Severe Ice Conditions Research Articles

Некоторые оценки тяжелых ледовых условий (сжатий) в Печорском море по данным наблюдений и моделирования (моделирование и анализ)

The work continues the study focused on the analysis of the severe ice conditions’ formation in the Pechora Sea during navigation in 2003 and 2018 (published in vol.12, no.4, 2022). Using a numerical model, the authors reproduce the dynamics and some elements of the morphometry of the ice cover during the indicated ice seasons. Thus, they reveal that the significant ice pressure (100—150 kPa and more) is caused by the strong on-shore wind, while the ice pressure related to the tidal phenomena have the predominant value at the weak winds. The tidal ice pressure occurs permanently and regularly, and varies mainly within the range of 10—50 kPa. The contribution of ice hummocks to the total ice volume becomes significant when strong ice pressure happens at the background of high ice thickness (close to the seasonal maximum, i.e. more than 60—70 cm). With small ice thicknesses, even strong ice pressure, as a rule, does not lead to a significant increase in the equivalent thickness of hummocks.

Анализ ледовых условий на судоходных трассах Каспийского моря

An analysis of ice conditions on the shipping routes in the northern part of the Caspian Sea is given. The thickness and concentration of sea ice on the routes in the winter seasons of 2011/2012, 2015/2016, and 2022/2023 are considered. The most severe ice conditions were observed in the winter season of 2011/2012. On the basis of satellite information, examples of the spread of stamukhas, which are the ice structures, dangerous for navigation, are given. Keywords: Caspian Sea, ice cover, shipping routes, thickness and concentration of sea ice, stamukhas

Theoretical foundations of freeing ships from heavy ice conditions

The topic of the study is to prevent damage to the ships hulls when sailing in polar waters in severe ice conditions, which is a dangerous situation that threatens environmental pollution and possible death of the vessel, its passengers and crew. It is noted that the intensive development of ice navigation in the development of the Arctic regions of the Russian Federation and other polar waters requires the development and improvement of methods for freeing ships trapped in heavy ice. Navigation of vessels in severe ice conditions is accompanied by significant difficulties and dangers for the vessel, its passengers and crew. This situation can be significantly aggravated if, at a certain stage of navigation in ice conditions, heavy ice begins to move, leading to compression of the ice channel in which the vessel is located. At the same time, the risk of the vessel hull destruction, the creation of water leakage and the possible death of the vessel, its passengers and crew increases, as well as environmental pollution occurs. The theoretical foundations of freeing a vessel from severe ice conditions, based on the principles of rocking and pushing, as well as cutting ice, clamping the vessel, which have proven their effectiveness in other fields of science and technology, are discussed in the paper. The use of the vessel theory apparatus and the experience of ice-breaking assistance make it possible to substantiate the possibility of effective application of methods of rocking, pushing and chopping ice to release ships caught in severe ice conditions. The theoretical possibility of using combinations of the operation of the ballast system, cargo booms and cranes, special actions of the crew trapped in the ice of the vessel, as well as its interaction with icebreakers and other vessels for cutting the clamping ice, rocking and pushing, increasing the efficiency of freeing the vessel from severe ice conditions, is shown. The materials of the paper can be used to develop practical recommendations for freeing ships from heavy ice conditions independently and using icebreakers and other vessels.

Search for optimal shipping routes in the Arctic seas

A method for choosing optimal shipping routes and determining the conditions under which the Northern Sea Route can be used year-round is developed in the paper. The topic and purpose of the study are directly related to the tasks, the implementation of which is provided by the Development Plan of the Northern Sea Route, approved by the decree of the Government of the Russian Federation on August 1, 2022, confirmed by the financing program for the development and implementation of the digital board of the Northern Sea Route, approved by the Government in mid-January, 2023. The assessment of the current state of the network of shipping routes, navigation, hydrographic and hydro meteorological support, as well as the structure and composition of the Arctic icebreaker and transport fleet is given. The main factors affecting the implementation of the year-round navigation program in the eastern sector of the Arctic include severe ice conditions, unreliable forecasts of the ice situation, the lack of a sufficient number of icebreakers and transport vessels capable of overcoming thick ice fields in the Arctic shallow waters. Based on the results of the review of existing methods for determining safe and cost-effective shipping routes, the basic requirements for methods of choosing optimal routes in the waters of the Arctic seas have been developed. Using the method of multi-criteria evaluation of alternative routes according to a variety of safety criteria depending on the navigation period and the method of transport vessels navigation in ice is justified. A list of information necessary for implementation of the developed multi-criteria method for finding optimal routes and a list of the main stages of its implementation have been compiled. The results of testing the method of comparative evaluation of alternative routes using a set of simulation models are presented. Recommendations on the use of the developed method are given. The main directions of further research are determined.

