Investigating ice-nucleating particles in a sub-Arctic region
The Pallas Cloud Experiment (PaCE) is happening again after a three-year hiatus since 2019. Aimed at measuring clouds on and in the surrounding area of the Finnish Meteorological Institute (FMI) Pallas-Sodankylä Global Atmosphere Watch (GAW) Sammaltunturi station (Sammal) in Lapland, northern Finland, the PaCE campaign is featuring multiple mobile platforms. The main contribution of the IMK-AAF WG Möhler are two fixed-wing UAVs that collect aerosol on a filter to subsequently analyze the collected aerosols on their ice-nucleating ability with INSEKT. In addition, the aerosol size distribution is measured with the Universal Cloud and Aerosol Sounding System (UCASS, Smith et al. 2019), while the temperature, the relative humidity and the pressure are measured with two sensors.
During this campaign, a PINE (Portable Ice Nucleation Experiment; Möhler et al., 2021) is installed at Sammal for INP concentration measurements in the temperature range of -20 °C and -30 °C, relevant for the formation of mixed-phase clouds. So far, no continuous INP measurements with a high temporal resolution of minutes were conducted in the sub-Arctic region to observe seasonal variations due to e.g., biological activity, snow coverage, and changing air mass conditions. As the station is frequently inside clouds, and ambient temperatures in autumn and winter times are sub-zero, the present aerosol population is directly relevant for the formation of ice crystals in clouds.
Contact and further Information
Möhler et al. (2021) The Portable Ice Nucleation Experiment (PINE): a new online instrument for laboratory studies and automated long-term field observations of ice-nucleating particles, ACP, DOI:10.5194/amt-14-1143-2021
Smith et al. (2019). The Universal Cloud and Aerosol Sounding System (UCASS): a low-cost miniature optical particle counter for use in dropsonde or balloon-borne sounding systems, AMT, DOI: 10.5194/amt-12-6579-2019