Observations of surface heat and moisture exchange in the marginal sea ice and implications for model parameterization
Aircraft observations from two Arctic field campaigns are used to derive ice surface characteristics and make recommendations for the parametrisation of surface heat and moisture exchange over sea ice and the marginal ice zone (MIZ). The observations were gathered in the Barents Sea and Fram Strait...
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ftnerc:oai:nora.nerc.ac.uk:530329 2023-05-15T13:11:51+02:00 Observations of surface heat and moisture exchange in the marginal sea ice and implications for model parameterization Elvidge, Andrew Renfrew, Ian Brooks, Ian Srivastava, Piyush Yelland, Margaret Prytherch, John 2021-04 http://nora.nerc.ac.uk/id/eprint/530329/ https://doi.org/10.5194/egusphere-egu21-11175 unknown Elvidge, Andrew; Renfrew, Ian; Brooks, Ian; Srivastava, Piyush; Yelland, Margaret orcid:0000-0002-0936-4957 Prytherch, John. 2021 Observations of surface heat and moisture exchange in the marginal sea ice and implications for model parameterization. In: EGU General Assembly 2021, Online, 19-30 April 2021. Publication - Conference Item PeerReviewed 2021 ftnerc https://doi.org/10.5194/egusphere-egu21-11175 2023-02-04T19:52:08Z Aircraft observations from two Arctic field campaigns are used to derive ice surface characteristics and make recommendations for the parametrisation of surface heat and moisture exchange over sea ice and the marginal ice zone (MIZ). The observations were gathered in the Barents Sea and Fram Strait as part of the Aerosol–Cloud Coupling And Climate Interactions in the Arctic (ACCACIA) project, and off the south-east coast of Greenland as part of the Iceland-Greenland Seas Project (IGP). Estimates of roughness lengths for momentum (z0), heat (z0T) and moisture (z0q) are derived from turbulent wind velocity, temperature and humidity measurements; while sea ice concentration is derived from albedo measurements. The two data sets cover a range of sea ice characteristics, being much rougher in general during IGP than during ACCACIA. Large fluxes of heat and moisture were observed in the vicinity of the MIZ during both field campaigns. We show that z0T and z0q over 100 % sea ice (z0Ti and z0qi) vary as a function of a roughness Reynolds number (R*; which itself is a function of z0 and wind stress), with a peak at the transition between the aerodynamically smooth (R*<0.135) and aerodynamically rough (R*>2.5) regimes. One of the few theory-based parameterisations available for z0Ti and z0qi (that of Andreas et al., 1987) reproduces these peaks, in contrast to the simple treatments currently employed in two leading numerical weather and climate prediction models – the Met Office Unified Model (MetUM) and the Integrated Forecast System (IFS) – which do not. The MetUM and IFS schemes perform adequately in smooth conditions, but greatly overestimate heat and moisture exchange in rough conditions. We develop a new parameterisation for heat and moisture exchange as a function of sea ice concentration, which blends the Andreas et al. (1987) scheme over sea ice with exchange over the ocean. This new parameterisation performs much better than the current MetUM and IFS schemes for the rough conditions observed during IGP, at ... Text albedo Arctic Barents Sea Fram Strait Greenland Iceland Sea ice Natural Environment Research Council: NERC Open Research Archive Arctic Barents Sea Greenland Andreas ENVELOPE(-60.729,-60.729,-64.008,-64.008) |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
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unknown |
description |
Aircraft observations from two Arctic field campaigns are used to derive ice surface characteristics and make recommendations for the parametrisation of surface heat and moisture exchange over sea ice and the marginal ice zone (MIZ). The observations were gathered in the Barents Sea and Fram Strait as part of the Aerosol–Cloud Coupling And Climate Interactions in the Arctic (ACCACIA) project, and off the south-east coast of Greenland as part of the Iceland-Greenland Seas Project (IGP). Estimates of roughness lengths for momentum (z0), heat (z0T) and moisture (z0q) are derived from turbulent wind velocity, temperature and humidity measurements; while sea ice concentration is derived from albedo measurements. The two data sets cover a range of sea ice characteristics, being much rougher in general during IGP than during ACCACIA. Large fluxes of heat and moisture were observed in the vicinity of the MIZ during both field campaigns. We show that z0T and z0q over 100 % sea ice (z0Ti and z0qi) vary as a function of a roughness Reynolds number (R*; which itself is a function of z0 and wind stress), with a peak at the transition between the aerodynamically smooth (R*<0.135) and aerodynamically rough (R*>2.5) regimes. One of the few theory-based parameterisations available for z0Ti and z0qi (that of Andreas et al., 1987) reproduces these peaks, in contrast to the simple treatments currently employed in two leading numerical weather and climate prediction models – the Met Office Unified Model (MetUM) and the Integrated Forecast System (IFS) – which do not. The MetUM and IFS schemes perform adequately in smooth conditions, but greatly overestimate heat and moisture exchange in rough conditions. We develop a new parameterisation for heat and moisture exchange as a function of sea ice concentration, which blends the Andreas et al. (1987) scheme over sea ice with exchange over the ocean. This new parameterisation performs much better than the current MetUM and IFS schemes for the rough conditions observed during IGP, at ... |
format |
Text |
author |
Elvidge, Andrew Renfrew, Ian Brooks, Ian Srivastava, Piyush Yelland, Margaret Prytherch, John |
spellingShingle |
Elvidge, Andrew Renfrew, Ian Brooks, Ian Srivastava, Piyush Yelland, Margaret Prytherch, John Observations of surface heat and moisture exchange in the marginal sea ice and implications for model parameterization |
author_facet |
Elvidge, Andrew Renfrew, Ian Brooks, Ian Srivastava, Piyush Yelland, Margaret Prytherch, John |
author_sort |
Elvidge, Andrew |
title |
Observations of surface heat and moisture exchange in the marginal sea ice and implications for model parameterization |
title_short |
Observations of surface heat and moisture exchange in the marginal sea ice and implications for model parameterization |
title_full |
Observations of surface heat and moisture exchange in the marginal sea ice and implications for model parameterization |
title_fullStr |
Observations of surface heat and moisture exchange in the marginal sea ice and implications for model parameterization |
title_full_unstemmed |
Observations of surface heat and moisture exchange in the marginal sea ice and implications for model parameterization |
title_sort |
observations of surface heat and moisture exchange in the marginal sea ice and implications for model parameterization |
publishDate |
2021 |
url |
http://nora.nerc.ac.uk/id/eprint/530329/ https://doi.org/10.5194/egusphere-egu21-11175 |
long_lat |
ENVELOPE(-60.729,-60.729,-64.008,-64.008) |
geographic |
Arctic Barents Sea Greenland Andreas |
geographic_facet |
Arctic Barents Sea Greenland Andreas |
genre |
albedo Arctic Barents Sea Fram Strait Greenland Iceland Sea ice |
genre_facet |
albedo Arctic Barents Sea Fram Strait Greenland Iceland Sea ice |
op_relation |
Elvidge, Andrew; Renfrew, Ian; Brooks, Ian; Srivastava, Piyush; Yelland, Margaret orcid:0000-0002-0936-4957 Prytherch, John. 2021 Observations of surface heat and moisture exchange in the marginal sea ice and implications for model parameterization. In: EGU General Assembly 2021, Online, 19-30 April 2021. |
op_doi |
https://doi.org/10.5194/egusphere-egu21-11175 |
_version_ |
1766249204616790016 |