Seasonal and interannual variations of the oceanic heat flux under a landfast Antarctic sea ice cover

1996 ◽  
Vol 101 (C11) ◽  
pp. 25741-25752 ◽  
Author(s):  
Petra Heil ◽  
Ian Allison ◽  
Victoria I. Lytle
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Ice Cover ◽  
Interannual Variations ◽  
Antarctic Sea Ice ◽  
Oceanic Heat Flux ◽  
Seasonal And Interannual Variations

scholarly journals Oceanic Heat Flux as a Component of the Heat Budget of Sea Ice

1985 ◽  
Vol 6 ◽  
pp. 171-173 ◽  
Author(s):  
M. P. Langleben
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Latent Heat ◽  
Heat Budget ◽  
Average Rate ◽  
Ice Cores ◽  
Ice Cover ◽  
Energy Balance Equation ◽  
Conductive Heat ◽  
Oceanic Heat Flux

Heat budget studies of the sea ice cover near Pond Inlet, NWT, were made using data obtained at two locations in Eclipse Sound, one about 0.5 km from shore and the other about 7.5 km from shore. The observations at intervals of one week included ice temperatures at 10 cm separation in vertical profile, salinities of adjacent 2.5 cm-thick slices from vertical ice cores, and ice thickness. The time series analysed extend from three to six months in the six data sets obtained for three winters of observations. Values of oceanic heat flux have been determined as residuals in the energy balance equation applied to the ice cover. The results show that in Eclipse Sound the oceanic heat flux is a significant component of the heat budget of the ice cover. Its value over the winter is typically about 6 W m-2about half as large as the average rate of release of the latent heat of freezing. There does not appear to be any systematic variation in value of the 4 week-average oceanic heat flux during the season. Nor is there any apparent correlation of oceanic heat flux with rate of release of latent heat (ie ice growth rate), or with the severity of the winter as measured by the magnitude of the conductive heat flux.

scholarly journals Oceanic Heat Flux as a Component of the Heat Budget of Sea Ice

1985 ◽  
Vol 6 ◽  
pp. 171-173
Author(s):  
M. P. Langleben
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Latent Heat ◽  
Heat Budget ◽  
Average Rate ◽  
Ice Cores ◽  
Ice Cover ◽  
Energy Balance Equation ◽  
Conductive Heat ◽  
Oceanic Heat Flux

Heat budget studies of the sea ice cover near Pond Inlet, NWT, were made using data obtained at two locations in Eclipse Sound, one about 0.5 km from shore and the other about 7.5 km from shore. The observations at intervals of one week included ice temperatures at 10 cm separation in vertical profile, salinities of adjacent 2.5 cm-thick slices from vertical ice cores, and ice thickness. The time series analysed extend from three to six months in the six data sets obtained for three winters of observations. Values of oceanic heat flux have been determined as residuals in the energy balance equation applied to the ice cover. The results show that in Eclipse Sound the oceanic heat flux is a significant component of the heat budget of the ice cover. Its value over the winter is typically about 6 W m-2 about half as large as the average rate of release of the latent heat of freezing. There does not appear to be any systematic variation in value of the 4 week-average oceanic heat flux during the season. Nor is there any apparent correlation of oceanic heat flux with rate of release of latent heat (ie ice growth rate), or with the severity of the winter as measured by the magnitude of the conductive heat flux.

scholarly journals Sensitivity of the Antarctic sea-ice distribution to oceanic heat flux in a coupled atmosphere-sea-ice model

2001 ◽  
Vol 33 ◽  
pp. 577-584 ◽  
Author(s):  
Xingren Wu ◽  
W. F. Budd ◽  
A. P. Worby ◽  
Ian Allison
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Ice Thickness ◽  
Sea Ice Thickness ◽  
Antarctic Sea Ice ◽  
Oceanic Heat Flux ◽  
Ice Concentration ◽  
Microwave Radiometers ◽  
The Antarctic ◽  
Ice Model

AbstractA coupled atmosphere-sea-ice model is used to study the sensitivity of the Antarctic sea-ice distribution to oceanic heat flux (OHF). Remote sensing of sea ice from microwave radiometers provides data on ice extent and ice concentration. The ice-thickness data used are from ship-based observations. Our simulations suggest that OHF values of 0−5 W m−2 will cause sea ice to be too thick in the model. A value of 20−25 Wm−2 throughout the year causes sea ice to be too thin in the model. The model results indicate that a seasonally varying OHF is required to match the modelled thickness with observations. Values of 5−30 Wm with an annual mean of 10−15 Wm−2, give a reasonable distribution of sea-ice thickness. This agrees with the limited observations of OHF available for the Antarctic. The model results also indicate that the OHF should be varied spatially. When a seasonally and spatially variable OHF is applied to the coupled atmosphere-sea-ice model a still better simulation of the sea-ice distribution is obtained. Our results also suggest that the role of ice advection is very important in the determination of the sea-ice distribution, and it can be quantified by the model.

