Long term and interannual rainfall variability in Argentinean Chaco plain region

The Argentinean Chaco plain region has a relevant biodiversity and it has experienced an important increase in annual rainfall during the last century. However, there is evidence that some rainfall decrease has happened in some sub-regions since 1980; such decrease could be related to deforestation...

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Autores principales: González, M.H., Dominguez, D., Nuñez, M.N.
Formato: CHAP
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_97816208_v_n_p69_Gonzalez
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spelling todo:paper_97816208_v_n_p69_Gonzalez2023-10-03T16:44:27Z Long term and interannual rainfall variability in Argentinean Chaco plain region González, M.H. Dominguez, D. Nuñez, M.N. Atmospheric circulation pattern Chaco region Climatic change Rainfall trends Variability The Argentinean Chaco plain region has a relevant biodiversity and it has experienced an important increase in annual rainfall during the last century. However, there is evidence that some rainfall decrease has happened in some sub-regions since 1980; such decrease could be related to deforestation carried out in order to increase the farming area. In this paper rainfall variability was analyzed to better understand its behavior in scales greater than a year. There are indicators of a cycle of 22 years in the west of Chaco and other of 6,6 years in the east. The annual cycle is present all over the region and more pronounced towards the west. The interannual rainfall variability shows that there are three main rainfall anomaly leading patterns. The first is associated with the SST in the subtropical Atlantic Ocean, the second leading is related to ENSO and a high pressure system centered in central-southern Brazil and the third is associated with positive correlation in the west tropical and subtropical Pacific and with a wave train extended from the western Pacific Ocean towards South America. The results indicate that rainfall must be monitored in order to determine its future evolution and if deforestation has influenced the climate of the region. Likewise, the relation between climate and deforestation must be best studied in order to mitigate the negative impacts over the region. In order to describe a possible situation in the future some simulations are detailed. The regional model MM5 was nested within time slice global atmospheric model experiments conducted by the HadAM3H model. The simulations cover a 10-year period representing present-day climate (1981-1990) and two future scenarios for the SRESA2 and B2 emission scenarios for the period 2081-2090. Both the A2 and B2 simulations show a general increase in precipitation in northern and central Argentina especially in summer and fall and a general decrease in precipitation in winter and spring. © 2012 by Nova Science Publishers, Inc. All rights reserved. Fil:González, M.H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Nuñez, M.N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. CHAP info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_97816208_v_n_p69_Gonzalez
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Atmospheric circulation pattern
Chaco region
Climatic change
Rainfall trends
Variability
spellingShingle Atmospheric circulation pattern
Chaco region
Climatic change
Rainfall trends
Variability
González, M.H.
Dominguez, D.
Nuñez, M.N.
Long term and interannual rainfall variability in Argentinean Chaco plain region
topic_facet Atmospheric circulation pattern
Chaco region
Climatic change
Rainfall trends
Variability
description The Argentinean Chaco plain region has a relevant biodiversity and it has experienced an important increase in annual rainfall during the last century. However, there is evidence that some rainfall decrease has happened in some sub-regions since 1980; such decrease could be related to deforestation carried out in order to increase the farming area. In this paper rainfall variability was analyzed to better understand its behavior in scales greater than a year. There are indicators of a cycle of 22 years in the west of Chaco and other of 6,6 years in the east. The annual cycle is present all over the region and more pronounced towards the west. The interannual rainfall variability shows that there are three main rainfall anomaly leading patterns. The first is associated with the SST in the subtropical Atlantic Ocean, the second leading is related to ENSO and a high pressure system centered in central-southern Brazil and the third is associated with positive correlation in the west tropical and subtropical Pacific and with a wave train extended from the western Pacific Ocean towards South America. The results indicate that rainfall must be monitored in order to determine its future evolution and if deforestation has influenced the climate of the region. Likewise, the relation between climate and deforestation must be best studied in order to mitigate the negative impacts over the region. In order to describe a possible situation in the future some simulations are detailed. The regional model MM5 was nested within time slice global atmospheric model experiments conducted by the HadAM3H model. The simulations cover a 10-year period representing present-day climate (1981-1990) and two future scenarios for the SRESA2 and B2 emission scenarios for the period 2081-2090. Both the A2 and B2 simulations show a general increase in precipitation in northern and central Argentina especially in summer and fall and a general decrease in precipitation in winter and spring. © 2012 by Nova Science Publishers, Inc. All rights reserved.
format CHAP
author González, M.H.
Dominguez, D.
Nuñez, M.N.
author_facet González, M.H.
Dominguez, D.
Nuñez, M.N.
author_sort González, M.H.
title Long term and interannual rainfall variability in Argentinean Chaco plain region
title_short Long term and interannual rainfall variability in Argentinean Chaco plain region
title_full Long term and interannual rainfall variability in Argentinean Chaco plain region
title_fullStr Long term and interannual rainfall variability in Argentinean Chaco plain region
title_full_unstemmed Long term and interannual rainfall variability in Argentinean Chaco plain region
title_sort long term and interannual rainfall variability in argentinean chaco plain region
url http://hdl.handle.net/20.500.12110/paper_97816208_v_n_p69_Gonzalez
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