Wetter Global Arid Regions Driven by Volcanic Eruptions

Abstract

AbstractArid regions are among the most sensitive areas to climate change; a better understanding of the impact of volcanic eruptions on the hydroclimate over global arid regions is helpful for adaptation but is not well studied. Here we show evidences that arid regions exhibit a wetter condition after volcanic eruptions based on reconstructions and observations, especially for volcanoes located in the Northern hemisphere and tropics. Such “dry gets wetter” response is further supported by climate model simulations driven by volcanic aerosol forcing. The dynamic processes related to changes in atmospheric circulation are found to play a dominant role in precipitation responses. The wetter condition over northern hemispheric (southern hemispheric) (NH (SH)) arid regions after southern (northern) hemispheric volcanic eruptions is caused by enhanced cross‐equator flow, while the increased precipitation over global arid regions and NH (SH) arid regions following tropical volcanic eruptions and northern (southern) eruptions, respectively, are mainly controlled by the monsoon‐desert coupling mechanism. The response of the extreme precipitation is consistent with that of the mean precipitation but more sensitive on a regional scale. The results indicate that volcanic eruptions at different latitudes should be considered in the design of near‐term decadal climate prediction experiments and the implementation of geoengineering activities.