Ice Destruction Research Articles

Cortisol concentration in hair of the Baikal seal (<i>Pusa sibirica</i> Gmelin 1788, Carnivora, Phocidae): the effects of sex, age, and the dynamics of ice destruction

Measuring hair cortisol concentrations is a widespread method of hormonal research in natural populations. In particular, it has increasingly been used for assessing the chronic physiological stress over long time periods. This study showed for the first time the experience of using hair of Baikal seals to examine their hormonal status. We collected hair samples from live Baikal seals captured during summer expeditions to the Ushkany Islands, Lake Baikal in 2019 and 2021. Age differences in hair cortisol concentration were found: hair cortisol levels were higher among the young seals and declined with age. We suppose this may be related to different extents of nutritional stress, hunting success and social factors on summer rookeries. There was no sex effect on hair cortisol in young animals. We observed that hair cortisol concentrations were higher in young animals captured in 2019 compared to seals taken in 2021, with no differences in ice conditions between these years found.

Влияние колебаний стока реки Лены на площадь льда в море Лаптевых

The ice regime of the Laptev Sea has significant changes during the last twenty years. After the changes in the ice regime of the Laptev Sea, the influence of river runoff on the processes of seasonal formation and destruction of sea ice have increased. During the period from 2004 to 2022, the average annual ice area in the Laptev Sea has a positive correlation with a fluctuations of Lena runoff. The high-water content years of Lena has stimulated to the speedup of the ice cover formation process in autumn and the shift of the beginning of ice melting in spring to a later date.

Simulation Analysis of Three-Point Bending Fracture Process of Yellow River Ice

During the ice flood period of the Yellow River, the fracture and destruction of river ice can easily lead to the formation of ice jams and ice dams in the curved and narrow reaches. However, the occurrence and development mechanism of river ice fracture remain incompletely understood in the Yellow River. Therefore, based on the three-point bending physical test of the Yellow River ice, a three-point bending fracture numerical model of the Yellow River ice was constructed. The fracture failure process of the Yellow River ice under three-point bending was simulated, and the effects of the crack-to-height ratio and ice grain size on the fracture properties of the river ice were analyzed. By comparing the results with those of physical tests on river ice, it is evident that the fracture model can effectively simulate the cracking process of river ice. Within the confines of the simulated sample size spectrum, as the crack-to-height ratio varies from 0.2 to 0.8, the fracture toughness value of the Yellow River ice spans a range from 115.01 to 143.37 KPa·m1/2. Correspondingly, within the simulated calculation values ranging from 5.38 mm to 24.07 mm for ice crystal size, the fracture toughness value of the Yellow River ice exhibits a range from 116.89 to 143.37 KPa·m1/2. The findings reveal that an increase in the crack-to-depth ratio leads to a decrement in the fracture toughness of river ice. Within the scale range encompassed by the model calculations, as the average size of the ice crystal grains augments, the fracture toughness of the river ice exhibits a gradual ascending trend. The research results provide a parameter basis for studying the fracture performance of the Yellow River ice using a numerical simulation method and lays a foundation for investigating the cracking process of river ice from macro and micro multi-scales.

The ephemeral state of ice in micro cold traps on the Moon

Micro cold traps stand out as promising targets for future investigation missions to the lunar polar regions, due to their greater accessibility compared to macro cold traps. However, this advantage naturally comes at the cost of their size, which limits the amount of ice they can potentially harbor. Here, we investigate the permanently shadowed volume (PSV) of micro cold traps — an upper limit for their potential ice capacity. We find that, as expected, the PSV depth increases with latitude and surface roughness, but is on average much shallower (∼0.5−1%) compared to the topographic baseline. By comparing the expected destruction and accumulation rates of ice to the potential maximum capacity of micro cold traps, we predict their infill as a function of lateral size, and the lifetime of the ice they harbor. Our results could be used by future investigation missions to the lunar polar regions to constrain the delivery rate and delivery mechanism of ice to the Moon.

Разрушение дорожного льда сферическим бойком

The article provides a brief overview of the state of the issue of the theoretical description of the process of ice destruction, presents a developed mechanical and mathematical model describing the process of ice destruction by a spherical striker, analyzes the results of calculations based on the obtained formulas for the adequacy of the quantitative assessment of the process. The model is illustrated by a computational scheme of the impact interaction of a striker and a half-space. Empirical correction of theoretical dependencies has been performed. Experimental studies are described, an analysis of their results and the identified conditions of the ice destruction process are presented, as well as the results of empirical correction of theoretical dependencies obtained on their basis, providing a correct quantitative assessment of the process of ice destruction by a spherical striker. The results of an experimental verification of the adequacy of the obtained refined empirical-theoretical dependencies and a method for determining the parameters of a working organ with spherical strikers for breaking ice based on them are presented. The dependences of the results of theoretical and experimental determination of the depth of penetration of the striker rod into the ice are compared. The patterns of crushing of thin ice are revealed depending on the speed of rotation of the rotor, the mass of the inertial strikers and their shape.

