Vertical Profiles Of Aerosol Properties Over The Western North Atlantic Ocean During The North Atlantic Aerosols And Marine Ecosystems Study (NAAMES)

The North Atlantic Aerosols and Marine Ecosystems Study (NAAMES) was deployed by NASA in the western subarctic Atlantic between the years 2015 and 2018. One of the primary goals of NAAMES was to improve the understanding of aerosol-cloud-climate interactions over the Atlantic Ocean, under different seasonal regimes, which currently represent the highest source of uncertainty in global climate models. During three NAAMES field campaigns (NAAMES-1 November 2015, NAAMES-2 May 2016, and NAAMES-3 September 2017) multiple 10-h science flights were conducted using the NAAMES C-130 aircraft to provide data on marine boundary layer aerosol and cloud properties and characterize the vertical structure of the atmosphere. The standard flight pattern included vertical spirals where the C-130 transitioned from high altitude to low-latitude (and vice versa) and collected in-situ measurements of aerosol, trace gases, clouds, and meteorological parameters as a function of altitude. In this study, we examine aerosols and clouds datasets collected from 37 spirals during the three NAAMES field campaigns under varying conditions, and we present a comprehensive characterization of the vertical profiles of aerosol properties. Submicron aerosol number concentrations showed strong seasonal variations exhibiting the highest concentrations during late summer (NAAMES-3) and the lowest in the winter (NAAMES-1). These variations are driven by different marine biogenic emissions, long-range transported continental emission, and aerosol controlling processes in the marine boundary layer and free troposphere. Summary statistics of the remote marine atmosphere prevalence of new particle formation and the competing influences of long-range transport versus local boundary layer aerosols will be discussed.