HR: 0800h
AN: SH32A-0791    [Abstracts]
TI: Imaging Solar Farside and Tachocline Using SOHO/MDI Data and Numerical Simulations
AU: * Zhao, J
EM: junwei@sun.stanford.edu
AF: W. W. Hansen Experimental Physics Laboratory, 491 South Service Road Stanford University, Stanford, CA 94305-4085, United States
AU: Hartlep, T
EM: thartlep@mail.arc.nasa.gov
AF: NASA Ames Research Center, NASA Ames Research Center, Moffett Field, CA 94035, United States
AU: Kosovichev, A G
EM: sasha@sun.stanford.edu
AF: W. W. Hansen Experimental Physics Laboratory, 491 South Service Road Stanford University, Stanford, CA 94305-4085, United States
AU: Mansour, N N
EM: Nagi.N.Mansour@nasa.gov
AF: NASA Ames Research Center, NASA Ames Research Center, Moffett Field, CA 94035, United States
AB: To be able to see large solar active regions when they are located on the farside of the Sun before rotating into the earth side is of great importance for space weather forecast. By analyzing acoustic wave signals that are reflected back to the near-side from the farside after four and five skips, we are able to map the real-time farside active regions with good signal to noise ratio by use of SOHO/MDI medium-l observations. This technique is validated by employing numerical data that simulate the solar global acoustic wavefields. Solar tachocline is generally believed as the location where solar dynamo operates. We have developed a time-distance helioseismology code to measure and invert sound speed perturbations at the tachocline area, and also tested the code by use of numerical simulation data. The technique is then used on SOHO/MDI medium-l observations to map the evolution of the tachocline from 1996 through 2007.
DE: 7522 Helioseismology
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting