Fast onboard detection of ice drift changes under stationkeeping in ice

2022 ◽  
pp. 103483
Author(s):  
Hans-Martin Heyn ◽  
Roger Skjetne
Keyword(s):  
Ice Drift

The Ice of the Central Polar Basin

1957 ◽  
Vol 3 (22) ◽  
pp. 104-110
Author(s):  
Terence Armstrong
Keyword(s):  
Vertical Section ◽  
Ice Drift ◽  
Local Winds

AbstractRecent investigations of the ice of the central polar basin have been largely done by Russians, and some of their results are given here. General characteristics of the ice and of the currents and bathymetry of the area are outlined. Attention is directed to advances in knowledge in two spheres; the effect of currents and local winds on ice drift, and the growth and structure of floes. To illustrate the latter, an explanation of the stratification of a 3 m. vertical section is quoted. In conclusion, the prospects of the work continuing, and of its results being made available, are assessed.

scholarly journals Improving Multiyear Sea Ice Concentration Estimates with Sea Ice Drift

2016 ◽  
Vol 8 (5) ◽  
pp. 397 ◽  
Author(s):  
Yufang Ye ◽  
Mohammed Shokr ◽  
Georg Heygster ◽  
Gunnar Spreen
Keyword(s):  
Sea Ice ◽  
Sea Ice Concentration ◽  
Ice Drift ◽  
Ice Concentration ◽  
Sea Ice Drift

Ice drift in Peter the Great Bay

2014 ◽  
Vol 178 (3) ◽  
pp. 148-156
Author(s):  
Vyacheslav A. Dubina ◽  
Vladimir V. Plotnikov ◽  
Nina S. Kot
Keyword(s):  
Satellite Images ◽  
High Spatial Resolution ◽  
Peter The Great Bay ◽  
Western Coast ◽  
Mean Values ◽  
Peter The Great ◽  
Great Bay ◽  
Ice Drift ◽  
The Right ◽  
First Time

Dynamics of the sea ice cover in Peter the Great Bay is considered, for the first time for its whole area, on the base of satellite images received in 2004-2011 from the spectroradiometers MODIS mounted on the satellites Terra and Aqua. High spatial resolution maps of the ice drift are constructed for various wind conditions. Mean values of the drift velocity and wind coefficient are calculated for four parts of the Bay. In usual conditions of winter monsoon, the ice in the central part of Peter the Great Bay drifts southward with the velocity 0.5-0.6 m/s with deviation from the wind direction about 40° to the right; the ice at the western coast drifts along the island chain with the velocity 0.1-0.4 m/s under wind of any direction in the quadrant from northwest to northeast.

Oceanic eddy signature on SAR-derived sea ice drift and vorticity

2021 ◽  
Author(s):  
Angelina Cassianides ◽  
Camillie Lique ◽  
Anton Korosov
Keyword(s):  
Sea Ice ◽  
Surface Current ◽  
Satellite Observation ◽  
The Arctic ◽  
Global Ocean ◽  
Sar Images ◽  
Surface Ocean ◽  
Ice Drift ◽  
Sea Ice Drift ◽  
Oceanic Eddy

<p>In the global ocean, mesoscale eddies are routinely observed from satellite observation. In the Arctic Ocean, however, their observation is impeded by the presence of sea ice, although there is a growing recognition that eddy may be important for the evolution of the sea ice cover. In this talk, we will present a new method of surface ocean eddy detection based on their signature in sea ice vorticity retrieved from Synthetic Aperture Radar (SAR) images. A combination of Feature Tracking and Pattern Matching algorithm is used to compute the sea ice drift from pairs of SAR images. We will mostly focus on the case of one eddy in October 2017 in the marginal ice zone of the Canadian Basin, which was sampled by mooring observations, allowing a detailed description of its characteristics. Although the eddy could not be identified by visual inspection of the SAR images, its signature is revealed as a dipole anomaly in sea ice vorticity, which suggests that the eddy is a dipole composed of a cyclone and an anticyclone, with a horizontal scale of 80-100 km and persisted over a week. We will also discuss the relative contributions of the wind and the surface current to the sea ice vorticity. We anticipate that the robustness of our method will allow us to detect more eddies as more SAR observations become available in the future.</p>

scholarly journals Studies of the Movement of Coastal Sea Ice Near Prudhoe Bay, Alaska, U.S.A.

