Speaker
Description
Cosmogenic $^{10}$Be isotope is an important proxy for past solar activity that can be measured from natural archives such as ice cores. It is mostly produced in the stratosphere and its atmospheric lifetime until the deposition to the surface depends on different transport processes. Notably, $^{10}$Be isotopes may attach to aerosol particles, where these are abundant, and subsequently follow their trajectories, leading to stronger sedimentation. This effect would yet be massively increased by strong volcanic eruptions, which has been proposed as a major complication in the interpretation of $^{10}$Be proxy records. In our study, we test this hypothesis by employing the state-of-the-art aerosol-chemistry-climate model SOCOL-AERv2-Be that has a full $^{10}$Be atmospheric cycle, in- cluding its attachment to aerosol particles. We isolate the effects of sedimentation by comparing simulations with and without it for the $^{10}$Be tracer. In these simulations we examine the long-term climatological effects of a background aerosol layer on the $^{10}$Be distribution in the atmosphere and the resulting deposition maps. In another set of simulations we specifically focus on the influence of the enhanced stratospheric aerosol layer after volcanic events. The results are compared with ice core data from polar stations.