The experimental development and model implementation of a lake spray aerosol source function

Abstract:

Sea spray aerosols (SSAs), emitted from saltwater breaking waves, contribute to Earth’s radiative budget and chemical cycling in the atmosphere. Due to these impacts on climate system and air quality, SSA emissions were implemented in atmospheric chemical transport models (CTMs) and have received significant attention in the scientific community. In contrast, the study of lake spray aerosols (LSAs), emitted from freshwater breaking waves, is still an emerging research area. Moreover, current CTMs do not account for LSA emissions largely because they are overshadowed by SSA emissions on a global and continental scale. However, due to the potential impacts of LSAs on regional climate and their association with pathogenic emissions, their incorporation in mesoscale atmospheric models is worth investigating. Yet, the lack of an LSA source function is a major impediment to their inclusion in such models. For the first time, experiments in a wave breaking analogue tank are carried out to develop an LSA source function by coupling measurements of foam area and size-resolved spray aerosol emissions. This newly developed source function is then implemented in the Community Multiscale Air Quality (CMAQ) modeling system to simulate LSA emissions from the Great Lakes. The ensuing effects of the updated CMAQ model on regional aerosol loading are explored.