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The 30–70 day oscillations in the tropical Atlantic
Author(s) -
Foltz Gregory R.,
McPhaden Michael J.
Publication year - 2004
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 - 10.1029/2004gl020023
Subject(s) - climatology , madden–julian oscillation , northern hemisphere , tropical atlantic , north atlantic oscillation , southern hemisphere , atlantic equatorial mode , sea surface temperature , boreal , seasonality , geology , atlantic multidecadal oscillation , atmospheric sciences , forcing (mathematics) , environmental science , oceanography , convection , geography , meteorology , paleontology , statistics , mathematics
Evidence is presented for intraseasonal oscillations in the trade winds of the northern and southern tropical Atlantic. The pattern of intraseasonal oscillations in surface pressure and wind speed in the Northern Hemisphere resembles that of the North Atlantic Oscillation (NAO). Like the NAO, these oscillations have a strong seasonal cycle, with a maximum amplitude in boreal winter/spring. Winds in the southern tropical Atlantic are related to the Southern Hemisphere equivalent of the NAO, exhibiting a weaker seasonality with peak amplitudes in austral winter. The Madden‐Julian Oscillation (MJO), which originates over the Indian Ocean, also exerts an influence on tropical Atlantic surface winds, particularly between about 10°N and 10°S. Where intraseasonal wind speed oscillations in the Atlantic are strong, they force changes in sea surface temperature (SST) through latent heat loss from the ocean, potentially affecting lower frequency climate variations.