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The São Paulo Macro Metropolis (SPMM) is composed of five metropolitan regions (i.e., São Paulo, Campinas, Paraíba Valley and North Coast, Sorocaba, and Santos), two urban agglomerations (i.e., Piracicaba and Jundiaí) and a microregion of Bragança. With an estimated 33 million inhabitants over an area 53,000 km2. Urban areas take up 11,000 km2 of this area, represented by 174 municipalities that account for nearly 73.9% of the state’s total population. The SPMM is already experiencing the impacts of severe climate events. It is situated along a transition climatic region between humid subtropical and tropical climates. Meteorological systems such as cold fronts, the South Atlantic Convergence Zone (ZCAS), sea breezes, urban heat islands, and other local circulations associated with topography favor the occurrence of severe weather at different time scales. The study aims at understanding climate change effects on the intensity and frequency of temperature and precipitation extremes in the SPMM, contributing to the establishment of policies to reduce the existing socioenvironmental risks in urban areas. For this, the ability of observation systems, reanalysis (ERA5, ERA40, NCEP/NCAR, and Terra Climate), and remote sensing (CMAP and CPC) were analyzed and used to show the decadal evolution of extreme events in SPMM. We also investigated the potential of CMIP5 models to simulate the extreme precipitation and temperature events in the SPMM that occurred between the 1950s and 2005. Future climate changes in the SPMM were analyzed based on CMIP5 models that best simulate past extreme events in the SPMM, considering the different carbon emission scenarios. This study is important to develop adaptive strategies to deal with climate change impacts on urban areas, such as droughts and floods.

In the present work, the trend of extreme rainfall indices in the Macro-Metropolis of São Paulo (MMSP) was analyzed and correlated with largescale climatic oscillations. A cluster analysis divided a set of rain gauge stations into three homogeneous regions within MMSP, according to the annual cycle of rainfall. The entire MMSP presented an increase in the total annual rainfall, from 1940 to 2016, of 3 mm per year on average, according to Mann-Kendall test. However, there is evidence that the more urbanized areas have a greater increase in the frequency and magnitude of extreme events, while coastal and mountainous areas, and regions outside large urban areas, have increasing rainfall in a better-distributed way throughout the year. The evolution of extreme rainfall (95th percentile) is significantly correlated with climatic indices. In the center-north part of the MMSP, the combination of Pacific Decadal Oscillation (PDO) and Antarctic Oscillation (AAO) explains 45% of the P95th increase during the wet season. In turn, in southern MMSP, the Temperature of South Atlantic (TSA), the AAO, the El Niño South Oscillation (ENSO) and the Multidecadal Oscillation of the North Atlantic (AMO) better explain the increase in extreme rainfall (R2 = 0.47). However, the same is not observed during the dry season, in which the P95th variation was only negatively correlated with the AMO, undergoing a decrease from the ‘70s until the beginning of this century. The occurrence of rainy anomalous months proved to be more frequent and associated with climatic indices than dry months.

Nas últimas décadas, o clima da Terra vem apresentando mudanças no seu comportamento, através do aumento da frequência de eventos climáticos extremos, associado muito provavelmente às mudanças climáticas globais, cujo tema tornou-se popular e motivo de discussão do público em geral. Neste contexto, o presente estudo apresenta uma análise das frequências dos eventos extremos de seca e chuva na Amazônia baseada em séries de precipitação mensal de quatro bancos de dados: GPCP (Global Precipitation Climatology Project), GPCC (Global Precipitation Climatology Center), CPC (Climate Prediction Center) e Era-Interim, no período de 1979 a 2014. Os eventos extremos de seca e chuva foram caracterizados pelo índice de precipitação padronizada (SPI) aplicado a diferentes escalas temporais (3, 6 e 12 meses). Os resultados mostraram diferenças expressivas nas frequências dos eventos extremos de seca e chuva, nos quatro bancos de dados. Todavia, constatou-se nas três escalas do SPI, em todas as estações do ano e nos quatro bancos de dados que, a Amazônia apresentou frequências de eventos extremos de chuva variando entre 3% a 6% no período em estudo. Por outro lado, observou-se nos eventos extremos de seca uma variação superior a 6% das frequências. A B S T R A C T In recent decades, the Earth's climate has been showing changes in their behavior by increasing the frequency of extreme climatic events, most likely associated to global climate change, whose theme became popular and point of discussion the general public. In this context, this study presents an analysis of the frequency of the extreme dry and rainy events in the Amazon based on monthly rainfall series of four databases GPCP (Global Precipitation Climatology Project), GPCC (Global Precipitation Climatology Center), CPC (Climate Prediction Center) e Era-Interim in the period 1979-2014. The extreme dry and rainy events were characterized by Standard Precipitation Index (SPI) being applied to different time scales (3, 6 and 12 months). The results showed expressive differences in the frequency of extreme dry and rainy events in the four databases. However, it was noted in the three scales of SPI, in all seasons and in the four databases that Amazon presented frequencies of extreme rainy events ranging from 3% to 6% in the study period. Moreover, it was observed in extreme dry events changes by more than 6% of frequencies. Keywords: Amazon, precipitation, extreme, SPI.

