AAS 204th Meeting, June 2004
Session 4 Plasma Astrophysics of Coronae
Poster, Monday, May 31, 2004, 9:20am-6:30pm, Ballroom

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[4.05] The FIP Effect is Solved!

J. M. Laming (NRL)

We discuss a further development of models along the lines originally suggested by Schwadron, Fisk and Zurbuchen (1999). These authors considered wave heated coronal loops where waves penetrate to loop footpoints, heating ions but not neutrals. This gives rise to abundance enhancements in elements which are ionized in the chromosphere (i.e. low first ionization potential) over those which are neutral through the higher ion scale height. Due to the low energy density residing in waves which can resonate with ion gyrofrequencies, we consider the effect of nonresonant waves through the ponderomotive force they exert on ions. For a broad class of solutions, an upward ponderomotive force exists on ions, and for quite reasonable wave energy densities reproduces the observed solar FIP abundance enhancement very well. Varying wave energy density varies the FIP enhancement, and for certain special cases a downwards ponderomotive force on ions may occur. The possible application of this to the inverse FIP effect observed in highly active stellar coronae will be discussed. Work supported by NASA Grant NAG5-9105, NASA Contract S13783G and by the NRL/ONR Solar Magnetism and the Earth's Environment 6.1 Research Option.

The author(s) of this abstract have provided an email address for comments about the abstract: jlaming@ssd5.nrl.navy.mil

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