arcticclouds
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arcticclouds [2021/09/24 14:29] – [Mixed-phase clouds in transforming Arctic air masses] neggers | arcticclouds [2024/01/26 19:20] (current) – [Cold air outbreaks] adding link to COMBLE chylik | ||
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====== Arctic clouds ====== | ====== Arctic clouds ====== | ||
- | {{ : | + | {{ : |
Arctic climate features an abundance of low-level clouds. It is well known from scientific studies in the past that these clouds can significantly affect the radiative energy budget of the atmosphere and at the surface(( Tsay, S. C., Stamnes, K. and K. Jayaweera (1989). //Radiative energy budget in the cloudy and hazy Arctic//. Journal of the atmospheric sciences, **46** (7), pp. 1002-1018. )). For these reasons it can be expected that low-level clouds could play an important role in the currently ongoing warming of the Arctic climate, a process also known as Arctic Amplification.(( Wendisch M., Yang, P., and Ehrlich, A. (2013). //Amplified climate changes in the Arctic: Role of clouds and | Arctic climate features an abundance of low-level clouds. It is well known from scientific studies in the past that these clouds can significantly affect the radiative energy budget of the atmosphere and at the surface(( Tsay, S. C., Stamnes, K. and K. Jayaweera (1989). //Radiative energy budget in the cloudy and hazy Arctic//. Journal of the atmospheric sciences, **46** (7), pp. 1002-1018. )). For these reasons it can be expected that low-level clouds could play an important role in the currently ongoing warming of the Arctic climate, a process also known as Arctic Amplification.(( Wendisch M., Yang, P., and Ehrlich, A. (2013). //Amplified climate changes in the Arctic: Role of clouds and | ||
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- | ===== Mixed-phase clouds in transforming | + | ===== Mixed-phase clouds in transforming air masses ===== |
Particles of liquid and frozen water in Earth' | Particles of liquid and frozen water in Earth' | ||
- | {{ :: | + | {{ :: |
- | Mixed phase clouds in the Arctic are typically embedded in a much larger air mass, the origin of which can be far remote, even outside the Arctic. Mixed phase clouds play a key role in how such air masses transform as they move in and out of the Arctic. The presence of liquid hydrometeors in such air masses has been reported to greatly affect the speed at which the sea ice melts in the warming Arctic climate. Accelerated melt has been observed to coincide with liquid cloud presence as part of intrusions of warm and moist air into the Artic. This is linked to the strong impact of liquid clouds on the downwelling long wave radiation at the surface. Another way in which mixed phase clouds interact with the Arctic climate system is through subsidence, which can act as a control on the persistence of mixed-phase cloud systems. This is illustrated in the schematic | + | Mixed phase clouds in the Arctic are typically embedded in a much larger air mass, the origin of which can be far remote, even outside the Arctic. Mixed phase clouds play a key role in how such air masses transform as they move in and out of the Arctic. The presence of liquid hydrometeors in such air masses has been reported to greatly affect the speed at which the sea ice melts in the warming Arctic climate. Accelerated melt has been observed to coincide with liquid cloud presence as part of intrusions of warm and moist air into the Artic. This is linked to the strong impact of liquid clouds on the downwelling long wave radiation at the surface. Another way in which mixed phase clouds interact with the Arctic climate system is through subsidence, which can act as a control on the persistence of mixed-phase cloud systems |
- | High-resolution simulations of mixed-phase clouds can provide insights, acting as a virtual laboratory for studies at process level. To gain confidence in the model, it is of key importance to thoroughly evaluate | + | High-resolution simulations of mixed-phase clouds can provide insights, acting as a virtual laboratory for studies at process level. To gain confidence in the model, it is of key importance to thoroughly evaluate |
Related papers: | Related papers: | ||
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* Local and remote controls on Arctic mixed layer evolution [[https:// | * Local and remote controls on Arctic mixed layer evolution [[https:// | ||
* Investigating Arctic humidity inversions using balloon-borne measurements and large-eddy simulations [[https:// | * Investigating Arctic humidity inversions using balloon-borne measurements and large-eddy simulations [[https:// | ||
- | * Aerosol-cloud-turbulence interactions in well-coupled Arctic boundary layers over open water. Chylik et al., in preparation for ACPD, September 2021 | + | * Aerosol-cloud-turbulence interactions in well-coupled Arctic boundary layers over open water. |
