George Mason University, Fairfax, VA, USA.
Center for Ocean-Land-Atmosphere Studies, George Mason University, Fairfax, VA, USA.
Nat Commun. 2023 Mar 1;14(1):1162. doi: 10.1038/s41467-023-36794-5.
When soil moisture (SM) content falls within a transitional regime between dry and wet conditions, it controls evaporation, affecting atmospheric heat and humidity. Accordingly, different SM regimes correspond to different gears of land-atmosphere coupling, affecting climate. Determining patterns of SM regimes and their future evolution is imperative. Here, we examine global SM regime distributions from ten climate models. Under increasing CO, the range of SM extends into unprecedented coupling regimes in many locations. Solely wet regime areas decline globally by 15.9%, while transitional regimes emerge in currently humid areas of the tropics and high latitudes. Many semiarid regions spend more days in the transitional regime and fewer in the dry regime. These imply that a larger fraction of the world will evolve to experience multiple gears of land-atmosphere coupling, with the strongly coupled transitional regime expanding the most. This could amplify future climate sensitivity to land-atmosphere feedbacks and land management.
当土壤湿度 (SM) 含量处于干燥和湿润条件之间的过渡状态时，它会控制蒸发，影响大气的热量和湿度。因此，不同的 SM 状态对应着不同的陆地-大气耦合阶段，从而影响气候。确定 SM 状态的模式及其未来的演变是至关重要的。在这里，我们从十个气候模型中研究了全球 SM 状态的分布。在 CO 增加的情况下，SM 的范围扩展到了许多地方以前未出现过的耦合状态。仅湿润状态的地区在全球范围内减少了 15.9%，而过渡状态则出现在热带和高纬度地区目前湿润的地区。许多半干旱地区处于过渡状态的天数更多，处于干燥状态的天数更少。这意味着世界上更多的地区将经历多个阶段的陆地-大气耦合，其中强烈耦合的过渡状态扩展得最多。这可能会放大未来气候对陆地-大气反馈和土地管理的敏感性。
