Aerosol and Clouds
Numerical simulations of the three-dimensional distribution of polar mesospheric clouds and comparisons with Cloud Imaging and Particle Size (CIPS) experiment and the Solar Occultation For Ice Experiment (SOFIE) observations
Article first published online: 18 MAY 2010
Copyright 2010 by the American Geophysical Union.
Journal of Geophysical Research: Atmospheres (1984–2012)
Volume 115, Issue D10, 27 May 2010
How to Cite
2010), Numerical simulations of the three-dimensional distribution of polar mesospheric clouds and comparisons with Cloud Imaging and Particle Size (CIPS) experiment and the Solar Occultation For Ice Experiment (SOFIE) observations, J. Geophys. Res., 115, D10204, doi:10.1029/2009JD012451., , , , , , , and (
- Issue published online: 18 MAY 2010
- Article first published online: 18 MAY 2010
- Manuscript Accepted: 8 DEC 2009
- Manuscript Revised: 2 NOV 2009
- Manuscript Received: 9 MAY 2009
 Polar mesospheric clouds (PMC) routinely form in the cold summer mesopause region when water vapor condenses to form ice. We use a three-dimensional chemistry-climate model based on the Whole-Atmosphere Community Climate Model (WACCM) with sectional microphysics from the Community Aerosol and Radiation Model for Atmospheres (CARMA) to study the distribution and characteristics of PMCs formed by heterogeneous nucleation of water vapor onto meteoric smoke particles. We find good agreement between these simulations and cloud properties for the Northern Hemisphere in 2007 retrieved from the Solar Occultation for Ice Experiment (SOFIE) and the Cloud Imaging and Particle Size (CIPS) experiment from the Aeronomy of Ice in the Mesosphere (AIM) mission. The main discrepancy is that simulated ice number densities are less than those retrieved by SOFIE. This discrepancy may indicate an underprediction of nucleation rates in the model, the lack of small-scale gravity waves in the model, or a bias in the SOFIE results. The WACCM/CARMA simulations are not very sensitive to large changes in the barrier to heterogeneous nucleation, which suggests that large supersaturations in the model nucleate smaller meteoric smoke particles than are traditionally assumed. Our simulations are very sensitive to the temperature structure of the summer mesopause, which in the model is largely dependent upon vertically propagating gravity waves that reach the mesopause region, break, and deposit momentum. We find that cloud radiative heating is important, with heating rates of up to 8 K/d.