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Intraseasonal variability of the subthermocline current east of Mindanao
Author(s) -
Wang Qingye,
Zhai Fangguo,
Wang Fujun,
Hu Dunxin
Publication year - 2014
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2014jc010343
Subject(s) - eddy , current (fluid) , thermocline , geology , oceanography , latitude , boundary current , mooring , subtropics , climatology , ocean current , geography , meteorology , turbulence , geodesy , fishery , biology
The intraseasonal variability (ISV) of the subthermocline current east of Mindanao was characterized and shown to be caused by the activity of subthermocline eddies using mooring observations at 8°N, 127.03°E and a high‐resolution numerical model. The ISV of the observed current east of Mindanao is vertically coherent in the upper 940 m but is significantly intensified below the thermocline. The ISV amplitude (8 cm s −1 ) of zonal subthermocline current is comparable with that (11 cm s −1 ) of the meridional current, revealing the nature of active eddies. The ISV of the subthermocline current was caused by the subthermocline eddies from three different pathways. The subthermocline eddies propagating along approximately 10°N–11°N contributed more to the ISV of the subthermocline current east of Mindanao than did those eddies propagating westward along 8°N or northwestward from the New Guinea coast. Subthermocline eddies mainly exist south of the bifurcation latitude of the North Equatorial Current in the western tropical Pacific, and their generation and propagation mechanisms are briefly discussed.