Surface heat and moisture exchange in the marginal ice zone: observations and a new parameterization scheme for weather and climate models

Elvidge, Andrew D., Renfrew, Ian A., Brooks, Ian M., Srivastava, Piyush, Yelland, Margaret J. and Prytherch, John (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). ISSN 2169-897X

[img] PDF (Accepted_Manuscript) - Accepted Version
Download (444kB)
[img] PDF (Published_Version) - Published Version
Available under License Creative Commons Attribution.

Download (3MB)

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 ((Formula presented.); itself a function of the roughness length for momentum, (Formula presented.), and surface wind stress), with a peak at the transition between aerodynamically smooth ((Formula presented.) <0.135) and aerodynamically rough ((Formula presented.) >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 (Formula presented.). 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 13 W m −2 for the new scheme, from 48 and 80 W m −2 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 (Formula presented.) is required.

Item Type: Article
Additional Information: This article also appears in: The Arctic: An AGU Joint Special Collection
Uncontrolled Keywords: air-sea-ice interaction,aircraft observations,sea ice,surface exchange parameterization,surface scalar exchange,turbulent fluxes,atmospheric science,geophysics,earth and planetary sciences (miscellaneous),space and planetary science ,/dk/atira/pure/subjectarea/asjc/1900/1902
Faculty \ School: Faculty of Science > School of Environmental Sciences
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 05 Aug 2021 00:07
Last Modified: 21 Sep 2021 01:32
URI: https://ueaeprints.uea.ac.uk/id/eprint/80976
DOI: 10.1029/2021JD034827

Actions (login required)

View Item View Item