Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the Community Earth System Model
©2018. American Geophysical Union. All Rights Reserved. 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 rea...
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Language: | English |
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ftcdlib:qt8ps974q7 2023-05-15T13:11:39+02:00 Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the Community Earth System Model Kuo, C Feldman, DR Huang, X Flanner, M Yang, P Chen, X 789 - 813 2018-01-27 application/pdf http://www.escholarship.org/uc/item/8ps974q7 english eng eScholarship, University of California qt8ps974q7 http://www.escholarship.org/uc/item/8ps974q7 public Kuo, C; Feldman, DR; Huang, X; Flanner, M; Yang, P; & Chen, X. (2018). Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the Community Earth System Model. Journal of Geophysical Research: Atmospheres, 123(2), 789 - 813. doi:10.1002/2017JD027595. Lawrence Berkeley National Laboratory: Retrieved from: http://www.escholarship.org/uc/item/8ps974q7 article 2018 ftcdlib https://doi.org/10.1002/2017JD027595 2018-09-28T22:52:56Z ©2018. American Geophysical Union. All Rights Reserved. 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. Article in Journal/Newspaper albedo Arctic Arctic Ocean University of California: eScholarship Arctic Arctic Ocean Journal of Geophysical Research: Atmospheres 123 2 789 813 |
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Open Polar |
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University of California: eScholarship |
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ftcdlib |
language |
English |
description |
©2018. American Geophysical Union. All Rights Reserved. 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. |
format |
Article in Journal/Newspaper |
author |
Kuo, C Feldman, DR Huang, X Flanner, M Yang, P Chen, X |
spellingShingle |
Kuo, C Feldman, DR Huang, X Flanner, M Yang, P Chen, X Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the Community Earth System Model |
author_facet |
Kuo, C Feldman, DR Huang, X Flanner, M Yang, P Chen, X |
author_sort |
Kuo, C |
title |
Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the Community Earth System Model |
title_short |
Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the Community Earth System Model |
title_full |
Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the Community Earth System Model |
title_fullStr |
Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the Community Earth System Model |
title_full_unstemmed |
Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the Community Earth System Model |
title_sort |
time-dependent cryospheric longwave surface emissivity feedback in the community earth system model |
publisher |
eScholarship, University of California |
publishDate |
2018 |
url |
http://www.escholarship.org/uc/item/8ps974q7 |
op_coverage |
789 - 813 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
albedo Arctic Arctic Ocean |
genre_facet |
albedo Arctic Arctic Ocean |
op_source |
Kuo, C; Feldman, DR; Huang, X; Flanner, M; Yang, P; & Chen, X. (2018). Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the Community Earth System Model. Journal of Geophysical Research: Atmospheres, 123(2), 789 - 813. doi:10.1002/2017JD027595. Lawrence Berkeley National Laboratory: Retrieved from: http://www.escholarship.org/uc/item/8ps974q7 |
op_relation |
qt8ps974q7 http://www.escholarship.org/uc/item/8ps974q7 |
op_rights |
public |
op_doi |
https://doi.org/10.1002/2017JD027595 |
container_title |
Journal of Geophysical Research: Atmospheres |
container_volume |
123 |
container_issue |
2 |
container_start_page |
789 |
op_container_end_page |
813 |
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1766248375558078464 |