Due to the high spatial and temporal variability of atmospheric water vapor associated with the deficient methodologies used in its quantification and the imperfect physics parameterizations incorporated in the models, there are significant uncertainties in characterizing the moisture field. The process responsible for incorporating the information provided by observation into the numerical weather prediction is denominated data assimilation. The best result in atmospheric moisture depend on the correct choice of the moisture control variable. Normalized relative humidity and pseudo-relative humidity are the variables usually used by the main weather prediction centers. The objective of this study is to assess the sensibility of the Center for Weather Forecast and Climate Studies to choose moisture control variable in the data assimilation scheme. Experiments using these variables are carried out. The results show that the pseudo-relative humidity improves the variables that depend on temperature values but damage the moisture field. The opposite results show when the simulation used the normalized relative humidity. These experiments suggest that the pseudo-relative humidity should be used in the cyclical process of data assimilation and the normalized relative humidity should be used in non-cyclic process (e.g., nowcasting application in high resolution).

Nas ultimas decadas, o clima da Terra vem apresentando mudancas no seu comportamento, atraves do aumento da frequencia de eventos climaticos extremos, associado muito provavelmente as mudancas climaticas globais, cujo tema tornou-se popular e motivo de discussao do publico em geral. Neste contexto, o presente estudo apresenta uma analise das frequencias dos eventos extremos de seca e chuva na Amazonia baseada em series de precipitacao mensal de quatro bancos de dados: GPCP (Global Precipitation Climatology Project), GPCC (Global Precipitation Climatology Center), CPC (Climate Prediction Center) e Era-Interim, no periodo de 1979 a 2014. Os eventos extremos de seca e chuva foram caracterizados pelo indice de precipitacao padronizada (SPI) aplicado a diferentes escalas temporais (3, 6 e 12 meses). Os resultados mostraram diferencas expressivas nas frequencias dos eventos extremos de seca e chuva, nos quatro bancos de dados. Todavia, constatou-se nas tres escalas do SPI, em todas as estacoes do ano e nos quatro bancos de dados que, a Amazonia apresentou frequencias de eventos extremos de chuva variando entre 3% a 6% no periodo em estudo. Por outro lado, observou-se nos eventos extremos de seca uma variacao superior a 6% das frequencias. Normal 0 false false false PT-BR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri",sans-serif; mso-ansi-language:PT-BR; mso-fareast-language:PT-BR;} A B S T R A C T In recent decades, the Earth's climate has been showing changes in their behavior by increasing the frequency of extreme climatic events, most likely associated to global climate change, whose theme became popular and point of discussion the general public. In this context, this study presents an analysis of the frequency of the extreme dry and rainy events in the Amazon based on monthly rainfall series of four databases GPCP ( Global Precipitation Climatology Project) , GPCC ( Global Precipitation Climatology Center) , CPC ( Climate Prediction Center ) e Era-Interim in the period 1979-2014. The extreme dry and rainy events were characterized by Standard Precipitation Index (SPI) being applied to different time scales (3, 6 and 12 months). The results showed expressive differences in the frequency of extreme dry and rainy events in the four databases. However, it was noted in the three scales of SPI, in all seasons and in the four databases that Amazon presented frequencies of extreme rainy events ranging from 3% to 6% in the study period . Moreover, it was observed in extreme dry events changes by more than 6% of frequencies . Keywords: Amazon, precipitation, extreme, SPI .