Hybrid causal logic model for estimating the probability of an icebreaker–ship collision in an ice channel during an escort operation along the Northeast Passage

Under severe Arctic ice conditions, escort operations are the most efficient methods for facilitating shipping. Nevertheless, escort operations are among the most dangerous operations, as they may result in icebreaker–ship collisions and/or ship besetting in ice. To mitigate the risk of collisions, it is essential to understand the event sequences of collisions and the risk control options that can be implemented to reduce the occurrence of undesired events. This paper proposes a hybrid causal logic model to estimate the likelihood of an icebreaker–ship collision while considering human factors during an escort operation along the Northeast Passage. The model relies on inputs from four icebreaker captains. Its applicability is demonstrated for a 2018 summer voyage of a cargo ship assisted by an icebreaker. Risk control options are then proposed based on qualitative and sensitivity analyses of the model. The results of this study can assist shipping companies to better understand the sequence of events prior to icebreaker–ship collisions during escort operations in ice-covered waters. This paper provides information on risk reduction measures. In addition, the proposed model can assist in route planning.

Анализ особенностей ледового режима юго-восточной части Tатарского пролива (Японское море)

The article considers the features of the ice regime of the southeastern part of the Tatar Strait during the period of the standard climatic norm 1991–2020. The analysis of inter-seasonal and intra-seasonal variability of ice cover was carried out, the dates of the main ice phases were determined. Based on satellite observations and the developed software package, the analysis was performed and maps of the spatial distribution of the ice period in the southeastern part of the Tatar Strait were constructed. It is established that the northern subzone of the southeastern part of the Tatar Strait has more severe ice conditions, which are due to its geographical location and the peculiarities of the ice regime of the Tatar Strait. It is noted that the northern subzone in some years can be filled with ice by 100 %, while the maximum occupancy of the southern subzone does not exceed 24 %. At the same time, on average for the period of the standard climatic norm of 1991–2020. the stage of maximum development of ice processes in the northern subzone lasts on average about 23 days—from February 10 to March 5, and on the intra-seasonal variability curve, 2 seasonal ice maxima are clearly distinguished—February 10 and March 5. The absolute values of the intra-seasonal variability of the ice cover of the southern subzone are several times lower than in the northern one: the phase of intensive development here lasts from February 15 to February 28, the phase of destruction from early March to mid-March. On average, during the study period, the largest number of days with ice is observed on the coast from the village of Krasnogorsk to the village of Ilyinskoye, the duration of the period with ice from 20 to 35 days is typical for the segment of the coast from Cape Staromayachny to Cape Yablonovy.

Пространственная организация освоения газовых ресурсов арктического шельфа Российской Федерации

Being strategic, the Arctic shelf is a region with an extremely low level of exploration. The undiscovered hydrocarbon resources on the Russian Arctic shelf exceed 90%. The long-term development of strategic programs and projects for the development of gas production on the shelf are constrained by insufficient technical accessibility of industrial development, as well as the difficulty of assessing the actual volume of initial potential oil and gas resources. The reproduction of free gas reserves has been assessed, the level of parity between production and growth of explored reserves has been determined. The state of the gas resources of the Arctic shelf was studied taking into account localization in oil and gas regions, which allowed to make a conclusion about the degree of exploration of the resource base and to identify the basis for the gas potential. The factors restraining the development of offshore projects were identified and analyzed. It was determined that offshore projects should be presented to investors with more attractive operational, technological and economic indicators than alternative onshore projects. The lack of tested methods for the development of hydrocarbons at superdeep depths under severe ice conditions does not allow to fully assessing the economic efficiency of offshore gas projects in the Arctic. It is concluded that within the resource base of Arctic offshore fields, it is necessary to allocate the static (probabilistic) potential of hydrocarbon resources of the Arctic region. The need to transform the Arctic foreign policy is identified.

