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We consider a liquid layer of a finite depth described by Euler's equations. The ice cover is geometrically modeled by a nonlinear elastic Kirchhoff–Love plate. We determine the trajectories of liquid particles under an ice cover in the field of a nonlinear surface traveling wave rapidly decaying at infinity, namely, a solitary wave packet (a monochromatic wave under the envelope, with the wave velocity equal to the envelope velocity) of a small but finite amplitude. Our analysis is based on the use of explicit asymptotic expressions for solutions describing the wave structures at the water–ice interface of a solitary wave packet type, as well as asymptotic solutions for the velocity field generated by these waves in the depth of the liquid. [ABSTRACT FROM AUTHOR]

Sea spray icing on ships and marine structures depends on a complex correlation between metocean parameters and vessel characteristics. Sea spray icing rates have mostly been investigated and given as a function of general metocean parameters. The existing models suffer from the lack of experimental data. More experimental data are required for better prediction models and understanding of the icing process. This article presents results from a comprehensive cold laboratory study of the dependence and trends of sea spray icing rates related to eight parameters. Experiments were performed simulating sea spray from a nozzle toward a vertical surface in the freezing environment. This study presents 20 unique tests structured into eight experiments, each of which focuses on change in icing rates due to one independent variable. Results showed that the sea spray rate dependence of the investigated parameters complies with the existing knowledge; however, preliminary analysis points out various unintentional covariates for most experiments that call for further investigations. This is the greatest number of variables tested in one set of experiments to date and serves as valuable sea spray icing data experimental data--a limitation for the evaluation of previous models that pointed out the lack of enough icing measurements in this field of research. [ABSTRACT FROM AUTHOR]

The Svalbard archipelago is particularly sensitive to climate change due to the relatively low altitude of its main ice fields and its geographical location in the higher North Atlantic, where the effect of Arctic amplification is more significant. The largest temperature increases have been observed during winter, but increasing summer temperatures, above the melting point, have led to increased glacier melt. Here, we evaluate the impact of this increased melt on the preservation of the oxygen isotope (δ18 O) signal in firn records. δ18 O is commonly used as a proxy for past atmospheric temperature reconstructions, and, when preserved, it is a crucial parameter to date and align ice cores. By comparing four different firn cores collected in 2012, 2015, 2017 and 2019 at the top of the Holtedahlfonna ice field (1100 m a.s.l.), we show a progressive deterioration of the isotope signal, and we link its degradation to the increased occurrence and intensity of melt events. Our findings indicate that, starting from 2015, there has been an escalation in melting and percolation resulting from changes in the overall atmospheric conditions. This has led to the deterioration of the climate signal preserved within the firn or ice. Our observations correspond with the model's calculations, demonstrating an increase in water percolation since 2014, potentially reaching deeper layers of the firn. Although the δ18 O signal still reflects the interannual temperature trend, more frequent melting events may in the future affect the interpretation of the isotopic signal, compromising the use of Svalbard ice cores. Our findings highlight the impact and the speed at which Arctic amplification is affecting Svalbard's cryosphere. [ABSTRACT FROM AUTHOR]

The solubility of the components in the ZnSO4 - KNO3 - H2O system was studied by the visual-polythermal method in the temperature range from -7.0°C to 42.0°C. The phase diagram delimits the fields of ice crystallization, KNO3, K2SO4·ZnSO4·6H2O, and ZnSO4. A solubility diagram was constructed, and a new compound K2SO4·ZnSO4·6H2O was separated. The new compound was identified by chemical, X-ray phase, thermogravimetric, and IR spectroscopic analysis. [ABSTRACT FROM AUTHOR]

