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Detection of vortices and saddle points in SST data
Author(s) -
Yang Q.,
Parvin B.,
Mariano A.
Publication year - 2001
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2000gl011408
Subject(s) - vortex , computation , saddle , algorithm , displacement (psychology) , divergence (linguistics) , feature (linguistics) , saddle point , representation (politics) , vector field , computer science , mathematics , physics , mathematical optimization , geometry , meteorology , psychology , linguistics , philosophy , politics , political science , law , psychotherapist
We extend the Horn‐Schunck model of flow field computation to incorporate incompressibility for tracking fluid motion. This is expressed as a weak form of zero‐divergence constraint in the variational problem and implemented with a multigrid approach for efficient computation. The resulting feature displacement velocity field provides the basis for higher level abstraction and representation of the data for data mining. A robust and efficient algorithm, based on the Jordan curve index, for detecting vortices and saddle points in feature displacement fields derived from sequences of satellite‐derived SST fields is presented.