Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling

Seasonal Dependent Impact of Ice‐Cloud Longwave Scattering on the Polar Climate

TitleSeasonal Dependent Impact of Ice‐Cloud Longwave Scattering on the Polar Climate
Publication TypeJournal Article
Year of Publication2020
AuthorsChen, Yi-Hsuan, Huang Xianglei, Yang Ping, Kuo Chia-Pang, and Chen Xiuhong
JournalGeophysical Research Letters
Abstract / Summary

Most climate models neglect cloud longwave (LW) scattering because scattering is considered negligible compared to strong LW absorption by clouds and greenhouse gases. While this rationale is valid for simulating extra‐polar regions, it is questionable for the polar regions, where the atmosphere is dry and hence has weak absorption, and ice clouds that have strong scattering capability frequently occur. Using the slab‐ocean Community Earth System Model, we show that ice cloud LW scattering can warm winter surface air temperature by 0.8‐1.8K in the Arctic and 1.3‐1.9K in the Antarctic, while this warming becomes much weaker in polar summer. Such scattering effect cannot be correctly assessed when sea surface temperature and sea ice are prescribed as its effect is manifest through a surface‐atmosphere coupling. Cloud longwave scattering is a necessity for the correct simulation of polar climate and surface radiation budget, especially in the winter.

URLhttp://dx.doi.org/10.1029/2020gl090534
DOI10.1029/2020gl090534
Journal: Geophysical Research Letters
Year of Publication: 2020
Publication Date: 11/2020

Most climate models neglect cloud longwave (LW) scattering because scattering is considered negligible compared to strong LW absorption by clouds and greenhouse gases. While this rationale is valid for simulating extra‐polar regions, it is questionable for the polar regions, where the atmosphere is dry and hence has weak absorption, and ice clouds that have strong scattering capability frequently occur. Using the slab‐ocean Community Earth System Model, we show that ice cloud LW scattering can warm winter surface air temperature by 0.8‐1.8K in the Arctic and 1.3‐1.9K in the Antarctic, while this warming becomes much weaker in polar summer. Such scattering effect cannot be correctly assessed when sea surface temperature and sea ice are prescribed as its effect is manifest through a surface‐atmosphere coupling. Cloud longwave scattering is a necessity for the correct simulation of polar climate and surface radiation budget, especially in the winter.

DOI: 10.1029/2020gl090534
Citation:
Chen, Y, X Huang, P Yang, C Kuo, and X Chen.  2020.  "Seasonal Dependent Impact of Ice‐Cloud Longwave Scattering on the Polar Climate."  Geophysical Research Letters.  https://doi.org/10.1029/2020gl090534.