scholarly journals An Isotopic Method of Estimating Conductive Heat Flux Through Antarctic First-Year Sea Ice

1990 ◽  
Vol 14 ◽  
pp. 270-272 ◽  
Author(s):  
R. Souchez ◽  
J. -L. Tison ◽  
J. Jouzel
Keyword(s):  
Heat Flux ◽  
Growth Rate ◽  
Sea Ice ◽  
Growth Period ◽  
Ice Cover ◽  
Rate Curve ◽  
First Year ◽  
Conductive Heat ◽  
Antarctic Sea Ice ◽  
Conductive Heat Flux

The deuterium concentration profile in a first-year Antarctic sea-ice cover is used to deduce a growth-rate curve, applying a previously published model. Time variations of the conductive heat flux throughout the growth period are then estimated from this growth-rate curve. Results indicate that the isotopic determination of sea ice growth rate can be considered as an alternate method for determining the conductive heat flux through a young sea-ice cover. However, there is need for a further test of the method by measuringin situtemperatures and growth rates during the formation of first-year sea ice, and by analyzing the isotopic composition of ice samples taken simultaneously along selected profiles during the growth period.

scholarly journals An Isotopic Method of Estimating Conductive Heat Flux Through Antarctic First-Year Sea Ice

1990 ◽  
Vol 14 ◽  
pp. 270-272
Author(s):  
R. Souchez ◽  
J. -L. Tison ◽  
J. Jouzel
Keyword(s):  
Heat Flux ◽  
Growth Rate ◽  
Sea Ice ◽  
Growth Period ◽  
Ice Cover ◽  
Rate Curve ◽  
First Year ◽  
Conductive Heat ◽  
Antarctic Sea Ice ◽  
Conductive Heat Flux

The deuterium concentration profile in a first-year Antarctic sea-ice cover is used to deduce a growth-rate curve, applying a previously published model. Time variations of the conductive heat flux throughout the growth period are then estimated from this growth-rate curve. Results indicate that the isotopic determination of sea ice growth rate can be considered as an alternate method for determining the conductive heat flux through a young sea-ice cover. However, there is need for a further test of the method by measuring in situ temperatures and growth rates during the formation of first-year sea ice, and by analyzing the isotopic composition of ice samples taken simultaneously along selected profiles during the growth period.

scholarly journals Growth of first-year landfast Antarctic sea ice determined from winter temperature measurements

2006 ◽  
Vol 44 ◽  
pp. 170-176 ◽  
Author(s):  
Craig R. Purdie ◽  
Patricia J. Langhorne ◽  
Greg H. Leonard ◽  
Tim G. Haskell
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Ice Cores ◽  
First Year ◽  
Conductive Heat ◽  
Ice Growth ◽  
Antarctic Sea Ice ◽  
Oceanic Heat Flux ◽  
Landfast Sea Ice ◽  
Platelet Ice

AbstractTemperature profiles of first-year landfast sea ice have been recorded continuously over the 2003 winter growth season at McMurdo Sound, Antarctica. The temperature gradients in the ice were used to calculate the growth rate due to conductive heat flux, which is shown to account for only part of the total ice growth. Remaining ice growth must be due to a negative oceanic heat flux. Significantly, this oceanic heat flux is shown to occur episodically, sometimes with sustained daily rates in excess of –30Wm–2. There is no direct correlation between oceanic heat flux and water temperature. Times of increased oceanic heat flux do coincide with the appearance of platelet ice in cores, and appear to account for the growth of 35% of the total platelet ice depth measured in ice cores.

scholarly journals Possible connections of the opposite trends in Arctic and Antarctic sea-ice cover

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Lejiang Yu ◽  
Shiyuan Zhong ◽  
Julie A. Winkler ◽  
Mingyu Zhou ◽  
Donald H. Lenschow ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Cover ◽  
Antarctic Sea Ice

scholarly journals Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean

2020 ◽  
Vol 33 (18) ◽  
pp. 8107-8123 ◽  
Author(s):  
Igor V. Polyakov ◽  
Tom P. Rippeth ◽  
Ilker Fer ◽  
Matthew B. Alkire ◽  
Till M. Baumann ◽  
...  
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Arctic Ocean ◽  
Mixed Layer ◽  
Winter Season ◽  
Atlantic Water ◽  
The Arctic ◽  
Surface Mixed Layer ◽  
Winter Convection ◽  
Oceanic Heat Flux