NUMERICAL SIMULATION OF GAS-DYNAMIC AND STRENGTH CHARACTERISTICS OF A FAN FOR THE EXPERIMENTAL TEST RIG FOR INVESTIGATION OF ICE BREAKDOWN ON ROTATING WORKING BLADES

The paper is devoted to modern experimental and computational studies analysis on the point of asymmetric destruction of ice on the surfaces of the working blades of gas-turbine engine blades. A schematic diagram of an experimental setup has been developed, which consists of the following main elements: a wind tunnel, a cold chamber, a model fan, an electric motor, and a high-speed video camera. The experimental setup makes it possible to carry out laboratory studies of the ice formation and destruction processes. The choice of the experimental test rig parameters was made to allow assessing the icing of the blades of a rotating fan, which reproduces the processes occurring on gas turbine engines. Based on the results of three-dimensional gas-dynamic and strength calculations, the design and basic geometrical parameters of the flow path and the dummy fan were determined. The dependences of compression ratio Pk and the power consumption of a model fan Wcons on the value of the mass air flow Gair for a different number of rotor blades are presented. The choice of materials for the disk hub and blades of a dummy fan which experience tensile and bending loads at high rotation speeds up to 12.000 rpm was made, that satisfies the conditions of static and dynamic strength, also the allowable safety factors were evaluated, and pressure characteristics were obtained.

ПОВЕРХНОСТНЫЕ ГРАВИТАЦИОННЫЕ ВОЛНЫ В СЕВЕРНОЙ АТЛАНТИКЕ И В ДРЕЙФУЮЩЕМ ЛЬДУ АРКТИКИ

Sea ice in the Arctic is one of the main dynamic elements in the interacting atmosphere–ice–ocean system. Currently, theoretical and experimental studies of drifting and soldered ice are used to develop predictive models of the mechanical state of sea ice. This paper presents the results of an experimental study of physical and mechanical processes on the surface of the Arctic Ocean. Field work was carried out using the spatial placement of autonomous seismic stations directly on the drifting ice. Data on surface gravitational waves of the ocean, accompanied by periodic deformations of bending and shear in the ice, have been obtained. On the basis of amplitude spectra, the features of the process of propagation of storm waves of swell in the ice cover are considered and a comparative analysis with map of maximum heights of sea waves is performed. A significant factor is the use of microseismic oscillations recorded at coastal stations of the Greenland Sea to determine the time and place of a powerful storm. The spectrum of the wave field in the ice sheet indicates an increase in the frequency of oscillations due to the dispersion of the wave field. New data have been obtained on the large-scale mechanics of the occurrence of cracks in the ice cover and discrete flexural-gravity waves as one of the main indicators of ice destruction. The results of the study are important for improving weather and climate forecasting models, as well as for solving engineering problems on the Arctic shelf.

Modeling the chemical evolution and kinetics of pure H2O Ices under various types of radiation employing the PROCODA code

Water is one of the most abundant molecules in space, especially in cold environments, where it is the main constituting of astrophysical ices. The space ionizing radiation affects these ices and induces chemical changes, including desorption to gas-phase, which increase the complexity of the interstellar medium. In this work, we employed the PROCODA code to investigate the behavior of several pure water ices under different type of ionizing radiation such as UV, X-rays, electrons and cosmic rays analogues. Here, we employ molecular column densities from laboratory and solved a set of coupled chemical reactions to calculated effective reaction rates (ERCs) and characterize the chemical equilibrium of water ices under high radiation fluences. Briefly, we monitored the evolution of nine species (including the observed ones H2O, H2O2, and O3, and the predicted ones H, O, H2, OH, O2, and HO2). A discussion on the branching ratio for the considered reactions with the type of ionizing radiation is provided. Among the results, we observed that approximately 63% of the modeled molecules quantified at chemical equilibrium were non-observed species in the X-rays experiment, highlighting the importance of this work in providing insights into the processes that occur on the surface of icy interstellar grains exposed to cosmic radiation, including the formation and destruction of water ice. Accurate modeling of these processes can lead to a better understanding of the chemical evolution of interstellar and circumstellar environments, as well as offer insight into the formation and composition of celestial objects such as comets.

