Semestral Journal of Centro Argentino de Meteorólogos, which is published  since 1970 and serves on the Core of Argentine Scientific Journals since 2005. Meteorologica publishes original papers in the field of atmospheric sciences and oceanography.

Registration number of intellectual property: RL-2018-42420861-APN-DNDA#MJ

ISSN 1850-468X

Volume 45 N° 1 MORE NOTES FROM THIS ISSUE

CHACO PROVINCE PRECIPITATION, A LOW FREQUENCY STUDY

Santiago I. Huratdo, Eduardo A. Agosta y Alejandro Godoy

Facultad de Ciencias Astronómicas y Geofísicas de la UNLP, Argentina
CONICET, Argentina
Servicio Meteorológico Nacional, Argentina

Manuscript received on June 12th, 2018 and in final form on October 31st, 2018

ABSTRACT

The Argentinian Chaco Province is located in an area with a strong zonal gradient of annual precipitation, wetter in the east and drier in the west. Precipitation variations affect farming in the east and it may make the access to water sources difficult in the dry western lands known as the “Impenetrable”. Low-frequency precipitation variability is studied in the period 1955-2010. The annual precipitation cycle can be divided into two seasons: a wet season (from October to April) and a dry season (from May to September). A spatial Principal Component Analysis classification yields four subregions: subregion I to the east, subregion II to the west, subregion III to north-center and subregion IV to south-center. Only two of these were studied in the present paper, the one most economically important and the one with more water access problems, these are the two extremes in the precipitation gradient, the subregion I the wettest and the subregion II the drier. For these subregions a representative precipitation series was performed and studied. The exploratory study of potentials forcings reveals that seasonal accumulated precipitation is modulated by ENSO and regional anomalous circulations that increase anomalous northerly warm and wet air mass transport.