ACEENAWINTERAPASI

ACE-ENA Winter IOP: Aerodynamic Particle Sizer

11 January 2018 - 25 February 2018

Lead Scientist: Mikhail Pekour

Observatory: ENA

The Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA) focused on low clouds and processes that affect cloud properties and their life cycle. One of the key factors in cloud formation is atmospheric aerosol; accurate particle size distribution data is essential for understanding impacts of aerosol properties on the cloud life cycle. While the standard suit of instruments deployed at the ARM ground site (Eastern North Atlantic, ENA) can measure particle sizes between 2.5 nm and 1 um (using the Scanning Mobility Particle Sizer, SMPS and the Ultra-High Sensitivity Aerosol Spectrometer, UHSAS), there is still a need to measure larger particles. In marine environments such as Azores, these larger particles are commonly associated with sea salt aerosol; however, due to geographical location of the Azores one should expect that the aerosol population there be influenced by long range-transport of dust as well. While large particles such as these do not contribute substantially to the particle number, they do make a substantial contribution to particle mass, to number concentration of cloud condensation nuclei, and strongly affect radiative properties of the aerosol. To fill this gap in particle measurements, scientists proposed to deploy a Pacific Northwest National Laboratory (PNNL) Aerodynamic Particle Sizer (APS) during the ACE-ENA winter intensive operational period to measure particles from 0.5 um to approximately 20 um in diameter. The ARM Aerial Facility G-1 aircraft operations were covered by the ACE-ENA experiment in January to February 2018.