Gravity Wave Tuning in WACCM/CARMA for Application to PMC Studies

We investigate the sensitivity of WACCM/CARMA simulations of Polar Mesospheric Clouds (PMCs) and the meteorology in the upper atmosphere to changes in the model gravity wave parameterization. WACCM/CARMA is a three-dimensional chemistry climate model based upon the Whole-Atmosphere Community Climate Model (WACCM) with sectional microphysics from the Community Aerosol and Radiation Model for Atmospheres (CARMA). The gravity wave parameterization in WACCM/CARMA has been tuned to give realistic polar summer mesopause temperatures in the northern hemisphere which resulted in simulations of PMCs that compare well with the Cloud Imaging and Particle Size Experiment (CIPS) and the Solar Occultation for Ice Experiment (SOFIE). However, this tuning resulted in a poor representation of the winter polar stratosphere and an improved but still biased SH polar summer mesopause. Our goal is to adjust the gravity wave parameterization to have improved results in both summer polar mesopause regions and both winter polar stratospheres making it suitable for multi-year simulations of PMCs. We will compare simulated PMCs and distributions of water and temperature to satellite datasets, for example SOFIE, the Microwave Limb Sounder (MLS) and the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument.