The Impact of CCN Concentrations on the Thermodynamic and Turbulent State of Arctic Mixed-Phase Clouds

Impacts of aerosol on mixed-phase cloud evolution play a potentially important role in Arctic climate, but remain poorly understood. The way in which aerosol, clouds and turbulence interact, is speculated to significantly modify the cloud evolution. There has been an increasing number of field obser...

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Main Authors: Chylik, Jan, Mertes, Stephan, Neggers, Roel A. J.
Format: Text
Language:English
Published: 2019
Subjects:
Online Access:https://doi.org/10.5194/acp-2019-637
https://www.atmos-chem-phys-discuss.net/acp-2019-637/
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spelling ftcopernicus:oai:publications.copernicus.org:acpd78146 2023-05-15T14:43:16+02:00 The Impact of CCN Concentrations on the Thermodynamic and Turbulent State of Arctic Mixed-Phase Clouds Chylik, Jan Mertes, Stephan Neggers, Roel A. J. 2019-07-17 application/pdf https://doi.org/10.5194/acp-2019-637 https://www.atmos-chem-phys-discuss.net/acp-2019-637/ eng eng doi:10.5194/acp-2019-637 https://www.atmos-chem-phys-discuss.net/acp-2019-637/ eISSN: 1680-7324 Text 2019 ftcopernicus https://doi.org/10.5194/acp-2019-637 2019-12-24T09:48:49Z Impacts of aerosol on mixed-phase cloud evolution play a potentially important role in Arctic climate, but remain poorly understood. The way in which aerosol, clouds and turbulence interact, is speculated to significantly modify the cloud evolution. There has been an increasing number of field observations of the ice clouds in Arctic, however it has proven hard to gain insight into these complex interactions using measurements alone. This model study aims to help filling this gap in the current understanding of low-level Arctic clouds, by combining high resolution simulations with new field campaign data. The main focus is on the impact of the cloud condensation nuclei concentration (CCN) on the properties of cloud and mixed-layer turbulence in an~evolving boundary layer. We configure semi-idealised model scenarios based on the weather situation observed over open ocean during two research flights of the ACLOUD campaign, which took place over Fram Strait northwest of Svalbard. A demi-Lagrangian frame of reference is adopted, with the model domain following low level air masses and the large-scale forcings derived from weather model analyses and short-range forecasts. Adjustments in the initial state are made based on comparison to dropsonde data. The simulations reproduce the observed general structure of the cloud-bearing Arctic mixed layer. Results further show that while the ice phase forms just a fraction of the mass of cloud water, it is responsible for most of the precipitation, in line with previous observational and LES studies. A lower initial CCN concentration generally results into a faster glaciation of the cloud, leading to a faster removal of the cloud water, and also affects the vertical structure of turbulence. Implications for radiative studies of clouds for the purpose of Arctic Amplification are discussed. Text Arctic Fram Strait Svalbard Copernicus Publications: E-Journals Arctic Svalbard
institution Open Polar
collection Copernicus Publications: E-Journals
op_collection_id ftcopernicus
language English
description Impacts of aerosol on mixed-phase cloud evolution play a potentially important role in Arctic climate, but remain poorly understood. The way in which aerosol, clouds and turbulence interact, is speculated to significantly modify the cloud evolution. There has been an increasing number of field observations of the ice clouds in Arctic, however it has proven hard to gain insight into these complex interactions using measurements alone. This model study aims to help filling this gap in the current understanding of low-level Arctic clouds, by combining high resolution simulations with new field campaign data. The main focus is on the impact of the cloud condensation nuclei concentration (CCN) on the properties of cloud and mixed-layer turbulence in an~evolving boundary layer. We configure semi-idealised model scenarios based on the weather situation observed over open ocean during two research flights of the ACLOUD campaign, which took place over Fram Strait northwest of Svalbard. A demi-Lagrangian frame of reference is adopted, with the model domain following low level air masses and the large-scale forcings derived from weather model analyses and short-range forecasts. Adjustments in the initial state are made based on comparison to dropsonde data. The simulations reproduce the observed general structure of the cloud-bearing Arctic mixed layer. Results further show that while the ice phase forms just a fraction of the mass of cloud water, it is responsible for most of the precipitation, in line with previous observational and LES studies. A lower initial CCN concentration generally results into a faster glaciation of the cloud, leading to a faster removal of the cloud water, and also affects the vertical structure of turbulence. Implications for radiative studies of clouds for the purpose of Arctic Amplification are discussed.
format Text
author Chylik, Jan
Mertes, Stephan
Neggers, Roel A. J.
spellingShingle Chylik, Jan
Mertes, Stephan
Neggers, Roel A. J.
The Impact of CCN Concentrations on the Thermodynamic and Turbulent State of Arctic Mixed-Phase Clouds
author_facet Chylik, Jan
Mertes, Stephan
Neggers, Roel A. J.
author_sort Chylik, Jan
title The Impact of CCN Concentrations on the Thermodynamic and Turbulent State of Arctic Mixed-Phase Clouds
title_short The Impact of CCN Concentrations on the Thermodynamic and Turbulent State of Arctic Mixed-Phase Clouds
title_full The Impact of CCN Concentrations on the Thermodynamic and Turbulent State of Arctic Mixed-Phase Clouds
title_fullStr The Impact of CCN Concentrations on the Thermodynamic and Turbulent State of Arctic Mixed-Phase Clouds
title_full_unstemmed The Impact of CCN Concentrations on the Thermodynamic and Turbulent State of Arctic Mixed-Phase Clouds
title_sort impact of ccn concentrations on the thermodynamic and turbulent state of arctic mixed-phase clouds
publishDate 2019
url https://doi.org/10.5194/acp-2019-637
https://www.atmos-chem-phys-discuss.net/acp-2019-637/
geographic Arctic
Svalbard
geographic_facet Arctic
Svalbard
genre Arctic
Fram Strait
Svalbard
genre_facet Arctic
Fram Strait
Svalbard
op_source eISSN: 1680-7324
op_relation doi:10.5194/acp-2019-637
https://www.atmos-chem-phys-discuss.net/acp-2019-637/
op_doi https://doi.org/10.5194/acp-2019-637
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