CMIP6 Model-projected Hydroclimatic and Drought Changes and Their Causes in the 21st Century
CMIP6 Model-projected Hydroclimatic and Drought Changes and Their Causes in the 21st Century
复制标题
CMIP6模型预测的21世纪水文气候和干旱变化及其原因
DOI：
10.1175/jcli-d-21-0442.1
复制
发表时间：
2021
影响因子：
4.9
通讯作者：
Dai, Aiguo
中科院分区：
文献类型：
--
作者：
Zhao, Tianbao;Dai, Aiguo
随着全球变暖在世纪的继续，预计干旱将变得更加严重和广泛，但耦合模式相互比较项目第六阶段的最新预测没有很好地审查水文气候变化及其驱动因素。在这里，降水（P），蒸散（E），土壤水分（SM），径流（R）从25个CMIP 6模式，以及自校准的帕尔默干旱严重程度指数与彭曼-蒙特斯潜在蒸散（scPDSIpm），分析量化水文气候和干旱变化在21世纪和潜在的原因。结果确认一致干燥在这些水文气候指标在大多数美洲（包括亚马逊），欧洲和地中海地区，南部非洲和澳大利亚，虽然干燥程度不同，干燥更严重，更广泛的表面SM比总SM。基于地表SM和scPDSIpm的全球干旱频率增加了25%-100% 21世纪世纪，SSP 2 -4.5（SSP 5 -8.5）情景下，干旱持续时间和干旱面积显著增加（50%-200%），这是由于SM和scPDSIpm概率分布函数均值减小和平坦化所致，而基于R的干旱变化相对较小。在亚热带地区，SM和E的变化都有贡献，而scPDSIpm的降低则是由于普遍存在的PET增加和P降低。R的变化主要由P的变化决定，而PET的变化解释了E的大部分增加。在地面SM和R变化的模型间传播很大，导致干旱projects.Significance StatementDrought大的不确定性可能会变得更加严重和广泛的温室气体（GHG）引起的全球变暖下，在21世纪世纪模型预测的基础上。然而，在预测的未来干旱变化方面仍然存在很大的不确定性，特别是干旱变化在多大程度上取决于干旱指数和所分析的未来排放情景。CMIP 6模型的最新预测再次证实，在21世纪的中高排放情景下，美洲大部分地区（包括亚马逊）、欧洲和地中海地区、南部非洲、东南亚和澳大利亚的大范围干旱和农业干旱增加高达200%，尽管个别预测存在很大的不确定性，部分原因是内部变化。在许多亚热带地区，气温上升和降水减少导致大气对水分的需求普遍增加，这是预计干燥和干旱增加的主要驱动力。
Drought is projected to become more severe and widespread as global warming continues in the twenty-first century, but hydroclimatic changes and their drivers are not well examined in the latest projections from phase 6 of the Coupled Model Intercomparison Project (CMIP6). Here, precipitation (P), evapotranspiration (E), soil moisture (SM), and runoff (R) from 25 CMIP6 models, together with self-calibrated Palmer drought severity index with Penman–Monteith potential evapotranspiration (scPDSIpm), are analyzed to quantify hydroclimatic and drought changes in the twenty-first century and the underlying causes. Results confirm consistent drying in these hydroclimatic metrics across most of the Americas (including the Amazon), Europe and the Mediterranean region, southern Africa, and Australia, although the drying magnitude differs, with the drying being more severe and widespread in surface SM than in total SM. Global drought frequency based on surface SM and scPDSIpm increases by ∼25%–100% (50%–200%) under the SSP2-4.5 (SSP5-8.5) scenario in the twenty-first century together with large increases in drought duration and areas, which result from a decrease in the mean and flattening of the probability distribution functions of SM and scPDSIpm, while theR-based drought changes are relatively small. Changes in bothPandEcontribute to the SM change, whereas scPDSIpm decreases result from ubiquitous PET increases andPdecreases over subtropical areas. TheRchanges are determined primarily byPchanges, while the PET change explains most of theEincrease. Intermodel spreads in surface SM andRchanges are large, leading to large uncertainties in the drought projections.SIGNIFICANCE STATEMENTDrought may become more severe and widespread under greenhouse gas (GHG)-induced global warming in the twenty-first century based on model projections. However, there are still large uncertainties in projected future drought changes, especially regarding the extent to which drought changes depend on drought indices and the future emissions scenarios analyzed. The latest projections from CMIP6 models reaffirm the widespread drying and increases in agricultural drought by up to 200% over most of the Americas (including the Amazon), Europe and the Mediterranean region, southern Africa, Southeast Asia, and Australia under moderate-to-high emissions scenarios in the twenty-first century, despite large uncertainties in individual projections partly due to internal variability. Ubiquitous increases in atmospheric demand for moisture under rising temperatures and precipitation decreases over many subtropical regions are the main driver of the projected drying and drought increases.
影响因子：
3.6
作者：
Ziehn, Tilo;Chamberlain, Matthew A.;Srbinovsky, Jhan
通讯作者：
Srbinovsky, Jhan
影响因子：
4.4
作者：
Morice, C. P.;Kennedy, J. J.;Simpson, I. R.
通讯作者：
Simpson, I. R.