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Development of a Polar Stratospheric Cloud Model Within the Community Earth System Model: Assessment of 2010 Antarctic Winter
Author(s) -
Zhu Yunqian,
Toon Owen B.,
Lambert Alyn,
Kinnison Douglas E.,
Bardeen Charles,
Pitts Michael C.
Publication year - 2017
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2017jd027003
Subject(s) - ice nucleus , ice cloud , nucleation , atmospheric sciences , aerosol , polar , supercooling , environmental science , meteorology , geology , physics , satellite , astronomy , thermodynamics
To simulate polar stratospheric clouds (PSCs) during the Antarctic winter of 2010, we have developed a PSC model within the Community Earth System Model framework that includes detailed microphysics of sulfuric aerosols and three types of PSCs: supercooled ternary solution (STS), nitric acid trihydrate (NAT), and ice. Our model includes two major NAT formation mechanisms, both of which are essential to reproduce the PSC and gas phase chemical features in the 2010 Antarctic winter. Homogeneous nucleation of NAT from STS produces NAT particles with sizes near 8 μm, which are important to properly simulate denitrification and the gas phase HNO 3 observed by the Microwave Limb Sounder (MLS). Heterogeneous nucleation of NAT on ice particles or ice particles on NAT and subsequent evaporation of the ice produces NAT particles with sizes from submicrometers to a few micrometers. These particles account for the large backscattering ratio from NAT observed by the Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observations satellite, especially in the midwinter season. Adding temperature fluctuations from gravity waves is important to produce larger number density and higher backscattering ratio from ice and NAT particles. However, our model needs a better representation of waves to improve the backscattering ratio and gas phase HNO 3 compared with observations. Our model also includes homogeneous nucleation of ice from STS and heterogeneous nucleation of ice on NAT. The model reproduces the gas phase H 2 O during the winter within the uncertainty of the MLS observations.