Including two missing physics for a more realistic representation of cloud-surface longwave radiative coupling in the earth system model ...

• Main Authors: Fan, Chongxing, Chen, Yi-Hsuan, Chen, Xiuhong, Lin, Wuyin, Huang, Xianglei, Yang, Ping
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: GFZ German Research Centre for Geosciences 2023
• Subjects: Arctic
• Online Access: https://dx.doi.org/10.57757/iugg23-0192; https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016293

<!--!introduction!--> Climate models often ignore cloud scattering and surface emissivity in the longwave (LW) for computational efficiency. Such approximations can cause biases in radiative fluxes and affect simulated climate, especially in the Arctic. We implemented treatments to both physics into the DoE Energy Exascale Earth System Model (E3SM) version 2 and assessed their impacts on the simulated mean-state global climate as well as climate sensitivity. By turning on and off the switches in the modified E3SMv2 model, we studied the changes in mean-state climate due to cloud LW scattering and surface emissivity effects. Cloud LW scattering warms the entire global troposphere by ~0.4 K on average; the warming is stronger in the Arctic (~0.8 K) than in the tropics due to the Arctic amplification phenomenon. When realistic emissivity is incorporated into the model, the surface skin temperature increases by 0.36 K instantaneously on a global average. Surface skin temperature, as well as surface air ... : The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) ...