Lake ice phenology (LIP), hiding information about lake energy and material exchange, serves as an important indicator of climate change. Utilizing an efficient technique to swiftly extract lake ice information is crucial in the field of lake ice research. The Bayesian ensemble change detection (BECD) algorithm stands out as a powerful tool, requiring no threshold compared to other algorithms and, instead, utilizing the probability of abrupt changes to detect positions. This method is predominantly employed by automatically extracting change points from time series data, showcasing its efficiency and accuracy, especially in revealing phenological and seasonal characteristics. This paper focuses on Bosten Lake (BL) and employs PMRS data in conjunction with the Bayesian change detection algorithm. It introduces an automated method for extracting LIP information based on the Bayesian change detection algorithm. In this study, the BECD algorithm was employed to extract lake ice phenology information from passive microwave remote sensing data on Bosten Lake. The reliability of the passive microwave remote sensing data was further investigated through cross-validation with MOD10A1 data. Additionally, the Mann–Kendall non-parametric test was applied to analyze the trends in lake ice phenology changes in Bosten Lake. Spatial variations were examined using MOD09GQ data. The results indicate: (1) The Bayesian change detection algorithm (BCDA), in conjunction with PMRS data, offers a high level of accuracy and reliability in extracting the lake ice freezing and thawing processes. It accurately captures the phenological parameters of BL's ice. (2) The average start date of lake ice freezing is in mid-December, lasting for about three months, and the start date of ice thawing is usually in mid-March. The freezing duration (FD) of lake ice is relatively short, shortening each year, while the thawing speed is faster. The stability of the lake ice complete ice cover duration is poor, averaging 84 days. (3) The dynamic evolution of BL ice is rapid and regionally distinct, with the lake center, southwest, and southeast regions being the earliest areas for ice formation and thawing, while the northwest coastal and Huang Shui Gou areas experience later ice formation. (4) Since 1978, BL's ice has exhibited noticeable trends: the onset of freezing, the commencement of thawing, complete thawing, and full freezing have progressively advanced in regard to dates. The periods of full ice coverage, ice presence, thawing, and freezing have all shown a tendency toward shorter durations. This study introduces an innovative method for LIP extraction, opening up new prospects for the study of lake ecosystem and strategy formulation, which is worthy of further exploration and application in other lakes and regions. [ABSTRACT FROM AUTHOR]

Dykes and sills occupy Mode I (extension), Mode II (shear), or hybrid mode fractures and most of the time transport and store magma from deep reservoirs to the surface. Subject to their successful propagation, they feed volcanic eruptions. Yet, dykes and sills can also stall and become arrested as a result of the crust's heterogeneous and anisotropic characteristics. Dykes can become deflected at mechanical discontinuities to form sills, and vice versa. Although several studies have examined dyke propagation in heterogeneous and anisotropic crustal segments before, the conditions under which dykes propagate in glacial-volcanotectonic regimes remain unclear. Here, we coupled field observations with 2D FEM numerical modelling to explore the mechanical conditions that encourage (or not) dyke-sill transitions in volcanotectonic or glacial settings. We used as a field example the Stardalur cone sheet-laccolith system, which lies on the Esja peninsula, close to the western rift zone, NW of the southern part of the Icelandic rift. The laccolith is composed of several vertical dykes that transition into sills and form a unique stacked sill 'flower' structure. Here, we investigate whether the Stardalur laccolith was formed under the influence of stresses caused by glacial retreat due to thickness variations (0–1 km) in addition to regional and local tectonic stresses (1–3 MPa extension or compression) and varied magma overpressure (1–30 MPa), as well as the influence of the mechanical properties of the lava/hyaloclastite contact. Our results show that the observed field structure in non-glacial regimes was formed as a result of either the mechanical (Young's modulus) contrast of the lava/hyaloclastite contact or a compressional regime due to pre-existing dykes or faulting. In the glacial domain, the extensional stress field below the ice cap encouraged the formation of the laccolith as the glacier became thinner (subject to a lower vertical load). In all cases, the local stress field influenced dyke to sill deflection in both volcanotectonic regimes. [ABSTRACT FROM AUTHOR]

Over the past four decades, Arctic sea ice coverage has steadily declined. This loss of sea ice has amplified solar radiation and heat absorption from the ocean, exacerbating both polar ice loss and global warming. It has also accelerated changes in sea ice movement, posing safety risks for ship navigation. In recent years, numerical prediction models have dominated the field of sea ice movement prediction. However, these models often rely on extensive data sources, which can be limited in specific time periods or regions, reducing their applicability. This study introduces a novel approach for predicting Arctic sea ice motion within a 10-day window. We employ a Self-Attention ConvLSTM deep learning network based on single-source data, specifically optical flow derived from the Advanced Microwave Scanning Radiometer Earth Observing System 36.5 GHz data, covering the entire Arctic region. Upon verification, our method shows a reduction of 0.80 to 1.18 km in average mean absolute error over a 10-day period when compared to ConvLSTM, demonstrating its improved ability to capture the spatiotemporal correlation of sea ice motion vector fields and provide accurate predictions. [ABSTRACT FROM AUTHOR]

