DOI: 10.1002/2017JD027595
Scopus记录号: 2-s2.0-85040724795
论文题名: Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the Community Earth System Model
作者: Kuo C. ; Feldman D.R. ; Huang X. ; Flanner M. ; Yang P. ; Chen X.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2018
卷: 123, 期: 2 起始页码: 789
结束页码: 813
语种: 英语
英文关键词: climate feedback
; emissivity
; longwave
; radiative kernel
; temporal
Scopus关键词: albedo
; amplitude
; cloud cover
; cryosphere
; emissivity
; frozen ground
; longwave radiation
; radiative transfer
; spatiotemporal analysis
; surface temperature
; temporal variation
; thermodynamics
; time dependent behavior
; Arctic Ocean
英文摘要: Frozen and unfrozen surfaces exhibit different longwave surface emissivities with different spectral characteristics, and outgoing longwave radiation and cooling rates are reduced for unfrozen scenes relative to frozen ones. Here physically realistic modeling of spectrally resolved surface emissivity throughout the coupled model components of the Community Earth System Model (CESM) is advanced, and implications for model high-latitude biases and feedbacks are evaluated. It is shown that despite a surface emissivity feedback amplitude that is, at most, a few percent of the surface albedo feedback amplitude, the inclusion of realistic, harmonized longwave, spectrally resolved emissivity information in CESM1.2.2 reduces wintertime Arctic surface temperature biases from −7.2 ± 0.9 K to −1.1 ± 1.2 K, relative to observations. The bias reduction is most pronounced in the Arctic Ocean, a region for which Coupled Model Intercomparison Project version 5 (CMIP5) models exhibit the largest mean wintertime cold bias, suggesting that persistent polar temperature biases can be lessened by including this physically based process across model components. The ice emissivity feedback of CESM1.2.2 is evaluated under a warming scenario with a kernel-based approach, and it is found that emissivity radiative kernels exhibit water vapor and cloud cover dependence, thereby varying spatially and decreasing in magnitude over the course of the scenario from secular changes in atmospheric thermodynamics and cloud patterns. Accounting for the temporally varying radiative responses can yield diagnosed feedbacks that differ in sign from those obtained from conventional climatological feedback analysis methods. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114638
Appears in Collections: 气候减缓与适应
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作者单位: Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States; Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, United States; Department of Atmospheric Sciences, Texas A&M University, College Station, TX, United States
Recommended Citation:
Kuo C.,Feldman D.R.,Huang X.,et al. Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the Community Earth System Model[J]. Journal of Geophysical Research: Atmospheres,2018-01-01,123(2)