Global surface-temperature responses to major volcanic eruptions

The impacts of pollution resulting from large explosive volcanic eruptions on the atmospheric heat budget and planetary albedo are not in doubt. However, the effects of volcanic aerosols on the surface climate are less clear and still controversial. In a previous study it was shown that significant surface cooling occurs over the landmasses of the Northern Hemisphere in the first few months after a major eruption in that hemisphere. Here we extend that work using new surface-air temperature compilations based on land and marine data for both the Northern and Southern Hemispheres. Our results indicate that major Northern Hemisphere average surface temperature but little or no effect on the Southern Hemisphere average.Southern Hemisphere eruptions affect both Southern and Northern Hemisphere temperatures after a lag of between six months and a year.