Drylands are highly vulnerable to climate change due to their fragile ecosystems and limited ability to adapt. In contrast to the global drying after tropical volcanic eruptions shown previously, we demonstrate that large tropical volcanic eruptions can induce significant two-year hydroclimatic wetting over drylands by employing the last millennium simulations. During this wetting period, which extends from the first to the third boreal winter after the eruption, several hydroclimatic indicators, such as self-calibrating Palmer Drought Severity Index based on the Penman-Monteith equation for potential evapotranspiration (scPDSIpm), standard precipitation evapotranspiration index (SPEI), aridity index (AI), top-10cm soil moisture (SM_10cm), and leaf area index (LAI), show significant positive anomalies over most drylands. The primary contribution to the wetting response is the potential evapotranspiration (PET) reduction resulting from dryland surface cooling and reduced solar radiation, as well as a weak contribution from increased precipitation. The latter is due to the wind convergence into drylands caused by slower tropical cooling compared to drylands. The wetting response of drylands to volcanic eruptions also demonstrates some benefits over the global hydrological slowdown resulting from stratospheric aerosol injection, which replicates the cooling effects of volcanic eruptions to address global warming.

由于生态系统脆弱且适应能力有限，旱地极易受到气候变化的影响。与之前显示的热带火山喷发后的全球干旱相反，我们通过使用上个千年的模拟证明，大型热带火山喷发可以在旱地引起显着的两年水文气候湿润。在这个从喷发后第一个到第三个北方冬季的湿润时期，一些水文气候指标，例如基于彭曼-蒙特斯潜在蒸散量方程（scPDSIpm）的自校准帕尔默干旱严重度指数、标准降水蒸散指数(SPEI)、干旱指数(AI)、顶部10厘米土壤湿度(SM _10cm )和叶面积指数(LAI)在大多数旱地显示出显着的正异常。对润湿响应的主要贡献是由于旱地表面冷却和太阳辐射减少而导致的潜在蒸散量（PET）减少，以及降水增加的微弱贡献。后者是由于与旱地相比热带降温速度较慢而导致风汇聚到旱地。旱地对火山喷发的湿润反应也表明，相对于平流层气溶胶注入导致的全球水文减缓有一些好处，平流层气溶胶注入复制了火山喷发的冷却效应，以解决全球变暖问题。