Isotopic composition of precipitation and its relationship with climatic variability in the southern central portion of São Paulo State (BR)

Abstract

Stable isotopes of hydrogen (1H/2H) and oxygen (16O/17O/18O) constitute excellent tracers of movement of the water molecule through the hydrological cycle, being used as an important tool in the interpretation of the origins of flows within river basins, climate controls on precipitation and groundwater origin, which enables its use in paleoclimatic reconstruction studies. In tropical areas, the climatic factors that govern the isotopic composition of precipitation remains a controversial question in the scientific community, while some authors propose that the isotopic composition of precipitation is influenced by aspects of local climatic dynamics, others advocate the importance of processes global scale, the type Rayleigh distillation. Based on the processes involved in the isotopic transformations undergone by the water along its path in the hydrologic cycle in continental areas, this project has for objective evaluate the isotopic variations of precipitation in some areas of the state of São Paulo, seeking to understand the climatic factors (local or regional) responsible for controlling isotopic variations in precipitation, especially those associated with the formation and the types of rain and its features. Therefore it will be analyzed together the isotopic composition of precipitation, weather information provided by the Tropical Rainfall Measurring Mission (TRMM) and HYSPLIT model. Such tools will be very important for evaluation of atmospheric systems that generate rain for the studied locations and what the effects of these on the isotopic composition of precipitation. The matrix of meteorological and isotopic data generated will be used in statistical regression testing, in order to create a robust model that correlates the isotopic content to local and regional climatic parameters or the atmospheric systems that operate in Brazil. (AU)