Seasonal and interannual variations of the oceanic heat flux under a landfast Antarctic sea ice cover
A multilayer thermodynamic model is used to simulate sea ice growth for 12 years between 1958 and 1986 in the vicinity of the Australian station Mawson on the coast of East Antarctica. The atmospheric forcing data for the model are derived from radiosonde profiles and from surface measurements. Glob...
Published in: | Journal of Geophysical Research: Oceans |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Amer Geophysical Union
1996
|
Subjects: | |
Online Access: | https://doi.org/10.1029/96JC01921 http://ecite.utas.edu.au/7071 |
id |
ftunivtasecite:oai:ecite.utas.edu.au:7071 |
---|---|
record_format |
openpolar |
spelling |
ftunivtasecite:oai:ecite.utas.edu.au:7071 2023-05-15T13:56:40+02:00 Seasonal and interannual variations of the oceanic heat flux under a landfast Antarctic sea ice cover Heil, P Allison, I Lytle, VI 1996 https://doi.org/10.1029/96JC01921 http://ecite.utas.edu.au/7071 en eng Amer Geophysical Union http://dx.doi.org/10.1029/96JC01921 Heil, P and Allison, I and Lytle, VI, Seasonal and interannual variations of the oceanic heat flux under a landfast Antarctic sea ice cover, Journal of Geophysical Research, 101, (C11) pp. 25741-25752. ISSN 0148-0227 (1996) [Refereed Article] http://ecite.utas.edu.au/7071 Earth Sciences Physical Geography and Environmental Geoscience Glaciology Refereed Article PeerReviewed 1996 ftunivtasecite https://doi.org/10.1029/96JC01921 2019-12-13T20:53:53Z A multilayer thermodynamic model is used to simulate sea ice growth for 12 years between 1958 and 1986 in the vicinity of the Australian station Mawson on the coast of East Antarctica. The atmospheric forcing data for the model are derived from radiosonde profiles and from surface measurements. Global radiation data are available for 4 years, and we use these measurements for comparison with the results of a Zillman-type model for global radiation. Combining the thermodynamic model with sea ice thickness measurements for 12 years, we solve the energy balance equation for the oceanic heat flux. The oceanic heat flux is not constant but changes with time within the year and from year to year. The oceanic heat flux averages 7.9 W/m2, and the yearly means vary between 5 and 12 W/m2. Seasonal values of the oceanic heat flux range from 0 to 18 W/ m2. From the yearly averaged values a decadal trend is evident: During the first years that were analyzed the yearly average lies well above 10 W/m2; then in the mid-1970s a decrease to 9 W/m2 occurs, while for all later years the values are 6-8 W/m2. In general, the oceanic heat flux increases from the start of the fast ice formation season in early April until it breaks out in December or January. To compare the calculated oceanic heat fluxes for different years, we divide the total ice season into three characteristic time regimes of the sea ice growth and calculate the averaged oceanic heat fluxes for each regime. For the first regime (through August) the mean flux is 2.7 W/m2, for the middle regime (September) it is 8.4 W/m2, and for the final regime (October-January) it is 17 W/m2. We discuss the results of our model calculations in conjunction with current meter observations, which give evidence of seasonally varying intrusions of relatively warm Circumpolar Deep Water into Prydz Bay. Comparison of passive microwave data of sea ice extent and concentration (from the scanning multichannel microwave radiometer sensor) with the model results reveals a correlation between the magnitude of the oceanic heat flux and local features such as polynyas. Copyright 1996 by the American Geophysical Union. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Prydz Bay Sea ice eCite UTAS (University of Tasmania) Antarctic East Antarctica Prydz Bay Journal of Geophysical Research: Oceans 101 C11 25741 25752 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Physical Geography and Environmental Geoscience Glaciology |
spellingShingle |
Earth Sciences Physical Geography and Environmental Geoscience Glaciology Heil, P Allison, I Lytle, VI Seasonal and interannual variations of the oceanic heat flux under a landfast Antarctic sea ice cover |
