Elvidge, AD, Renfrew, IA, Brooks, IM orcid.org/0000-0002-5051-1322 et al. (3 more authors) (2021) Surface Heat and Moisture Exchange in the Marginal Ice Zone: Observations and a New Parameterization Scheme for Weather and Climate Models. Journal of Geophysical Research: Atmospheres, 126 (17). e2021JD034827. ISSN 2169-897X
Abstract
Aircraft observations from two Arctic field campaigns are used to characterize and model surface heat and moisture exchange over the marginal ice zone (MIZ). We show that the surface roughness lengths for heat and moisture over uninterrupted sea ice vary with roughness Reynolds number (R; itself a function of the roughness length for momentum, 0z, and surface wind stress), with a peak at the transition between aerodynamically smooth (R<0.135) and aerodynamically rough (R>2.5) regimes. A pre-existing theoretical model based on surface-renewal theory accurately reproduces this peak, in contrast to the simple parameterizations currently employed in two state-of-the-art numerical weather prediction models, which are insensitive to R. We propose a new, simple parameterization for surface exchange over the MIZ that blends this theoretical model for sea ice with surface exchange over water as a function of sea ice concentration. In offline tests, this new scheme performs much better than the existing schemes for the rough conditions observed during the ‘Iceland Greenland Seas Project’ field campaign. The bias in total turbulent heat flux across the MIZ is reduced to only 13W m2 for the new scheme, from 48 and 80W m2 for the Met Office Unified Model and ECMWF Integrated Forecast System schemes, respectively. It also performs marginally better for the comparatively smooth conditions observed during the ‘Aerosol-Cloud Coupling and Climate Interactions in the Arctic’ field campaign. The new surface exchange scheme has the benefit of being physically-motivated, comparatively accurate and straightforward to implement, although to reap the full benefits an improvement to the representation of sea ice topography via 0zis required
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021, The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
Keywords: | sea ice; turbulent fluxes; air-sea-ice interaction; surface scalar exchange; aircraft observations; surface exchange parameterization |
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 (Natural Environment Research Council) NE/I028858/1 NERC (Natural Environment Research Council) NE/S000690/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 03 Sep 2021 16:37 |
Last Modified: | 03 Sep 2021 16:37 |
Status: | Published |
Publisher: | American Geophysical Union (AGU) |
Identification Number: | 10.1029/2021jd034827 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:177750 |