ANÁLISE DA VARIABILIDADE TEMPORAL DA PRECIPITAÇÃO EM RECIFE-PE

The city of Recife-PE has geographic singularities that interfere in the temporal and spatial distribution of precipitation, which is associated with topographical factors, wind displacement, vegetation, urbanization, among others. Thus, this location has a strong potential for the occurrence of extreme precipitation events, whether by flooding, flooding or landslides affecting the population's quality of life. We sought to analyze the behavior of this variable through monthly precipitation data covering the period 1961 to 2019, obtained from the Meteorological Database for Education and Research (BDMEP) of the National Institute of Meteorology (INMET), satellite images GOES-12, from the database of the Center for Weather Forecasting and Climate Studies (CPTEC/INPE) and data from the Tropical Rainfall Measuring Mission (TRMM) satellite. To verify the occurrence or not of trends in the time series, the Mann-Kendall (MK) test was used. This test uses the null hypothesis H0, when there is no precipitation trend, and the alternative hypothesis H1, when there is a trend in the data series, for the month of March negatively at the level of 5% (p<0.05), rejecting the null hypothesis. From the TRMM satellite images, INMET data and GOES-12 satellite images, it was evidenced that the Intertropical Convergence Zone (ITCZ) meteorological system, with its favorable convective activity and its climatological position further south of the Equator contributed to the accumulated precipitation observed in Recife-PE.La ciudad de Recife-PE tiene singularidades geográficas que interfieren en la distribución temporal y espacial de la precipitación, que se asocia con factores topográficos, desplazamiento del viento, vegetación, urbanización, entre otros. Por lo tanto, esta localidad tiene un fuerte potencial para la ocurrencia de eventos de precipitaciones extremas, ya sean inundaciones, inundaciones o deslizamientos de tierra que afectan la calidad de vida de la población. Se buscó analizar el comportamiento de esta variable a través de datos mensuales de precipitación que comprenden el período de 1961 a 2019, obtenidos de la Base de Datos Meteorológicos para la Enseñanza y la Investigación (BDMEP) del Instituto Nacional de Meteorología (INMET), imágenes del satélite GOES-12, la base de datos del Centro de Pronósticos Meteorológicos y Estudios Climáticos (CPTEC/INPE) y datos del satélite tropical Rainfall Measuring Mission (TRMM). Para verificar la ocurrencia o no de tendencias en la serie temporal, se utilizó la prueba de Mann-Kendall (MK). Esta prueba utiliza la hipótesis nula H0, cuando no hay tendencia de precipitación y la hipótesis alternativa H1, cuando hay una tendencia en la serie de datos, para el mes de marzo negativamente en el nivel de 5% (p<0,05), rechazando la hipótesis nula. A partir de las imágenes satelitales del TRMM, datos del INMET e imágenes satelitales GOES-12, se evidenció que la Zona de Convergencia Intertropical del Sistema Meteorológico (CIIC), con su actividad convectiva favorable y su posición climatológica más al sur de Ecuador, contribuyó a la precipitación acumulada observada en Recife-PE.A cidade de Recife-PE possui singularidades geográficas que interferem na distribuição temporal e espacial da precipitação, que está associada com fatores topográficos, deslocamento dos ventos, vegetação, urbanização, entre outros. Dessa forma, essa localidade apresenta um forte potencial para ocorrência de eventos extremos de precipitação, seja ele por alagamentos, inundações ou deslizamentos de terra afetando a qualidade de vida da população. Buscou-se analisar o comportamento dessa variável por meio dos dados mensais de precipitação compreendendo o período de 1961 a 2019, obtidos a partir do Banco de Dados Meteorológicos para Ensino e Pesquisa (BDMEP) do Instituto Nacional de Meteorologia (INMET), imagens do satélite GOES-12, do banco de dados do Centro de Previsão de Tempo e Estudos Climáticos (CPTEC/INPE) e dados do satélite Tropical Rainfall Measuring Mission (TRMM). Para verificar a ocorrência ou não de tendências nas séries temporais, utilizou-se o teste de Mann-Kendall (MK). Esse teste utiliza a hipótese nula H0, quando não há tendência de precipitação e a hipótese alternativa H1, quando há tendência na série de dados, para o mês de março negativamente ao nível de 5% (p<0,05), rejeitando-se a hipótese nula. A partir das imagens do satélite TRMM, dos dados do INMET e das imagens de satélite GOES-12, evidenciou-se que o sistema meteorológico Zona de Convergência Intertropical (ZCIT), com sua atividade convectiva favorável e sua posição climatológica mais ao sul do Equador contribuiu nos acumulados de precipitação observados em Recife-PE

Seasonal Ecosystem Productivity in a Seasonally Dry Tropical Forest (Caatinga) Using Flux Tower Measurements and Remote Sensing Data

The Caatinga dry forest encompasses 11% of the total continental territory of Brazil. Nevertheless, most research on the relationship between phenology and ecosystem productivity of Brazilian tropical forests is aimed at the Amazon basin. Thus, in this study we evaluated the seasonality of ecosystem productivity (gross primary production—GPP) in a preserved Caatinga environment in northeast Brazil. Analyses were carried out using eddy covariance measurements and satellite-derived data from sensor MODIS (MODerate Resolution Imaging Spectroradiometer, MOD17 and MOD13 products). In addition to GPP, we investigated water use efficiency (WUE) and meteorological and phenological aspects through remotely sensed vegetation indices (NDVI and EVI). We verified that ecosystem productivity is limited mainly by evapotranspiration, with maximum GPP values registered in the wetter months, indicating a strong dependency on water availability. NDVI and EVI were positively associated with GPP (r = 0.69 and 0.81, respectively), suggesting a coupling between the emergence of new leaves and the phenology of local photosynthetic capacity. WUE, on the other hand, was strongly controlled by consecutive dry days and not necessarily by total precipitation amount. The vegetation indices adequately described interannual variations of the forest response to environmental factors, and GPP MODIS presented a good relationship with tower-measured GPP in dry (R2 = 0.76) and wet (R2 = 0.62) periods

Seasonal Ecosystem Productivity in a Seasonally Dry Tropical Forest (Caatinga) Using Flux Tower Measurements and Remote Sensing Data

The Caatinga dry forest encompasses 11% of the total continental territory of Brazil. Nevertheless, most research on the relationship between phenology and ecosystem productivity of Brazilian tropical forests is aimed at the Amazon basin. Thus, in this study we evaluated the seasonality of ecosystem productivity (gross primary production—GPP) in a preserved Caatinga environment in northeast Brazil. Analyses were carried out using eddy covariance measurements and satellite-derived data from sensor MODIS (MODerate Resolution Imaging Spectroradiometer, MOD17 and MOD13 products). In addition to GPP, we investigated water use efficiency (WUE) and meteorological and phenological aspects through remotely sensed vegetation indices (NDVI and EVI). We verified that ecosystem productivity is limited mainly by evapotranspiration, with maximum GPP values registered in the wetter months, indicating a strong dependency on water availability. NDVI and EVI were positively associated with GPP (r = 0.69 and 0.81, respectively), suggesting a coupling between the emergence of new leaves and the phenology of local photosynthetic capacity. WUE, on the other hand, was strongly controlled by consecutive dry days and not necessarily by total precipitation amount. The vegetation indices adequately described interannual variations of the forest response to environmental factors, and GPP MODIS presented a good relationship with tower-measured GPP in dry (R2 = 0.76) and wet (R2 = 0.62) periods