Tethered balloon measurements reveal enhanced aerosol occurrence aloft interacting with Arctic low-level clouds DOI Creative Commons
Christian Pilz, John J. Cassano, Gijs de Boer

et al.

Elementa Science of the Anthropocene, Journal Year: 2024, Volume and Issue: 12(1)

Published: Jan. 1, 2024

Low-level clouds in the Arctic affect surface energy budget and vertical transport of heat moisture. The limited availability cloud-droplet-forming aerosol particles strongly impacts cloud properties lifetime. Vertical particle distributions are required to study aerosol–cloud interaction over sea ice comprehensively. This article presents vertically resolved measurements number concentrations sizes using tethered balloons. data were collected during Multidisciplinary drifting Observatory for Study Climate expedition summer 2020. Thirty-four profiles concentration observed 2 size ranges: 12–150 nm (N12−150) above 150 (N>150). Concurrent balloon-borne meteorological provided context continuous through cloudy atmospheric boundary layer. Radiosoundings, remote sensing data, 5-day back trajectories supplemented analysis. majority showed more lowest temperature inversion, on average, double compared below. Increased N12−150 up 3,000 cm−3 free troposphere low-level related secondary formation. Long-range pollution increased N>150 310 a warm, moist air mass. Droplet activation inside caused reductions by 100%, while decrease was less than 50%. When thermodynamically coupled with surface, 5 times higher values below cloud-capping inversion. Enhanced interacting advected inversion from beyond edge when decoupled surface. Vertically discontinuous suggest that emitted at not transported these conditions. It is concluded cloud-surface coupling state tropospheric abundance crucial assessing ice.

Language: Английский

Above-cloud concentrations of cloud condensation nuclei help to sustain some Arctic low-level clouds DOI Creative Commons
Lucas Sterzinger, Adele L. Igel

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(6), P. 3529 - 3540

Published: March 20, 2024

Abstract. Previous studies have found that low-level Arctic clouds often persist for long periods even in the face of very low surface cloud condensation nuclei (CCN) concentrations. Here, we investigate whether these conditions could occur due to continuous entrainment aerosol particles from free troposphere (FT). We use an idealized large eddy simulation (LES) modeling framework, where concentrations are boundary layer (BL) but increased up 50× troposphere. find tests with higher tropospheric simulated clouds, which persisted longer and maintained liquid water paths (LWPs). This is direct into layer, results a precipitation suppression increase droplet number stronger cloud-top radiative cooling, causes circulations maintaining absence forcing. Together, two responses result more well-mixed top remains contact reservoir can maintain those particles. The concentrations, however, remained all simulations. free-tropospheric concentration necessary consistent frequently seen observations.

Language: Английский

Citations

3
Aitken Mode Aerosols Buffer Decoupled Mid‐Latitude Boundary Layer Clouds Against Precipitation Depletion DOI Creative Commons
Isabel L. McCoy, M. C. Wyant, Peter N. Blossey

et al.

Journal of Geophysical Research Atmospheres, Journal Year: 2024, Volume and Issue: 129(12)

Published: June 22, 2024

Abstract Aerosol‐cloud‐precipitation interactions are a leading source of uncertainty in estimating climate sensitivity. Remote marine boundary layers where accumulation mode (∼100–400 nm diameter) aerosol concentrations relatively low very susceptible to changes. These regions also experience heightened Aitken (∼10–100 nm) associated with ocean biology. aerosols may significantly influence cloud properties and evolution by replenishing condensation nuclei droplet number lost through precipitation (i.e., buffering). We use large‐eddy simulation an Aitken‐mode enabled microphysics scheme examine the role buffering mid‐latitude decoupled layer regime observed on 15 July 2017 during Aerosol Cloud Experiments Eastern North Atlantic flight campaign: cumulus rising into stratocumulus under elevated (∼100–200 mg −1 ). In situ measurements used constrain evaluate this case study. Our accurately captures aerosol‐cloud‐precipitation reveals time‐evolving processes driving development evolution. activation provides reservoir for turbulence convection carry drizzling above. Further occurs aloft layer. Together, these events buffer against removal, reducing break‐up increases heterogeneity. sensitivity initial conditions. With halved number, restore concentrations, maintain similar original values, prevent break‐up. Without aerosols, precipitation‐driven rapidly. regime, sustains brighter, more homogeneous clouds longer.

Language: Английский

Citations

3
Air Composition over the Russian Arctic–4: Atmospheric Aerosols DOI Creative Commons
O. Yu. Antokhina, P. N. Antokhin,

V. G. Arshinova

et al.

Atmospheric and Oceanic Optics, Journal Year: 2024, Volume and Issue: 37(3), P. 357 - 372

Published: June 1, 2024

Language: Английский

Citations

3
Tethered balloon measurements reveal enhanced aerosol occurrence aloft interacting with Arctic low-level clouds DOI Creative Commons
Christian Pilz, John J. Cassano, Gijs de Boer

et al.

Elementa Science of the Anthropocene, Journal Year: 2024, Volume and Issue: 12(1)

Published: Jan. 1, 2024

Low-level clouds in the Arctic affect surface energy budget and vertical transport of heat moisture. The limited availability cloud-droplet-forming aerosol particles strongly impacts cloud properties lifetime. Vertical particle distributions are required to study aerosol–cloud interaction over sea ice comprehensively. This article presents vertically resolved measurements number concentrations sizes using tethered balloons. data were collected during Multidisciplinary drifting Observatory for Study Climate expedition summer 2020. Thirty-four profiles concentration observed 2 size ranges: 12–150 nm (N12−150) above 150 (N>150). Concurrent balloon-borne meteorological provided context continuous through cloudy atmospheric boundary layer. Radiosoundings, remote sensing data, 5-day back trajectories supplemented analysis. majority showed more lowest temperature inversion, on average, double compared below. Increased N12−150 up 3,000 cm−3 free troposphere low-level related secondary formation. Long-range pollution increased N>150 310 a warm, moist air mass. Droplet activation inside caused reductions by 100%, while decrease was less than 50%. When thermodynamically coupled with surface, 5 times higher values below cloud-capping inversion. Enhanced interacting advected inversion from beyond edge when decoupled surface. Vertically discontinuous suggest that emitted at not transported these conditions. It is concluded cloud-surface coupling state tropospheric abundance crucial assessing ice.

Language: Английский

Citations

1