Climatic process associated to variation on stable isotopic composition of precipitation in central region of São Paulo State - br

Abstract

Climate changes, and their consequences, represent nowadays one of the most important scientific research fields. In this way, precipitation stable isotopic composition, and their temporal variations, constitute an important tool used for improve the understanding about the mechanisms responsible by these changes. Stable isotopes of hydrogen and oxygen, also called environmental isotopes because of their abundance in the environment, constitute the water molecule, representing an excellent tracer for water movement through the water cycle, and it is being used as an important tool for the interpretation about the climatic controls on precipitation, which enables its use for paleoclimatic reconstitution studies. In temperate climatic zones relationships between the precipitation isotopic composition and climatic parameters like temperature and precipitation amount are quite well established, however in tropical zones the climatic controls over isotopic composition of the precipitation remains a controversial subject in the scientific community. Some researchers have proposed the influence of local process over precipitations, while other researchers have proposed the importance of process in regional scale, as Rayleigh distillation. In this way, the continuous monitoring of the isotopic composition in different temporal scales is fundamental. Since 2013 a rainwater collect station was installed on CEA/UNESP-Rio Claro, incorporated into GNIP network, operated by the International Atomic Energy Agency. The aim of GNIP is to contribute to generate important precipitation isotopic data, subsidizing for the increase on the amount of data require for understanding the regional climate conditions. The main purpose of this scientific initiation project is to evaluate the temporal variation of precipitation isotopic composition (´2H and ´18O) in the city of Rio Claro, based on daily precipitation sampling program, and their relationships with local and regional climate parameters, trying to understand the climatic key drivers (local or regional), complementing the results obtained in previous Project scientific initiation developed with support from FAPESP.