Editing IPCC:AR6/WGI/Chapter-11 (section)

==== 11.6.2.5 Atmospheric-based Drought Indices ====

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Globally, trends in SPEI-PM and PDSI-PM suggest slightly higher increases of drought frequency and severity in regions affected by drying over the last decades in comparison to the SPI ( [[#Dai--2017|Dai and Zhao, 2017]] ; [[#Spinoni--2019|Spinoni et al., 2019]] ; [[#Song--2020|Song et al., 2020]] ), mainly in regions of Western and Southern Africa, the Mediterranean and East Asia (Figure 11.17), which is consistent with observed soil moisture trends ( [[#11.6.2.3|Section 11.6.2.3]] ). These indices suggest that AED has contributed to increase the severity of agricultural and ecological droughts compared to meteorological droughts ( [[#García-Herrera--2019|García-Herrera et al., 2019]] ; [[#Williams--2020|Williams et al., 2020]] ), reduce soil moisture during the dry season ( [[#Padrón--2020|Padrón et al., 2020]] ), increase plant water stress ( [[#Allen--2015|Allen et al., 2015]] ; [[#Grossiord--2020|Grossiord et al., 2020]] ; [[#Solander--2020|Solander et al., 2020]] ) and trigger more severe forest fires ( [[#Abatzoglou--2016|Abatzoglou and Williams, 2016]] ; [[#Turco--2019|Turco et al., 2019]] ; [[#Nolan--2020|Nolan et al., 2020]] ). A number of regional studies based on these drought indices have also shown stronger drying trends in comparison to trends in precipitation-based indices in the following AR6 regions (see also [[#11.9|Section 11.9]] ): NSA (R. [[#Fu--2013|]] [[#Fu--2013|Fu et al., 2013]] ; [[#Marengo--2016|Marengo and Espinoza, 2016]] ), SCA ( [[#Hidalgo--2017|Hidalgo et al., 2017]] ), WCA ( [[#Tabari--2013|Tabari and Aghajanloo, 2013]] ; [[#Sharafati--2020|Sharafati et al., 2020]] ), SAS ( [[#Niranjan%20Kumar--2013|Niranjan Kumar et al., 2013]] ), NEAF ( [[#Zeleke--2017|Zeleke et al., 2017]] ), WSAF ( [[#Edossa--2016|Edossa et al., 2016]] ), NWN and NEN ( [[#Bonsal--2013|Bonsal et al., 2013]] ), EAS ( [[#Yu--2014|Yu et al., 2014]] ; [[#Chen--2015b|Chen and Sun, 2015b]] ; L. [[#Li--2020|]] [[#Li--2020|]] [[#Li--2020|Li et al., 2020]] ; [[#Liang--2020|Liang et al., 2020]] ; Z. [[#Wu--2020|]] [[#Wu--2020|Wu et al., 2020]] ) and MED ( [[#Kelley--2015|Kelley et al., 2015]] ; [[#Stagge--2017|Stagge et al., 2017]] ; [[#González-Hidalgo--2018|González-Hidalgo et al., 2018]] ; [[#Mathbout--2018a|Mathbout et al., 2018a]] ).

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