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Atmospheric Blocking in the South Atlantic during the Summer 2014: A Synoptic Analysis of the Phenomenon

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DOI: 10.4236/acs.2015.54030    4,076 Downloads   4,538 Views   Citations

ABSTRACT

Under conditions of atmospheric blocking, the presence of a quasi-stationary anticyclone of large amplitude disrupts the normal eastward progression of the synoptic systems. These blockings correspond mainly to a positive anomaly of the air pressure. As a result, in the regions affected by the blocking occur several consecutive dry days and temperatures above average. This paper aims to discuss synoptically the atmospheric blocking phenomenon occurred in January and February 2014 in the South Atlantic Ocean, affecting especially the Southeastern Brazil and sectors that depend on the quantity of water for their activities in the region, such as agriculture and electricity generation. The significant population concentration makes this area emphatically vulnerable to long periods of drought, especially during the summer, affecting the water supply for the population. In order to achieve this goal, data of geopotential height at 850/500 hPa, streamlines in 850/500 hPa, pressure, temperature, humidity and wind at surface were evaluated through NCEP/ NCAR reanalysis (CFSRv2—Climate Forecast System Reanalysis Version 2) with 0.2° × 0.2° resolution. The analysis showed that the stationary anticyclone was configured dynamically favorable to blocking in the lower and middle levels of the atmosphere. Thus, atmospheric pressure at mean sea level presented values above normal combined with high average air temperature. By the climatological analysis, it was noted that there were emphatic negative precipitation anomalies over Southeastern Brazil. This atmospheric blocking was characterized as anomalous due to its long duration in a considered rainy season.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

Luiz Silva, W. , Nascimento, M. and Menezes, W. (2015) Atmospheric Blocking in the South Atlantic during the Summer 2014: A Synoptic Analysis of the Phenomenon. Atmospheric and Climate Sciences, 5, 386-393. doi: 10.4236/acs.2015.54030.

References

[1] Casarin, D.P. (1983) Um Estudo Observacional sobre os Sistemas de Bloqueio no Hemisfério Sul. Masters Dissertation, National Institute for Space Research, 69 p.
[2] Fuentes, M.V. (1997) Climatologia de Bloqueios Próximos à América do Sul e seus Efeitos. Masters Dissertation, National Institute for Space Research, 91 p.
[3] Ambrizzi, T., Marques, R.F.C. and Nascimento, E.L. (2009) Bloqueios Atmosféricos. Tempo e Clima no Brasil, 18, 279-296.
[4] Oliveira, F.N.M. (2011) Climatologia de Bloqueios Atmosféricos no Hemisfério Sul: Observacoes, Simulacoes do Clima do Século XX e Cenários Futuros de Mudancas Climáticas. Doctoral Thesis, University of Sao Paulo, 158 p.
[5] Nascimento, E.L. and Ambrizzi, T. (2002) The Influence of Atmospheric Blocking on the Rossby Wave Propagation in Southern Hemisphere Flows. Journal of the Meteorological Society of Japan, 80, 139-159.
http://dx.doi.org/10.2151/jmsj.80.139
[6] Nunes, L.H., Vicente, A.K. and Candido, D.H. (2009) Clima da Regiao Sudeste do Brasil. Tempo e Clima no Brasil, 16, 243-258.
[7] Saha, S., et al. (2014) The NCEP Climate Forecast System Version 2. Journal of Climate, 27, 2185-2208.
http://dx.doi.org/10.1175/JCLI-D-12-00823.1
[8] Van Loon, H. (1956) Blocking Action in the Southern Hemisphere—Part I. Notos, 5, 171-175.
[9] Wiedenmann, J.M., Lupo, A.R., Mokhov, I. and Tikhonova, E.A. (2002) The Climatology of Blocking Anticyclones for the Northern and Southern Hemisphere Block Intensity as a Diagnostic. Journal of Climate, 15, 3459-3473.
http://dx.doi.org/10.1175/1520-0442(2002)015<3459:TCOBAF>2.0.CO;2
[10] Luiz Silva, W. and Dereczynski, C.P. (2014) Caracterizacao Climatológica e Tendências Observadas em Extremos Climáticos no Estado do Rio de Janeiro. Anuário do Instituto de Geociências, Federal University of Rio de Janeiro, 37, 123-138.
[11] Carvalho, L.M.V. and Jones, C. (2009) Zona de Convergência do Atlantico Sul. Tempo e Clima no Brasil, 6, 95-109.
[12] Instituto Nacional de Meteorologia—INMET (2009) Normais Climatológicas do Brasil 1961-1990. In: Ramos, A.M., Santos, L.A.R. and Fortes, L.T.G., Eds., INMET, Brazil, 465 p.
[13] Centro de Previsao de Tempo e Estudos Climáticos—CPTEC (2014) Boletim de Monitoramento e Análise Climática. In: Cavalcanti, I.F.A., Ed., Climanálise, 29.
[14] Marques, R.F.C. (1996) Bloqueio Atmosférico no Hemisfério Sul. Doctoral Thesis, National Institute for Space Research, 158 p.

  
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