From the Arctic to Antarctica: Observations of vertical aerosol distribution from tethered balloon measurements

Vertical profile measurements of aerosol properties in the lower atmosphere still constitute a major observational gap. Focusing on the polar regions, where the planetary boundary layer often forms temperature inversions that inhibit vertical mixing of the lowermost atmosphere, surface measure-ments can often not represent aerosol properties further aloft. However, understanding vertical aerosol distribution is critical for several reasons. From a climate perspective, in the Arctic and Antarctic, cloud formation is often sensitive to aerosol availability. Because clouds strongly influence the surface radiation budget and primarily exert warming, it is important to understand aerosols at cloud level.

Overall, understanding the thermodynamic structure of the lower atmosphere and the dynamics of vertical mixing is critical to answer questions on cloud formation. In situ measurements that describe the (thermo)dynamic, aerosol and cloud variables are indispensible to understand relevant process mechanisms and to improve models that typically struggle to simulate polar lower atmospheric aerosols. 

Here we present results obtained with the Modular Multiplatform Compatible Air Measure-ment System (MoMuCAMS). MoMuCAMS can observe particle number size distributions (8-3000 nm) and overall concentrations, aerosol absorption, cloud droplet size distributions, and trace gas mixing ratios (CO₂, CO, O₃). Based on filter measurements, aerosol chemical composition and INP number concentrations can be obtained. Wind speed and direction, as well as temperature and relative humidity and video images are recorded.

We deployed MoMuCAMS up to 800 m with a payload of ~20 kg in Fairbanks, Alaska (Jan-Feb 2022), Pallas, Finland (Sep-Oct 2022), the Arctic Ocean (May-Jun 2023), southern Greenland (Jun-Aug 2023), and at Neumayer, Antarctica (Dec 2024 – Feb 2025). Overall, more than 350 profiles were flown. This contribution synthesizes observations of aerosol properties below, in and above clouds, and vertically resolved contributions of local and long-range transported particles.