文献类型：期刊文献

英文题名：Transition of Low Clouds in the East China Sea and Kuroshio Region in Winter: A Regional Atmospheric Model Study

作者：Long, Jingchao[1,2,3,4,5,6];Wang, Yuqing[5,6];Zhang, Suping[3,4];Liu, Jingwu[3,4]

机构：[1]Guangdong Ocean Univ, Coll Ocean & Meteorol, South China Sea Inst Marine & Meteorol, Zhanjiang, Peoples R China;[2]Marine Resources Big Data Ctr South China Sea, Southern Marine Sci & Engn Guangdong Lab, Zhanjiang, Peoples R China;[3]Ocean Univ China, Phys Oceanog Lab, Qingdao, Peoples R China;[4]Ocean Univ China, Ocean Atmosphere Interact & Climate Lab, Qingdao, Peoples R China;[5]Univ Hawaii Manoa, Int Pacific Res Ctr, Honolulu, HI 96822 USA;[6]Univ Hawaii Manoa, Dept Atmospher Sci, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA

年份：2020

卷号：125

期号：17

外文期刊名：JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES

收录：SCI-EXPANDED(收录号：WOS:000571890800025)、、WOS

基金：The authors are grateful to three anonymous reviewers for constructive review comments, which helped improve our manuscript. This study has been jointly supported by the National Key R&D Program of China (Grant 2018YFC1505902) and the National Natural Science Foundation of China (Grants 41905006 and 41876130). The authors wish to thank Drs. Chunxi Zhang and Jiuwei Zhao for their valuable discussions. Part of the work was completed when Jingchao Long was a visiting PhD student in IPRC at University of Hawaii at Manoa supported by the China Scholarship Council.

语种：英文

外文关键词：low cloud transition; SST front; Kuroshio; synoptic disturbances; ensemble simulation

外文摘要：Bias in simulating the stratocumulus-to-cumulus transition remains a main source of uncertainties in climate projection and can significantly affect the energy budget in climate models. To gain insights into the transition, this study investigates the cloud transition forced by the sea surface temperature (SST) front and synoptic disturbances in the East China Sea and Kuroshio region in winter based on both observations and regional atmospheric model simulations. The Kuroshio SST front greatly accelerates cloud transition by enhancing surface latent heat flux, marine atmospheric boundary layer (MABL) dynamical adjustment, and cloud top entrainment. With the sharp SST increase from the cold flank to the Kuroshio SST warm tongue (KWT), surface wind convergence (SWC) over the KWT induced by the SST front and synoptic disturbances enhances the coupling between the cloud layer and subcloud layer. An underlying positive feedback between the SWC and latent heating in the cloud layer can enhance abrupt change in cloud properties and maintain cloud band over the KWT against the decoupling through the so-called "Deepening-Warming" mechanism induced by latent heating. From the KWT downwind southward, the surface layer turbulent mixing weakens, while latent heating in the cloud layer and cloud top longwave radiative cooling enhance buoyancy and vertical mixing in the cloud layer. This difference in vertical mixing between the cloud layer and subcloud layer facilitates the MABL decoupling and impedes upward moisture transport. Meanwhile, decreasing lower tropospheric stability is conducive to the entrainment of drier and warmer air from above into the cloud layer, strengthening cloud evaporation.