Abstract

MESA-SANCHEZ, Óscar José  and  ROJO-HERNANDEZ, Julián David. On the general circulation of the atmosphere around Colombia. Rev. acad. colomb. cienc. exact. fis. nat. [online]. 2020, vol.44, n.172, pp.857-875.  Epub July 22, 2021. ISSN 0370-3908.  https://doi.org/10.18257/raccefyn.899.

The average annual precipitation in the Pacific coast of Colombia ranges from 8,000 to 13,000 mm. The annual average (1960-2018) in Puerto López (Cauca) rain gauge (77°14'56.3"W, 2°50'43.0"N) is 13.159 mm making it, probably, the rainiest place on the Earth. Such a large amount of precipitation also means a sizeable diabatic heating source over western Colombia, which is responsible for driving the circulation in northern South America and Mesoamerica from mid-March to the end of November. We applied a simple conceptual model to study the heat-induced circulation. Our results indicated that the heating source over western Colombia produces a steady, low-level westerly inflow as a result of a half planetary wave propagating over Mesoamerica and the far eastern Pacific that generates two cyclonical flows. On the east side of the heating source, a Kelvin wave generates a low-level easterly flow from the tropical Atlantic Ocean and the Northern Amazon and Orinoco basins in a Walker-type circulation. This Rossby and Kelvin patterns create information pathways, which, in their turn, dominate the low- and upper-level wind fields. Documented observations about the atmosphere's general circulation over northern South America and Mesoamérica are consistent enough to support the assertion that a set of waves trapped in the tropics induced by a heating source explains the circulation over Colombia and its surroundings.

Keywords : Equatorial waves; South America; Mesoamerica; Colombia; Hydroclimatology.

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