Teleconnections of the Southern Oscillation in the tropical Atlantic sector in the OSU coupled upper ocean-atomosphere GCM
- State Univ. of New York, Stony Brook (United States)
- Lawrence Livermore National Lab., CA (United States)
The Oregon State University coupled upper ocean-atmosphere GCM has been shown to qualitatively simulate the Southern Oscillation. A composite analysis of the warm and cold events simulated in this 23-year integration has been performed. During the low phase of the Southern Oscillation, when warm anomalies occur in the eastern Pacific, the model simulates for the Atlantic region during March-May (1) a deficit of precipitation over the tropical South American continent, (2) Caribbean and Gulf of Mexico sea level pressure and sea surface temperature are in phase with the eastern Pacific anomalies, while those east of the Nordeste region are out of phase, and (3) northeast trade winds are anomalously weak and southwest trade winds are anomalously strong (as inferred from surface current anomalies). The anomalies in the oceanic processes are induced by perturbations in the atmospheric circulation over the Atlantic and are coupled to changes in the Walker circulation. During the high phase of the simulated Southern Oscillation, conditions in the atmosphere and ocean are essentially the reverse of the low phase. The model produces a response in the South American region during the opposing phases of the Southern Oscillation that is in general agreement with observations. The interannual variation of Nordeste rainfall is shown to be dominated by a few band-limited frequencies. These frequencies are found in the SST series of those regions of the Atlantic and Pacific oceans where strong correlations with Nordeste precipitation exist.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 6531750
- Journal Information:
- Journal of Climate; (United States), Vol. 6:3; ISSN 0894-8755
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SOUTHERN OSCILLATION
GENERAL CIRCULATION MODELS
ANNUAL VARIATIONS
ATLANTIC OCEAN
ATMOSPHERIC CIRCULATION
ATMOSPHERIC PRECIPITATIONS
ATMOSPHERIC PRESSURE
CARIBBEAN SEA
GULF OF MEXICO
OCEANIC CIRCULATION
SEA LEVEL
SEAS
SOUTH AMERICA
SURFACE WATERS
TEMPERATURE MEASUREMENT
TROPICAL REGIONS
WIND
LATIN AMERICA
LEVELS
MATHEMATICAL MODELS
VARIATIONS
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