Severe compound drought-heatwave events were observed over three regions of the Contiguous United States (CONUS), Northwest (NW), Great Plains (GP), and Northeast (NE) regions, during July and August 2022. In this study, we have found that the developments of these drought-heatwave events were shaped by different land-atmosphere coupling behaviors which are associated with water and energy limitation regimes in these regions. In the NW and GP regions, the surface soil moisture (SM) and evapotranspiration (ET) were coupled through water-limited processes. Heatwaves in these two regions were affected by the decrease of ET and the available SM due to the precipitation deficit. This type of land-atmosphere coupling was especially prominent in the GP. In the NE region, the heatwave governed ET through the increase of potential ET (PET) based on energy-limited coupling, which played a crucial role in the development of drought.

中文翻译：

---

陆地-大气耦合对 2022 年 CONUS 复合干旱-热浪事件的贡献及其对预报的意义


2022 年 7 月和 8 月，在美国本土 （CONUS）、西北 （NW）、大平原 （GP） 和东北部 （NE） 地区的三个地区观察到严重的复合干旱-热浪事件。在这项研究中，我们发现这些干旱-热浪事件的发展是由不同的陆地-大气耦合行为塑造的，这些耦合行为与这些地区的水和能源限制机制有关。在 NW 和 GP 地区，表层土壤水分 （SM） 和蒸散 （ET） 通过限水过程耦合。由于降水不足，这两个地区的热浪受到 ET 和有效 SM 减少的影响。这种类型的陆地-大气耦合在 GP 中尤为突出。在 NE 地区，热浪通过基于能量限制耦合的电位 ET （PET） 的增加来控制 ET，这在干旱的发展中起了至关重要的作用。