ATMOSPHERIC AND OCEANIC PATTERNS RELATED TO DRY EVENTS IN THE AMAZON BASIN DURING 1982/83, 2004/05 AND 2009/10

Franci Flores Vargas, José Augusto Paixão Veiga

Abstract


This study aimed to determine the atmospheric and oceanic patterns related to changes in precipitation over the Amazon basin during the episodes of extreme drought occurred in the years of 1982/83, 2004/2005 and 2009/10. Data from the zonal and meridional components of the wind vector, wind speed, omega, specific humidity, precipitation and sea surface temperature was used. The data was obtained from the reanalysis-2 NCPE/NCAR (except for the variable precipitation which was obtained from the CMAP). The anomalous composition method was used to determine the atmospheric and ocean fields that were characteristic of episodes of intense drought. The results show a deficit in rainfall in the rainy pre-season (SON) in part of the northern region of South America and northeastern Brazil. The lower level of rainfall also persists during the rainy season (December to April). Associated with these anomalous patterns of rainfall, positive anomalies of SST were observed which were similar to El Niño events, followed by anomalous subsidence in the Amazon. In the rainy pre-season, wind divergence over the state of Amazonas and the north of South America was observed. During the rainy season, the divergence in streamlines shows the weakening of the northeast trade winds. In addition, the anomalous divergence of vertically integrated moisture flux reveals consistency with rainfall deficits in theipre and rainy season in the Amazon basin.

Keywords


Extreme Events; Drought episodes; Amazon; Reanalysis 2.

References


BORMA, L. D. S., NOBRE, C. A. (2013). Secas na Amazônia Causas e Consequências, 19o edn. Oficina de Textos, São Paulo.

LEWIS, S. L., BRANDAO, P. M., PHILLIPS, O. L., DER HEIJDEN, G. M. F. V., NEPSTAND, D. (2011). The 2010 amazon drought. Science, 331(6017), 554.

MARENGO, J. A., ESPINOZA, J. C. (2015). Review extreme seasonal droughts and floods in amazonia: causes, trends and impacts. International Jour of Climatology, 9(4420), 124,007.

MARENGO, J. A., HASTENRATH, S. (1993). Case studies climatic events in the amazon basin. Jour of Climate, 14(2), 617–627.

MARENGO, J. A., NOBRE, C. A., TOMASELLA, J., OYAMA, M. D., DE OLIVEIRA, G. S., DE OLIVERIA, R., CAMARGO, H., ALVES, L. M. (2008). The drought of amazonia in 2005. Jour of Climate, 40(50245), 495–516.

MARENGO, J. A., TOMASELLA, J., ALVES, L. M., SOARES, W. R., RODRIGUEZ, D. A. (2011). The drought of 2010 in the context of historical droughts in the amazon region. Geophysical Research Letter, 38(1), 71–97.

MARENGO, J. A., SIMONE, B. L., RODRIGUEZ, D. A., P., P., WAGNER, S. R., LINCOLN, A. M. (2013). Recent extremes of drought and flooding in amazonia: Vulnerabilities and human adaptation. American Jour of Climate Change, 14(2), 87–96.

SAHA, S., MOORTHI, S., PAN, H. L. (2010). The ncep climate forecast system reanalysis. Bull Amer Meteor Soc, 8(91),–2558.

SMITH, T. M., W., R. R., C., P. T., J., L. (2008). Improvements to noaa’s historical merged land-ocean surface temperature analysis (1980-2006). Jour of Hydrometeorology, 21, 2283–2296.

TOMASELLA, J., BORMA, L. S., MARENGO, J. A., RODRIGUEZ, D. A., CUARTAS, L. A., NOBRE, C. A., PRADO, M. C. R. (2011). The droughts of 1996-1997 and 2004-2005 in amaznia: hydrological response in the river main-stem. Hydrological Processes, 25(7889), 1228–1242.

VEIGA, J. A. P., BRAHMANANDA, R., FRANCHITO, S. H. (2005). Heat and moisture buggets of the walker circulation and associated rainfall anomalies during el niño events. Jour of Climatology, 25(101002), 193–213.

XIE, P., ARKIN, A. (1997). Global precipitation: a 17-year monthly analysis based on gauge observation, satellite estimates, and numerical model outputs. Bull Amer Meteor Soc, 10(78), 2539–2558.

ZENG, N., JIN-HO, Y., MARENGO, J. A., SUBRAMANIAM, A., NOBRE, C. A., MARIOTTI, A., NEELIN, J. D. (2008). Causes and impacts of the 2005 amazon drought. Environmental Research Letters, 3(014002), 1–9.




DOI: http://dx.doi.org/10.5902/2179460X22687

Refbacks

  • There are currently no refbacks.


Ciência e Natura

EISSN  2179-460X

ISSN 0100-8307

DOI 10.5902

 

contador de visitas
Access since January, 18th, 2013.


Licença Creative Commons

This work is licensed under a

 Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0).