AbstractA 15-yr duration record of mooring observations from the eastern (>70°E) Eurasian Basin (EB) of the Arctic Ocean is used to show and quantify the recently increased oceanic heat flux from intermediate-depth (~150–900 m) warm Atlantic Water (AW) to the surface mixed layer and sea ice. The upward release of AW heat is regulated by the stability of the overlying halocline, which we show has weakened substantially in recent years. Shoaling of the AW has also contributed, with observations in winter 2017–18 showing AW at only 80 m depth, just below the wintertime surface mixed layer, the shallowest in our mooring records. The weakening of the halocline for several months at this time implies that AW heat was linked to winter convection associated with brine rejection during sea ice formation. This resulted in a substantial increase of upward oceanic heat flux during the winter season, from an average of 3–4 W m−2 in 2007–08 to >10 W m−2 in 2016–18. This seasonal AW heat loss in the eastern EB is equivalent to a more than a twofold reduction of winter ice growth. These changes imply a positive feedback as reduced sea ice cover permits increased mixing, augmenting the summer-dominated ice-albedo feedback.

scholarly journals Antarctic sea ice variability and trends, 1979–2010

2012 ◽  
Vol 6 (2) ◽  
pp. 931-956 ◽  
Author(s):  
C. L. Parkinson ◽  
D. J. Cavalieri
Keyword(s):  
Indian Ocean ◽  
Sea Ice ◽  
Ross Sea ◽  
Ice Cover ◽  
Weddell Sea ◽  
The Arctic ◽  
Future Research ◽  
Positive Trend ◽  
Antarctic Sea Ice ◽  
Ice Coverage

Abstract. In sharp contrast to the decreasing sea ice coverage of the Arctic, in the Antarctic the sea ice cover has, on average, expanded since the late 1970s. More specifically, satellite passive-microwave data for the period November 1978–December 2010 reveal an overall positive trend in ice extents of 17 100 ± 2300 km2 yr−1. Much of the increase, at 13 700 ± 1500 km2 yr−1, has occurred in the region of the Ross Sea, with lesser contributions from the Weddell Sea and Indian Ocean. One region, that of the Bellingshausen/Amundsen Seas, has, like the Arctic, instead experienced significant sea ice decreases, with an overall ice extent trend of −8200 ± 1200 km2 yr−1. When examined through the annual cycle over the 32-yr period 1979–2010, the Southern Hemisphere sea ice cover as a whole experienced positive ice extent trends in every month, ranging in magnitude from a low of 9100 ± 6300 km2 yr−1 in February to a high of 24 700 ± 10 000 km2 yr−1 in May. The Ross Sea and Indian Ocean also had positive trends in each month, while the Bellingshausen/Amundsen Seas had negative trends in each month, and the Weddell Sea and Western Pacific Ocean had a mixture of positive and negative trends. Comparing ice-area results to ice-extent results, in each case the ice-area trend has the same sign as the ice-extent trend, but differences in the magnitudes of the two trends identify regions with overall increasing ice concentrations and others with overall decreasing ice concentrations. The strong pattern of decreasing ice coverage in the Bellingshausen/Amundsen Seas region and increasing ice coverage in the Ross Sea region is suggestive of changes in atmospheric circulation. This is a key topic for future research.

scholarly journals Seasonal Variations In The Surface Energy Exchanges Over Antarctic Sea Ice and Coastal Waters

1982 ◽  
Vol 3 ◽  
pp. 12-16 ◽  
Author(s):  
I. Allison ◽  
C.M. Tivendale ◽  
G.J. Akerman ◽  
J.M. Tann ◽  
R.H. Wills
Keyword(s):  
Heat Transfer ◽  
Sea Ice ◽  
Seasonal Variations ◽  
Lower Boundary ◽  
Open Water ◽  
Ice Cover ◽  
Turbulent Fluxes ◽  
Turbulent Heat ◽  
Radiative Heat Loss ◽  
Antarctic Sea Ice

Seasonal variations in radiative and turbulent fluxes at the surface of, and in the heat transfer within, sea ice are discussed from results of energy balance studies at a site of annual ice cover near Mawson, Antarctica. In mid-summer, the open water gains heat mostly by radiation but by early February the ocean is cooling predominantly by strong turbulent losses, with some radiative heat loss occurring also by March. When an ice cover forms, turbulent fluxes decrease from several 100 W m−2over open water to only 40 w m−2over ice less than 0.2 m thick and even less over thicker ice.Net radiative losses over mature ice in mid-winter are balanced mostly by conduction through the ice cover but with some turbulent heat gain at the surface. By mid-spring, there is a net radiative gain, the turbulent fluxes are again outgoing, and there is little total heat transfer through the ice. At break-out, the albedo increase from ice to open water causes a large increase in the net radiative gain.At the lower boundary of the ice, the oceanic heat flux provides an important contribution. A net advection of heat into the region is shown from temperature profiles in the water under the ice. Salinity changes in the water during the period of ice melt are also discussed.

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