scholarly journals Reduced Sea Ice Production Due to Upwelled Oceanic Heat Flux in Prydz Bay, East Antarctica

2019 ◽  
Vol 46 (9) ◽  
pp. 4782-4789 ◽  
Author(s):  
Guijun Guo ◽  
Jiuxin Shi ◽  
Libao Gao ◽  
Takeshi Tamura ◽  
Guy D. Williams
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
East Antarctica ◽  
Prydz Bay ◽  
Oceanic Heat Flux ◽  
Ice Production

scholarly journals Observations and modelling of first-year ice growth and simultaneous second-year ice ablation in the Prydz Bay, East Antarctica

2017 ◽  
Vol 58 (75pt1) ◽  
pp. 59-67 ◽  
Author(s):  
Jiechen Zhao ◽  
Bin Cheng ◽  
Qinghua Yang ◽  
Timo Vihma ◽  
Lin Zhang
Keyword(s):  
Heat Flux ◽  
Temperature Gradient ◽  
East Antarctica ◽  
Prydz Bay ◽  
Large Temperature ◽  
First Year ◽  
Conductive Heat ◽  
Oceanic Heat Flux ◽  
Conductive Heat Flux ◽  
Second Year

ABSTRACT The seasonal cycle of fast ice thickness in Prydz Bay, East Antarctica, was observed between March and December 2012. In March, we observed a 0.16 m thickness gain of 0.22 m-thick first-year ice (FYI), while 1.16 m-thick second-year ice (SYI) nearby simultaneously ablated by 0.59 m. A 1-D thermodynamic sea-ice model was applied to identify the factors that led to the simultaneous growth of FYI and melt of SYI. The different evolutions were explained by the difference in the conductive heat flux between the FYI and SYI. As the FYI was thin, there was a large temperature gradient between the ice base and the colder ice surface. This generated an upward conductive heat flux, which was larger than the heat flux from the ocean to the ice base, yielding basal growth of ice. In the case of the thicker SYI the temperature gradient and, hence, the conductive heat flux were smaller, and not sufficient to balance the oceanic heat flux at the ice base, yielding basal ablation. Penetration of solar radiation affected the conductive heat flux in both cases, and the model results were sensitive to the initial ice temperature profile and the uncertainty of the oceanic heat flux.

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 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.

Atmospheric and Oceanic Contributions to Irreducible Forecast Uncertainty of Arctic Surface Climate

2015 ◽  
Vol 29 (1) ◽  
pp. 331-346 ◽  
Author(s):  
Steffen Tietsche ◽  
Ed Hawkins ◽  
Jonathan J. Day
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Time Scales ◽  
Surface Heat Flux ◽  
Surface Heat ◽  
Initial State ◽  
Forecast Uncertainty ◽  
Surface Climate ◽  
Oceanic Heat Flux ◽  
Arctic Surface

Abstract Uncertainty of Arctic seasonal to interannual predictions arising from model errors and initial state uncertainty has been widely discussed in the literature, whereas the irreducible forecast uncertainty (IFU) arising from the chaoticity of the climate system has received less attention. However, IFU provides important insights into the mechanisms through which predictability is lost and hence can inform prioritization of model development and observations deployment. Here, the authors characterize how internal oceanic and surface atmospheric heat fluxes contribute to the IFU of Arctic sea ice and upper-ocean heat content in an Earth system model by analyzing a set of idealized ensemble prediction experiments. It is found that atmospheric and oceanic heat flux are often equally important for driving unpredictable Arctic-wide changes in sea ice and surface water temperatures and hence contribute equally to IFU. Atmospheric surface heat flux tends to dominate Arctic-wide changes for lead times of up to a year, whereas oceanic heat flux tends to dominate regionally and on interannual time scales. There is in general a strong negative covariance between surface heat flux and ocean vertical heat flux at depth, and anomalies of lateral ocean heat transport are wind driven, which suggests that the unpredictable oceanic heat flux variability is mainly forced by the atmosphere. These results are qualitatively robust across different initial states, but substantial variations in the amplitude of IFU exist. It is concluded that both atmospheric variability and the initial state of the upper ocean are key ingredients for predictions of Arctic surface climate on seasonal to interannual time scales.

