Aerosol Particle Measurements and Cloud Properties During the Southern Ocean Clouds (SOC) Campaign in November and December 2024

LEAH WILLIAMS, James Allan, Michael Flynn, David Beddows, James Brean, Simone Louw, Irina Gorodetskaya, Timothy Onasch, Stephen Jones, Mark Tarn, Imogen Wadlow, Nina Kinney, Manuel Dall’Osto, Amélie Kirchgaessner, Thomas Lachlan-Cope, Aerodyne Research, Inc.

     Abstract Number: 530
     Working Group: Aerosols, Clouds and Climate

Abstract
We deployed an Aerosol Mass Spectrometer (AMS) on the British Antarctic Survey Research Vessel Sir David Attenborough (SDA) during November and December 2024 as part of the Southern Ocean Clouds (SOC) campaign. The AMS measures sub 1 micron aerosol particle chemical composition and size distributions, using thermal vaporization and electron impact ionization, followed by time-of-flight mass spectrometry.

The cruise track covered a broad area (50 S to 67 S and 70 W to 25 W) and encountered a variety of atmospheric environments, including seasonal sea ice zones, open ocean, and areas near islands with penguin colonies and volcanoes. Different ratios of organics, sulphate, methane sulphonic acid (MSA) and ammonium were observed and associated with distinct aerosol size distributions. The results will be discussed in the context of different air mass sources, varying gas-phase concentrations of aerosol precursors and real-time cloud property measurements.