Potential influences of volcanic eruptions on future global land monsoon precipitation changes

Major volcanic eruptions strongly influence global land monsoon (GLM) precipitation change. By using 60 plausible eruption scenarios sampled from reconstructed volcanic proxies over the past 2,500 years, 21st century volcanic influences on GLM precipitation projections are examined with an Earth system model under a moderate emission scenario.

The decadal-scale ensemble spread with realistic eruptions (VOLC) increases by 17.5% and 20.1% compared to no-volcanic (NO-VOLC) and constant background-volcanic (VOLC-CONST) scenarios, respectively. Compared with NO-VOLC, the centennial mean VOLC GLM precipitation shows a 10% overall reduction and regionally, Asia is the most impacted. Changes in atmospheric circulation in the aftermath of large volcanic eruptions match the global warming response patterns well with opposite sign, with the North American monsoon precipitation enhanced following large volcanic eruptions, which is in sharp contrast to the robust decrease in Asian monsoon rainfall.