational evidence for the existence of magnetic field concentrations at or below the spatial resolution limit with strengths ~ 10² - 10³ G, the positive correlation between magnetic field strength and net radiative loss, and the differences between network, internetwork, and active regions in terms of magnetic field filling factor and net radiative loss suggest that a single MHD mechanism heats the network, internetwork, and active region chromospheres outside of flaring regions, and operates largely at or below the spatial resolution limit. A discussion of this suggestion in the context of the critical need to model proposed chromospheric heating mechanisms using realistic transport processes is presented along with an indication of why this heating mechanism is not effective in the transition region or corona, except possibly on spatial scales believed to characterize current sheets. This work was supported by NSF grant ATM-0242820 to the Institute for Scientific Research.
DE: 7507 Chromosphere
DE: 7524 Magnetic fields
DE: 7529 Photosphere
DE: 7827 Kinetic and MHD theory
DE: 7859 Transport processes
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly