HR: 0800h
AN: SA51B-0517    [Abstracts]
TI: Mesospheric Joule Heating During the 2003 Halloween Superstorm
AU: * Brower, L
EM: Laura.brower@colorado.edu
AF: University Of Colorado Aerospace Engineering Sciences Department, UCB 431, Boulder, CO 80309, United States
AU: Thayer, J P
EM: jeffrey.thayer@colorado.edu
AF: University Of Colorado Aerospace Engineering Sciences Department, UCB 431, Boulder, CO 80309, United States
AU: Lu, G
EM: ganglu@ucar.edu
AF: National Center for Atmospheric Research, 3450 Mitchell Lane, Boulder, CO 80301, United States
AB: A large solar flare and coronal mass ejection produced an intense geomagnetic storm on 28-30 Oct 2003, referred to as the Halloween Storm. From 6 to 10 UT on 29 Oct 2003, the Sondrestrom incoherent scatter radar (ISR) observed enhanced high-latitude D-region electron densities and electric fields between 65 and 95 km. The observations indicate discrete enhancements of electron density associated with relativistic electron precipitation and diffuse enhancements, measuring 10x1011 m-3, due to proton precipitation. Diffuse enhancements were sustained for the four hour observing period. The large electron density, in combination with co-located electric fields observed to be in excess of 70 mV/m, leads to significant electron frictional heating. Using the TIME-GCM, it is shown that Joule heating rivals chemical and solar heating in the mesosphere during the observing period. We also demonstrate a sensitivity of mesospheric Joule heating to electron temperature, requiring the re- examination of the electron energy balance in the mesosphere.
DE: 2467 Plasma temperature and density
DE: 2475 Polar cap ionosphere
SC: SPA-Aeronomy [SA]
MN: 2007 Fall Meeting