In this work, we projected future drought risks over East Asia from the perspective of evapotranspiration (ET) deficit using the new climate projections of the Coupled Model Intercomparison Project Phase 6 (CMIP6). For the regional drought projections, we employed a state-of-the-art complementary relationship (CR) method to estimate ET and atmospheric evaporative demand (E_p) that quantify the combined impact of water deficiency and vapor pressure deficit stress. The performance of the CR method was validated using the reanalysis climate data and independent water-balance ET estimates. The same CR method was again applied to hindcasts and projections of seven global climate models (GCM) in the CMIP6 archive. Results showed that the CR ET estimates and the GCM-driven ET products were both able to approximately close the basin-scale water balance and tightly correlated with each other. The application with the CMIP6 GCM hindcasts provided the same indication that the CR ET and the GCM-driven ET are consistent. The drought assessments using the ET deficit (ET − E_p) from the CMIP6 projections implicates that future drought risks over East Asia would be much higher than indicated by precipitation or soil moisture projections. Rising trends of E_p are expected to outpace those of ET even under the medium-level greenhouse gas emission scenario. Our new drought projections suggest that E_p amplified by soil water deficiency could raise agricultural and wildfire risks substantially by the end of the 21st century.

中文翻译：

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使用来自 CMIP6 变暖情景的蒸散赤字对东亚新的干旱预测

在这项工作中，我们使用耦合模型比对项目第 6 阶段 (CMIP6) 的新气候预测，从蒸散量 (ET) 赤字的角度预测了东亚未来的干旱风险。对于区域干旱预测，我们采用了最先进的互补关系 (CR) 方法来估计 ET 和大气蒸发需求 ( E _p) 量化缺水和蒸气压不足压力的综合影响。使用再分析气候数据和独立的水平衡 ET 估计值验证了 CR 方法的性能。相同的 CR 方法再次应用于 CMIP6 档案中七个全球气候模型 (GCM) 的后报和预测。结果表明，CR ET 估计和GCM 驱动的ET 产品都能够近似接近流域尺度的水平衡，并且彼此紧密相关。具有 CMIP6 GCM 后报的应用程序提供了相同的指示，即 CR ET 和 GCM 驱动的 ET 是一致的。使用 ET 赤字 (ET −  E _p) 来自 CMIP6 的预测意味着东亚未来的干旱风险将远高于降水或土壤水分预测所表明的。即使在中等水平的温室气体排放情景下，E _{p 的}上升趋势预计也将超过 ET 的上升趋势。我们新的干旱预测表明，到 21 世纪末，因土壤缺水而放大的E _p可能会大大增加农业和野火风险。