Results of Experimental and Theoretical Studies of the Possibilities of the Resonance Method of Ice Cover Destruction

Based on experiments carried out: in ice basins; with large-scale models of hovercraft in the field; with full-scale hovercraft, as well as using theoretical dependencies for calculating the stressstrain state of the ice cover from the action of moving loads, the possibilities (patterns) of the resonant method of ice destruction, i.e., by excitation of resonant flexural-gravity waves (FGW), were studied. Its physical essence, the expediency of its implementation by a hovercraft are explained, the possible areas of effective use of this method are indicated. The results of the information review on the topic of the work are given, on the basis of which the purpose of the research is set. When describing the viscoelastic nature of the relationship between stresses and strains in ice, the Kelvin-Voigt law of deformation of an elastically retarded medium was used. The theoretical bending potential energy density of an infinite plate was taken as a criterion for the ice breaking capacity of FGW. In this case, the condition is used that when it reaches a certain value, complete (with the opening of cracks) destruction of ice occurs. The initial data for these calculations are taken from the performed experiments. Dependences are given that make it possible to determine the parameters of a load moving at a resonant speed (hovercraft parameters) sufficient to destroy an ice cover of a given thickness under given ice conditions.

Simulation of CH3OH ice UV photolysis under laboratory conditions

Context. Methanol is the most complex molecule that is securely identified in interstellar ices. It is a key chemical species for understanding chemical complexity in astrophysical environments. Important aspects of the methanol ice photochemistry are still unclear, such as the branching ratios and photodissociation cross sections at different temperatures and irradiation fluxes. Aims. This work aims at a quantitative agreement between laboratory experiments and astrochemical modelling of the CH3OH ice UV photolysis. Ultimately, this work allows us to better understand which processes govern the methanol ice photochemistry present in laboratory experiments. Methods. We used the code ProDiMo to simulate the radiation fields, pressures, and pumping efficiencies characteristic of laboratory measurements. The simulations started with simple chemistry consisting only of methanol ice and helium to mimic the residual gas in the experimental chamber. A surface chemical network enlarged by photodissociation reactions was used to study the chemical reactions within the ice. Additionally, different surface chemistry parameters such as surface competition, tunnelling, thermal diffusion, and reactive desorption were adopted to check those that reproduce the experimental results. Results. The chemical models with the code ProDiMo that include surface chemistry parameters can reproduce the methanol ice destruction via UV photodissociation at temperatures of 20, 30, 50, and 70 K as observed in the experiments. We also note that the results are sensitive to different branching ratios after photolysis and to the mechanisms of reactive desorption. In the simulations of a molecular cloud at 20 K, we observed an increase in the methanol gas abundance of one order of magnitude, with a similar decrease in the solid-phase abundance. Conclusions. Comprehensive astrochemical models provide new insights into laboratory experiments as the quantitative understanding of the processes that govern the reactions within the ice. Ultimately, these insights can help us to better interpret astronomical observations.

Influence of early melting of the ice cover and high water level on functioning of the coastal rookery for baikal seal (<i>Pusa sibirica</i> Gm.) on Dolgiy Island (Lake Baikal), on materials of 2020

Functioning of a coastal seal rookery is considered on example of those located on Dolgiy Island in Lake Baikal, regularly visited by baikal seal <i>Pusa sibirica</i> Gm., which is constantly monitored by video surveillance. A case of the year 2020 with extremely early (comparing to 2011–2019) destruction and disappearance of ice in the northern part of the lake and rapid rise of the water level in summer-autumn is analyzed. Timing of the seals haul onshore and their abundance in rookery depend on the ice conditions: the lower ice cover – the earlier hauling-out and the higher abundance. Since the beginning of the rookery formation in May, up to 400 animals roosted there at the same time. Too early disappearance of the floating ice caused an abnormally large portion of individuals with incomplete molting on the rookery, and the delay in molting affected likely negatively on the animals health. Other negative factor was the deficit of available solid substrate for hauling-out because of rapid rise of the water level, particular in early summer. However, a large number of very well-fed adult females and males was observed on the rookery in May; presumably they did not participate in reproduction of population in 2020.