Сжатия ледяного покрова в Печорском море: природное явление и его влияние на морские операции

The Pechora Sea is an essential region of the Russian Arctic shelf in terms of hydrocarbon production and cargo transit along the NSR (mainly from the Ob’ Bay area). Occasionally, heavy ice conditions form in this area, manifested in the compression of the ice cover, which lead to a serious complication of navigation and operation of vessels supporting the Prirazlomnaya ice resisting platform. Based on the analysis of various sources, the authors consider the processes of formation of severe ice conditions in 2003 and 2018, as well as their impact on the operation of ships. They demonstrate that the only vessel able to operate steadily in such conditions is a nuclear icebreaker. The authors suggest that ice compressions of varying intensity are quite typical for the area and can repeat occasionally

Climate signal strength in tree-ring width of spruce growing in the Solovetsky Islands (Russia)

In this study we used 14 spruce tree-ring width local chronologies from sites that are located in different landscape conditions. The climatic response function for the entire period (116 years) shows that all local chronologies without exception have a positive relationship with June temperature (from 0.196 to 0.408) despite quite different local environmental conditions. This finding allowed us to combine all tree-ring width local chronologies into a composite spruce chronology covering the period of 1676–2016 CE with EPS exceeding the 0.85 threshold. The composite chronology was scaled against June air temperatures (CRU TS 4.01) in order to reconstruct it. Monthly air temperature records from the Arkhangelsk weather station were used as an additional source to validate tree-ring based June temperature reconstruction. It is quite remarkable that our reconstruction matches the Archangelsk records not only in the 20th-early 21st centuries but also in the 19th century, confirming the reliability of the reconstruction over more than two centuries. We also used daily records from the nearest Kem’-Port station to identify a more precise target-window. Current research shows that the spruce response to daily temperature is not limited by June, but also extends up to almost half of July. The warmest reconstructed year occurred in 1856 as confirmed by the data published in the local chronicle. The cooling recorded in the historical evidences (describing extremely severe ice conditions in the Arctic seas during the Great Northern Expedition (1733–1743)) was not corroborated by our reconstruction. In the study, we discuss the reasons of the discrepancies found between Solovki June temperature reconstructions and other data such as different seasonality of the compared records, real local climate warming in Solovki, the applied standardization technique, and low of chronologies’ replication. The most reliable part of the reconstruction part lasting from the early 19th to the early 21st centuries is also discussed in terms of its properties like wavelength analyses, and the assessment of influence of volcanic eruptions.

Impacts of sea ice on marine dynamics in western Laizhou Bay, Bohai Sea

The Bohai Sea is a region with wintertime sea ice development and high levels of human economic activity, where sea ice has a powerful destructive effect on maritime transportation and ocean engineering. In the Bohai Sea, sediment resuspension caused by waves and currents has not previously been systematically studied during periods of ice cover. In the winter of 2009–2010, severe ice conditions with a recurrence period of 30 years occurred. In this study, wave, residual water level (RWL), residual current (RC), and suspended sediment concentration (SSC) data were collected by two seabed-based observation stations (QD12 and QDG2) for one continuous year during both ice-covered and ice-free conditions. The data were systematically compared and analyzed. Generally, the results showed that sea ice coverage had a clear suppressing effect on the significant wave height (Hs) and RWL. Hs decreased by almost 50%, and RWL decreased by 0.19 m and 0.10 m during ice-covered conditions at two stations. Sea ice coverage had a suppressing effect on the sediment resuspension due to a reduction in wave induced shear stress. The reduction of sea level and SSC was mainly reflected in the decrease of fluctuation amplitude and overall magnitude, and the suppression effect was more obvious in conditions of strong wind. The RC velocity varied during periods of ice cover in Laizhou Bay. Sea ice enhanced RC velocity during the destruction period. The RC velocity increased dramatically at station QD12 probably due to the long length of the destruction period, but decreased slightly at station QDG2 possibly due to a shorter destruction period and the blocking of Weifang Port. The enhanced RC in the destruction period carrying broken ice caused significant damage to coastal engineering projects. The suppressing effects of sea ice on Hs, RWL, and sediment resuspension, and the strengthening effects on RC velocity were both closely related to the wind speed and direction. This study reveals the effects of sea ice on local hydrodynamics and sediments, providing important reference values for the generation and disappearance of sea ice in mid- and high-latitude bays under the background of dramatic global climate change.

Ice Sensing Technologies with Applications in Augmented Situational Awareness

This paper contains a literature review of technologies employed in the scientific literature to provide data on ice severity to augment situational awareness of human operators (aboard a ship or in a remote control center) and eventually autonomous navigation algorithms. As ships navigate in ice, masters use a wide source of information to assess the ice conditions along their planned route. This information is used to make ongoing assessments of the ice severity and to decide how to optimize the route to avoid damage to the ship, besetting, etc. Typically, this assessment is made by the officers in charge of the ship based on observations, experience, and metocean publications such as weather forecasts and ice charts. Significant levels of experience needed to safely assess and navigate in complex or severe ice conditions. A fundamental challenge in allowing autonomy or decision-support for navigation of ice-covered waters is providing accurate and relevant ice severity data that feeds decision-making.

Sharp Profile for Icebreaking Propellers to Improve Their Ice and Hydrodynamic Characteristics

Stern-first operation under severe ice conditions (ridges) is one of the most effective modes to increase the operating efficiency of icebreakers and ice ships. However, when a ship overcomes the ridge astern, the propellers continuously interact with ice blocks, and ice moment affects the propeller and the main engine. This leads to propeller speed drop and propeller thrust reduction. Propeller stop is also possible. This is the reason why the propeller ice moment needs to be decreased. Blade profiles with a sharp leading edge are used for this purpose because their thickness is significantly less than that of a traditional icebreaking profile. The application of sharp profiling makes it possible to significantly reduce the ice moment (ice loads) on the propeller, reduce the drop in its speed, and increase the hydrodynamic thrust. The main task when installing blades with sharp profiles is to ensure the strength of their leading edges exposed to ice pressure. In this article, the authors tackle upon some methods of assigning integral and local ice loads on propellers. Solutions for ensuring the local strength of the blade edges were developed and presented. The influence of sharp profiling on the hydrodynamic and cavitation characteristics of ice propellers was considered. The article presents examples of calculating the hydrodynamic propeller thrust and moment, as well as ice loads on a propeller with a sharp and traditional profile, when an ice ship moves through a ridged ice isthmus with its stern first.

A Measurement System to Monitor Propulsion Performance and Ice-Induced Shaftline Dynamic Response of Icebreakers

Polar navigation entails challenges that affect the continuation of ship operations in severe ice conditions. Due to ice-propeller interaction, propulsion shafting segments are often at a high risk of failure. Efficient methods for shaft line design are hence needed to ensure the safety of ice-going vessels and propulsion reliability. To this end, full-scale measurements have proven essential to support the development of ship-design tools and updated safety regulations for ice-going vessels. This paper presents a unique integrated measurement system that employs measuring equipment to monitor Polar-Class vessel performance and shaft line dynamics during ice navigation. The system was installed on board the Canadian Coast Guard (CCG) icebreaker Henry Larsen. This experimental concept aims to monitor the shaft’s torque and thrust fluctuations during ice navigation to obtain information about the ship’s propulsion efficiency. In the paper, we describe the arrangement of the measurement system and the components it features. Finally, we present preliminary datasets acquired during two icebreaking expeditions. This work is framed into a broader research project, which includes the long-term objective to determine a correlation between sea ice conditions and the dynamic response of shaft lines.

NEMO-Bohai 1.0: a high-resolution ocean and sea ice modelling system for the Bohai Sea, China