This study presents a numerical investigation of free field ice gouging in layered cohesive seabeds comprising stiff over soft clay. A three-dimensional, half-space, dynamic large deformation finite element analysis was conducted using the Coupled Eulerian Lagrangian approach. To simulate the seabed, a Tresca soil model with the strain rate and strain-softening effects was coded into a user subroutine. The accuracy of the model was verified by comparing its results with those of published experimental studies. Additionally, a comprehensive parametric study was conducted to examine the effect of various ice gouging scenarios and seabed soil parameters on the subgouge soil deformation and the ice keel reaction forces. Our findings revealed that an interactive response occurs between the soil layers and the ice keel that may cause the peak subgouge soil deformation and keel reaction magnitudes to differ from those observed under uniform soil condition. The developed model was found to be an efficient tool for free field ice gouging analysis in cohesive layered seabeds. [ABSTRACT FROM AUTHOR]

For ships navigating in ice floe fields, ship-ice-wave interactions may affect ship performance and ice impact forces. This paper presents an approach to evaluate the cross-coupling added mass and hydrodynamic damping between a passing ship and a free-floating small/medium size ice floe based on the boundary element method (BEM). The influences of added mass and hydrodynamic damping are explored for different wave frequencies and headings. Results are presented for a regular waves scenario whereby a tanker progressing at a slow speed is passing by a free-floating ice floe modeled as a round disk. Radiation and diffraction potentials of the interacting floating bodies are linearly superimposed to reflect the influence of hydromechanical coupling on responses. Parametric analysis of response amplitude operators (RAOs) indicates that the cross-coupling terms of added mass and hydrodynamic damping are of the same order of magnitude as those of the ice floe but smaller by one or two orders of magnitude than those of the ship. It is concluded that hydrodynamic interactions primarily influence the motions of the ice floe and are significant attributes in terms of suitably idealizing ship-ice system dynamics. [ABSTRACT FROM AUTHOR]

The Antarctica ice sheet thickness is one of the important information to know the dynamics of changes in the Earth's environment. Geospatial data of the ice sheet surface, land surface and underwater topography, and vertical deformation can be used for ice sheet thickness measurement and calculation. They can be extracted from the latest DTM. The latest DTM is one of the methods and products to extract up-to-date and detailed topography based on the dynamics of the vertical deformation period. This study aims to measure the Antarctica ice sheet thickness based on land surface dynamics and underwater topography from the latest DTM extraction. The vertical accuracy of the DTM, DSM, and vertical deformation uses a 95 % (1.96σ) confidence level. The ice thickness is divided into three types of ice layers according to the reference field: ice thickness above land, ice thickness (above the sea), and ice thickness (underwater). Ice thickness above land has a volume (3,700,299.5 km³), an area (6,767,772 km²), and a total length perimeter (114,569 km). Ice thickness (above the sea) has a volume (28,103,427.8 km³), an area (13,438,789 km²), and a total perimeter length (27,199 km). Ice thickness (underwater) has a volume (1,793,778.6 km³), an area (3,223,036 km²), and a total length perimeter (46,556 km). Antarctica's ice sheet thickness results can be used for various thematic applications of the dynamics of the Earth's environment. [ABSTRACT FROM AUTHOR]

