Trends in drought indices on the tropical-subtropical region and its correlation with the global warming

The Tropical-Subtropical region of the Earth is home to the main watersheds, sources of water and food on the planet. It is the domain of the Hadley’s global convective circulation, affected by major changes in its vertical movements of the air, resulting in the generation of cloudiness, precipitati...

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Detalles Bibliográficos
Autores: Minetti, Juan Leonidas, Ovejero, Dario Pedro, Vargas, Walter Mario
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/162250
Acceso en línea:http://hdl.handle.net/11336/162250
Access Level:acceso abierto
Palabra clave:REGIONAL INDEX OF DROUGHTS
TELECONNECTIONS
GLOBAL WARMING
https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
Descripción
Sumario:The Tropical-Subtropical region of the Earth is home to the main watersheds, sources of water and food on the planet. It is the domain of the Hadley’s global convective circulation, affected by major changes in its vertical movements of the air, resulting in the generation of cloudiness, precipitation and drought. In the last decades, persistent droughts have been observed in the subtropical zone of the planet, particularly in Chile Central, South of Africa and Mediterranean Zone called Type K. Also in the instrumental period it was possible to observe two atmospheric warming processes with positive trends, which were later correlated to regional drought annual indices. This study shows the relationship between Global Warming and the drought indexes standing out: I) positive or increasing trends of drought indices in the Subtropics, and II) decreasing negative trends in Ecuador and monsoonal zone. Also, in parts of the Subtropics there are two distinct periods, one with frequent droughts in the first half of the last century, and a second with excessive rainfall in the second half of the 20th century. In the last ten years there have also been long drought processes that would be contributing to changes in the general trends. From the study it is concluded that the Global Warming would be contributing to the drying process of the subtropical regions in 25% of the regions analyzed, while 58% of the regions show a Type F oscillation that extends throughout the past century XX, end of the XIX century and beginning of the XXI.