Ice and Mixed-Phase Cloud Microphysical and Macrophysical Properties in the High Latitudes: Linking in Situ, Remote Sensing Observations and Climate Simulations

Abstract:

Ice and mixed-phase clouds in the high latitudes are difficult to represent in global climate models due complex microphysical processes and phase partitioning. To improve the understanding of cloud microphysical properties in the Antarctic and Arctic, ground‐based remote sensing data and in-situ radiosonde data will be used to compare cloud properties between the DOE ARM West Antarctic Radiation Experiment (AWARE) and the DOE ARM North Slope of Alaska (NSA) observations. This study examines the long-term statistical trends of cloud occurrence frequencies, vertical profiles of temperature, relative humidity (RH), and liquid mass fractions of these two locations. Cloud microphysical and macrophysical properties are also compared with the National Center for Atmospheric Research (NCAR) Community Atmosphere Model Version 6 (CAM6) climate model. The observed cloud fraction data are used to identify the discrepancies in the CAM6 model simulations compared with observations. Case studies will show the typical conditions present when the CAM6 model cloud output misses or spuriously produces low-, mid-, and high-level clouds. The variations of cloud characteristics and thermodynamic conditions between these two locations can also be used to better understand the processes involved with cloud formation in the polar regions. Identifying the typical thermodynamic conditions and altitudes of misrepresented clouds in the CAM6 model simulation can help to improve parameterizations of future global climate models for ice and mixed-phase clouds.