Constraining the role of the marine sulfur cycle in the Earth System (CARES)

The marine sulfur cycle is a key biogeochemical process with significant climatic implications. Marine sulfate aerosol, produced from biogenic dimethyl sulfide (DMS), is a major natural aerosol component over many oceanic regions and serves as a baseline for assessing anthropogenic aerosol radiative forcing. However, recent discoveries of new sulfur molecules formed from DMS challenge current understanding of marine sulfur’s role in the climate system.

The CARES project will address these knowledge gaps by combining intensive aircraft and ship observations with multi-scale model experiments. Advancements in modeling, supported by new laboratory data, will enhance the understanding of both contemporary and historical sulfur and climate observations. This will lead to a significant revision in the understanding of the fate and impact of natural sulfur emissions. The findings will be used to correct inaccuracies in the representation of sulfur processes in Earth system models, refine the role of marine sulfur in the Earth system, and increase confidence in simulations that project future climate changes.