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.

Observation and thermodynamic modeling of the influence of snow cover on landfast sea ice thickness in Prydz Bay, East Antarctica

2020 ◽  
Author(s):  
Jiechen Zhao ◽  
Bin Cheng ◽  
Timo Vihma ◽  
Qinghua Yang ◽  
Fengming Hui ◽  
...  
Keyword(s):  
Sea Ice ◽  
Snow Cover ◽  
Annual Cycle ◽  
Snow Depth ◽  
Snow Accumulation ◽  
East Antarctica ◽  
Prydz Bay ◽  
Ice Thickness ◽  
Sea Ice Thickness ◽  
Landfast Sea Ice

<p>The observed snow depth and ice thickness on landfast sea ice in Prydz Bay, East Antarctica, were used to determine the role of snow in (a) the annual cycle of sea ice thickness at a fixed location (SIP) where snow usually blows away after snowfall and (b) early summer sea ice thickness within the transportation route surveys (TRS) domain farther from coast, where annual snow accumulation is substantial. The annual mean snow depth and maximum ice thickness had a negative relationship (r = −0.58, p < 0.05) at SIP, indicating a primary insulation effect of snow on ice thickness. However, in the TRS domain, this effect was negligible because snow contributes to ice thickness. A one-dimensional thermodynamic sea ice model, forced by local weather observations, reproduced the annual cycle of ice thickness at SIP well. During the freeze season, the modeled maximum difference of ice thickness using different snowfall scenarios ranged from 0.53–0.61 m. Snow cover delayed ice surface and ice bottom melting by 45 and 24 days, respectively. The modeled snow ice and superimposed ice accounted for 4–23% and 5–8% of the total maximum ice thickness on an annual basis in the case of initial ice thickness ranging from 0.05–2 m, respectively.</p>

On the modified Circumpolar Deep Water upwelling over the Four Ladies Bank in Prydz Bay, East Antarctica

2020 ◽  
Author(s):  
Chengyan Liu ◽  
Zhaomin Wang ◽  
Chen Cheng ◽  
Xi Liang ◽  
Yang Wu ◽  
...  
Keyword(s):  
Heat Flux ◽  
Standard Deviation ◽  
Kinetic Energy ◽  
Potential Temperature ◽  
Weddell Sea ◽  
East Antarctica ◽  
Prydz Bay ◽  
Ice Shelf ◽  
Borehole Data ◽  
Amery Ice Shelf

<p>We report on mooring observations of tidal currents in Prydz Bay, East Antarctica. Tides in Prydz Bay are mixed diurnal-semidiurnal and much weaker than that in the Ross Sea and the Weddell Sea, with the spatial and temporal averaged value of 2.58 cm s<sup>-1</sup> for all the current meter observations over the continental shelf. The major axes of the tidal ellipses are generally aligned south-north, probably steered by the topography. The tidal phases are modulated by both the baroclinic and barotropic tidal components. The averaged tidal kinetic energy can account for a fraction of ~13% with respect to the total kinetic energy at the Amery Ice Shelf calving front during the observing period. The long-term average tidal heat flux across the Amery Ice Shelf calving front is negligible, but the ratio of the tidal heat flux standard deviation to the residual heat flux standard deviation can be up to 41%. We also report on borehole observations of tide-like pulsing of potential temperature and salinity, indicating the indispensable tidal influences in the ice-ocean boundary layer. These mooring and borehole data support that the tidal processes should be highlighted in the investigations of the interaction between the Amery Ice Shelf and ocean.</p>

scholarly journals The 2007 Bering Strait oceanic heat flux and anomalous Arctic sea-ice retreat

2010 ◽  
Vol 37 (1) ◽  
pp. n/a-n/a ◽  
Author(s):  
Rebecca A. Woodgate ◽  
Tom Weingartner ◽  
Ron Lindsay
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Arctic Sea Ice ◽  
Bering Strait ◽  
Oceanic Heat Flux ◽  
Arctic Sea ◽  
Ice Retreat ◽  
Sea Ice Retreat
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