scholarly journals Heat loss from the Atlantic water layer in the northern Kara Sea: causes and consequences

Ocean Science ◽  
2014 ◽  
Vol 10 (4) ◽  
pp. 719-730 ◽  
Author(s):  
I. A. Dmitrenko ◽  
S. A. Kirillov ◽  
N. Serra ◽  
N. V. Koldunov ◽  
V. V. Ivanov ◽  
...  
Keyword(s):  
Sea Ice ◽  
Heat Loss ◽  
Water Layer ◽  
Atlantic Water ◽  
Kara Sea ◽  
Ice Thickness ◽  
Sea Ice Thickness ◽  
Model Simulations ◽  
Anna Trough ◽  
Water Pathway

Abstract. A distinct, subsurface density front along the eastern St. Anna Trough in the northern Kara Sea is inferred from hydrographic observations in 1996 and 2008–2010. Direct velocity measurements show a persistent northward subsurface current (~ 18 cm s−1) along the St. Anna Trough eastern flank. This sheared flow, carrying the outflow from the Barents and Kara seas to the Arctic Ocean, is also evident from shipboard observations as well as from geostrophic velocities and numerical model simulations. Although we cannot substantiate our conclusions by direct observation-based estimates of mixing rates in the area, we hypothesize that the enhanced vertical mixing along the St. Anna Trough eastern flank favors the upward heat loss from the intermediate warm Atlantic water layer. Modeling results support this hypothesis. The upward heat flux inferred from hydrographic data and model simulations is of O(30–100) W m−2. The region of lowered sea ice thickness and concentration seen both in sea ice remote sensing observations and model simulations marks the Atlantic water pathway in the St. Anna Trough and adjacent Nansen Basin continental margin. In fact, the sea ice shows a delayed freeze-up onset during fall and a reduction in the sea ice thickness during winter. This is consistent with our results on the enhanced Atlantic water heat loss along the Atlantic water pathway in the St. Anna Trough.

scholarly journals Heat loss from the Atlantic water layer in the St. Anna Trough (northern Kara Sea): causes and consequences

2014 ◽  
Vol 11 (1) ◽  
pp. 543-573 ◽  
Author(s):  
I. A. Dmitrenko ◽  
S. A. Kirillov ◽  
N. Serra ◽  
N. V. Koldunov ◽  
V. V. Ivanov ◽  
...  
Keyword(s):  
Sea Ice ◽  
Heat Loss ◽  
Water Layer ◽  
Atlantic Water ◽  
Kara Sea ◽  
The Arctic ◽  
Model Simulations ◽  
Eastern Flank ◽  
Anna Trough ◽  
Water Pathway

Abstract. A distinct, subsurface density front along the eastern St. Anna Trough in the northern Kara Sea is inferred from hydrographic observations in 1996 and 2008–2010. Direct velocity measurements show a persistent northward subsurface current (~ 20 cm s−1) along the St. Anna Trough eastern flank. This sheared flow, carrying the outflow from the Barents and Kara Seas to the Arctic Ocean, is also evident from shipboard observations as well as from geostrophic velocities and numerical model simulations. Although no clear evidence for the occurrence of shear instabilities could be obtained, we speculate that the enhanced vertical mixing along the St. Anna Trough eastern flank promoted by a vertical velocity shear favors the upward heat loss from the intermediate warm Atlantic water layer. The associated upward heat flux is inferred to 50–100 W m−2 using hydrographic data and model simulations. The zone of lowered sea ice thickness and concentration essentially marks the Atlantic water pathway in the St. Anna Trough and adjacent Nansen Basin continental margin from both sea-ice remote sensing observations and model simulations. In fact, the seaice shows a consistently delayed freeze-up onset during fall and a reduction in the seaice thickness during winter. This is consistent with our results on the enhanced Atlantic water heat loss along the Atlantic water pathway in the St. Anna Trough.1 1Dedicated to the memory of our colleague Klaus Hochheim who tragically lost his life in the Arctic expedition in September 2013

Design Optimization of Ship’s Bow Sailing in Kara Sea and Barents Sea

2019 ◽  
Author(s):  
Jianfei Liu ◽  
Guoqing Feng ◽  
Huilong Ren ◽  
Wenjia Hu ◽  
Yuwei Sun
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Kara Sea ◽  
Structural Safety ◽  
Ice Thickness ◽  
Polar Regions ◽  
Sea Ice Thickness ◽  
Collision Model ◽  
The Barents Sea ◽  
Probability Density Curve

