Characterization of wet and dry periods over southern South America

This study characterizes wet and dry conditions in southern South America, defined through the standardized precipitation evapotranspiration index (SPEI), considering short and long timescales. Prior to analysis, a regionalization was conducted considering the area’s diverse climatological regimes,...

Full description

Saved in:
Bibliographic Details
Published in:Climate dynamics 2024-06, Vol.62 (6), p.5701-5715
Main Authors: Pérez de Mendiola, María Eugenia, Blázquez, Josefina, Solman, Silvina Alicia
Format: Article
Language:English
Subjects:
Algorithms
Climatology
Cluster analysis
Clustering
Coherence
Drought
Dry periods
Earth and Environmental Science
Earth Sciences
Evapotranspiration
Evapotranspiration-precipitation relationships
Floods
Geophysics/Geodesy
Oceanography
Original Article
Precipitation
Principal components analysis
Spatial analysis
Temperature
Vector quantization
Wavelet analysis
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This study characterizes wet and dry conditions in southern South America, defined through the standardized precipitation evapotranspiration index (SPEI), considering short and long timescales. Prior to analysis, a regionalization was conducted considering the area’s diverse climatological regimes, employing a combination of the k-means clustering algorithm and principal component analysis. Dry and wet events were analyzed over six homogeneous regions, defined as wet or dry conditions with time and spatial coherence. Generally, smaller events ( 50% of a region) occurred less frequently and varied in size over time. Event intensity varied, with no prolonged preference for a specific intensity. Certain regions, notably southern Bolivia and northwestern Argentina showed a discernible tendency towards drier conditions over time, with wet events becoming more intense despite reduced coverage. The events defined with shorter SPEI timescales showed similar behavior to those defined with longer SPEI timescales but with higher month-to-month variability and less spatial coherence. A wavelet analysis revealed punctual, significant periods on the interannual timescale and more persistent ones on the interdecadal and decadal timescales. Mechanisms associated with event behavior were analyzed. Characterizing events in terms of their intensity, duration, and spatial extent revealed that moderate events were predominantly short (
ISSN:0930-7575
1432-0894
DOI:10.1007/s00382-024-07217-y