scholarly journals Identificação das causas climáticas dos eventos extremos e dos impactos dos ENOS Canônico e Modoki nas macrorregiões de Alagoas

2021 ◽  
Vol 14 (4) ◽  
pp. 1880-1897
Author(s):  
Djane Fonseca Da Silva ◽  
Pedro Fernandes de Souza Neto ◽  
Silvania Donato da Silva ◽  
Maria José da Silva Lima ◽  
Iara Bezerra da Silva Cavalcante ◽  
...  

Anomalies of sea surface temperature that occur in some regions of the Equatorial Pacific Ocean are being studied because their cause different impacts and originate in different ways, are the ENOS, Modoki and Canonical. The objective of this work is to identify the climatic causes of the extreme events that occurred in the macro-regions of Alagoas, and at the same time, to compare the effects of ENOS Canonical and Modoki and their classes on the macro-regions of Alagoas. The daily precipitation data for 21 municipalities in the State of Alagoas were obtained through the National Water Agency from 1963 to 2014. EN Modoki and low promoted an increase in rainfall in the Eastern region. EN Fortes, on the other hand, caused a decrease in rainfall in the Sertão. Canonical LN events caused a significant increase in rainfall in the three macro-regions, but the effect was better in LN Forte. During the phases of the Atlantic Dipole, the negative phase generated positive SPI across the state, and in the positive phase, there was a decrease in SPI in the East, and a negative SPI record in Sertão and Agreste. The climatic causes of the extreme events were the combination of semiannual, interannual scales, scale between 1-2 years of ENOS, scale of ENOS extended and scale of 11 years (Dipole and sunspots), potentiating the local total rainfall, and for cases of drought , your absence. It was found, through cluster analysis, similarity between the SPIs of La Niña low and La Niña Canonical, and between El Niño Canonical is linked to El Niño Forte. Mathematically, the categories of El Niño and La Niña strong and weak showed better correlations with ENOS Modoki and Canonical, suggesting a pattern for Alagoas.

2013 ◽  
Vol 6 (5) ◽  
pp. 1316
Author(s):  
Pâmela Lorena Ribeiro Ávila ◽  
Everaldo Barreiros de Souza ◽  
Amanda Nascimento Pinheiro

Este trabalho apresenta uma contribuição aos estudos de modelagem climática com ênfase na variabilidade pluviométrica sazonal do estado do Pará, durante as estações de verão e outono (DJF e MAM). Baseado nos resultados das simulações regionais do RegCM4 para os anos de El Niño (1982/83) e Lã Niña (1988/89) usando domínio em alta resolução espacial (50 Km) e dois diferentes esquemas de convecção (Grell e MIT), foi investigado o desempenho do modelo em simular a distribuição regional de precipitação sazonal no estado do Pará. As análises quantitativas evidenciaram que o RegCM4 apresenta erros sistemáticos, sobretudo aqueles relacionados a uma subestimativa das chuvas nas três grades (G1, G2, G3) para os anos de El Niño e Lã Niña sendo representativo apenas em pequenas áreas na região sudeste do estado no período do verão para o esquema Grell, e mostrou-se mais representativo na grade G2 do para o ano de El Niño no esquema MIT. Além disso, através da técnica de composições, também foi investigado o desempenho do RegCM4 em reproduzir os padrões espaciais anômalos de precipitação sazonal em associação aos episódios ENOS, e as fases do gradiente térmico sobre o Atlântico intertropical. Os resultados demonstraram que o modelo conseguiu representar realisticamente bem o padrão espacial das anomalias pluviométricas acima (abaixo) do normal em grande parte da Amazônia oriental, durante os conhecidos cenários favoráveis, i.e., condições de La Niña e gradiente de aTSM para o Atlântico sul (desfavoráveis, i.e., El Niño e gradiente de aTSM para o Atlântico norte). A B S T R A C T This paper presents a contribution to studies of climate modeling with emphasis on seasonal rainfall variability in the state of Pará, during the summer and autumn (DJF and MAM). Based on the results of simulations of regional RegCM4 for El Niño years (1982/83) and La Niña (1988/89) using the field at high spatial resolution (40 km) and two different convection schemes (Grell and MIT), was investigated the performance of the model to simulate the regional distribution of seasonal rainfall in the state of Pará. The quantitative analysis showed that the RegCM4 presents systematic errors, especially those related to an underestimation of rain in three grades (G1, G2, G3) for the years of El Niño and La Niña are representative only in small areas in the southeastern state in summer period for the Grell scheme, and was more representative of the grid G2 for the year of El Niño in the MIT scheme. Moreover, using the technique of composition, was also investigated in the performance of RegCM4 reproduce the spatial patterns of anomalous seasonal rainfall in association with ENSO episodes and phases of the thermal gradient over the Atlantic intertropical. The results showed that the model represented realistically and spatial patterns of rainfall anomalies above (below) of normal in much of the eastern Amazon, during the known favorable scenarios, ie, La Niña and gradient SSTa South Atlantic (unfavorable, ie, El Niño and gradient SSTa North Atlantic). Keywords: seasonal rainfall, El Nino, La Nina, Amazon, ENSO, RegCM4.


