Two years of aerosol and cloud observations from the Antarctic Peninsula.

Clouds over the Southern Ocean and Antarctica are poorly represented within climate models. It is thought that our poor understanding of aerosol-cloud interaction at these latitudes could play a major role in biasing models towards consistently underpredicting cloud formation in these regions. Unfortunately, there are few studies of aerosols and their impact on clouds at high southern latitudes and those that do exist concentrate on the summer period. Here we present two years of observations from Rothera Station on the Antarctic Peninsula. The East Beach Hut clean air facility at Rothera Station has a comprehensive set of online aerosol instruments measuring size, composition, and the capacity to act as a Cloud Condensation Nuclei (CCN) in addition to offline filter samplers from which the concentration of Ice Nucleating Particle (INP) can be derived. Measurements of the aerosol precursor gas, dimethly sulphide are also available in addition to a micropulse LiDAR to give information on cloud properties. The object of these measurements is to identify the composition and source of the cloud nuclei active at high latitudes so they can be correctly incorporated within climate models through new or revised parameterisations. Here we report on the first two years of measurements and identify the correlation between chemical composition, biological activity and cloud nuclei activation.. We will present a comparison of aerosol and cloud nuclei during the Antarctic Summer and Winter of 2021-2023, offering an initial assessment of the different sources of CCN and INP observed during these periods.