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Using satellite observations to evaluate model microphysical representation of Arctic mixed-phase clouds
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  • Jonah K Shaw,
  • Zachary McGraw,
  • Olimpia Bruno,
  • Trude Storelvmo,
  • Stefan Hofer
Jonah K Shaw
University of Colorado at Boulder, University of Colorado at Boulder

Corresponding Author:[email protected]

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Zachary McGraw
University of Oslo, University of Oslo
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Olimpia Bruno
Karlsruhe Institute of Technology, Karlsruhe Institute of Technology
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Trude Storelvmo
University of Oslo, University of Oslo
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Stefan Hofer
University of Oslo, University of Oslo
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Abstract

Mixed-phase clouds play an important role in determining Arctic warming, but are parametrized in models and difficult to constrain with observations. We use two satellite-derived cloud phase metrics to investigate the vertical structure of Arctic clouds in two global climate models that use the Community Atmosphere Model version 6 (CAM6) atmospheric component. We report a model error limiting ice nucleation, produce a set of Arctic-constrained model runs by adjusting model microphysical variables to match the cloud phase metrics, and evaluate cloud feedbacks for all simulations. Models in this small ensemble uniformly overestimate total cloud fraction in the summer, but have variable representation of cloud fraction and phase in the winter and spring. By relating modelled cloud phase metrics and changes in low-level liquid cloud amount under warming to longwave cloud feedback, we show that mixed-phase processes mediate the Arctic climate by modifying how wintertime and springtime clouds respond to warming.
16 Feb 2022Published in Geophysical Research Letters volume 49 issue 3. 10.1029/2021GL096191