2016 ◽  
Vol 38 (2) ◽  
pp. 209 ◽  
Author(s):  
Mariane Furtado Gonçalves ◽  
Claudio José Cavalcante Blanco ◽  
Vanessa Conceição dos Santos ◽  
Luciana Leal dos Santos Oliveira ◽  
Francisco Carlos Lira Pessoa
Keyword(s):  
El Niño ◽  
El Nino ◽  
La Niña ◽  

2018 ◽  
Vol 40 (1) ◽  
pp. 37742 ◽  
Author(s):  
Mariane Furtado Gonçalves ◽  
Claudio José Cavalcante Blanco ◽  
Vanessa Conceição dos Santos ◽  
Luciana Leal dos Santos Oliveira

2021 ◽  
pp. 1-50

Abstract El Niño–Southern Oscillation (ENSO) has a huge influence on Antarctic climate variability via Rossby wave trains. In this study, the asymmetry of the ENSO teleconnection in the Southern Hemisphere, as along with the mechanisms involved, is systematically investigated. In four reanalysis datasets, the composite atmospheric circulation anomaly in austral winter over the Amundsen Sea during La Niña is situated more to the west than during El Niño. This asymmetric feature is reproduced by ECHAM5.3.2 forced with both composite and idealized symmetric sea surface temperature anomalies. Utilizing a linear baroclinic model, we find that ENSO-triggered circulation anomalies in the subtropics can readily extract kinetic energy from the climatological mean flow and develop efficiently at the exit of the subtropical jet stream (STJ). The discrepancy in the location of the STJ between El Niño and La Niña causes asymmetric circulation responses by affecting the energy conversion. During El Niño years, anomalous tropical convective precipitation increases the meridional temperature gradient, which in turn leads to the strengthening of the STJ and the eastward movement of the jet core and jet exit in the Pacific. With the movement of the STJ exit, the wave train tends to develop over the eastern region. The opposite is the case during La Niña when the westward shift of the jet exit favors the development of the wave train in the western region. Our findings expand the current understanding regarding ENSO teleconnection.


2000 ◽  
Vol 105 (C1) ◽  
pp. 1037-1053 ◽  
Author(s):  
Gregory C. Johnson ◽  
Michael J. McPhaden ◽  
G. Dail Rowe ◽  
Kristene E. McTaggart

2020 ◽  
Vol 13 (4) ◽  
pp. 1502
Author(s):  
Leandro De Santana Santos ◽  
Ludmilson Abritta Mendes

Diante do cenário de estresse hídrico e alteração dos regimes pluviométricos, neste trabalho foi realizada uma avaliação da interferência do El Niño Oscilação Sul no regime pluviométrico da Região Hidrográfica do Atlântico Leste. Para tal, utilizou-se os testes não paramétricos de Kruskall-Wallis e Mann-Whitney para avaliar se, no período entre os anos de 1950 e 2018, há interferência dos fenômenos El Niño e La Niña na precipitação registrada nos períodos úmido e seco da região. Foi encontrada uma relação entre a ocorrência das anomalias climáticas sobre as médias das chuvas tanto nos meses secos quanto nos meses úmidos. Verificou-se que existe uma predominância dos efeitos de La Niña no período seco e que, no período úmido, La Niña influencia a porção norte da bacia e El Niño a porção sul. Influence of Equatorial Pacific Ocean Temperature Oscillation on the Precipitation Regime of the East Atlantic Hydrographic Region     A B S T R A C T   Given the scenario of water stress and alteration of rainfall regimes, in this work an evaluation of the interference of El Niño Southern Oscillation in the rainfall of the East Atlantic Hydrographic Region was performed. For this purpose, the nonparametric Kruskall-Wallis and Mann-Whitney tests were used to evaluate the stationarity of the basin rainfall series from 1950 to 2018. A relationship was found between the occurrence of climatic anomalies on the mean rain both in the dry and wet periods. It was found that there is a predominance of La Niña effects in the dry season and that in the wet season La Niña influences the northern portion of the basin and El Niño the southern portion. Keywords: ENSO, Climate Variability, Precipitation.