Abstract. Severe ice conditions in the Bohai Sea could cause serious harm to maritime traffic, offshore oil exploitation, aquaculture, and other economic activities in the surrounding regions. In addition to providing sea ice forecasts for disaster prevention and risk mitigation, sea ice numerical models could help explain the sea ice variability within the context of climate change in marine ecosystems, such as spotted seals, which are the only ice-dependent animal that breeds in Chinese waters. Here, we developed NEMO-Bohai, an ocean–ice coupled model based on the Nucleus for European Modelling of the Ocean (NEMO) model version 4.0 and Sea Ice Modelling Integrated Initiative (SI3) (NEMO4.0-SI3) for the Bohai Sea. This study will present the scientific design and technical choices of the parameterizations for the NEMO-Bohai model. The model was calibrated and evaluated with in situ and satellite observations of the ocean and sea ice. The model simulations agree with the observations with respect to sea surface height (SSH), temperature (SST), salinity (SSS), currents, and temperature and salinity stratification. The seasonal variation of the sea ice area is well simulated by the model compared to the satellite remote sensing data for the period of 1996–2017. Overall agreement is found for the occurrence dates of the annual maximum sea ice area. The simulated sea ice thickness and volume are in general agreement with the observations with slight overestimations. NEMO-Bohai can simulate seasonal sea ice evolution and long-term interannual variations. Hence, NEMO-Bohai is a valuable tool for long-term ocean and ice simulations and climate change studies.

Research on navigation risk of the Arctic Northeast Passage based on POLARIS

AbstractThe complex sea ice conditions in Arctic waters has different impacts on the legs of the Arctic passage, and ships of specific ice classes face different navigation risks. Therefore, the quantitative analysis of the navigation risks faced in different legs has important practical significance. Based on the POLARIS introduced by IMO, the sea ice condition data from 2011 to 2020 was used to quantify the navigation risk of the Arctic Northeast passage. The risk index outcome (RIO) of the Arctic Northeast Passage were calculated. The navigable windows of the route for ice class 1A ships sailing independently under different sea ice conditions in the last decade were determined, with a navigable period of 91 days under normal sea ice conditions, approximately 175 days under light sea ice conditions and only week 40 close to navigation under severe sea ice conditions. The three critical waters affecting the safety of ships were identified. Combined with the navigable windows and critical waters, recommendations on ship's navigation and manipulation and recommendations for stakeholders were given. The method and results provided reference and support for the assessment of the navigation risk of ships in the Northeast Passage and safety navigation and operations of ships, and satisfied the needs of relevant countries and enterprises to rationally arrange shipment dates and sailing plans based on different ice classes of ships.

A method for evaluating operational implications of regulatory constraints on Arctic shipping

Development of effective marine policy necessitates evidence-based, data-driven evaluations of the effects of regulatory constraints on operations. This is essential to better understand implications of policy decisions on complex socio-technical systems. This paper demonstrates a generalized methodology for evaluating operational implications associated with implementing maritime regulations. The method combines a ship performance model, regulatory constraint models, and multi-criteria pathfinding and optimization algorithms to evaluate and compare the operational implications of different regulatory constraints. The method is applied to Arctic shipping. The Polar Operational Limit Assessment Risk Indexing System (POLARIS) and the Arctic Ice Regimes Shipping System (AIRSS) are considered. POLARIS and AIRSS are regulatory guidelines used to assign structural safety constraints on ships in ice. Four approaches for assigning structural safety constraints are modelled: 1) POLARIS, 2) AIRSS, 3) speed limits established through a first-principles ship-ice interaction model, and 4) navigation in the absence of structural safety constraints. Operational implications are measured as distance, voyage time, and fuel consumption. Route optimization is validated against expert opinion of Arctic ship captains. Results indicate AIRSS is the more conservative regulatory guideline, yet associated with decreased voyage time and fuel consumption. Implications for marine policy and safe navigation are that, while POLARIS offers flexibility to operate in more severe ice conditions, it increases voyage time, fuel consumption, and the risk of vessel damage. Competent Arctic seafarers are critical for safe and efficient operations. The generalized methodology provides marine policy-makers and industry stakeholders with a means to evaluate operational implications of maritime regulations.