Atmospheric ice nucleation plays an important role in modulating the global hydrological cycle and atmospheric radiation balance. To date, few comprehensive field observations of ice nuclei have been carried out at high-altitude sites, which are close to the height of mixed-phase cloud formation. In this study, we measured the concentration of ice-nucleating particles (INPs) in the immersion freezing mode at the summit of the Changbai Mountains (2623 m above sea level), northeast Asia, in summer 2021. The cumulative number concentration of INPs varied from 1.6 × 10 -3 to 78.3 L -1 over the temperature range of - 5.5 to - 29.0 °C. Proteinaceous-based biological materials accounted for the majority of INPs, with the proportion of biological INPs (bio-INPs) exceeding 67 % across the entire freezing-temperature range, with this proportion even exceeding 90 % above - 13.0 °C. At freezing temperatures ranging from - 11.0 to - 8.0 °C, bio-INPs were found to significantly correlate with wind speed (r = 0.5–0.8, p < 0.05) and Ca 2+ (r = 0.6–0.9), and good but not significant correlation was found with isoprene (r = 0.6–0.7) and its oxidation products (isoprene × O 3) (r = 0.7), suggesting that biological aerosols may attach to or mix with soil dust and contribute to INPs. During the daytime, bio-INPs showed a positive correlation with the planetary boundary layer (PBL) height at freezing temperatures ranging from - 22.0 to - 19.5 °C (r > 0.7, p < 0.05), with the valley breezes from southern mountainous regions also influencing the concentration of INPs. Moreover, the long-distance transport of air mass from the Japan Sea and South Korea significantly contributed to the high concentrations of bio-INPs. Our study emphasizes the important role of biological sources of INPs in the high-altitude atmosphere of northeastern Asia and the significant contribution of long-range transport to the INP concentrations in this region. [ABSTRACT FROM AUTHOR]

Accurately assessing ice loads is a fundamental issue in the field of structural design for ships in ice-covered regions. In this paper, we conducted research on extreme ice load estimation for icebreaking ships, combining stochastic theory with numerical simulation. Firstly, using sea ice data from the Arctic region of the United States National Snow and Ice Data Center, a stochastic ice field model was established under Arctic sea ice conditions using non-parametric estimation and the rejection sampling method, and ice field data were generated stochastically. Then, based on the stochastic ice field data, a three-dimensional numerical model of the interaction between the ice field and the ship hull was established, and the reliability of the numerical model was verified by experimental results. Finally, based on the numerical model of the interaction between the ice field and the ship hull, asymptotic methods were used to study the extreme ice load estimation in different parts of the ship hull, revealing the variation law of the extreme ice load in different parts of the ship hull. This study provides basic theory and technical support for the structural design of ships in polar regions and has engineering application value. [ABSTRACT FROM AUTHOR]

• -The geology of a newly discovered putative cryovolcanic field is introduced. • -Regional cryotectonic stress fields are reconstructed and compared to global models. • -The potential triggers of cryovolcanic activity in the region is summarized. More and more attention is devoted to the icy moons of the Solar System, including Europa, the second Galilean satellite of Jupiter, since the discovery of potential liquid water and the possibility of extra-terrestrial life harbored in its subsurface ocean below its icy crust. Along with the renaissance of the study of icy satellites, the ongoing missions, such as Europa Clipper and JUICE (JUpiter ICy moons Explorer), are also part of such rejuvenation of icy satellite research. One of the leading research topics connected to Europa is understanding its surface renewal, including the interaction between the subsurface ocean and the icy crust. One of the longest-lasting and still unsettled debates related to Europa is about the nature of the potentially active cryovolcanism, which may play an essential role in the interaction between the surface of the Jovian moon and the underlying subsurface ocean. Our study focuses on the geological-geomorphological characterization of a newly identified putative cryovolcanic field found on the surface of Europa. Various volcanic structures, possibly in multiple stages of maturity, were identified. The executed geological analysis in the surroundings of the volcanoes suggests strong local influence during the formation of cryovolcanic cones working together with the overall global-scale stress fields appearing in the ice crust of Europa. [ABSTRACT FROM AUTHOR]

The uniaxial compressive strength (UCS) of ice materials, as an important indicate to assess safety of ice and snow buildings, is difficult to measure quickly using existing methods. The rebound method is widely used for the Non-Destructive Testing (NDT) of the UCS of building materials. Therefore, firstly, rebound methods of ice materials were established. In this study, the Leeb hardness tester and Schmidt hammer were selected to test plain ice and fiber-reinforced ice (FRI), respectively. Then, the rebound test and uniaxial compression test were performed under different temperatures (− 20, − 15, − 10 and − 5 °C) and different fiber content (0, 1, 2 and 4%). The result of rebound showed that the rebound value of 1, 2 and 4% FRI was 1.33, 1.09 and 1.08 times, respectively, that of plain ice at – 20 °C. The rebound value of plain ice at − 20 °C was 1.32 times higher than that at − 5 °C. Secondly, the correlation between rebound value and UCS of the ice material was established. The UCS of plain ice has a linear relationship with rebound value, while FRI exhibited a power law relationship. Finally, the rebound method was applied to field NDT of ice and snow buildings in Harbin. The test results showed that the estimated UCS of ice materials was conservative due to freezing patterns, and the error between the estimated and the measured UCS of the FRI was about 10%. The NDT method for ice materials in this study has a positive effect on the safety assessment of ice and snow building. [ABSTRACT FROM AUTHOR]

