The 2022 Hunga eruption caused unprecedented stratospheric hydration. Aura Microwave Limb Sounder (MLS) measurements show that the stratospheric water vapor mass remains essentially unchanged as of early 2024 and that the Hunga hydration occurred atop a robust (possibly accelerating) moistening trend in the stratosphere. Enhanced by the excess Hunga water vapor, dehydration via polar stratospheric cloud sedimentation in the 2023 Antarctic vortex exceeded climatological values by $\sim$50%. Simple projections based on modeled exponential decay illustrate that the timing of the return to humidity levels that would have been expected absent the Hunga hydration depends on the ongoing stratospheric water vapor trend. With the Hunga hydration compounding an underlying moistening trend, the stratosphere could remain anomalously humid for an extended period.

中文翻译：

---

湿润平流层中洪加水合作用的演变


2022 年洪加火山喷发造成了前所未有的平流层水合作用。 Aura 微波临边探测器 (MLS) 测量显示，截至 2024 年初，平流层水蒸气质量基本保持不变，并且洪加水合作用发生在平流层强劲（可能加速）的湿润趋势之上。由于洪加水蒸气过多，2023 年南极涡旋极地平流层云沉积造成的脱水超过了气候学值$～$ 50%。基于模型指数衰减的简单预测表明，在没有洪加水合作用的情况下，恢复到预期湿度水平的时间取决于正在进行的平流层水蒸气趋势。由于洪加水合作用加剧了潜在的湿润趋势，平流层可能会在较长时间内保持异常潮湿。