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Neste estudo utilizou-se a equacao de Penman-Monteith para analisar os padroes temporais de mudancas da Evapotranspiracao Potencial (ETP), para as tres mesorregioes do Estado de Alagoas: sertao, agreste e litoral, com base na composicao regional das series temporais desta variavel a partir de estacoes meteorologicas localizadas em cada uma das regioes, para o periodo 1961-2016. Os maiores valores medios diarios da ETP ocorrem no sertao, seguido do agreste e litoral, com maximos de outubro a marco, e minimos de abril a setembro. As tendencias foram analisadas para trimestres representativos das estacoes do ano, e em nivel anual, via regressao linear pelo metodo dos minimos quadrados, e pelo teste sequencial de Mann-Kendall, com o objetivo de encontrar tambem os pontos de ruptura que indicam o provavel inicio das tendencias. No verao observou-se tendencias positivas e estatisticamente significativas, por regressao linear e teste de MK apenas para o agreste, assim como no outono, a partir da decada de 80. O inverno foi a unica estacao onde as tres regioes apresentaram a mesma tendencia, negativa, e com significância estatistica. Na primavera o sertao apresenta tendencia de decrescimo dos valores diarios da ETP, estatisticamente significante, enquanto no agreste a tendencia e de aumento tambem com significância pelos dois metodos de analise, com o litoral apresenta tendencia negativa mas sem significância. Em suma, anualmente, percebe-se tendencias estatisticamente significantes de decrescimo da ETP media diaria no sertao e de aumento no agreste, enquanto ha predominio de neutralidade no litoral. Investigar estas diferencas torna-se um objetivo futuro de pesquisa, a fim de analisar a maior contribuicao para as tendencias, seja pela componente radiativa ou pela componente aerodinâmica da equacao de PM. A B S T R A C T In this study, the Penman-Monteith equation was used to analyze the temporal patterns of Potential Evapotranspiration (PET) changes for the three mesoregions of the State of Alagoas: sertao, agreste and litoral, based on the regional composition of the time series of this variable from meteorological stations located in each of the regions, for the period 1961-2016. The highest daily mean values of ETP occur in the sertao, followed by the agreste and litoral, with maximum and minimum values from October to March, and April to September, respectively. The trends were analyzed for the three representative months of the seasons, and at the annual level, using linear regression using the least squares method, and by the Mann-Kendall sequential test, with the objective of also finding the break points that indicate the probable beginning trends. In the summer, positive and statistically significant trends were observed, by linear regression and MK test, only for the agreste, as well as in autumn, starting from the 80's. Winter was the only season where the three regions showed the same trend, negative, and with statistical significance. In the spring the sertao shows a tendency to decrease the daily values of the ETP, statistically significant, while in the agreste the trend is also increased with significance by the two methods of analysis, with the litoral showing a negative but not significant trend. In summary, annually, there are statistically significant decreases in the mean daily ETP in the sertao and increase in the agreste, while there is a predominance of neutrality in the littoral. Investigating these differences becomes a future research goal in order to analyze the major contribution to the trends, be it by the radiative component or the aerodynamic component of the PM equation.

