Evaluation of Mixed-Phase Cloud Microphysics Parameterizations with the NCAR Single Column Climate Model (SCAM) and ARM Observations

Liu, X ; Ghan, SJ ; Xie, S

Pacific Northwest National Laboratory (U.S.)

关键词: Clouds;    Water;    Atmospheric Chemistry;    Simulation;    Nucleation;   

DOI  :  10.2172/1021005
RP-ID  :  DOE/SC-ARM-P-07-006
RP-ID  :  DE-AC05-7601830
RP-ID  :  1021005

美国|英语

来源: UNT Digital Library

【 摘 要 】

Mixed-phase stratus clouds are ubiquitous in the Arctic and play an important role in climate in this region. However, climate models have generally proven unsuccessful at simulating the partitioning of condensed water into liquid droplets and ice crystals in these Arctic clouds, which affect modeled cloud phase, cloud lifetime and radiative properties. An ice nucleation parameterization and a vapor deposition scheme were developed that together provide a physically-consistent treatment of mixed-phase clouds in global climate models. These schemes have been implemented in the National Center for Atmospheric Research (NCAR) Community Atmospheric Model Version 3 (CAM3). This report documents the performance of these schemes against ARM Mixed-phase Arctic Cloud Experiment (M-PACE) observations using the CAM single column model version (SCAM). SCAM with our new schemes has a more realistic simulation of the cloud phase structure and the partitioning of condensed water into liquid droplets against observations during the M-PACE than the standard CAM simulations.