South–north heterogeneity of the effect of volcanic eruptions on dryness/wetness in Central and Eastern China

Abstract

AbstractVolcanic eruptions are an important driver for climate changes. However, the response of climate to volcanic eruptions sometimes varies from region to region. Although some studies reported that volcanic eruptions induced drought in Eastern China, the others argued that there is a possibility of wetter condition after volcanic eruptions in Eastern China. Until now, the response of dryness/wetness changes in this region to volcanic eruptions is controversial. Based on the dryness/wetness indexes from 100 sites in Central and Eastern China (CEC) over the past 500 years (1470–1999), the effects of volcanic eruptions occurred in the northern mid‐high latitudes (17 events) and the tropics (19 events) on dryness/wetness changes in CEC were analysed. Our results show that the significant response of dryness/wetness changes in CEC to volcanic eruptions occurred in the third or fourth year after the eruptions. Moreover, there is a significant north–south heterogeneity of the response of dryness/wetness changes in CEC to volcanic eruptions. Specifically, the response of dryness/wetness changes in northern CEC to volcanic eruptions is generally more sensitive than that in southern CEC. A persistent drying during the first to the fourth years post the volcanic events occurred in the northern mid‐high latitudes was found in north CEC, but not in south CEC. After the tropical volcanic events, there is a generally wetting in CEC, but it is stronger in north CEC than in south CEC. These results imply that, to some extent, volcanic eruptions occurred in the northern mid‐high latitudes may amplify dryness in north CEC, but may mitigate wetness in south CEC, while tropical volcanic eruptions may mitigate dryness in north CEC and amplify wetness in south CEC.