topic_facet |
Earth Sciences Physical Geography and Environmental Geoscience Glaciology |
description |
A multilayer thermodynamic model is used to simulate sea ice growth for 12 years between 1958 and 1986 in the vicinity of the Australian station Mawson on the coast of East Antarctica. The atmospheric forcing data for the model are derived from radiosonde profiles and from surface measurements. Global radiation data are available for 4 years, and we use these measurements for comparison with the results of a Zillman-type model for global radiation. Combining the thermodynamic model with sea ice thickness measurements for 12 years, we solve the energy balance equation for the oceanic heat flux. The oceanic heat flux is not constant but changes with time within the year and from year to year. The oceanic heat flux averages 7.9 W/m2, and the yearly means vary between 5 and 12 W/m2. Seasonal values of the oceanic heat flux range from 0 to 18 W/ m2. From the yearly averaged values a decadal trend is evident: During the first years that were analyzed the yearly average lies well above 10 W/m2; then in the mid-1970s a decrease to 9 W/m2 occurs, while for all later years the values are 6-8 W/m2. In general, the oceanic heat flux increases from the start of the fast ice formation season in early April until it breaks out in December or January. To compare the calculated oceanic heat fluxes for different years, we divide the total ice season into three characteristic time regimes of the sea ice growth and calculate the averaged oceanic heat fluxes for each regime. For the first regime (through August) the mean flux is 2.7 W/m2, for the middle regime (September) it is 8.4 W/m2, and for the final regime (October-January) it is 17 W/m2. We discuss the results of our model calculations in conjunction with current meter observations, which give evidence of seasonally varying intrusions of relatively warm Circumpolar Deep Water into Prydz Bay. Comparison of passive microwave data of sea ice extent and concentration (from the scanning multichannel microwave radiometer sensor) with the model results reveals a correlation between the magnitude of the oceanic heat flux and local features such as polynyas. Copyright 1996 by the American Geophysical Union. |
format |
Article in Journal/Newspaper |
author |
Heil, P Allison, I Lytle, VI |
author_facet |
Heil, P Allison, I Lytle, VI |
author_sort |
Heil, P |
title |
Seasonal and interannual variations of the oceanic heat flux under a landfast Antarctic sea ice cover |
title_short |
Seasonal and interannual variations of the oceanic heat flux under a landfast Antarctic sea ice cover |
title_full |
Seasonal and interannual variations of the oceanic heat flux under a landfast Antarctic sea ice cover |
title_fullStr |
Seasonal and interannual variations of the oceanic heat flux under a landfast Antarctic sea ice cover |
title_full_unstemmed |
Seasonal and interannual variations of the oceanic heat flux under a landfast Antarctic sea ice cover |
title_sort |
seasonal and interannual variations of the oceanic heat flux under a landfast antarctic sea ice cover |
publisher |
Amer Geophysical Union |
publishDate |
1996 |
url |
https://doi.org/10.1029/96JC01921 http://ecite.utas.edu.au/7071 |
geographic |
Antarctic East Antarctica Prydz Bay |
geographic_facet |
Antarctic East Antarctica Prydz Bay |
genre |
Antarc* Antarctic Antarctica East Antarctica Prydz Bay Sea ice |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Prydz Bay Sea ice |
op_relation |
http://dx.doi.org/10.1029/96JC01921 Heil, P and Allison, I and Lytle, VI, Seasonal and interannual variations of the oceanic heat flux under a landfast Antarctic sea ice cover, Journal of Geophysical Research, 101, (C11) pp. 25741-25752. ISSN 0148-0227 (1996) [Refereed Article] http://ecite.utas.edu.au/7071 |
op_doi |
https://doi.org/10.1029/96JC01921 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
101 |
container_issue |
C11 |
container_start_page |
25741 |
op_container_end_page |
25752 |
_version_ |
1766264213482766336 |