2002/12/04 by H. M. Antia, S. M. Chitre, M. J. Thompson · 37 citations
Biochemistry, Genetics and Molecular Biology · Engineering · Physics and Astronomy · #Convection #Convection zone #Fluid dynamics and aerodynamics studies #Geomagnetism and Paleomagnetism Studies #Helioseismology #Radiation zone #Solar and Space Plasma Dynamics #Solar physics #Variation (astronomy) #astro-ph
paper · pdf · doi:10.1051/0004-6361:20021760
published in Astronomy and Astrophysics 399(1), 329-336 (EDP Sciences) · 9 pages, to appear in Astron. Astrophys
arxiv created 2002/12/04 · openalex publication_date 2003/02/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The latitudinal sound-speed structure of the Sun's convection zone gives insight into the physical processes occurring there, specifically the cellular convection and possibly the presence of magnetic fields. Using helioseismic data from the GONG network and MDI instrument on SOHO, we map the latitudinal acoustic structure of the convection zone from 1995 to 2002. The temporally averaged structure confirms previous findings of an excess in sound speed at the 10-4 level at 60 degrees latitude. There also appear to be some variation with time, with the peak in sound-speed asphericity at 60 degrees growing towards the maximum of solar activity according to the MDI data. However, we present some evidence that such variation may be associated with instrumental variation between the epochs before and after SOHO was temporarily lost in 1998. Nonetheless, some genuine temporal variation may be present, and we discuss the possible physical causes of that.