The Model of Ice Destruction on a Solid Surface by Spherical Striker Impact

Nowadays, there is a problem related to the difficulties of the vehicles and pedestrians’ movement in the cold season due to the formation of an ice layer on roads and sidewalks. As a variant of the problem solution, the mechanical ice destruction by impact-destructive working body with spherical strikers is applied. The use of the spherical strikers provides not only effective ice destruction but it also prevents from damage of the road and sidewalks pavement. In order to achieve the effectiveness of the ice destruction, it is necessary to use appropriate mathematical dependencies for calculation of the working body parameters. In the paper, mathematical model of the ice destruction process using spherical strikers has been conducted. Theoretical dependencies of the mathematical model have been corrected based on the experimental studies.

North Pole ice-resistant self-propelled platform as an innovative complex for research in the Arctic

The Russian presence in the Arctic Region and the development of the Arctic is one of the most important geopolitical interests of Russia. At the beginning of the 21st century, the problem of using innovative methods in Arctic research came to the fore. Based on the analysis of the unique work experience of drifting stations “Severniy Polus” (“North Pole”) (1937-2015), Arctic and Antarctic Research Institute specialists have concluded that the stations should be replaced by a modern scientific complex, capable of solving a wider range of problems. As a result, it was proposed to create an ice-resistant self-propelled platform (IRSPP) – an engineering structure for permanent basing of scientific observatories. The IRSPP is designed to conduct year-round comprehensive scientific research in the high latitudes of the Arctic Ocean and should make a long drift of at least one year together with the surrounding ice massive. The scientific complex of the IRSPP includes 16 different laboratories, including an ice load monitoring laboratory. A unique ice load monitoring system (ILMS) has been developed for the IRSPP. The ILMS will be an essential part of the system of safe operation and persistence of the IRSPP and will provide the platform hull with a measurement tool for studying the mechanics of deformation and destruction of sea ice in its interaction with the engineering structures. In all respects, the IRSPP is unparalleled in the world. Its use can open a new chapter in the exploration of the Russian Arctic and in international collaboration aimed at studying the northern latitudes. The platform was put into operation in 2022.

Воздействие флюидодинамического фактора на формирование и изменения ледяного покрова в Северном Ледовитом океане

In recent decades, the reduction in the area of Arctic ice and its thickness has accelerated. These phenomena are associated with global warming. But the ice cover is destroyed not only under the influence of external causes, but also under the influence of the deep fluid-dynamic factor of the lithosphere. The authors analyzed the satellite observations of ice thickness together with the interpretation of the anomalies of the geomagnetic field and the gravity field. The studies made it possible to put forward an assumption about the influence of thermofluid channels of faults on the formation of the ice cover due to a decrease in the thickness of the ice. The paper presents the results of studying the structure of the lithosphere of the Arctic Ocean in the zones of accelerated ice melting above the outlets of thermofluid channels to the bottom surface. The mechanism of influence of the endogenous factor on the processes of ice destruction is considered. It is noted that the nature of the horizontal layering of the earth's crust affects the process of ice formation. Taking into account the fluid dynamic factor and the layering of the earth's crust on the formation of the ice regime can be useful in determining the optimal transport and logistics routes for year-round navigation along the Northern Sea Route and safe navigation.

Численное моделирование разрушения льда газодинамической струей

When operating gas compressor stations during heavy snowfalls, uncontrolled formation of ice build-up on the filters of air-purifying devices (ACDs) can occur, which leads to accidents and downtime. Previously, it was proposed to use a gas-dynamic system for cleaning gas-permeable deformable surfaces (GPDS) to clean HEU filters. An experimental setup has been created. The paper discusses numerical modeling of ice destruction on the gas turbine engine. To destroy ice, the energy of a gas-dynamic jet is used, modeled as a short-term pulse. The study is carried out in a 3D setting, taking into account the suction flow pressure and the interaction of the deformable substrate with the ice crust. The results obtained were verified. The research is carried out using ANSYS Explicit Dynamics on the high-performance computing complex of PNRPU. The main results on the influence of a gas-dynamic jet on the cleaning ability of a gas turbine engine are presented

FEATURES OF SPRING ICE PHENOMENA ON BALKASH LAKE IN EXTREMELY WARM MONTHS

In this paper we are considering the processes of ice destruction on Balkash Lake during extremely warm months. A significant correlation found between the average monthly air temperature of March and the dates of ice destruction beginning, complete freezing ending and water clear of ice. The Bagrov-Tokarev anomaly criterion for March was calculated and the extreme months were determined. The features of ice destruction during the spring season for the years with extremely warm months were analyzed. The number of days with certain types of ice phenomena are calculated, the various types of ice phenomena were analyzed for extremely warm months. The maps of ice thickness distribution were compiled. The deviation of the dates of ice destruction beginning, complete freezing ending and water clear of ice from the averages dates in extremely warm months was found. The data source were hydrological guides, monthly average air temperature data, and data reanalysis using the CDS Copernicus climate database of the European Center.

