Estimating turbulent energy flux vertical profiles from uncrewed aircraft system measurements: exemplary results for the MOSAiC campaign

Egerer, Ulrike; Cassano, John J.; Shupe, Matthew D.; Boer, Gijs de; Lawrence, Dale; Doddi, Abhiram; Siebert, Holger; Jozef, Gina; Calmer, Radiance; Hamilton, Jonathan; Pilz, Christian; Lonardi, Michael

doi:10.5194/amt-16-2297-2023

Cited by 6 publications

(2 citation statements)

References 83 publications

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“…For example, by installing a lightweight optical particle counter or particulate matter sensor, UAVs are well-suited for measuring vertical and/or horizontal distribution of aerosol in the polluted boundary layer (e.g., Weber et al, 2017;Mamali et al, 2018;Samad et al, 2022;Li et al, 2022;Suchanek et al, 2022;Pusfitasari et al, 2023;Järvi et al, 2023). Other examples of UAVs used in atmospheric research include estimating atmospheric turbulence (e.g., Fuertes et al, 2019;Alaoui-Sosse et al, 2019;Egerer et al, 2023), measuring volcanic plumes and their dispersions (e.g., McGonigle et al, 2008;Mori et al, 2016;Albadra et al, 2020), and for meteorological profiling (e.g., Holland et al, 2001;Reuder et al, 2009;Brosy et al, 2017;Koch et al, 2018;Leuenberger et al, 2020;Brus et al, 2021;Bärfuss et al, 2022).…”

Section: Introductionmentioning

confidence: 99%

Two new multirotor UAVs for glaciogenic cloud seeding and aerosol measurements within the CLOUDLAB project

Miller,

Ramelli,

Fuchs

et al. 2023

Preprint

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Abstract. Uncrewed Aerial Vehicles (UAVs) have become widely used in a range of atmospheric science research applications. Because of their small size, flexible range of motion, adaptability, and low cost, multirotor UAVs are especially well-suited for probing the lower atmosphere. However, their use so far has been limited to conditions outside of clouds, first because of the difficulty of flying beyond visual line of sight, and second because of the challenge of flying in icing conditions in supercooled clouds. Here, we present two UAVs for cloud microphysical research: one UAV (the measurement UAV) equipped with a Portable Optical Particle Spectrometer (POPS) and meteorological sensors to probe the aerosol and meteorological properties in the boundary layer, and one UAV (the seeding UAV) equipped with seeding flares to produce a plume of particles that can initiate ice in supercooled clouds. A propeller heating mechanism on both UAVs allows for operating in supercooled clouds with icing conditions. These UAVs are an integral part of the CLOUDLAB project in which glaciogenic cloud seeding of supercooled low stratus clouds is utilized for studying aerosol-cloud interactions and ice crystal formation and growth. In this paper, we first show validations of the POPS onboard the measurement UAV, demonstrating that the rotor turbulence has a negligible effect on aerosol measurements. We exemplify its applicability for profiling the planetary boundary layer, as well as for sampling and characterizing aerosol plumes, in this case, the seeding plume. We explain the different flight patterns that are possible for both UAVs, namely horizontal or vertical leg patterns or hovering, with an extensive and flexible parameter space for designing the flight patterns according to our scientific goals. Finally, we show two examples of seeding experiments: first characterizing an out-of-cloud seeding plume with the measurement UAV flying horizontal transects through the plume, and second, characterizing an in-cloud seeding plume with downstream measurements with POPS on a tethered balloon. Particle concentrations and size distributions of the seeding plume from the experiments reveal that we can successfully produce and measure the seeding plume, both in-cloud and out-of-cloud. The methods presented here will be useful for probing the lower atmosphere, for characterizing aerosol plumes, and for deepening our cloud microphysical understanding through cloud seeding experiments, all of which have the potential to benefit the atmospheric science community.