Os eventos climáticos extremos demonstram um papel significativo das sociedades, seja por sua intensidade, pela frequência de ocorrência ou pela vulnerabilidade socioambiental. Objetiva-se classificar e quantificar as precipitações na porção leste da região Nordeste (NE) do Brasil através do índice SPI, como também detectar maiores déficits e/ou excesso de precipitação. O Standardized Precipitation Index (SPI) foi utilizado para quantificar déficits de precipitação e identificar eventos secos e chuvosos em diferentes escalas temporais, auxiliando no monitoramento da sua dinâmica temporal. No cálculo do SPI foi utilizado a distribuição gama, e estimados os limites de precipitação que representam a cada categoria do índice. Foram utilizados dados pluviométricos das capitais dos estados que compõem no leste do Nordeste do Brasil, no período de 1961 a 2014 provenientes da Agência Nacional das Águas (ANA). A análise de Ondeletas foi utilizada com objetivo de identificar ciclos de extremos pluviométricos e de suas causas através das escalas temporais detectadas em séries de precipitação para as capitais do leste do Nordeste do Brasil. Os resultados mostraram que as ocorrências de secas foram as maiores em todas as cidades, todavia na categoria extrema os eventos chuvosos revelaram-se mais frequentes. Os anos normais foram os mais persistentes em todas cidades analisadas. Recife apresentou máximas ocorrências de eventos chuvosos. Os eventos com intensidade extrema, seja chuvoso ou seco, ocorreram em boa parte da série em anos de ENOS. O SPI revelou-se uma excelente ferramenta na detecção e no monitoramento de seca/chuvas na região analisada. A presença de escalas temporais relacionadas com eventos ENOS, Dipolo do Atlântico, ciclo de manchas solares e Oscilação Decadal do Pacífico foram identificadas em todas as capitais do leste do NEB. Characterization of Drought Events Based on the Standardized of Precipitation Index for the East NortheastA B S T R A C TExtreme weather events demonstrate a significant role for societies, whether by their intensity, frequency of occurrence or socio-environmental vulnerability. Objective-classify and quantify as precipitation in the eastern portion of the Northeast (NE) of Brazil through the SPI index, as well as detect larger deficits and / or excess occurrence. The Standardized Precipitation Index (SPI) was used to quantify use deficits and to identify dry and rainy events in different temporal variations, helping to monitor their temporal utilization. No SPI calculations were used for gamma distribution, and estimated capture limits representing each category of the index. Rainfall data were used from the capitals of the states that make up the eastern Northeast of Brazil, with no period from 1961 to 2014, Registration of the National Water Agency (ANA). A wave analysis was used to identify extreme rainfall cycles and their causes caused by temporary variations detected in monitoring series for the eastern capitals of Brazil. The results shown as drought occurrences were the highest in all cities, however in the extreme category of rain events most frequently revealed. The normal years were the most persistent in all cities analyzed. Recife presents maximum occurrences of rain events. Extreme intensity events, whether rainy or dry, occur in much of the series in ENSO years. The SPI revealed an excellent tool for detection and monitoring of drought / gloves in the analyzed region. The presence of temporary variations related to ENOS, Atlantic Dipole, sunspot cycle and Pacific Oscillation events are identified in all eastern NEB capitals.Keywords: SPI; extreme rainfall; drought; Wavelet analysis.

Esta pesquisa avaliou as tendencias balanco de ondas curtas (BOC) e balanco de ondas longas (BOL) e do saldo de radiacao (SR), para relacionar com a tendencia observada do numero de horas de frio (NHF) para a cidade de Cruz Alta-RS, a partir de dados horarios da estacao meteorologica automatica do Instituto Nacional de Meteorologia. O periodo analisado foi de 2010 a 2018. As analises foram relativas aos periodos das estacoes do ano, e para obtencao das tendencias foi utilizado o teste nao parametrico de Mann-Kendall. O BOC e o BOL apresentaram tendencias positivas no inverno e primavera, e negativas no verao e outono. O SR apresentou tendencias negativas no outono, inverno e primavera, e positiva no verao. Nao foram observada horas de frio no verao. No outono houve a tendencia de aumento estatisticamente significante do NHF, enquanto no inverno e primavera as tendencias foram de reducao do NHF, com significância estatistica no inverno. A tendencia de reducao de -1,4 horas de frio no inverno e preocupante, pois esta e a estacao do ano para o acumulo natural de NHF para diversas culturas, e anos com NHF reduzido estao associados aos piores indices de produtividade destas culturas. Trend analysis of the radiation balance components and number of cold hours in Cruz Alta-RS A B S T R A C T This research evaluated the shortwave balance (BOC), longwave balance (BOL) and net radiation (SR) trends to correlate with the observed trend of chill hours (NHF) for the city of Cruz Alta-RS. Hourly data from the INMET automatic weather station were used from 2010 to 2018. The analyzes were relative to the seasons, and to obtain the trends, the nonparametric Mann-Kendall test was used. BOC and BOL showed positive trends in winter and negative trends in summer and fall. SR showed negative trends in fall, spring and summer, and positive trends in winter. No cold hours were observed in summer. In the fall there was a trend of statistically significant increase in NHF, while in winter and spring the trends were in NHF reduction, with statistical significance in winter. The tendency to reduce -1.39 chill hours in winter and -0.11 chill hours in spring may be associated with a significant reduction in cold front passage and cold air masses in southern Brazil in the last years of analysis. These results need attention, as it is mainly in winter that natural accumulation of NHF should occur for several crops. In general, years with reduced NHF are associated with worse crop yields that need to accumulate chili hours. Keywords: radiation, temperature, agriculture.

