Spatial and temporal variability of daily precipitation concentration in southeastern South America

Abstract

AbstractThe study of the spatial and temporal variability of the precipitation concentration is necessary, due to its high environmental and socioeconomic impact. For this reason, this study aims to contribute to the knowledge of daily rainfall in southeastern South America. Daily records of precipitation for 48 stations are used (period 1979–2018) to calculate the concentration index (CI). High CI is linked to rapid physical processes such as convection, and low CI can be interpreted as a consequence of regular patterns such as the continuous passage of fronts. The spatial and temporal distribution of CI brings information about frequency and changes in heavy rainfall days. The spatial distribution of the CI at an annual level has a range of variation between 0.54 and 0.68. The CI temporal variation shows different regional behaviour. In Brazil, there is an increase in the CI, while in Uruguay and the north‐central part of Argentina negative trends are present in the four seasons.