Premium
Solar rotation effect on the measurement of sub‐photospheric flows at high latitudes in a synoptic view using ring diagram analysis
Author(s) -
Zaatri A.
Publication year - 2012
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.201211828
Subject(s) - latitude , low latitude , grid , geodesy , physics , meridian (astronomy) , diagram , rotation (mathematics) , ring (chemistry) , meteorology , geology , geometry , astrophysics , astronomy , computer science , mathematics , chemistry , organic chemistry , database
The dense‐pack grid is commonly used to get a synoptic view of the sub‐photospheric dynamics when using ring diagram analysis (Haber et al 2002). This grid is based on a fixed distribution of patches in central meridian distance (cmd) at all latitudes. A shortcoming of the dense‐pack grid is that the true motion of tracked areas at slower rotating latitudes is not handled correctly. For instance, a 15° × 15° area, centered at a cmd of 0° and a latitude of 60°, that rotates only 12° in 1664 minutes (ring day), is considered tobe centered at cmd = 15° in the subsequent ring day. In order to avoid this issue, another distribution is suggested where the grid point in central meridian distance is latitude dependant (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)