Astronomy and Astrophysics – Astronomy
Scientific paper
Feb 2006
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006apj...638..576g&link_type=abstract
The Astrophysical Journal, Volume 638, Issue 1, pp. 576-583.
Astronomy and Astrophysics
Astronomy
44
Sun: Helioseismology, Sun: Interior, Sun: Oscillations
Scientific paper
Ring-diagram analysis, a local helioseismology technique, has proven to be very useful for studying solar subsurface velocity flows down to a depth of about 0.97 Rsolar. The depth range is determined by the modes used in this type of analysis, and thus depends on the size of the area analyzed. Extending the area allows us to detect lower spherical harmonic degree (l) modes which, at a constant frequency, penetrate deeper in the Sun. However, there is a compromise between the size of the area and the validity of the plane-wave approximation used by the technique. We present the results of applying the ring diagrams to 30° diameter areas over the solar surface in an attempt to reach deeper into the solar interior. Meridional flows for 25 consecutive Carrington rotations (1985-2009) are derived by applying this technique to Global Oscillation Network Group (GONG) and Michelson Doppler Imager (MDI) data. This covers a time span of almost 2 yr, starting at the beginning of 2002. The amplitude of the meridional flow shows a variation of the order of 5 m s-1 during this period. Our results indicate that the flows increase toward the interior of the Sun for the depth range studied. We find a 1 yr periodicity in the appearance of an equatorward meridional cell at high latitudes that coincides with maximum values of the solar inclination toward the Earth (B0 angle).
Corbard Thierry
González Hernández Irene
Haber Deborah A.
Hill F. F.
Howe Rachel
No associations
LandOfFree
Meridional Circulation Variability from Large-Aperture Ring-Diagram Analysis of Global Oscillation Network Group and Michelson Doppler Imager Data does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Meridional Circulation Variability from Large-Aperture Ring-Diagram Analysis of Global Oscillation Network Group and Michelson Doppler Imager Data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Meridional Circulation Variability from Large-Aperture Ring-Diagram Analysis of Global Oscillation Network Group and Michelson Doppler Imager Data will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1766641