An Evaluation of Candidate Scheme(s) of Future CAM5 in CAPT simulations with Ground-based Observations in the Azores
Authors
Stephen Klein — Lawrence Livermore National Laboratory
Peter A Bogenschutz — National Center for Atmospheric Research
Andrew Gettelman — National Center for Atmospheric Research (NCAR)
Hsi-Yen Ma — Lawrence Livermore National Laboratory
Xue Zheng — Lawrence Livermore National Laboratory
Category
Warm Low Clouds and Interactions with Aerosol
Description
The Department of Energy’s Atmospheric Radiation Measurements (ARM) Mobile Facility (AMF) was on Graciosa Island in the Azores from June 2009 to December 2010 as part of the Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) field campaign. CAP-MBL obtained 19 months of intensive cloud and radiation observations on Graciosa Island in the Azores, which offered us a good opportunity to evaluate the modeled low clouds with observations.
The Cloud-Layers Unified By Binormals (CLUBB) with MG2 microphysics scheme and the Unified Convection scheme (UNICON) are the two candidate schemes of future CAM5 for use by other CESM working groups in CMIP6 experiments. This study compared the hourly CAM5 simulations with CLUBB+MG2 at the grid column (39.1N, 27.5W), which is the nearest grid to Graciosa Island (39.1N, 28.0W), with continuous surface observations of marine boundary layer clouds (including stratocumulus, cumulus, and stratocumulus with cumulus) from the CAP-MBL field campaign. For each scheme, we will use the CAPT simulation output on Day 2 to evaluate the representation of low clouds and their radiative impacts. The origin of the model bias for different schemes will also be discussed.
Acknowledgement: This work is supported by the ASR Program for the Office of Science of the U.S. DOE. This work was performed under the auspices of the U.S. DOE by LLNL under contract DE-AC52-07NA27344.LLNL-ABS-666463.