Abstract Ships performing their missions in the polar regions will inevitably suffer from sea ice collision, which will lead to structural safety problems. Therefore, ships should be designed according to the characteristics of polar sea ice to enable them to navigate safely in the polar regions. Based on the probability density curve of sea ice thickness and the occurrence frequency of sea ices of different sizes of the Kara Sea and the Barents Sea, this paper preliminarily designs ship’s bow sailing in the Kara Sea and the Barents Sea, establishes the ship’s bow-ice collision model and carries out numerical simulation to obtain the stress distribution. Then it optimizes the structure of the parts of the ship’s bow. After the optimization, the bow structure meets the strength requirements and the weight of the ship’s bow is relatively light.

scholarly journals Multisensor data and thermodynamic sea-ice model based sea-ice thickness chart with application to the Kara Sea, Arctic Russia

2013 ◽  
Vol 54 (62) ◽  
pp. 241-252 ◽  
Author(s):  
M. Similä ◽  
M. Mäkynen ◽  
B. Cheng ◽  
E. Rinne
Keyword(s):  
Sea Ice ◽  
Background Level ◽  
Kara Sea ◽  
Ice Thickness ◽  
Sea Ice Concentration ◽  
Ice Dynamics ◽  
Sea Ice Thickness ◽  
Ice Surface Temperature ◽  
Arctic Russia ◽  
Ice Model

AbstractWe introduce a method to construct an ice thickness chart using two satellite datasets and a one-dimensional high-resolution thermodynamic snow and sea-ice model (HIGHTSI). Thin-ice thickness up to 40 cm is retrieved using MODIS ice surface temperature data. For thicker ice, thickness is retrieved from a combination of SAR image and background level ice thickness chart Hi provided by HIGHTSI. Because Hi is inherently static, we utilize passive microwave data based sea-ice concentration charts to introduce mesoscale ice dynamics into Hi. In order to create the thickness chart, the value of modified Hi is scaled by a factor which depends on the magnitude of backscattering coefficient σ0. The proposed method is effective in cold winter conditions. We calculated a series of ice thickness charts covering the Kara Sea, Arctic Russia, during winter 2008/09. The ice thickness charts were validated against Russian ice charts. Our method gave realistic results in the thickness range 30–120 cm and was uncertain for the detection of thinner-ice areas. Due to the limitations in our reference dataset, more validation work is needed to establish the accuracy in more detail. Our thickness charts can be used for operational purposes and in climate studies.

Boundary current heat loss and mixing processes at the Arctic Ocean continental margin

2021 ◽  
Author(s):  
Kirstin Schulz ◽  
Markus Janout ◽  
Yueng-Djern Lenn ◽  
Eugenio Ruiz-Castillo ◽  
Igor Polyakov ◽  
...  
Keyword(s):  
Sea Ice ◽  
Heat Loss ◽  
Barents Sea ◽  
Arctic Basin ◽  
Water Layer ◽  
Bottom Layer ◽  
Atlantic Water ◽  
The Arctic ◽  
Mixing Processes ◽  
Boundary Mixing

<p>Inflowing Atlantic Water forms a significant heat reservoir in the Arctic Ocean. In the Barents Sea, where the Atlantic Water layer resides close to the surface, strong upward heat fluxes reduce the sea ice cover. Along with a warming climate, an eastward progression of these conditions typical for the Barents Sea is anticipated. These new conditions have the potential to cause dramatic regime shifts in the Laptev Sea region, where the sea ice and the oceanic surface layer are currently sheltered from the warm Atlantic Water by a permanent halocline. Understanding and quantifying the dominant mixing processes in the Siberian Seas is hence crucial to predict how mixing and sea ice conditions, as well as particle and nutrient transport pathways will evolve in the future.</p><p>Based on recent temperature and current velocity profiles from this region, we quantify the Atlantic Water heat loss along its pathway around the Arctic basin margins. Contemporaneous turbulent microstructure measurement reveal that only 20% of this heat loss takes place in the deep basin, emphasizing the important role of stronger mixing in the continental slope region. Observed boundary mixing processes include:</p><ul><li> <p>Mixing in the frictional near bottom layer, strongly enhanced at the lee side of a topographic features and where large temperature gradients associated with the upper bound of the Atlantic Water layer are present in the turbulent near bottom layer.</p> </li> <li> <p>Spatially confined but energetic mixing events over the whole water column. These events are ephemeral but re-occurring and can homogenize the intermediate water column down to a depth of over 300m, with substantial implications for heat transport, the vertical distribution of nutrients and cross-slope particle transport.</p> </li> </ul><p>The presented results provide new insights into the complex mixing and transport patterns at the Arctic basin margins, and further emphasize the importance of boundary mixing across disciplines.</p>