Winter Zooplankton in a Small Arctic Lake: Abundance and Vertical Distribution

Zooplankton assemblages are of great importance in aquatic food webs because they link lower (microplankton) and higher trophic levels (top predators). Small water bodies in the Arctic regions of Russia are less studied in winter because of severe ice conditions. For this reason, we analyzed the winter zooplankton community in Lake Kulonga (western coast of Kola Bay, Barents Sea). A total of 9 taxa were found in the samples. The total abundance varied from 200 to 1320 ind. m−3, averaging 705 ind. m−3. The total zooplankton biomass was 1.8–72.8 mg of wet mass m−3 with an average of 30 mg m−3. These parameters were lower than in other Russian Arctic and sub-arctic lakes in summer. Old copepodites of Cyclops spp. dominated the zooplankton community at deep-water stations in terms of the total abundance consisting of 24–33%. The copepod Macrocyclops albidus prevailed in terms of the total zooplankton biomass comprising 30–33% at deep-water stations while Cyclops scutifer and copepodites Cyclops spp. had the highest biomass at shallow water stations. Vertical distribution demonstrated different patterns at neighboring stations, probably as a result of differences in the density of fish predators.

Research on key problems of Arctic navigation safety

Arctic shipping can bring significantly potential business profit, which has become a focal point at present. However, compared to the enormous risk, related research on the safety and security issues are not sufficient. In the essay, the natural factors, such as weather, ice are summarized, and the facility insufficiency and human factors aroused by low temperature and severe ice conditions are analyzed. Besides that, the requirement of international conventions has already proposed the basic technical demand for the ship facilities and lifeboat in Arctic area. In the end, the suggestions for safety and security, providing better equipment and facilities, enhancing crew competence, decent preparations before navigation are proposed.

Study of changes of vessel’s speed in ice conditions on the Northern Sea Route

Based on archive information of automatic identification system (AIS), studies of changes in the commercial speed of large-capacity ice-class vessels Arc7 along the route in the Kara Sea on the Northern Sea Route are carried out. To plan maritime traffic in the Arctic seas, it is necessary to have objective data on the influence of various factors on speed and time of transition. To ensure the safety of Arctic shipping, it is necessary to have objective data on the effect of ice on speed and maneuverability of vessels. It was proposed to use a geographic information system (GIS), the layers of which include data on the speeds and routes of vessels of various capacities and data on monitoring ice conditions. Detailed attention was paid to the route in the Kara Sea, as it the main entrance to the Northern Sea Route from the west, the movement of vessels was studied during the winter navigation period under the most severe ice conditions (March) and during the summer navigation period for clean water (September). It was found that in the dense stream of ships in summer navigation, the speed of ships varies slightly and depends on the density and intensity of traffic, and in winter navigation, the speed of ships has dramatic changes as ships go along the route with a large lateral deviation from the route. Research is performed at the Arctic Faculty of Admiral Makarov State University of Maritime and Inland Shipping. In future, all obtained relationships can be used for modeling the maritime traffic on the Northern Sea Route with an increase in the number of large-capacity vessels with Arc7 ice-class.

О НЕОБХОДИМОСТИ СОЗДАНИЯ ПОДВОДНОГО НЕФТЕГАЗОПРОМЫСЛОВОГО ФЛОТА ДЛЯ ОСВОЕНИЯ НЕФТЕГАЗОВЫХ МЕСТОРОЖДЕНИЙ НА ДЛИТЕЛЬНО ЗАМЕРЗАЮЩИХ ГЛУБОКОВОДНЫХ АРКТИЧЕСКИХ АКВАТОРИЯХ

The article dwells upon the problem of developing offshore oil and gas fields around the world accompanied by producing not only stationary and semi-submersible rigs and drilling vessels, but also a large number of auxiliary vessels for various functional purposes. It would be impossible to extract offshore hydrocarbons under the sea bed without them. Special fleet was formed during the years of development of offshore oil and gas fields in the Russian Federation, the part of it being imported. In the upcoming years, our country will face some challenges related to the development of Arctic reservoirs which are mainly located in the long-frozen deep seas. Their development in deep water will only be possible with auxiliary fleet, as it will be necessary to build deep water drilling vessels and other facilities/vessels. The types of vessels of the modern oil and gas fleet are presented, depending on the area of navigation, the depth of use and the specifics of the work performed. It is noted that currently in world practice there are no examples of using proven drilling and production technologies in severe ice conditions, when ice thickness exceeds 2-3 m, because the modern ice-resistant stationary platforms can not withstand the load at a depth of more than 80-100 m. The auxiliary fleet will both service offshore rigs and ensure their long-term productivity and functionality. For the development of oil and gas fields in the long-frozen Arctic deep-sea areas it is necessary to create a full-fledged underwater oil and gas fleet.