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Cold air outbreaks (CAOs) in the Arctic are situations in which a low level mass of cold air initially situated over the sea ice is advected across the ice edge and continues over open water. This process is accompanied by the formation of a convective boundary layer that deepens rapidly, featuring strong surface heat fluxes as well as the formation of low-level mixed-phase clouds. The dynamics in the CAO boundary layer are often complex, as illustrated in Fig. 2. Often these clouds are organized into streets, which at some point downstream of the ice edge tend to break up into bigger individual cells. These cells, often arranged into a spoke-pattern, | Cold air outbreaks (CAOs) in the Arctic are situations in which a low level mass of cold air initially situated over the sea ice is advected across the ice edge and continues over open water. This process is accompanied by the formation of a convective boundary layer that deepens rapidly, featuring strong surface heat fluxes as well as the formation of low-level mixed-phase clouds. The dynamics in the CAO boundary layer are often complex, as illustrated in Fig. 2. Often these clouds are organized into streets, which at some point downstream of the ice edge tend to break up into bigger individual cells. These cells, often arranged into a spoke-pattern, | ||
- | In the recent ACLOUD field campaign in May 2017, which is part of the ongoing (AC)< | + | In the recent ACLOUD field campaign in May 2017, which is part of the ongoing (AC)< |
Related papers: | Related papers: | ||
* Turbulent transport in the Grey Zone: A large-eddy simulation model intercomparison study of the CONSTRAIN cold air outbreak case [[https:// | * Turbulent transport in the Grey Zone: A large-eddy simulation model intercomparison study of the CONSTRAIN cold air outbreak case [[https:// | ||
+ | |||
+ | Ongoing projects: | ||
+ | * COMBLE Model-Observation Intercomparison Project: 13 March 2020 cold-air outbreak over Fram Strait [[https:// | ||
===== Arctic clouds in complex terrain ===== | ===== Arctic clouds in complex terrain ===== | ||
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Various field campaigns have taken place near the Svalbard archipelago in the context of the ongoing (AC)< | Various field campaigns have taken place near the Svalbard archipelago in the context of the ongoing (AC)< | ||
- | More information about the (AC)< | + | More information about the (AC)< |
Related datasets and papers: | Related datasets and papers: | ||
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* LES results to accompany measurements at the POLARSTERN Research Vessel during the PASCAL field campaign on 7 June 2017 [[https:// | * LES results to accompany measurements at the POLARSTERN Research Vessel during the PASCAL field campaign on 7 June 2017 [[https:// | ||
* Glimpsing the ins and outs of the Arctic atmospheric cauldron [[https:// | * Glimpsing the ins and outs of the Arctic atmospheric cauldron [[https:// | ||
+ | * Case study of a humidity layer above Arctic stratocumulus using balloon-borne turbulence and radiation measurements and large eddy simulations [[https:// | ||
+ | * The COMBLE campaign: a study of marine boundary-layer clouds in Arctic cold-air outbreaks [[https:// | ||
===== Large Eddy Simulations ===== | ===== Large Eddy Simulations ===== | ||
==== Model codes ==== | ==== Model codes ==== | ||
- | At InScAPE the fine-scale simulations of Arctic clouds are performed with two models. The Dutch Atmospheric Large Eddy Simulation model (DALES) | + | At InScAPE the fine-scale simulations of Arctic clouds are performed with two models. The Dutch Atmospheric Large Eddy Simulation model ([[https:// |
(( Heus, T., Heerwaarden, | (( Heus, T., Heerwaarden, | ||
- | Simulation (DALES) and overview of its applications.// | + | Simulation (DALES) and overview of its applications.// |
- | The DALES and ICON models are described in more detail [[models|here]]. | + | The DALES and ICON models are described in more detail |
==== Mixed-Phase Microphysics in LES ==== | ==== Mixed-Phase Microphysics in LES ==== | ||
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* CCN and INP concentration can differ with altitude, not just a constant | * CCN and INP concentration can differ with altitude, not just a constant | ||
* latent heat of freezing included in the heat budget | * latent heat of freezing included in the heat budget | ||
- | * initial conditions and large-scale forcings derived from large-scale models following the method used in parameterization testbeds (( Neggers, R. A. J., A. P. Siebesma and T. Heus, 2012: Continuous single-column model evaluation at a permanent meteorological supersite. Bull. Amer. Meteor. Soc., 93, p1389-1400, DOI: | + | * initial conditions and large-scale forcings derived from large-scale models following the method used in [[testbed|parameterization testbeds]] (( Neggers, R. A. J., A. P. Siebesma and T. Heus, 2012: Continuous single-column model evaluation at a permanent meteorological supersite. Bull. Amer. Meteor. Soc., 93, p1389-1400, DOI: |
The performance of this implementation has been tested on chosen semi-idealised cold-air outbreak cases. This includes the including M-PACE (( Solomon, A., Morrison, H., Persson, O., Shupe, M. D., and J. W. Bao (2009). // | The performance of this implementation has been tested on chosen semi-idealised cold-air outbreak cases. This includes the including M-PACE (( Solomon, A., Morrison, H., Persson, O., Shupe, M. D., and J. W. Bao (2009). // |
arcticclouds.1632486541.txt.gz · Last modified: 2021/09/24 14:29 by neggers