Analysis of Precipitation Characteristics in Marine Boundary Layer Cellular Convective Clouds in the Eastern North Atlantic

Marine boundary layer clouds are poorly represented in today's climate models, despite their strong impacts on the global energy budget. By investigating the different cloud behaviors and variability, we can better understand their lifecycle with the goal of improving their representation in climate models. This study focuses on the precipitation properties of open and closed cellular marine boundary layer clouds in the Eastern North Atlantic (ENA). Marine boundary layer clouds often exhibit organization on horizontal scales of 5-100km. Open cell clouds are composed of rings of narrow cumulus clouds with broad clearing in between, and closed cell clouds are composed of thick centers of stratiform clouds with narrowing or clearing on the edges. We explore the variability in precipitation characteristics (e.g., rain rate and drop size distribution) of these cloud types over a two-year period using disdrometer observations from the Atmospheric Radiation Measurement facility on Graciosa Island, Azores. The closed cell clouds were found to have properties of smaller drop sizes and lower rain rate than open cell clouds, which had larger drop sizes and higher rain rates, but for shorter periods of time. These findings bring with them a deeper understanding of ENA clouds and raise more questions about the differences between open and closed cell clouds and their behavior.