Open AccessTropical instability waves at 0°N, 23°W in the Atlantic: A case study using Pilot Research Moored Array in the Tropical Atlantic (PIRATA) mooring data
Author(s) -
Grodsky Semyon A.,
Carton James A.,
Provost Christine,
Servain Jacques,
Lorenzzetti Joao A.,
McPhaden Michael J.
Publication year - 2005
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2005jc002941
Subject(s) - baroclinity , mooring , barotropic fluid , climatology , ekman transport , environmental science , mixed layer , salinity , sea surface temperature , tropical atlantic , temperature salinity diagrams , oceanography , instability , geology , atmospheric sciences , physics , mechanics , upwelling
Temperature, salinity, velocity, and wind from a mooring at 0°N, 23°W are used along with satellite data for sea surface temperature and sea level to examine the contribution of tropical instability waves (TIWs) to the energy and heat balance of the equatorial Atlantic mixed layer. The TIWs appear as periodic 20–30 day fluctuations of currents, temperature, and salinity, which intensify beginning in June and peak in late boreal summer. The intensification occurs in phase with strengthening of the southeasterly trade winds and the seasonal appearance of the equatorial tongue of cold mixed layer temperatures. In 2002 these waves, which warm the mixed layer by 0.35°C during summer months, are maintained by both barotropic and baroclinic conversions that are of comparable size. Salinity fluctuations, previously neglected, increase the magnitude of baroclinic energy conversion.