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Global pattern of short‐term concurrent hot and dry extremes and its relationship to large‐scale climate indices
Author(s) -
Zhang Haoyue,
Wu Chuanhao,
Yeh Pat J.F.,
Hu Bill X.
Publication year - 2020
Publication title -
international journal of climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.58
H-Index - 166
eISSN - 1097-0088
pISSN - 0899-8418
DOI - 10.1002/joc.6555
Subject(s) - climatology , environmental science , precipitation , pacific decadal oscillation , evapotranspiration , equator , northern hemisphere , latitude , surface air temperature , climate change , atmospheric sciences , teleconnection , el niño southern oscillation , geography , geology , meteorology , ecology , oceanography , geodesy , biology
Abstract The short‐term concurrent hot and dry extreme (SCHDE) event has recently stimulated intensive scientific interests due to its rapid onset, severe intensity, and devastating impacts on agriculture and natural ecosystems. The SCHDE is mainly caused by an increase in actual evapotranspiration (ET) accompanied with a decrease in soil moisture (SM) due to anomalously high surface temperature ( T air ). Based on the daily datasets of precipitation ( P ), T air , ET, and SM from four global modelling products as well as large‐scale climate indices, we analyse globally the spatio‐temporal evolution of SCHDE events at both grid and basin scales. Results indicate that SCHDE events occur mostly in Northern Hemisphere regions with relatively low P . During 1980–2010, due to significant global warming (0.30°C·decade −1 ) the global mean occurrence frequency of SCHDE has an increasing trend (0.34%·decade −1 ) along with a weakly decreasing trend of SM (~−0.08%·decade −1 ) and a significantly increasing trend of ET (~8.34 mm·decade −1 ). Overall, North America and Asia have a higher frequency of SCHDE occurrence than other continents. The variability of T air is mainly responsible for the variability of SCHDE occurrence over the equator regions, while the variability of ET (SM) plays an important role in SCHDE occurrence variability in the cropland‐dominant (mid‐ and high‐latitude) regions. Globally, the relative contribution of T air to SCHDE variability is the largest, followed by ET and SM. Lastly, we found that the cold phases of the Pacific Decadal Oscillation during the La Niña events (i.e., negative Multivariate ENSO Index) are conducive to the intensification of SCHDE events in southern South America and Australia.