文章基本信息

标题：New Optical Properties of Ice Crystals for Multiclass Cloud Microphysics
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作者：Sunghye Baek ; Soo Ya Bae
期刊名称：Journal of Advances in Modeling Earth Systems
电子版ISSN：1942-2466
出版年度：2018
卷号：10
期号：11
页码：2971-2982
DOI：10.1029/2018MS001398
出版社：John Wiley & Sons, Ltd.
摘要：New optical properties of ice crystals were implemented in a general circulation model. Ebert and Curry's (1992, https://doi.org/10.1029/91JD02472 ) and Fu's (1996, https://doi.org/10.1175/1520‐0442(1996)0092.0.CO;2 ) parameterizations are widely used in the general circulation model radiation scheme. However, the validity of the data is limited to an effective radius (size) of 130 or 140 μm . This limit exceeds the median of the effective radius of snow (~200 μm ), which is computed from the multiclass cloud microphysics scheme. A comparable amount of snow exists in the upper atmosphere near the lower part of ice clouds. Although the cross section of snow (extinction probability) is smaller than cloud ice, its impact on radiation has not been properly considered so far. We constructed a new lookup table of optical properties based on recent data for an extended effective radius up to 500 μm . The old data (<130 μm ) also need to be updated with a more recent and elaborate method. We processed extensive data provided by Yang et al. (2013, https://doi.org/10.1175/JAS‐D‐12‐039.1 ) and linked to the radiation module of the Korean Integrated Model (KIM). The new optical properties change the shortwave scattering features, thus increasing the heating rate. This tendency is checked in both one‐dimensional and global weather forecast simulations. With the new optical properties, KIM shows better performance by reducing bias with respect to the Integrated Forecasting Systems (IFS) analysis data.
关键词：NWP;scattering;ice crystal;optical properties