This article describes a probabilistic model (stochastic generator) of spatiotemporal variability of sea ice concentration. The values of the concentration are generated at the nodes of the spatial grid with 10‑km resolution; the model time step is 1 day. The change in ice concentration with time (temporal variability) is modeled on the basis of a matrix of transient probabilities (discrete Markov chain), each row of which is a distribution function of the conditional probability of changes in the concentration. Spatial variability is determined by empirical probability fields, with which the observed changes in fields of concentration are associated with known conditional probability distribution functions. To identify the parameters of the stochastic generator, satellite data from the OSI SAF project for 1987–2019 were used. The generator takes into account seasonal, interannual, and climatic variability. Interannual and climatic variability are determined on the basis of a stochastic model of changes in the types of ice coverage. In order to verify the developed stochastic generator, we compare the statistical indicators of observed and calculated ice fields. The results show that the field-average absolute error of statistical characteristics of the ice concentration (average and standard deviation) does not exceed 3.3%. The discrepancy between the correlation intervals of ice coverage calculated from the model and measured ice concentration fields does not exceed 2 days. The variograms of the modeled and observed fields have a similar form and close values. As an example, we determine the duration of navigation of Arc4 ice class ships between the Barents and Kara seas using synthetic fields of the concentration reproduced by the stochastic generator. [ABSTRACT FROM AUTHOR]

• Design and construction of single wheel test rig for Ocean World rover is presented. • Built using commercially available mechanical parts, motors, actuators, and sensors. • Test rig allows control of slip ratio, vertical load, slip angle, and camber angle. • Modular test-bed can simulate fine-grained ice, sharp ice, and ice boulder fields. Ocean Worlds such as Europa and Enceladus are known to harbor subsurface liquid water oceans under their icy crust and are high-priority targets for in situ exploration. Compared to the Moon and Mars, Ocean Worlds likely present a significantly more challenging environment for surface mobility systems due to the extremely cold temperature, high radiation dosage, and poorly constrained material properties under these conditions. Small-diameter wheels such as those used by Mars rovers are prone to slip-sinkage in loose soil and damage from sharp rock and ice formations. A 4-wheel rover with a simple drive system and large deployable compliant tires is proposed as a solution for extreme terrain mobility on Ocean World surfaces. The present work describes the design and construction of a single wheel test rig and a prototype large-diameter deployable wheel for Ocean World rovers and initial test results. The test rig allows independent control of the vertical load, slip ratio, slip angle, and camber angle, and accommodates large-diameter deployable wheels. The test rig features a modular test bed that can simulate varied surface features such as fine-grained ice, smooth hard ice, sharp ice formations, and large ice boulder fields. [ABSTRACT FROM AUTHOR]

A large ensemble of ice sheet projections to the end of the 21st century have been compiled within community-based initiatives. These ensembles allow for assessment of uncertainties in projections associated with climate forcing and a wide range of parameters governing ice sheet and shelf dynamics, including ice-ocean interactions. Herein, we compute geographically variable sea level 'fingerprints' associated with ∼320 simulations of polar ice sheet projections included in the Ice Sheet Model Intercomparison Project for CMIP6 and ∼180 projections of glacier mass changes from the Glacier Model Intercomparison Project. We find a strong correlation (coefficient > 0.97) between all fingerprints of Greenland Ice Sheet projections when considering a global region outside the near field of the ice sheet. Consistency in the fingerprints for the Antarctic Ice Sheet (AIS) projections is much weaker, though correlation coefficients > 0.80 were found for all projections with global mean sea level (GMSL) greater than 10 cm. The far-field variability in the fingerprints associated with the AIS is due in large part to the sea level change driven by Earth rotation changes. The size and position of the AIS on the south pole makes the rotational component of the sea level fingerprint highly sensitive to the geometry of the ice mass flux, a geometry that becomes more consistent as the GMSL associated with the ice sheet projection increases. Finally, the fingerprints of glacier mass flux show an intermediate level of consistency, with contributions from Antarctic glaciers being the primary driver of decorrelation. [ABSTRACT FROM AUTHOR]

