HR: 0830h
AN: SP11B-06    [Abstracts]
TI: Local Helioseismic Mode Frequency Shifts With Magnetic Activity, From GONG and MDI
AU: * Howe, R
EM: rhowe@noao.edu
AF: National Solar Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 United States
AU: Komm, R W
EM: komm@noao.edu
AF: National Solar Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 United States
AU: Gonzalez Hernandez, I
EM: irenegh@noao.edu
AF: National Solar Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 United States
AU: Hill, F
EM: hill@noao.edu
AF: National Solar Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 United States
AU: Haber, D A
EM: dhaber@solarz.colorado.edu
AF: JILA and Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 United States
AU: Hindman, B W
EM: hindman@solarz.colorado.edu
AF: JILA and Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 United States
AB: We use the ring-diagram technique of local helioseismology to study the frequency shifts of high-degree solar acoustic modes from over 600 days of data from the Global Oscillations Network Group (GONG), covering the period 2001-2004. The data are compared with contemporaneous data from the Michelson Doppler Imager (MDI) dynamics program, where available. We examine both synoptic charts and the day-to-day variations in selected active regions. The results, once instrumental effects have been removed, show strong dependence of the mode frequency on the local magnetic flux, with the frequencies generally increasing with magnetic index. We relate these findings to results from global modes. This work was supported by the National Science Foundation and NASA
DE: 7500 SOLAR PHYSICS, ASTROPHYSICS, AND ASTRONOMY
DE: 7522 Helioseismology
DE: 7536 Solar activity cycle (2162)
SC: Solar Physics Division - AAS [SP]
MN: 2005 Joint Assembly