Eventos extremos de precipitação no estado do Ceará e suas relações com a temperatura dos oceanos tropicais

Abstract

O principal objetivo deste trabalho é prover informações sobre as tendências recentes dos eventos extremos de precipitação sobre o Estado do Ceará, associando esses eventos extremos às anomalias de Temperatura da Superfície do Mar (TSM) nos Oceanos Pacífico e Atlântico. Foram utilizados dados pluviométricos de 18 postos de 1971 a 2006 e o método de Mann-Kendall foi utilizado na obtenção das tendências. Os resultados mostram que existem características de aumento nas intensidades das secas e diminuição dos eventos de precipitação forte, e que o aumento nas anomalias de TSM no Pacífico e ao norte do equador, no Oceano Atlântico, acarreta em um aumento do número de dias consecutivos secos no norte do Ceará. Os índices extremos de precipitação mostraram correlações negativas com as anomalias de TSM nas regiões do Pacífico do Atlântico Tropical Norte e positivas com a região do Atlântico Tropical Sul. Entretanto, para a região sul do Ceará, o comportamento dos dias consecutivos chuvosos indica que o período chuvoso é governado por outros sistemas atmosféricos, necessitando assim, ser melhor estudado para o entendimento desse comportamento.

<b>Detection of climate trends in macroregions of the Ceará State using FUNCEME data

“…Thus, our results are coherent with those reported by Minetti (1998) and Minetti et al (2003), Rusticucci and Penalba (2000), Haylock et al (2006) Santos and Brito (2007) and Santos and Manzi (2011). …”

“…Santos, Brito, Ramana Rao, and Menezes (2009) identified local changes in rainfall and an increase in humidity conditions for the Ceará State. At last, Santos and Manzi (2011) verified that only the northern region of the Ceará had trends with high statistical significance for the indices of extreme events used in the study.…”

Influence of oceanic-atmospheric interactions on extreme events of daily rainfall in the Sub-basin 39 located in Northeastern Brazil

“…As observed by Santos and Brito (2007) and Santos and Manzi (2011), the SST negative anomalies (positive) over the North Atlantic Ocean, and the positive (negative) anomalies over the South Atlantic Ocean, produced the displacement of the ITCZ southwards (northwards), favoring rainfall events (inhibition of rain) on the NEB. Moura et al (2009) noticed that, when the ITCZ takes place in the northern hemisphere, it exhibits an SST much warmer than usual.…”

“…Such order of magnitude is considered normal for correlations of SST indices for the NEB region: as investigated by Santos and Manzi (2011) for the state of Ceará, and by Santos and Brito (2007) for the Brazilian semi-arid and by Araújo and Brito (2011) for Bahia and Sergipe.…”

Uncertainties of the rainfall regime in a tropical semi-arid region: the case of the State of Ceará

“…This variability, whether on an annual or monthly scale, is defined by the different weather systems which are related to sea surface temperatures (SST) in the Pacific or tropical Atlantic (HASTENRATH, 2012;ALVES et al, 2006;SUN et al, 2006). The source inducing rainfall from February to May is related to the advancement of the Intertropical Convergence Zone (ITCZ) over the southern hemisphere (SANTOS; BRITO, 2007, MENEZES et al, 2008MANZI, 2011). When the SST in the Atlantic favour formation of more-intense southeasterly trade winds, and northeasterly trade winds of low intensity, there is a reduction or absence of rainfall between March and April over the Brazilian Northeast (HASTENRATH, 2012).…”