Influence of the Shape of a Submarine Vessel on the Ice Breaking Capacity of Flexural-Gravity Waves

The severe climatic conditions of the Arctic Regions impose great constraints on traditional methods of hydrocarbon extraction. That is why underwater technologies used for raw material extraction and handling are very promising. The influential factor for the safe operation of an submarine vessel (SV) during under-ice navigation is breaking the surface through the ice cover. The traditional method of coming to the surface does not always apply because of the difficult and dangerous maneuvering and ice partial depth of the broken ice. In fact, the load that arises in the ice moves generates a system of progressive flexural-gravity waves (FGW). In case the waves are intensive to a certain extent, the ice of heavy thickness can destruct. The paper informs on an experimental study of FGW ice-breaking capacity generated due to SV of different projects running. The experiments were conducted in an ice tank. The ice destruction efficiency is determined using the ice-breaking criterion. The authors conclude that the principal factor affecting the ice-breaking capacity is not the displacement of water, but a fineness ratio of a submarine ship, as well as a cross-section ship shape. The subject of the influence of the vessel depth on FGW characteristics is explored.

Winter thermal and ice regimes of small Karelian lakes against the background of regional climatic variability

This article investigates regularities of thermal and ice regimes of three small lakes of Karelia under current climatic conditions. Data of measurements of water temperature at autonomous stations and results of numerical calculations of the dates of ice-on and ice-off and the thickness of ice in these lakes using the one-dimensional parameterized model FLake in the anomalously warm winter season of 2019-2020 are analyzed. Data obtained are compared with long-term values over 1994-2019. The dates of the ice-on and ice-off on the lakes were quite close; however, on two larger lakes, intermediate ice destruction was observed at the beginning of winter, due to which the duration of the ice season differed between lakes by two weeks. The winter months of 2019-2020 were 6.4-9.4 ° C warmer than the baseline, which was reflected in a noticeably smaller ice thickness on the lakes compared to previous years of measurements (40-48 cm at the end of March 2020 compared to the values ​​in mid-April in 1994-2004 - 65-85 cm and in 2005-2018 - 50-65 cm). The decrease in ice thickness contributed to an early onset (mid-March) and long duration (more than five weeks) of spring subglacial convection. The model calculation, taking into account the atmospheric impact based on the ERA-5 re-analysis, reproduced the main features of the ice regime of the lakes, including the intermediate destruction of ice at the beginning of winter on two larger lakes. Significant regression relationships have been obtained between the dates of ice-on and ice-off on Lake Vendyurskoe, the dates of the onset and duration of spring under-ice convection, and the characteristics of the regional climate of southern Karelia (air temperature and the number of days with thaw in winter and spring months) for 1994-2020. The relationship between the dates of ice-on and the water temperature in the lake in winter is shown.

Determination of the Relationship between the Parameters of the Impact Working Body for the Destruction of Ice on Highways Taking Into Account the Characteristics of Ice

Determination of the Relationship between the Parameters of the Impact Working Body for the Destruction of Ice on Highways Taking Into Account the Characteristics of Ice

Mechanical Properties of Frozen Glacial Tills due to Short Periods of Thawing

Due to the warming climate, glacier retreat has left massive glacial tills in steep gullies; ice in the soil is prone to change phase resulting in the decrease of the ice strength and bonding of soil particles; collapse of thawing tills can lead to debris flows with disastrous consequences for geotechnical infrastructures. To improve our understanding of the mechanics of thawing glacial tills, we conducted unconsolidated–undrained direct shear tests on glacial tills from Tianmo gully on the southeastern Tibetan Plateau. Control specimens were not subjected to freeze–thaw action. A total of 648 specimens with three different dry densities, three initial water contents, and 18 thawing times were tested. Peak shear strength, peak stress to displacement ratio (0.857), and cohesion were the highest in frozen specimens. After a thawing time of 0.25 h, there was a marked decline in shear strength; maximum friction was 2.58, which was far below the value of cohesive strength. For thawing times of 0.25–4 h, peak strength varied little with thawing time, but cohesion decreased and internal friction angle increased with increasing thawing time. Our results indicate that thawing of the solid ice in the till during the initial phase of till thawing is the key control of peak till strength; the effect of ice on cohesion is greater during the initial phase of thawing and in loose tills. Moreover, frequent sediment recharge of gullies may be explained by the decrease of cohesion with increasing thawing time caused by short-term destruction of ice bonding.