Major Differences in Regional Climate Impact Between High- and Low-Latitude Volcanic Eruptions

Major low-latitude volcanic eruptions cool Earth’s climate, and can lead to a positive phase of the North Atlantic Oscillation (NAO) during winter. However, the question of the climate and circulation impact of Northern Hemisphere high-latitude eruptions has received less attention. Here we show that, contrary to low-latitude eruptions, the response to high-latitude eruptions can be associated with negative NAO both winter and summer. We furthermore demonstrate that also the response to low-latitude eruptions prevails during summer months, and corroborates previous findings of an extended impact on winter circulation lasting up to 5 years. Our analysis of novel climate field reconstructions supports this extended response, with the addition of showing a positive NAO during summer after low-latitude eruptions. The differences in the effect of high- and low-latitude eruptions on atmospheric circulation and regional temperature provide important insights for the understanding of past and future climate changes in response to volcanic forcing.