Contributions of Clouds, Surface Albedos, and Mixed-Phase Ice Nucleation Schemes to Arctic Radiation Biases in CAM5
The Arctic radiation balance is strongly affected by clouds and surface albedo. Prior work has identified Arctic cloud liquid water path (LWP) and surface radiative flux biases in the Community Atmosphere Model, version 5 (CAMS), and reductions to these biases with improved mixed-phase ice nucleatio...
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ftmountainschol:oai:mountainscholar.org:20.500.11919/692 2023-05-15T13:11:18+02:00 Contributions of Clouds, Surface Albedos, and Mixed-Phase Ice Nucleation Schemes to Arctic Radiation Biases in CAM5 English, Jason M. Kay, Jennifer E. Gettelman, Andrew Liu, Xiaohong Wang, Yong Zhang, Yuying Chepfer, Helene 2014-07-01 application/pdf https://hdl.handle.net/20.500.11919/692 https://doi.org/10.1175/JCLI-D-13-00608.1 English eng eng University of Wyoming. Libraries Faculty Publications - Atmospheric Science https://hdl.handle.net/20.500.11919/692 doi:10.1175/JCLI-D-13-00608.1 Atmospheric Science Faculty Publications Engineering Journal contribution 2014 ftmountainschol https://doi.org/20.500.11919/692 https://doi.org/10.1175/JCLI-D-13-00608.1 2022-03-07T21:05:32Z The Arctic radiation balance is strongly affected by clouds and surface albedo. Prior work has identified Arctic cloud liquid water path (LWP) and surface radiative flux biases in the Community Atmosphere Model, version 5 (CAMS), and reductions to these biases with improved mixed-phase ice nucleation schemes. Here, CAMS net top-of-atmosphere (TOA) Arctic radiative flux biases are quantified along with the contributions of clouds, surface albedos, and new mixed-phase ice nucleation schemes to these biases. CAMS net TOA all-sky shortwave (SW) and outgoing longwave radiation (OLR) fluxes are generally within 10W m-2 of Clouds and the Earth's Radiant Energy System Energy Balanced and Filled (CERES-EBAF) observations. However, CAMS has compensating SW errors: Surface albedos over snow are too high while cloud amount and LWP are too low. Use of a new CAMS Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) lidar simulator that corrects an error in the treatment of snow crystal size confirms insufficient cloud amount in CAMS year-round. CAMS OLR is too low because of low surface temperature in winter, excessive atmospheric water vapor in summer, and excessive cloud heights year-round. Simulations with two new mixed-phase ice nucleation schemes-one based on an empirical fit to ice nuclei observations and one based on classical nucleation theory with prognostic ice nuclei improve surface climate in winter by increasing cloud amount and LWP. However, net TOA and surface radiation biases remain because of increases in midlevel clouds and a persistent deficit in cloud LWP. These findings highlight challenges with evaluating and modeling Arctic cloud, radiation, and climate processes. Other Non-Article Part of Journal/Newspaper albedo Arctic Mountain Scholar (Digital Collections of Colorado and Wyoming) Arctic Journal of Climate 27 13 5174 5197 |
institution |
Open Polar |
collection |
Mountain Scholar (Digital Collections of Colorado and Wyoming) |
op_collection_id |
ftmountainschol |
language |
English |
topic |
Engineering |
spellingShingle |
Engineering English, Jason M. Kay, Jennifer E. Gettelman, Andrew Liu, Xiaohong Wang, Yong Zhang, Yuying Chepfer, Helene Contributions of Clouds, Surface Albedos, and Mixed-Phase Ice Nucleation Schemes to Arctic Radiation Biases in CAM5 |
topic_facet |
Engineering |
description |
The Arctic radiation balance is strongly affected by clouds and surface albedo. Prior work has identified Arctic cloud liquid water path (LWP) and surface radiative flux biases in the Community Atmosphere Model, version 5 (CAMS), and reductions to these biases with improved mixed-phase ice nucleation schemes. Here, CAMS net top-of-atmosphere (TOA) Arctic radiative flux biases are quantified along with the contributions of clouds, surface albedos, and new mixed-phase ice nucleation schemes to these biases. CAMS net TOA all-sky shortwave (SW) and outgoing longwave radiation (OLR) fluxes are generally within 10W m-2 of Clouds and the Earth's Radiant Energy System Energy Balanced and Filled (CERES-EBAF) observations. However, CAMS has compensating SW errors: Surface albedos over snow are too high while cloud amount and LWP are too low. Use of a new CAMS Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) lidar simulator that corrects an error in the treatment of snow crystal size confirms insufficient cloud amount in CAMS year-round. CAMS OLR is too low because of low surface temperature in winter, excessive atmospheric water vapor in summer, and excessive cloud heights year-round. Simulations with two new mixed-phase ice nucleation schemes-one based on an empirical fit to ice nuclei observations and one based on classical nucleation theory with prognostic ice nuclei improve surface climate in winter by increasing cloud amount and LWP. However, net TOA and surface radiation biases remain because of increases in midlevel clouds and a persistent deficit in cloud LWP. These findings highlight challenges with evaluating and modeling Arctic cloud, radiation, and climate processes. |
format |
Other Non-Article Part of Journal/Newspaper |
author |
English, Jason M. Kay, Jennifer E. Gettelman, Andrew Liu, Xiaohong Wang, Yong Zhang, Yuying Chepfer, Helene |
author_facet |
English, Jason M. Kay, Jennifer E. Gettelman, Andrew Liu, Xiaohong Wang, Yong Zhang, Yuying Chepfer, Helene |
author_sort |
English, Jason M. |
title |
Contributions of Clouds, Surface Albedos, and Mixed-Phase Ice Nucleation Schemes to Arctic Radiation Biases in CAM5 |
title_short |
Contributions of Clouds, Surface Albedos, and Mixed-Phase Ice Nucleation Schemes to Arctic Radiation Biases in CAM5 |
title_full |
Contributions of Clouds, Surface Albedos, and Mixed-Phase Ice Nucleation Schemes to Arctic Radiation Biases in CAM5 |
title_fullStr |
Contributions of Clouds, Surface Albedos, and Mixed-Phase Ice Nucleation Schemes to Arctic Radiation Biases in CAM5 |
title_full_unstemmed |
Contributions of Clouds, Surface Albedos, and Mixed-Phase Ice Nucleation Schemes to Arctic Radiation Biases in CAM5 |
title_sort |
contributions of clouds, surface albedos, and mixed-phase ice nucleation schemes to arctic radiation biases in cam5 |
publisher |
University of Wyoming. Libraries |
publishDate |
2014 |
url |
https://hdl.handle.net/20.500.11919/692 https://doi.org/10.1175/JCLI-D-13-00608.1 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
albedo Arctic |
genre_facet |
albedo Arctic |
op_source |
Atmospheric Science Faculty Publications |
op_relation |
Faculty Publications - Atmospheric Science https://hdl.handle.net/20.500.11919/692 doi:10.1175/JCLI-D-13-00608.1 |
op_doi |
https://doi.org/20.500.11919/692 https://doi.org/10.1175/JCLI-D-13-00608.1 |
container_title |
Journal of Climate |
container_volume |
27 |
container_issue |
13 |
container_start_page |
5174 |
op_container_end_page |
5197 |
_version_ |
1766246781836853248 |