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Climatic variations in Central America: further exploration
Author(s) -
Polzin Dierk,
Guirola Luis Garcia,
Hastenrath Stefan
Publication year - 2014
Publication title -
international journal of climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.58
H-Index - 166
eISSN - 1097-0088
pISSN - 0899-8418
DOI - 10.1002/joc.4111
Subject(s) - intertropical convergence zone , climatology , walker circulation , subtropical ridge , precipitation , atmospheric circulation , circulation (fluid dynamics) , subtropics , tropical atlantic , hadley cell , trade wind , ocean current , geology , oceanography , sea surface temperature , environmental science , general circulation model , geography , climate change , meteorology , physics , fishery , biology , thermodynamics
Resuming earlier work and based on recently available data sources, this study explores interannual rainfall variability in Central America and underlying circulation mechanisms during 1958–2012. With the changes of circulation in the annual cycle, precipitation increases into May–June, become scarcer in July–August (JA), yet most abundant in September–October; the edge of the Atlantic subtropical high extending westward most markedly and the Pacific Intertropical Convergence Zone (ITCZ) retreating southward in JA. Interannual variations of rainfall are accompanied with circulation changes involving vertical motion over Central America. Overall, with weaker Atlantic trade winds southerly wind component over Pacific tends to be stronger and Central America rains more abundant. Regarding long‐term variations from protracted dry regime 1971–1978 to protracted wet regime 2005–2012, on the Atlantic side ocean surface warmed, pressure dropped, trade winds weakened, whereas over the Pacific northward pressure gradient and winds increased. The study builds on work half a century ago and extends analysis into the most recent decades, using recent and updated circulation and raingauge data sets.