Artículo
Abstract:
The objective of this work is to provide a detailed description of the onset of the South American Monsoon based on precipitation observations available over tropical and subtropical South America. The analysis was also performed using outgoing longwave radiation (OLR) data in order to assess the ability of this particular dataset to reproduce the main features associated with precipitation evolution during austral spring. Results show that both OLR and precipitation data agree in describing the progression of convection from the northwest and southeast into central Brazil by the beginning of October. Moreover the assessment of available methods to identify onset dates shows that the method of Kousky (1988), based on the OLR evolution, provides the onset date in most of South America, without regionally adaptation, as the methods based on rainfall generally require. Composite fields show that rainfall in central Brazil begins with moderate rates, which are still lower than those observed over the northwestern and southeastern tropical regions. After the rainfall jump, that on average occurs three pentads later than the onset of rainfall, precipitation rates increase over central Brazil and similar rates are observed over the entire tropical region. It is suggested that transient activity, which occurs around the onset period when the atmospheric mean conditions are getting more unstable as they approach summer-like conditions, is the one that imprints a rainfall-jump feature in the precipitation evolution. The character of changes in the precipitation rate, as the rainy season develops, provides complementary information that can be used together with onset date.
Registro:
| Documento: | Artículo |
| Título: | The nature of the rainfall onset over central South America |
| Autor: | González, M.; Vera, C.S.; Liebmann, B.; Marengo, J.A.; Kousky, V.; Allured, D. |
| Filiación: | Centro de Investigaciones del Mar y la Atmósfera (CIMA), CONICET, Universidad de Buenos Aires, 2do. Piso, Pab. II, 1428 Buenos Aires, Argentina Climate Diagnostics Center, NOAA, University of Colorado, Boulder, CO, United States Centro de Previsão de Tempo e Estudos Climáticos (CTPEC), Sao Paulo, Brazil Climate Prediction Center, NCEP, NOAA, Baltimore, MD, United States |
| Palabras clave: | Onset; Rainfall; South America; Summer monsoon; Tropical climate; atmospheric convection; climate conditions; longwave radiation; monsoon; observational method; precipitation assessment; rainfall; regional climate; summer; tropical meteorology; Brazil; South America |
| Año: | 2007 |
| Volumen: | 20 |
| Número: | 4 |
| Página de inicio: | 377 |
| Página de fin: | 394 |
| Título revista: | Atmosfera |
| Título revista abreviado: | Atmosfera |
| ISSN: | 01876236 |
| Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01876236_v20_n4_p377_Gonzalez |
Referencias:
- Figueroa, S.N., Nobre, C., Precipitation distribution over central and western tropical South America (1990) Climanalise, 5, pp. 36-44
- Gan, M.A., Kousky, V.E., Ropelewski, C.F., The South America monsoon rainfall over west-central Brazil (2004) J. Climate, 17, pp. 47-66
- González, M., Barros, V., On the forecast of the onset and end of convective season in the Amazon (2002) Theor. Appl. Climatol, 73, pp. 169-188
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- Kousky, V.E., Pentad outgoing longwave radiation climatology for the South America sector (1988) Revista Brasileira de Meteorologia, 3, pp. 217-231
- Liebmann, B., Allured, D., Daily precipitation grids for South America (2005) B. Am. Meteorol. Soc, 86, pp. 1567-1570
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- Liebmann, B., Smith, C., Description of a complete (interpolated) outgoing longwave radiation dataset (1996) B. Am. Meteorol. Soc, 77, pp. 1275-1277
- Marengo, J., Liebmann, B., Kousky, V., Filizola, N., Wainer, I., Onset and end of the rainy season in the Brazilian Amazon basin (2001) J. Climate, 14, pp. 833-852
- Schmetz, J., Liu, Q., Outgoing longwave radiation and its diurnal variation at regional scales derived from Meteosat (1988) J. Geophys. Res, 11, pp. 192-203
- Souza E. and T. Ambrizzi, 2003. Pentad precipitation climatology over Brazil and the associated atmospheric mechanisms. Climanalise 12 no1 Electronic Version at http://WWW6.cptec.br/revclima/revista/pdf/ artigo_pentad_jan03.pdf Consulted on October, 2005; Sugahara S., 1991. Fluctuacoes interanuais, sazonais e intrasazonais da precipitacao no estado de Sao Paulo. Tese de Doutorado. Departamento de Ciencias Atmosfericas. Universidade de Sao Paulo, Brasil, 140 pp; Vera, C., Higgins, W., Amador, J., Ambrizzi, T., Garreaud, R., Gochis, D., Gutzler, D., Zhang, C., Toward a unified view of the American Monsoon Systems (2006) J. Climate, 19, pp. 4977-5000
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Citas:
---------- APA ----------
González, M., Vera, C.S., Liebmann, B., Marengo, J.A., Kousky, V. & Allured, D. (2007) . The nature of the rainfall onset over central South America. Atmosfera, 20(4), 377-394.Recuperado de https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01876236_v20_n4_p377_Gonzalez [ ]
---------- CHICAGO ----------
González, M., Vera, C.S., Liebmann, B., Marengo, J.A., Kousky, V., Allured, D. "The nature of the rainfall onset over central South America" . Atmosfera 20, no. 4 (2007) : 377-394.Recuperado de https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01876236_v20_n4_p377_Gonzalez [ ]
---------- MLA ----------
González, M., Vera, C.S., Liebmann, B., Marengo, J.A., Kousky, V., Allured, D. "The nature of the rainfall onset over central South America" . Atmosfera, vol. 20, no. 4, 2007, pp. 377-394.Recuperado de https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01876236_v20_n4_p377_Gonzalez [ ]
---------- VANCOUVER ----------
González, M., Vera, C.S., Liebmann, B., Marengo, J.A., Kousky, V., Allured, D. The nature of the rainfall onset over central South America. Atmosfera. 2007;20(4):377-394.Available from: https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01876236_v20_n4_p377_Gonzalez [ ]