The Northern and Southern Patagonian Icefields are rapidly losing volume, with current volume loss rates greater than 20 km3 a−1. However, details of the spatial and temporal distribution of their volume loss remain uncertain. We evaluate the rate of 21st-century glacier volume loss using the hydrological balance of four glacierised Patagonian river basins. We isolate the streamflow contribution from changes in ice volume and evaluate whether the rate of volume loss has decreased, increased, or remained constant. Out of 11 glacierised sub-basins, seven exhibit significant increases in the rate of ice volume loss, with a 2006–2019 time integrated anomaly in the rate of glacier volume loss of 135 ± 50 km3. This anomaly in the rate of glacier-volume-loss is spatially heterogeneous, varying from a 7.06 ± 1.69 m a−1 increase in ice loss to a 3.18 ± 1.48 m a−1 decrease in ice loss. Greatest increases in the rate of ice loss are found in the early spring and late summer, suggesting a prolonging of the melt season. Our results highlight increasing, and in some cases accelerating, rates of volume loss of Patagonia's lake-terminating glaciers, with a 2006–2019 anomaly in the rate of glacier volume loss contributing an additional 0.027 ± 0.01 mm a−1 of global mean sea-level rise. [ABSTRACT FROM AUTHOR]

Background. The interaction of calcium and magnesium chlorides with ammonia solution during the isolation of salts from a solution of calcium and magnesium chlorides by the polythermal method in a wide range of temperatures and concentrations has not been previously considered. Purpose. Study of the polythermal solubility of CaCl2 · 2H2O--[25%N3+75%H2O]-H2O and MgCl2 · 6H2O--[25%N3+75%H2O]-H2O systems in a wide range of temperatures and concentrations. Methodology. The visual-polythermal method was used, ammonia was determined by the Keldahl method, chloride ions - by the Mohr method. Originality. A polythermal solubility diagram has been constructed for the systems CaCl2 · 2H2O-- [25%N3+75%H2O]-H2O and MgCl2 · 6H2O--[25%N3+75%H2O]-H2O over a wide range of temperatures and concentrations. Findings. The diagram of the CaCl2 · 2H2O--[25%N3+75%H2O]-H2O system was constructed by drawing six internal sections in the temperature range from -49.7 to 45.2°C, and MgCl2 · 6H2O-- [25%N3+75%H2O]-H2O - by making seven internal cuts in the temperature range from -36.0 to 40.0°C. The boundaries of the crystallization fields of ice, 6 aqueous magnesium chloride, 12 aqueous magnesium chloride and the double salt of magnesium hydroxychloride and ammonium chloride were determined. [ABSTRACT FROM AUTHOR]

In this paper we present a reconstruction of climate conditions during the Last Glacial Maximum on a karst plateau in Dinaric Mountains (southern Slovenia) that bares evidence of glaciation. The reconstruction merges geomorphological ice limits, classified as either clear or unclear, and computer modelling approach based on Parallel Ice Sheet Model, which is an established numerical model for simulating glacier dynamics ranging from ice sheets to alpine glaciers. Based on extensive numerical experiments, where we studied the agreements between simulated and geomorphological ice extent, we propose to use a combination of high resolution precipitation model that accounts for orographic precipitation combined with simple elevation based temperature model. The geomorphological ice extent can be simulated with climate around 6 °C colder than modern and with a lower than modern amount of precipitation, which matches other state-of-the art climate reconstructions for the era. The results indicate that orographic precipitation model is essential for accurate simulation of the Snežnik with moist southern winds from the nearby Adriatic Sea having predominant effect on the precipitation patterns. Finally, this study shows that transforming climate conditions towards wetter and warmer or drier and colder does not significantly change conditions for glacier formation. [ABSTRACT FROM AUTHOR]