Este trabalho teve como objetivo aplicar e estudar 11 indices de extremos de precipitacao formulados pelo ETCCDI (Expert Team on Climate Change Detection and Indices, www.clivar.org/organization/etccdi), para a cidade de Cabaceiras-PB, utilizando dados diarios de precipitacao continuos de 90 anos. Os indices foram calculados para o comprimento total da serie, 1928 a 2017, assim como para tres segmentos de 30 anos (1928-1957, 1958-1987 e 1988-2017). Os resultados evidenciaram que para muitos indices, tendencias opostas e estatisticamente significativas podem ser observadas a depender do subperiodo estudado, assim como haver diferenca entre estas tendencias e as obtidas ao analisar-se o periodo total dos dados. Exemplos disso aconteceram para os indices R1mm, R10mm, R20mm, CWD e PRCPTOT. Trends in extreme precipitation indexes in Cabaceiras (PB) for different periods A B S T R A C T This work aimed to apply and analyze 11 precipitation extremes indexes formulated by ETCCDI (Expert Team on Climate Change Detection and Indices, www.clivar.org/organization/etccdi), for the city of Cabaceiras, located in the Borborema mesoregion and microregion of Paraiba Oriental Cariri. A municipality in the semiarid region, it has the title of municipality where it rains less in Brazil, with an annual average of just over 300mm. Daily 90-year continuous precipitation data were used for the extreme indices, with the time series analyzed for four distinct periods, the total length of the series, 1928 to 2017, as well as three 30-year segments (1928-1957, 1958- 1987 and 1988-2017). The results showed that for many indices, opposite and significant trends can be observed depending on the sub period studied, as well as differences between these trends and those obtained by analyzing the total data period. The R1, R10 and R20mm indices show significant negative trends in the 1928-1957 sub period, but positive in the following two sub periods, reflecting a significant positive trend in the total period from 1928 to 2017. Other interesting examples are CDD indices for consecutive dry days, and PRCPTOT, for total annual rainfall with rainfall greater than 1mm. The CDD showed significant positive trend only in the 1928-1957 sub period, but non-significant negative trends in the subsequent sub periods, reflecting non-significant negative trends in the total length of the series. The PRCPTOT index shows behavior opposite to the CDD index, with a significant negative trend in the 1928-1957 sub period, positive in 1958-1987 and negative again in 1988-2017, but for the total length of the series the trend is positive and significant. These results show that the analysis of extreme trends is noticeably sensitive to the sample of the analyzed period, and may not reflect the reality of the time series the longer the total length of the time series, and need to be used with caution. Keywords: climate variability, dry and wet periods, semiarid.

Neste trabalho utilizou-se a tecnica MICE (do ingles “Multivariate Imputation by Chained Equations”) para imputacao de dados diarios de variaveis meteorologicas, para series temporais provenientes de 96 estacoes convencionais do INMET, entre periodo de 1961 e 2012, para em seguida aplicar os testes de um sistema de controle de qualidade desenvolvido para deteccao, correcao e possivel substituicao de dados suspeitos. Tanto as tecnicas de preenchimento de falhas utilizadas, quanto do sistema de controle de qualidade, evidenciaram ser possivel solucionar dois dos maiores problemas encontrados nas series temporais de dados diarios medidos em estacoes meteorologicas: a geracao de valores plausiveis, para cada variavel de interesse, a fim de sanar a ausencia de observacoes, como detectar e permitir a devida correcao, a valores suspeitos provenientes das observacoes. A B S T R A C T In this work we used the technique MICE ("; Multivariate imputation by Chained Equations ";) for allocating daily data of meteorological variables for time series from 96 conventional stations of INMET , between 1961 and 2012 , and then to apply the tests for a system of quality control developed for detection , correction and possible replacement of suspect data . Both gap filling technique used , as the system of quality control , showed to be possible to solve two major problems encountered in time series of daily data measured at weather stations : the generation of plausible values ​​ for each variable of interest , the order to remedy the lack of observations , how to detect and allow correction due to suspicious values ​​ from the observations .