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Section: Introductionmentioning

confidence: 99%

Two new multirotor UAVs for glaciogenic cloud seeding and aerosol measurements within the CLOUDLAB project

Miller,

Ramelli,

Fuchs

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Nevertheless, in recent years a significant number of data were collected with the help of aircraft (Ehrlich et al, 2019;Wendisch et al, , 2023bBecker et al, 2023), free-flying balloons (Philipona et al, 2020), and tethered balloons (Lawson et al, 2011;Sikand et al, 2013;Dexheimer et al, 2019;Becker et al, 2020;Inoue et al, 2021). In particular, combined measurements of thermodynamic properties (Egerer et al, 2021), broadband irradiances (Lonardi et al, 2022), turbulence (Egerer et al, 2019(Egerer et al, , 2023, and aerosol particle properties (Pilz et al, 2022) were obtained with the tethered balloon-borne system BELUGA (Balloon-bornE moduLar Utility for profilinG the lower Atmosphere; Egerer et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Tethered balloon-borne observations of thermal-infrared irradiance and cooling rate profiles in the Arctic atmospheric boundary layer

Lonardi

Akansu

Ehrlich

et al. 2023

Preprint

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Abstract. Clouds play an important role in controlling the radiative energy budget of the Arctic atmospheric boundary layer. To quantify their impact on diabatic heating or cooling of the atmosphere and of the surface, vertical profile observations of thermal-infrared irradiances were collected using a tethered balloon. We present 70 profiles of thermal-infrared radiative quantities measured in summer 2020 at the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition, and in autumn 2021 and spring 2022 in Ny-Ålesund, Svalbard. Measurements are classified into four groups: cloudless, low-level liquid-bearing cloud, elevated liquid-bearing cloud, and elevated ice cloud. Cloudless cases display a radiative cooling rate of about -2 K day-1. Observed low-level liquid-bearing clouds are characterized by a radiative cooling up to -80 K day-1 in a shallow layer at cloud top. Radiative transfer simulations are performed to quantify the sensitivity of radiative cooling rates to cloud microphysical properties. In particular, cloud top cooling has a strong response to variation of the liquid water path, especially in optically thin clouds, while for optically thick clouds the cloud droplet number concentration has an increased relative importance. Two case studies with a changing cloud cover are presented to investigate the temporal evolution of radiation profiles during the transitions between (a) cloudy to cloudless and (b) low-level to elevated clouds. Additional radiative transfer simulations are used to reproduce the observed scenarios and to showcase the radiative impacts of elevated liquid and ice clouds, demonstrating the increased radiative significance of the liquid clouds.

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Tethered Balloon-Borne Turbulence Measurements in Winter and Spring during the MOSAiC Expedition

Akansu,

Siebert,

Dahlke

et al. 2023

Sci Data

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During the Multidisciplinary Drifting Observatory for the Study of Arctic Climate expedition, a tethered balloon system was operated with a turbulence probe attached to study the lower troposphere in the high Arctic. Overall, measurements were conducted on 34 days between December 2019 and May 2020, resulting in 47 quality-assured sampling records consisting of vertical profiles and constant-altitude measurements. The continuous profiles extend from the surface, i.e., the sea ice floe, to a height of several hundred meters typically. The high-resolution wind velocity measurements using a hot-wire anemometer and temperature measurements using a thermocouple provide a comprehensive basis for examining the dynamical processes and thermodynamic stratification in the Arctic atmospheric boundary layer under cloudless and cloudy conditions. This paper provides a detailed technical description of the turbulence payload, including calibration and quality assurance, and a general overview of the data. A particular focus of this work is the estimation of local energy dissipation rates. The data are freely available from the World Data Center PANGAEA.

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Estimating turbulent energy flux vertical profiles from uncrewed aircraft system measurements: exemplary results for the MOSAiC campaign

Cited by 6 publications

References 83 publications

Two new multirotor UAVs for glaciogenic cloud seeding and aerosol measurements within the CLOUDLAB project

Two new multirotor UAVs for glaciogenic cloud seeding and aerosol measurements within the CLOUDLAB project

Tethered balloon-borne observations of thermal-infrared irradiance and cooling rate profiles in the Arctic atmospheric boundary layer

Tethered Balloon-Borne Turbulence Measurements in Winter and Spring during the MOSAiC Expedition

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