O método da Análise Fatorial em Componentes Principais e dos Agrupamentos Hierárquicos foram utilizados para determinar os padrões principais de variabilidade temporal e espacial, assim como identificação dos grupos homogêneos, da precipitação no Estado do Pará. Para isso utilizaram-se dados mensais de 72 postos pluviométricos distribuídos no Estado do Pará. As três primeiras Componentes Principais explicaram 92,91% da variância total dos dados mensais de precipitação. O Primeiro padrão espacial definiu áreas de chuva que são influenciadas pela atuação da Zona de Convergência Intertropical (ZCIT). O segundo padrão espacial está associado a sistemas transientes ou até mesmo da Zona de Convergência do Atlântico Sul que favorecem as chuvas na região no final da primavera e no início do verão austral. Já o terceiro padrão espacial evidencia a influência da atuação da ZCIT, das linhas de instabilidade e da convecção local. Identificaram-se e caracterizaram-se três regiões homogêneas (RH-1, RH-2 e RH-3) em relação à variabilidade sazonal de precipitação no Estado do Pará. A RH-1 ocupa as porções noroeste-nordeste do Estado com maior volume pluviométrico, a RH-2 está situada na região central do Pará e a RH-3 localizada no sudoeste-sudeste do Estado com menor índice pluviométrico. A B S T R A C T The methods of the Principal Component Factor Analysis and the Hierarchical Cluster were used to determine the mains patterns of temporal and spatial variability, as well as to identify homogeneous groups, of rainfall in the State of Pará. For this the data for 72 rainfall posts were used, where were distributed in the State of Pará. The first three Principal Component explained 92.91% of the total variance of monthly rainfall data. The first spatial pattern defined rainfall areas that are influenced by the influence of the Intertropical Convergence Zone (ITCZ). The second spatial pattern is associated with transient systems or even South Atlantic Convergence Zone (SACZ) that favors rainfall in the region in the late spring and early summer austral. The third spatial pattern shows the influence by ITCZ activity, squall lines and local convection. This study identified and characterized three homogeneous regions (HR-1, HR-2 and HR-3 ) in relation to the seasonal variability of precipitation in the State of Pará. The RH-1 occupies the northwest and northeast portions of the state with the largest volume rainfall , the RH- 2 is located in the central region of Pará and RH- 3 located in the southwest - southeast of the state with lower rainfall. Keywords: Pará, Precipitation, Principal Components Analysis (PCA)

A rapid increase in atmospheric water vapor is a fundamental ingredient for many intense rainfall events. High-frequency precipitable water vapor (PWV) estimates from a Global Positioning System meteorological site (GPS) are evaluated here for intense rainfall events during the CHUVA Vale field campaign in Brazil (November–December 2011), in which precipitation events of differing intensities and spatial dimensions, as observed by an X-band radar, have been explored. A wavelet cross-correlation analysis shows that there are important spikes in the PWV that precede the more intense rainfall events on a timescale from 30 to 60 minutes. The correlation and lags between the GPS-PWV and rainfall events are evaluated, and a sharp increase in the GPS-PWV prior to the more intense events has been found and termed GPS-PWV "jumps". These jumps are associated with water vapor convergence and the continued formation of cloud condensate and precipitation particles. The GPS-PWV time-derivative histogram for the period of 60 minutes before the rainfall event reveals different distributions for higher intensity events. This feature could indicate the occurrence of severe precipitation and consequently has the potential for application in nowcasting activities.

Os impactos socioeconômicos dos Eventos Extremos de Precipitação Diária em Belém-Pará foram estudados com base em histórias relatadas nas notícias dos jornais da cidade durante o período de 1987 a 2009. Estes eventos foram caracterizados como extremos por meio da Técnica do Decil. O objetivo foi identificar as consequências e os principais bairros afetados pelos eventos extremos de precipitação diária. Os anos que estiveram sob influência do fenômeno El Niño (La Niña) foram os que apresentaram menor (maior) frequência de Eventos Extremos de Precipitação e de noticias publicadas nos jornais da cidade. A variação mensal mostrou que os Eventos Extremos e as notícias dos jornais foram maiores no período "mais chuvoso" (verão/outono austral). As histórias relatadas nas notícias dos jornais da cidade indicaram que o alagamento das ruas é a principal consequência dos eventos extremos para a cidade de Belém-Pará e os bairros mais afetados são Cremação, Jurunas e Batista Campos. Esses bairros são vizinhos e tem como fator comum a presença da bacia hidrográfica da Travessa Quintino Bocaiúva, a qual apresenta baixa declividade e dificulta o escoamento da água, favorecendo a formação de pontos de alagamentos. Identificou-se que a falta de infraestrutura da cidade é o fator predominante quanto à consequência dos eventos extremos de precipitação diária. This study examined the socioeconomic impacts of Daily Extreme Precipitation Events (hereafter "DEPEs") in Belem-Pará during the period 1987-2009. The DEPEs were characterized as "extreme" using the Decile technique. The objective of the study was to identify the consequences and the main neighborhoods affected by these events. The years influenced by occurrences of El Niño or La Niña had the lowest or the highest rates of DEPEs, respectively, and as well as the number of articles published in the city's newspapers. The monthly variation showed that the DEPEs and resulting newspaper articles were higher in the "wettest" (summer / austral autumn) period. The newspaper articles indicated that street flooding is the main consequence of DEPEs in the city of Belém-Pará, and that the most affected districts are Cremação, Jurunas and Batista Campos. These neighborhoods are near to one another and are all located in the Travessa Quintino Bocaiúva watershed, which has a low slope that delays the flow of water, favoring flooding. The city's lack of infrastructure is the main reason for the severe consequences of DEPEs.