South America: Extreme precipitation events in Southeastern South America: a proposal for a better understanding and modeling

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Southeastern South America (SESA) is a highly populated region where socio-economic activities are mainly based on rainfed agriculture and cattle rising, for   both domestic consumption and exports. The hydroelectric power utilities are also very important as they supply energy to the region and rivers provide the water for consumption.

SESA has   been characterized by a remarkable increment in the frequency and intensity of heavy precipitation events, particularly during the late 20th century. The region is particularly vulnerable to extreme events due to adaptation measures have not been performed at the same rate as changes in these extreme   events. However, it is still a challenge to better identify the factors and mechanisms that determine the location, intensity and frequency of the precipitation extremes and their large hydrologic impacts.

The main objectives of the SESA-FPS are to study multi-scale processes and interactions (convection, local, regional and remote processes, including the   co-behaviour of processes) that result in these extreme precipitation events; and to develop actionable climate information from multiple sources (statistical and dynamical downscaling products) based on co-production with the impact and user community.

This initiative seeks to promote inter-institutional collaboration and further networking, integrating not only South American research communities but also   European communities, taking into account that, in the recent years, there have been little or scattered activities related with inter-institutional coordinated regional climate modeling.

Multi-scale aspects, processes and interactions that result in extreme precipitation events will be investigated using dynamical models (high resolution, convection permitting and coupled models) and statistical models. ESD and RCM products will be compared and validated exploring the added value of downscaling. This will allow for a strengthened cooperation between ESD and RCM communities to jointly tackle key issues of regional climate change research. The impact of   heavy precipitations on flooding and soil moisture conditions will be assessed using a water balance model, and hydrological models will be used to   simulate ground water and soil moisture to drive crop models. In this   context, an increased cooperation and integration of RCM, ESD and VIA communities is expected towards a distillation of actionable information from multiple sources of downscaled products.

Data from RELAMPAGO, CHUVA and SALLJEX field campaigns will be available to perform the proposed studies, providing highly temporal-spatial resolution data to   characterize the synoptic scale, mesoscale, and convective scale flows in the region. Observed long records from surface meteorological and hydrological stations from different local institutions and the CLARIS-LPB initiative as well as a net of meteorological stations which includes the measurement of soil moisture at different levels will be available for calibration and validation of models (ESD, RCM, impact models.