Arctic sea ice prediction is of great practical significance in facilitating Arctic route planning, optimizing fisheries management, and advancing the field of sea ice dynamics research. While various deep learning models have been developed for sea ice prediction, they predominantly operate at the seasonal or sub-seasonal scale, often focusing on localized areas, and few cater to full-region daily-scale prediction. This study introduces the use of spatiotemporal sequence data prediction models, namely, the convolutional LSTM (ConvLSTM) and predictive recurrent neural network (PredRNN), for the prediction of sea ice concentration (SIC). Our analysis reveals that, when solely utilizing SIC historical data as the input, the ConvLSTM model outperforms the PredRNN model in SIC prediction. To enhance the models' capacity to capture spatiotemporal relationships between multiple variables, we expanded the range of input data types to form the ConvLSTM-multi and PredRNN-multi models. Experimental findings demonstrate that the prediction accuracy of the four models significantly surpasses the CMIP6 model in three prospective climate scenarios (SSP126, SSP245, and SSP585). Of the four models, the ConvLSTM-multi model excels in assimilating the influence of reanalysis data on sea ice within the sea ice edge region, thus exhibiting superior performance than the PredRNN-multi model in predicting daily Arctic SIC over the subsequent 10 days. Furthermore, sensitivity tests on various model parameters highlight the substantial impact of sea surface temperature and prediction date on the accuracy of daily sea ice prediction, and meteorological and oceanographic parameters primarily affect the prediction accuracy of the thin-ice region at the edge of the sea ice. [ABSTRACT FROM AUTHOR]

The effects of an AC electric field on ice nucleation temperature and nucleation rate were investigated by freezing distilled water while exposing it to varied AC electric field strengths and frequencies. To eliminate the influence of ion injections and electric field concentrations at a metal electrode surface on ice nucleation, distilled water filled in resin cuvettes are used as samples. The samples are exposed to AC electric field induced by parallel plate electrodes placed outside of the cuvettes. The cuvettes and parallel plate electrodes placed in a freezer with an inside temperature fixed at −15°C. The electric field strength in the sample is 2 or 7.5 kV/m and frequency varies from 50 Hz to 10 kHz. The ice nucleation temperature and the nucleation rate of distilled water increase with increasing the electric field strength and the frequency. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The speed‐up of glaciers following ice shelf collapse can accelerate ice mass loss dramatically. Investigating the deformation of landfast sea ice enables studying its resistive (buttressing) stresses and mechanisms driving ice collapse. Here, we apply offset tracking to Sentinel‐1A/B synthetic aperture radar data to obtain a 2014–2022 time‐series of horizontal velocity and strain rate fields of landfast ice filling the embayment formerly covered by the Larsen B Ice Shelf, Antarctic Peninsula until 2002. The landfast ice disintegrated in 2022, and we find that it was precipitated by a few large opening rifts. Grounded glaciers did not accelerate instantaneously after the collapse, which implies little buttressing effect from landfast ice, a conclusion also supported by the near‐zero correlation between glacier velocity and landfast ice area. Our observations suggest that buttressing stresses are unlikely to be recovered by landfast sea ice over sub‐decadal timescales following the collapse of an ice shelf. Plain Language Summary: The Antarctic Ice Sheet is a potentially major contributor to sea‐level rise due to glaciers' dynamic response to changing oceanic and atmospheric conditions. Its floating extensions, ice shelves, play a critical role in stabilizing the ice sheet by resisting the flow of glaciers that feed into them. However, ice shelves can collapse rapidly. In 2002, a Rhode Island‐sized section of the Larsen B Ice Shelf disintegrated, causing adjacent glaciers to speed up. In 2011, landfast sea ice replaced the ice shelf in the Larsen B embayment, but it broke up in 2022. We use remote sensing data to investigate why the landfast ice collapsed and whether it resisted glacier flow as the ice shelf did. We show that opening rifts may be responsible for ice disintegration. We find no detectable buttressing effect from the landfast ice because glaciers did not speed up after removing landfast ice, and seasonal change of landfast ice extent did not affect the grounded glacier velocities. It may be because landfast ice is thinner and easier to deform than the ice shelf. Our observations suggest a possible precursor to ice collapse and highlight the limited role that landfast ice plays in slowing down ice mass loss. Key Points: We produce time‐dependent velocity and strain rate fields over Larsen B landfast sea ice from 2014 to 2022Opening rifts within the landfast sea ice may contribute to its disintegration in 2022Landfast sea ice provides no apparent buttressing to the upstream grounded glaciers [ABSTRACT FROM AUTHOR]

