TITLE:
Future Changes in Drought Characteristics over Southern South America Projected by a CMIP5 Multi-Model Ensemble
AUTHORS:
Olga C. Penalba, Juan A. Rivera
KEYWORDS:
CMIP5 Models; Drought; Standardized Precipitation Index; Climate Change; Southern South America
JOURNAL NAME:
American Journal of Climate Change,
Vol.2 No.3,
September
26,
2013
ABSTRACT: The impact of climate change on drought main characteristics was
assessed over Southern South America. This was done through the precipitation
outputs from a multi-model ensemble of 15 climate models of the Coupled Model
Intercomparison Project Phase 5 (CMIP5). The Standardized Precipitation Index
was used as a drought indicator, given its temporal flexibility and simplicity.
Changes in drought characteristics were identified by the difference for early
(2011-2040) and late (2071-2100) 21st century values with respect to the
1979-2008 baseline. In order to evaluate the multi-model outputs, model biases
were identified through a comparison with the drought characteristics from the
Global Precipitation Climatology Centre database for the baseline period.
Future climate projections under moderate and high-emission scenarios showed
that the occurrence of short-term and long-term droughts will be more frequent
in the 21st century, with shorter durations and greater severities over much of
the study area. These changes in drought characteristics are independent on the
scenario considered, since no significant differences were observed on drought
changes. The future changes scenario might be even more dramatic, taking into
account that in most of the region the multi-model ensemble tends to produce
less number of droughts, with higher duration and lower severity. Therefore,
drought contingency plans should take these results into account in order to
alleviate future water shortages that can have significant economic losses in
the agricultural and water resources sectors of Southern South America.