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Variability of soil moisture proxies and hot days across the climate regimes of Australia
Author(s) -
Holmes A.,
Rüdiger C.,
Mueller B.,
Hirschi M.,
Tapper N.
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl073793
Subject(s) - dryness , environmental science , water content , precipitation , moisture , arid , climatology , aridity index , climate change , temperate climate , atmospheric sciences , geology , geography , ecology , meteorology , medicine , paleontology , oceanography , geotechnical engineering , surgery , biology
The frequency of extreme events such as heat waves are expected to increase due to the effect of climate change, particularly in semiarid regions of Australia. Recent studies have indicated a link between soil moisture deficits and heat extremes, focusing on the coupling between the two. This study investigates the relationship between the number of hot days (Tx90) and four soil moisture proxies (Standardized Precipitation Index, Antecedent Precipitation Index, Mount's Soil Dryness Index, and Keetch‐Byram Drought Index), and how the strength of this relationship changes across various climate regimes within Australia. A strong anticorrelation between Tx90 and each moisture index is found, particularly for tropical savannas and temperate regions. However, the magnitude of the increase in Tx90 with decreasing moisture is strongest in semiarid and arid regions. It is also shown that the Tx90‐soil moisture relationship strengthens during the El Niño phases of El Niño–Southern Oscillation in regions which are more sensitive to changes in soil moisture.