Turbulent Transport from an Arctic Lead: A Large-Eddy Simulation
The upward transfer of heat from ocean to atmosphere is examined for an Arctic 'lead,' a break in the Arctic ice which allows contact between the cold atmosphere and the relatively warm ocean. We employ a large-eddy model to compute explicitly the three dimensional turbulent response of th...
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ftdtic:ADA254396 2023-05-15T14:50:11+02:00 Turbulent Transport from an Arctic Lead: A Large-Eddy Simulation Glendening, John W. Burk, Stephen D. NAVAL OCEANOGRAPHIC AND ATMOSPHERIC RESEARCH LAB STENNIS SPACE CENTER MS 1992 text/html http://www.dtic.mil/docs/citations/ADA254396 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA254396 en eng http://www.dtic.mil/docs/citations/ADA254396 Approved for public release; distribution is unlimited. DTIC AND NTIS Meteorology Physical and Dynamic Oceanography Thermodynamics Fluid Mechanics *HEAT TRANSFER *TURBULENCE *ATMOSPHERIC MOTION *EDDIES(FLUID MECHANICS) SIMULATION AIR WATER INTERACTIONS ADVECTION ARCTIC REGIONS ATMOSPHERE MODELS HEAT FLUX PLUMES REPRINTS WIND VELOCITY BOUNDARY LAYER UPDRAFTS MESOSCALE ARCTIC LEADS PE61153N WU14411A Text 1992 ftdtic 2016-02-22T13:46:01Z The upward transfer of heat from ocean to atmosphere is examined for an Arctic 'lead,' a break in the Arctic ice which allows contact between the cold atmosphere and the relatively warm ocean. We employ a large-eddy model to compute explicitly the three dimensional turbulent response of the atmosphere to a lead of 200 m width. The surface heat flux creates a turbulent 'plume' of individual quasi-random eddies, not a continuous updraft, which penetrate into the stable atmosphere and transport heat upward. Maximum updraft velocities and turbulence occur downwind of the lead rather than over the lead itself, because the development time of an individual thermal eddy is longer than its transit time across the lead. The affected vertical region, while shallow over the lead itself, grows to a height of 65 m at 600 m downwind of the lead; beyond that, the depth of the turbulent region decreases as the eddies weaken. The maximum vertical turbulent heat flux occurs at the downwind edge of the lead, beyond which a relative maximum extends upward into the plume. Negative surface heat flux immediately downwind of the lead creates a growing stable layer, but above that internal boundary layer the turbulent heat flux is still positive. Updraft maxima are typically 28 cm/s, but compensating downdrafts result in time-averaged vertical velocities of less than 1 cm/s in the plume. Conditional sampling separates the updraft and downdraft contributions. Formulas for the horizontal eddy development distance and for the vertical plume penetration height are presented. Published in Boundary-Layer Meteorology, v59, p315-339, 1992. Text Arctic Defense Technical Information Center: DTIC Technical Reports database Arctic |
institution |
Open Polar |
collection |
Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Meteorology Physical and Dynamic Oceanography Thermodynamics Fluid Mechanics *HEAT TRANSFER *TURBULENCE *ATMOSPHERIC MOTION *EDDIES(FLUID MECHANICS) SIMULATION AIR WATER INTERACTIONS ADVECTION ARCTIC REGIONS ATMOSPHERE MODELS HEAT FLUX PLUMES REPRINTS WIND VELOCITY BOUNDARY LAYER UPDRAFTS MESOSCALE ARCTIC LEADS PE61153N WU14411A |
spellingShingle |
Meteorology Physical and Dynamic Oceanography Thermodynamics Fluid Mechanics *HEAT TRANSFER *TURBULENCE *ATMOSPHERIC MOTION *EDDIES(FLUID MECHANICS) SIMULATION AIR WATER INTERACTIONS ADVECTION ARCTIC REGIONS ATMOSPHERE MODELS HEAT FLUX PLUMES REPRINTS WIND VELOCITY BOUNDARY LAYER UPDRAFTS MESOSCALE ARCTIC LEADS PE61153N WU14411A Glendening, John W. Burk, Stephen D. Turbulent Transport from an Arctic Lead: A Large-Eddy Simulation |
topic_facet |
Meteorology Physical and Dynamic Oceanography Thermodynamics Fluid Mechanics *HEAT TRANSFER *TURBULENCE *ATMOSPHERIC MOTION *EDDIES(FLUID MECHANICS) SIMULATION AIR WATER INTERACTIONS ADVECTION ARCTIC REGIONS ATMOSPHERE MODELS HEAT FLUX PLUMES REPRINTS WIND VELOCITY BOUNDARY LAYER UPDRAFTS MESOSCALE ARCTIC LEADS PE61153N WU14411A |
description |
The upward transfer of heat from ocean to atmosphere is examined for an Arctic 'lead,' a break in the Arctic ice which allows contact between the cold atmosphere and the relatively warm ocean. We employ a large-eddy model to compute explicitly the three dimensional turbulent response of the atmosphere to a lead of 200 m width. The surface heat flux creates a turbulent 'plume' of individual quasi-random eddies, not a continuous updraft, which penetrate into the stable atmosphere and transport heat upward. Maximum updraft velocities and turbulence occur downwind of the lead rather than over the lead itself, because the development time of an individual thermal eddy is longer than its transit time across the lead. The affected vertical region, while shallow over the lead itself, grows to a height of 65 m at 600 m downwind of the lead; beyond that, the depth of the turbulent region decreases as the eddies weaken. The maximum vertical turbulent heat flux occurs at the downwind edge of the lead, beyond which a relative maximum extends upward into the plume. Negative surface heat flux immediately downwind of the lead creates a growing stable layer, but above that internal boundary layer the turbulent heat flux is still positive. Updraft maxima are typically 28 cm/s, but compensating downdrafts result in time-averaged vertical velocities of less than 1 cm/s in the plume. Conditional sampling separates the updraft and downdraft contributions. Formulas for the horizontal eddy development distance and for the vertical plume penetration height are presented. Published in Boundary-Layer Meteorology, v59, p315-339, 1992. |
author2 |
NAVAL OCEANOGRAPHIC AND ATMOSPHERIC RESEARCH LAB STENNIS SPACE CENTER MS |
format |
Text |
author |
Glendening, John W. Burk, Stephen D. |
author_facet |
Glendening, John W. Burk, Stephen D. |
author_sort |
Glendening, John W. |
title |
Turbulent Transport from an Arctic Lead: A Large-Eddy Simulation |
title_short |
Turbulent Transport from an Arctic Lead: A Large-Eddy Simulation |
title_full |
Turbulent Transport from an Arctic Lead: A Large-Eddy Simulation |
title_fullStr |
Turbulent Transport from an Arctic Lead: A Large-Eddy Simulation |
title_full_unstemmed |
Turbulent Transport from an Arctic Lead: A Large-Eddy Simulation |
title_sort |
turbulent transport from an arctic lead: a large-eddy simulation |
publishDate |
1992 |
url |
http://www.dtic.mil/docs/citations/ADA254396 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA254396 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA254396 |
op_rights |
Approved for public release; distribution is unlimited. |
_version_ |
1766321238458761216 |