Tethered balloon-borne profile measurements of atmospheric properties in the cloudy atmospheric boundary layer over the Arctic sea ice during MOSAiC: Overview and first results

The tethered balloon-borne measurement system BELUGA (Balloon-bornE moduLar Utility for profilinG the lower Atmosphere) was deployed over the Arctic sea ice for 4 weeks in summer 2020 as part of the Multidisciplinary drifting Observatory for the Study of Arctic Climate expedition. Using BELUGA, vertical profiles of dynamic, thermodynamic, aerosol particle, cloud, radiation, and turbulence properties were measured from the ground up to a height of 1,500 m. BELUGA was operated during an anomalously warm period with frequent liquid water clouds and variable sea ice conditions. Three case studies of liquid water phase, single-layer clouds observed on 3 days (July 13, 23, and 24, 2020) are discussed to show the potential of the collected data set to comprehensively investigate cloud properties determining cloud evolution in the inner Arctic over sea ice. Simulated back-trajectories show that the observed clouds have evolved within 3 different air masses (“aged Arctic,” “advected over sea ice,” and “advected over open ocean”), which left distinct fingerprints in the cloud properties. Strong cloud top radiative cooling rates agree with simulated results of previous studies. The weak warming at cloud base is mostly driven by the vertical temperature profile between the surface and cloud base. In-cloud turbulence induced by the cloud top cooling was similar in strength compared to former studies. From the extent of the mixing layer, it is speculated that the overall cloud cooling is stronger and thus faster in the warm oceanic air mass. Larger aerosol particle number concentrations and larger sizes were observed in the air mass advected over the sea ice and in the air mass advected over the open ocean

Energy dissipation rate profiles derived from tethered balloon-borne measurements on 2020-04-10 from 14:26 to 14:48 during MOSAiC leg 3

This is a dataset of energy dissipation rates that were derived from turbulence measurements with a tethered balloon. A hot-wire anemometer package was operated during Legs 1, 2, and 3 of the MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition. From the temporal high-resolution wind velocity records, energy dissipation rate (EDR) profiles were derived for non-overlapping 1 s time periods. With that, vertical profiles of the turbulence quantity are available for 34 days between 2019-12-06 and 2020-05-06 covering polar night and spring. The vertical profiles of turbulence measurements reach typically up to a height of several hundred meters (~200 m to ~1400 m). The data set contains not only the time stamps of the intervals used to calculate the EDR and the derived EDR values, but also the altitude values, the applied scaling coefficient and the upper bound of the inertial subrange

Energy dissipation rate profiles derived from tethered balloon-borne measurements on 2020-01-06 from 10:57 to 11:15 during MOSAiC leg 2

This is a dataset of energy dissipation rates that were derived from turbulence measurements with a tethered balloon. A hot-wire anemometer package was operated during Legs 1, 2, and 3 of the MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition. From the temporal high-resolution wind velocity records, energy dissipation rate (EDR) profiles were derived for non-overlapping 1 s time periods. With that, vertical profiles of the turbulence quantity are available for 34 days between 2019-12-06 and 2020-05-06 covering polar night and spring. The vertical profiles of turbulence measurements reach typically up to a height of several hundred meters (~200 m to ~1400 m). The data set contains not only the time stamps of the intervals used to calculate the EDR and the derived EDR values, but also the altitude values, the applied scaling coefficient and the upper bound of the inertial subrange

Energy dissipation rate profiles derived from tethered balloon-borne measurements on 2020-04-27 from 08:52 to 09:06 during MOSAiC leg 3

This is a dataset of energy dissipation rates that were derived from turbulence measurements with a tethered balloon. A hot-wire anemometer package was operated during Legs 1, 2, and 3 of the MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition. From the temporal high-resolution wind velocity records, energy dissipation rate (EDR) profiles were derived for non-overlapping 1 s time periods. With that, vertical profiles of the turbulence quantity are available for 34 days between 2019-12-06 and 2020-05-06 covering polar night and spring. The vertical profiles of turbulence measurements reach typically up to a height of several hundred meters (~200 m to ~1400 m). The data set contains not only the time stamps of the intervals used to calculate the EDR and the derived EDR values, but also the altitude values, the applied scaling coefficient and the upper bound of the inertial subrange