1977 ◽  
Vol 19 (81) ◽  
pp. 533-546 ◽  
Author(s):  
W. F. Weeks ◽  
A. Kovacs ◽  
S. J. Mock ◽  
W. B. Tucker ◽  
W. D. Hibler ◽  
...  
Keyword(s):  
Prediction Models ◽  
Stress Transfer ◽  
Short Term ◽  
Laser Measurements ◽  
A Value ◽  
Pack Ice ◽  
Ice Drift ◽  
Coastal Sea ◽  
Fast Ice ◽  
Prudhoe Bay

Abstract During March-May 1976, a combination of laser and radar ranging systems was used to study the motion of both the fast ice and the pack ice near Narwhal and Cross Islands, two barrier islands located 16 and 21 km offshore in the vicinity of Prudhoe Bay, Alaska. Laser measurements of targets on the fast ice near Narwhal Island indicate small net displacements of approximately 1 m over the period of study (71 d) with short-term displacements of up to 40 cm occurring over 3 d periods. The main motion was outward normal to the coast and was believed to be the result of thermal expansion of the ice. The radar records of fast-ice sites farther offshore show a systematic increase in the standard deviation of the displacements as measured parallel to the coast, reaching a value of ±6.6 m at 31 km. The farthest fast-ice sites show short-term displacements of up to 12 m. There are also trends in the records that are believed to be the result of the general warming of the fast ice with time. Radar targets located on the pack ice showed large short-term displacements (up to 2.7 km) but negligible net ice drift along the coast. There was no significant correlation between the movement of the pack and the local wind, suggesting that coastal ice prediction models can only succeed if handled as part of a regional model which incorporates stress transfer through the pack. The apparent fast-ice-pack-ice boundary in the study area was located in 30-35 m of water.

scholarly journals On the effect of rheology on seasonal sea-ice simulations

1991 ◽  
Vol 15 ◽  
pp. 17-25 ◽  
Author(s):  
Chi F. Ip ◽  
William D. Hibler ◽  
Gregory M. Flato
Keyword(s):  
Shear Stress ◽  
Sea Ice ◽  
Correlation Coefficients ◽  
Arctic Basin ◽  
The Arctic ◽  
Flow Rule ◽  
Average Model ◽  
Ice Drift ◽  
Cavitating Fluid

A generalized numerical model which allows for a variety of non-linear rheologies is developed for the seasonal simulation of sea-ice circulation and thickness. The model is used to investigate the effects (such as the role of shear stress and the existence of a flow rule) of different rheologies on the ice-drift pattern and build-up in the Arctic Basin. Differences in local drift seem to be closely related to the amount of allowable shear stress. Similarities are found between the elliptical and square cases and between the Mohr-Coulomb and cavitating fluid cases. Comparisons between observed and simulated buoy drift are made for several buoy tracks in the Arctic Basin. Correlation coefficients to the observed buoy drift range from 0.83 for the cavitating fluid to 0.86 for the square rheology. The average ratio of buoy-drift distance to average model-drift distance for several buoys is 1.15 (square), 1.18 (elliptical), 1.30 (Mohr-Coulomb) and 1.40 (cavitating fluid).

scholarly journals Operational SAR-based sea ice drift monitoring over the Baltic Sea

Ocean Science ◽  
2012 ◽  
Vol 8 (4) ◽  
pp. 473-483 ◽  
Author(s):  
J. Karvonen
Keyword(s):  
Sea Ice ◽  
Baltic Sea ◽  
Vector Fields ◽  
Phase Correlation ◽  
The Baltic Sea ◽  
Sar Images ◽  
Envisat Asar ◽  
Ice Drift ◽  
Sea Ice Drift ◽  
The Baltic

Abstract. An algorithm for computing ice drift from pairs of synthetic aperture radar (SAR) images covering a common area has been developed at FMI. The algorithm has been developed based on the C-band SAR data over the Baltic Sea. It is based on phase correlation in two scales (coarse and fine) with some additional constraints. The algorithm has been running operationally in the Baltic Sea from the beginning of 2011, using Radarsat-1 ScanSAR wide mode and Envisat ASAR wide swath mode data. The resulting ice drift fields are publicly available as part of the MyOcean EC project. The SAR-based ice drift vectors have been compared to the drift vectors from drifter buoys in the Baltic Sea during the first operational season, and also these validation results are shown in this paper. Also some navigationally useful sea ice quantities, which can be derived from ice drift vector fields, are presented.

Arctic Offshore Loading Downtime Due to Variability in Ice Drift Direction

2005 ◽  
Vol 59 (1) ◽  
pp. 9-26
Author(s):  
Basile Bonnemaire
Keyword(s):  
Risk Analysis ◽  
Ice Drift ◽  
Ice Conditions ◽  
Qualitative Risk Analysis ◽  
Drift Direction

Four arctic offshore loading concepts are selected, loading from the corner of a platform, loading in the wake of a loading tower, Submerged Turret Loading (STL) and Single Anchor Loading (SAL). The influence of variations in the ice drift direction on the performance of these concepts is discussed and critical drift events are determined. Ice drift measurements from eight ARGOS/GPS buoys deployed in the Pechora Sea in winters 1995 and 1998 are analysed to estimate downtime rates of these loading systems due to ice drift heading changes. Depending on the location in the Pechora Sea and the chosen concept, downtime rates range from 6 to 72%. A discussion on how these rates will vary with different assumptions, different ice conditions or different ice management is given. Finally the loading concepts are compared through a qualitative risk analysis.

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