HR: 1340h
AN: SH53A-1063    [Abstracts]
TI: The Connection Between Alfven Waves and the FIP Effect
AU: * Laming, J M
EM: laming@nrl.navy.mil
AF: Naval Research Laboratory, 4555 Overlook Ave, S.W., Washington, DC 20375, United States
AB: The FIP (First Ionization Potential) Effect is the by now well known element abundance anomaly in the corona, whereby elements that have FIP lower than about 10 eV (i.e. those that are ionized in large portions of the chromosphere) have their abundance enhanced by a factor typically 3-4 with respect to high FIP elements, the abundances of which are essentially unchanged. Laming (2004) proposed that this abundance modification is due to the action of the ponderomotive force in the chromosphere, arising as Alfven waves propagate through a region where the Alfven speed increases with height. I this talk I will describe some new results, based on a non-WKB treatment of chromospheric Alfven waves. This will include the possible differences in FIP fractionation due to Alfven waves originating as sound waves at the base of the chromosphere, or impinging on the top of the chromosphere from a coronal source, and a consideration of the possible effect on abundances of the generation of Alfven waves at the β = 1 region in the low chromosphere. This work is supported by NASA SEC GI Grant NNG05HL39I, and by basic research funds of the Office of Naval Research.
DE: 7507 Chromosphere
DE: 7509 Corona
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting