UAV-based atmospheric measurements
The Aerosols and Clouds group uses uncrewed aerial vehicles (UAVs) to investigate atmospheric structure, aerosols, clouds and their interactions. Fixed-wing and multirotor platforms provide detailed in situ measurements that complement surface observations and ground-based remote sensing measurements.
Field activities are centred on the Pallas Atmosphere–Ecosystem Supersite in Finnish Lapland, including the Pallas Cloud Experiment (PaCE) campaigns. Coordinated measurements from UAVs, tethered balloons, surface instruments and remote-sensing systems allow researchers to investigate the vertical and horizontal variability of the subarctic atmosphere.
High-altitude research at Pallas
In October 2026, Traficom established a permissive UAS geographical zone enabling FMI scientific operations up to 10 kilometres above ground level within the activated PALLAS C temporary danger area (EFD546). This expands the altitude range available for atmospheric research and provides a framework for developing high-altitude UAV measurement systems. Flight altitudes depend on the aircraft, scientific payload, weather conditions and applicable operational arrangements.
The expanded airspace opens opportunities to sample cloud layers and their surrounding atmosphere across a much greater vertical range. Combining these measurements with cloud radar and microwave radiometer observations will provide reference data for evaluating and improving remote-sensing retrievals of cloud and atmospheric properties.
Measurements and scientific objectives
Depending on the platform and mission, UAV payloads measure aerosol and cloud-particle size distributions, temperature, humidity and pressure, and collect aerosol samples for laboratory analysis of ice-nucleating particles. Instrument development also includes UAV-mounted holographic imaging of cloud particles.
The observations support research into cloud microphysics, aerosol–cloud interactions, atmospheric thermodynamics and cloud dynamics, as well as the evaluation of remote-sensing products and atmospheric models.
These activities directly support the Research Council of Finland-funded project 4Dcloud, “Lifecycle of stratiform clouds in the Finnish subarctic; 4D variability of cloud microphysics and turbulence”. The project investigates how cloud microphysics and turbulence vary in space and time and influence the lifecycle of subarctic stratiform clouds.
Developing aircraft and scientific payloads for high-altitude measurements is an integral part of this work. Low temperatures, reduced air density and demanding atmospheric conditions require advances in aircraft performance, power systems, communications and instrument integration.
The group contributes to ACTRIS and collaborates with national and international partners through coordinated field campaigns, instrument development and openly available observational datasets.
Publications
Girdwood, J., Brus, D., Doulgeris, K.-M., and Böhmländer, A.: Small uncrewed aircraft based microphysical measurements of polar stratus cloud during the Pallas Cloud Experiment 2022, Earth Syst. Sci. Data, 18, 2819–2828, https://doi.org/10.5194/essd-18-2819-2026, 2026.
Leskinen, A., Radlwimmer, A., Isopahkala, U., Calderón, S., Brus, D., Doulgeris, K., Kaikkonen, V., Molkoselkä, E., Moiseev, D., Hirschy, M. L., Mäkynen, A., Romakkaniemi, S., and Komppula, M.: Novel Possibilities of In-Situ Cloud Observation with Drone-Mountable Holographic Imager, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2026-2088, 2026.
Le, V., Doulgeris, K., Komppula, M., Backman, J., Bagheri, G., Bodenschatz, E., and Brus, D.: Dataset of airborne measurements of aerosol, cloud droplets and meteorology by tethered balloon during PaCE 2022, Earth Syst. Sci. Data Discuss. [preprint], https://doi.org/10.5194/essd-2026-135, in review, 2026.
Brus, D., Le, V., Kuula, J., and Doulgeris, K.: Data collected by a drone backpack for air quality and atmospheric state measurements during Pallas Cloud Experiment 2022 (PaCE2022), Earth Syst. Sci. Data, 17, 5209–5219, https://doi.org/10.5194/essd-17-5209-2025, 2025.
Böhmländer, A., Lacher, L., Brus, D., Doulgeris, K.-M., Brasseur, Z., Boyer, M., Kuula, J., Leisner, T., and Möhler, O.: A novel aerosol filter sampler for measuring the vertical distribution of ice-nucleating particles via fixed-wing uncrewed aerial vehicles, Atmos. Meas. Tech., 18, 3959–3975, https://doi.org/10.5194/amt-18-3959-2025, 2025.
Böhmländer, A., Lacher, L., Höhler, K., Brus, D., Doulgeris, K.-M., Girdwood, J., Leisner, T., and Möhler, O.: Measurement of the ice-nucleating particle concentration using a mobile filter-based sampler on-board of a fixed-wing uncrewed aerial vehicle during the Pallas Cloud Experiment 2022, Earth Syst. Sci. Data, 17, 6157–6164, https://doi.org/10.5194/essd-17-6157-2025, 2025.