In-situ automatic observations of ice thickness of seas

2012 ◽  
Vol 19 (3) ◽  
pp. 583-592 ◽  
Author(s):  
Yinke Dou ◽  
Xiaomin Chang
Keyword(s):  
Sea Ice ◽  
New Technologies ◽  
Capacitive Sensor ◽  
Automatic Monitoring ◽  
Ice Thickness ◽  
In Situ Observation ◽  
Glacier Surface ◽  
Sea Ice Thickness ◽  
Surface Ice

Abstract Ice thickness is one of the most critical physical indicators in the ice science and engineering. It is therefore very necessary to develop in-situ automatic observation technologies of ice thickness. This paper proposes the principle of three new technologies of in-situ automatic observations of sea ice thickness and provides the findings of laboratory applications. The results show that the in-situ observation accuracy of the monitor apparatus based on the Magnetostrictive Delay Line (MDL) principle can reach ±2 mm, which has solved the “bottleneck” problem of restricting the fine development of a sea ice thermodynamic model, and the resistance accuracy of monitor apparatus with temperature gradient can reach the centimeter level and research the ice and snow substance balance by automatically measuring the glacier surface ice and snow change. The measurement accuracy of the capacitive sensor for ice thickness can also reach ±4 mm and the capacitive sensor is of the potential for automatic monitoring the water level under the ice and the ice formation and development process in water. Such three new technologies can meet different needs of fixed-point ice thickness observation and realize the simultaneous measurement in order to accurately judge the ice thickness.

Assimilation of SMOS sea ice thickness in the regional ice prediction system

2021 ◽  
Vol 42 (12) ◽  
pp. 4583-4606
Author(s):  
Mukesh Gupta ◽  
Alain Caya ◽  
Mark Buehner
Keyword(s):  
Sea Ice ◽  
Ice Thickness ◽  
Prediction System ◽  
Sea Ice Thickness

scholarly journals Antarctic sea-ice thickness and volume estimates from ice charts between 1995 and 1998

2015 ◽  
Vol 56 (69) ◽  
pp. 383-393 ◽  
Author(s):  
E. Rachel Bernstein ◽  
Cathleen A. Geiger ◽  
Tracy L. Deliberty ◽  
Mary D. Lemcke-Stampone
Keyword(s):  
Sea Ice ◽  
Regional Scale ◽  
Weighted Average ◽  
Ice Thickness ◽  
Average Thickness ◽  
Sea Ice Thickness ◽  
Subjective Analysis ◽  
Stage Of Development ◽  
Volume Estimates ◽  
The Impact

AbstractThis work evaluates two distinct calculations of central tendency for sea-ice thickness and quantifies the impact such calculations have on ice volume for the Southern Ocean. The first calculation, area-weighted average thickness, is computed from polygonal ice features and then upscaled to regions. The second calculation, integrated thickness, is a measure of the central value of thickness categories tracked across different scales and subsequently summed to chosen regions. Both methods yield the same result from one scale to the next, but subsequent scales develop diverging solutions when distributions are strongly non-Gaussian. Data for this evaluation are sea-ice stage-of-development records from US National Ice Center ice charts from 1995 to 1998, as proxy records of ice thickness. Results show regionally integrated thickness exceeds area-weighted average thickness by as much as 60% in summer with as few as five bins in thickness distribution. Year-round, the difference between the two calculations yields volume differences consistently >10%. The largest discrepancies arise due to bimodal distributions which are common in ice charts based on current subjective-analysis protocols. We recommend that integrated distribution be used for regional-scale sea-ice thickness and volume estimates from ice charts and encourage similar testing of other large-scale thickness data archives.

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