Hughes, JK, Ross, AN, Vosper, SB et al. (2 more authors) (2015) Assessment of valley cold pools and clouds in a very high-resolution numerical weather prediction model. Geoscientific Model Development, 8 (10). 3105 - 3117. ISSN 1991-959X
Abstract
The formation of cold air pools in valleys under stable conditions represents an important challenge for numerical weather prediction (NWP). The challenge is increased when the valleys that dominate cold pool formation are on scales unresolved by NWP models, which can lead to substantial local errors in temperature forecasts. In this study a 2-month simulation is presented using a nested model con- figuration with a finest horizontal grid spacing of 100 m. The simulation is compared with observations from the recent COLd air Pooling Experiment (COLPEX) project and the model’s ability to represent cold pool formation, and the surface energy balance is assessed. The results reveal a bias in the model long-wave radiation that results from the assumptions made about the sub-grid variability in humidity in the cloud parametrization scheme. The cloud scheme assumes relative humidity thresholds below 100 % to diagnose partial cloudiness, an approach common to schemes used in many other models. The biases in radiation, and resulting biases in screen temperature and cold pool properties are shown to be sensitive to the choice of critical relative humidity, suggesting that this is a key area that should be improved for very high-resolution modeling.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © Author(s) 2015. This work is distributed under the Creative Commons Attribution 3.0 License. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Funding Information: | Funder Grant number NERC NE/I007679/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 09 Oct 2015 11:56 |
Last Modified: | 09 Oct 2015 11:56 |
Published Version: | http://dx.doi.org/10.5194/gmd-8-3105-2015 |
Status: | Published |
Publisher: | European Geosciences Union |
Identification Number: | 10.5194/gmd-8-3105-2015 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:90573 |