Factors controlling marine aerosol size distributions and their climate effects over the northwest Atlantic Ocean region

摘要: Abstract. Aerosols over Earth's remote and spatially extensive ocean surfaces have important influences on planetary climate. However, these aerosols their effects remain poorly understood, in part due to the remoteness limited observations regions. In this study, we seek understand factors that shape marine aerosol size distributions composition Northwest Atlantic Ocean region. We use GEOS-Chem-TOMAS model interpret measurements collected from ship aircraft during four seasonal campaigns of North Marine Ecosystems Study (NAAMES) conducted between 2015 2018. Observations NAAMES show enhancements total number concentration at atmospheric altitudes about 1 km, most pronounced phytoplankton bloom maxima (May/June). Our simulations, combined with measurements, suggest several key contribute lower troposphere, significant regional-mean (40–60° N, 20–50° W) aerosol-cloud albedo indirect (AIE) direct radiative (DRE) bloom. These associated region are: (1) particle formation above/near boundary layer (MBL) top (AIE: −3.37 W m−2, DRE: −0.62 W m−2), (2) growth secondary organic (MSOA) as nascent particles subside into MBL, enabling them become cloud-condensation-nuclei-size −2.27 W m−2, −0.10 W m−2), (3) formation/growth products dimethyl sulfide, above/within MBL (−1.29 W m−2, −0.06 W m−2), (4) emissions −0.62 W m−2, −0.05 W m−2). results a synergy near by MSOA contributes strongly cloud-condensation-nuclei-sized regional Atlantic. Future work is needed sources temperature-dependence condensable vapors forming species can form new grow they descend layer.