CONTRIBUCIÓN PRELIMINAR A LA INTERPRETACIÓN DEL ORIGEN DE LAS

DAPEÑA, C.; PANARELLO, H.O.; CERNE, B.; GONZALEZ M,; SANCHEZ CCOYLLO, O

Río Cuarto, Córdoba

Congreso; IV Congreso Hidrogeológico Argentino; 2005

Universidad de Rio Cuarto

ABSTRACTThe isotopic composition of precipitation is of great importance to understand theinterpretation of the hydrologic systems. Rainfall is the main recharge mechanism so the evaluation of the spatial and temporal distribution of isotope contents in precipitation and their dependence on relevant meteorological parameters provide basic input data.  Investigations concerning the sources of vapour in the Argentina subtropical are scarce: air oceanic trajectory induced by the Atlantic Anticyclone which transport vapour to the continent and in summer, the north humid wind, which pass through the Amazonian forest (Low Level Jet -LLJ). During summer 2002-2003 SALLJEX (South American Low Level Jet Experiment) experiment was performed to study tri-dimensional LLJ structure and its atmospheric related features. Daily rainfall water samples were collected in Resistencia and Salta stations. Isotope analysis showed a good correspondence with the meteoric water line. It is a usefultool to infer if rainfall in both locations was originated in air masses with similar features. Dataset is scarce but results show that the 18O and deuterium excess in rainfall water seem to be related to the Low Level Jet occurrence. This result lets give importance to long term and daily measurements of rainfall isotopic content in Argentina. To estimate the track of the air masses and to analyse the sample isotope content, a trajectory analysis was used. Keywords: Environmental Isotopes, Low Level Jet, Precipitations, subtropical Argentina.