Irriga ◽  
2017 ◽  
Vol 22 (3) ◽  
pp. 547-559
Author(s):  
Rafael Coll Delgado ◽  
Leonardo Paula de Souza ◽  
Marcos Gervásio Pereira ◽  
Catherine Torres de Almeida ◽  
Rafael De Ávila Rodrigues

ORBITAL AND SURFACE EVAPOTRANSPIRATION COMPARED TO FAO-56 STANDARD IN STATE OF ACRE  RAFAEL COLL DELGADO1; LEONARDO PAULA DE SOUZA2; MARCOS GERVASIO PEREIRA3; CATHERINE TORRES DE ALMEIDA4 E RAFAEL DE ÁVILA RODRIGUES5 1Universidade Federal Rural do Rio de Janeiro, Professor Doutor do Instituto de Florestas, Departamento de Ciências Ambientais, UFRRJ, CEP 23890-000, Seropédica, RJ, Brasil, [email protected]; 2Universidade Federal do Acre, Professor Doutor do Centro de Ciências Biológicas e da Natureza, UFAC, CEP 69.920-900, Rio Branco, AC, Brasil,  [email protected];   3Universidade Federal Rural do Rio de Janeiro, Professor Doutor do Departamento de Solos, UFRRJ, CEP 23890-000, Seropédica, RJ, Brasil,  [email protected];4Instituto Nacional de Pesquisas Espaciais, Doutoranda em Sensoriamento Remoto, INPE, CEP 65250-000, São José dos Campos, SP, Brasil, [email protected];5Universidade Federal de Goiás, Professor Doutor da Unidade Acadêmica Especial, Instituto de Geografia, UFG, CEP 75704-020, Catalão, GO, Brasil, [email protected].  1 ABSTRACT Evapotranspiration is a critical component of the hydrological and life cycles, with a major impact on water consumption by the population, agricultural activities, and the global climate. This study aims to compare the reference evapotranspiration (ETo) eight different empirical methods with the FAO-56 standard, using orbital and surface data for the years 2003 and 2008 in the State of Acre. For surface data methods, the Irmak-2 and Val-4 showed a higher performance and the Alexandris method showed the worst performance compared with the FAO-56 standard. The spatial distribution of ETo derived of the orbital data method were compared based on the annual mean, presenting lower ETo (2.26 mm d-1) in 2003 and higher average (3.94 mm d-1) in 2008. This interannual variability of ETo may be associated with moderate El Niño events in 2003 and strong La Niña in 2008. The statistical analysis showed satisfactory results of the evapotranspiration mean values for the years 2003 and 2008 obtained by MODIS sensor data, but it is important to have a greater representation of weather stations in the state for future studies. The results serve as a subsidy for water demand estimates of vegetation, as well for biomass productivity and changing landscape studies. Keywords: orbital platforms, water availability, weather stations.  DELGADO, R. C.; SOUZA, L. P.; PEREIRA, M. G.; ALMEIDA, C. T.; RODRIGUES, R. A. EVAPOTRANSPIRAÇÃO ORBITAL E DE SUPERFÍCIE COMPARADOS AO PADRÃO FAO-56 NO ESTADO DO ACRE  2 RESUMO A Evapotranspiração é um componente crítico do ciclo hidrológico e da vida, com grande impacto no consumo de água pela população, em atividades agrícolas e no clima global. O presente trabalho tem por objetivo comparar a evapotranspiração de referência (ETo) a partir de diferentes métodos ao padrão FAO-56, utilizando dados orbitais e de superfície para os anos de 2003 e 2008 no Estado do Acre. Para os dados de superfície, o Irmak-2 e o Val-4 mostraram um maior desempenho e o método proposto por Alexandris o pior desempenho em comparação ao padrão FAO-56. A distribuição espacial dos valores de ETo foi comparada com base nos valores médios anuais, sendo que o período de 2003 apresentou ETo mais baixa (2.26 mm d-1) e o ano de 2008 os valores mais elevados (3.94 mm d-1). Esta variabilidade de ETo pode estar associada aos eventos de El Niño moderado em 2003 e La Niña forte em 2008. A análise estatística apresentou resultados satisfatórios dos valores médios para os anos de 2003 e 2008 de evapotranspiração obtidos pelo sensor MODIS, porém é importante que haja uma maior representativadade das EMS no estado para estudos futuros. Os resultados servem como subsídio para estimativas de demanda hídrica da vegetação, como também para estudos de produtividade de fitomassa e mudança da paisagem. Palavras-Chave: plataformas orbitais, disponibilidade de água, estações meteorológicas.


Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2099
Author(s):  
Fernando Salas-Martínez ◽  
Ofelia Andrea Valdés-Rodríguez ◽  
Olivia Margarita Palacios-Wassenaar ◽  
Aldo Márquez-Grajales

Agriculture and raising livestock are human activities highly affected by drought. In Mexico, the Veracruz territory is seriously affected by this phenomenon. Our study had two objectives: (1) to analyze the drought evolution through the Standardized Precipitation Index (SPI) and the maximum temperature in the central zone of the state of Veracruz for the period 1980–2018; and (2) to describe the relationship between the yield of corn grain and cattle, and the SPI, in the study area. The methodology consisted of calculating the SPI to estimate the drought conditions in the mentioned area. Subsequently, we determined the relationship of these conditions with the maximum temperature increase and the presence of El Niño/La Niña events. The results showed that the drought has intensified during 1980–2018, having a presence in almost 50% of the area. Additionally, the maximum temperature increased by approximately 6 °C. As a result, the cultivation of corn grain under rain conditions showed reductions in 48% of the analyzed municipalities. Concerning livestock variables, lower reductions were reported (42–32%) for the same period. Therefore, we can conclude that the drought has intensified in recent years due to an increase in the maximum temperature and El Niño/La Niña events, and these factors have had a higher impact on the agricultural sector.


2009 ◽  
Vol 22 (7) ◽  
pp. 1589-1609 ◽  
Author(s):  
Alice M. Grimm ◽  
Renata G. Tedeschi

Abstract The influence of the opposite phases of ENSO on the frequency of extreme rainfall events over South America is analyzed for each month of the ENSO cycle on the basis of a large set of daily station rainfall data and compared with the influence of ENSO on the monthly total rainfall. The analysis is carried out with station data and their gridded version and the results are consistent. Extreme events are defined as 3-day mean precipitation above the 90th percentile. The mean frequencies of extreme events are determined for each month and for each category of year (El Niño, La Niña, and neutral), and the differences between El Niño and neutral years and La Niña and neutral years are computed. Changes in the mean intensity of extreme events are also investigated. Significant ENSO signals in the frequency of extreme events are found over extensive regions of South America during different periods of the ENSO cycle. Although ENSO-related changes in intensity show less significance and spatial coherence, there are some robust changes in several regions, especially in southeastern South America. The ENSO-related changes in the frequency of extreme rainfall events are generally coherent with changes in total monthly rainfall quantities. However, significant changes in extremes are much more extensive than the corresponding changes in monthly rainfall because the highest sensitivity to ENSO seems to be in the extreme range of daily precipitation. This is important, since the most dramatic consequences of climate variability result from changes in extreme events. The pattern of frequency changes produced by El Niño and La Niña episodes with respect to neutral years is roughly symmetric, but there are several examples of nonlinearity in the ENSO regional teleconnections.


2015 ◽  
Vol 7 (5) ◽  
pp. 969
Author(s):  
Virgínia Fátima Bezerra Nogueira ◽  
VALNER SILVA NOGUEIRA ◽  
ENILSON PALMEIRA CAVALCANTI ◽  
RILDO GONÇALVES MOURA ◽  
ALEX ALMEIDA FERNANDES

Os Sistemas Convectivos de Mesoescala (SCM) contribuem substancialmente para a estação chuvosa da Região Nordeste do Brasil. Variações na Temperatura da Superfície do Mar (TSM) dos Oceanos Pacífico Equatorial e Atlântico Tropical impactam diretamente na intensidade dos SCMs que por sua vez influenciam na qualidade da estação chuvosa. Neste sentido, identificou-se em um acervo de 41 anos de dados de precipitação diária de 31 postos pluviométricos localizados sobre o Estado da Paraíba, os SCMs, afim de conhecer a influência do El Niño, La Niña e as fases do Dipolo de TSM no Atlântico Tropical (DTAT) sobre os sistemas precipitantes em mesoescala. Os SCMs são mais numerosos em anos de DTAT negativo e de El Niño. Porém, quando subtraídos os episódios fracos de El Niño, o número de sistemas se mantém abaixo dos observados em anos normais. Contudo, os SCMs são mais intensos nos episódios de DTAT e de La Niña quando comparado com anos normais.   A B S T R A C T Mesoscale Convective Systems (MCS) contribute substantially to the rainy season in the Northeast of Brazil. Variations in sea surface temperature (SST) of the Equatorial Pacific Ocean and the Atlantic directly impact the intensity of MCSs which in turn influence the quality of the rainy season. In this sense, it is identified in a collection of 41 years of daily rainfall data from 31 rain gauge stations located on the State of Paraíba, the MCSs, in order to determine the influence of El Niño, La Niña and the phases of the SST Dipole Tropical Atlantic (DTAT) on the mesoscale precipitation systems. The MCSs are more numerous in years of negative DTAT and El Niño. However, when subtracted from the weak El Niño events, the number of systems remains below those observed in normal years. However, SCMs are more intense episodes of DTAT and La Niña compared to normal years.   Key word: convective system mesoscale, El Niño, La Niña, dipole phases  


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