An asthenospheric window underneath much of the South American continent increases the heat flow in the Southern Patagonian Andes, where glacial-interglacial cycles drive the building and melting of the Patagonian Icefields since the latest Miocene. The Last Glacial Maximum (LGM) was reached ~20000 years ago, and an acceleration of the deglaciation rate is recorded since the Little Ice Age (LIA), ~400 years ago. Fast uplift rates of up to 41 ±3 mm/yr are measured by GNSS around the Southern Patagonian Icefield and currently ascribed to post-LIA lithospheric rebound, but the possible longer-term post-LGM rebound is poorly constrained. These uplift rates, in addition, are one order of magnitude higher than those measured on other glaciated orogens (e.g., the European Alps), which raises questions about the role of the asthenospheric window in affecting the vertical surface displacement rates. Here, we perform geodynamic thermo-mechanical numerical modelling to estimate the surface uplift rates induced by post-LIA and post-LGM deglaciation accounting for temperature dependent rheologies and different thermal regimes in the asthenosphere. Our modelled maximum postglacial rebound matches the observed uplift rate budget only when both post-LIA and post-LGM deglaciation are accounted for and if a standard continental mantle potential temperature is increased by 150-200 °C. The asthenospheric window thus plays a key role in controlling the magnitude of presently observed uplift rates in the Southern Patagonian Andes. [ABSTRACT FROM AUTHOR]

In situ observations of wave attenuation by sea ice are required to develop and validate wave–ice interaction parameterizations in coupled wave models. To estimate ice-induced wave attenuation in the field, the wave field is typically assumed to be stationary. In this study we investigate the validity of this assumption by creating a synthetic wave field in sea ice for different attenuation rates. We observe that errors in estimates of the wave attenuation rates are largest when attenuation rates are small or temporal averaging periods are short. Moreover, the adoption of the wave stationarity assumption can lead to negative estimates of the instantaneous wave attenuation rate. These apparent negative values should therefore not be attributed to wave growth or erroneous measurements a priori. Surprisingly, we observe that the validity of the wave stationarity assumption is irrelevant to the accuracy of estimates of wave attenuation rates as long as the temporal averaging period is taken sufficiently long. This may provide opportunities in using satellite-derived products to estimate wave attenuation rates in sea ice at global scales. [ABSTRACT FROM AUTHOR]

Simulation of atmosphere–ocean–ice interactions in coupled Earth modeling systems with kilometer-scale resolution is a new challenge in operational numerical weather prediction. This study presents an assessment of sensitivity experiments performed with different sea ice products in a convective-scale weather forecasting system for the European Arctic. On kilometer-scale resolution sea ice products are challenged by the large footprint of passive microwave satellite observations and issues with spurious sea ice detection of the higher-resolution retrievals based on synthetic aperture radar instruments. We perform sensitivity experiments with sea ice concentration fields of 1) the global ECMWF-IFS forecast system, 2) a newly developed multisensor product processed through a coupled sea ice–ocean forecasting system, and 3) the AMSR2 product based on passive microwave observations. There are significant differences between the products on O(100) km scales in the northern Barents Sea and along the Marginal Ice Zone north of the Svalbard archipelago and toward the Fram Strait. These differences have a direct impact on the modeled surface skin temperature over ocean and sea ice, the turbulent heat flux, and 2-m air temperature (T2M). An assessment of Arctic weather stations shows a significant improvement of forecasted T2M in the north and east of Svalbard when using the new multisensor product; however, south of Svalbard this product has a negative impact. The different sea ice products are resulting in changes of the surface turbulent heat flux of up to 400 W m−2, which in turn results in T2M variations of up to 5°C. Over a 2-day forecast lead time this can lead to uncertainties in weather forecasts of about 1°C even hundreds of kilometers away from the sea ice. Significance Statement: Weather forecasting in polar regions requires an accurate description of sea ice properties due to the very important atmosphere–ocean–ice interactions. With the increasing resolution of weather forecasting systems, there is also a need to advance the resolution of the sea ice characteristics in the models. This is, however, not straightforward due to various issues in the sea ice satellite products. This study explores new products and approaches to integrate high-resolution sea ice in a weather prediction system. We find that the model is sensitive to the choice of the sea ice product and that it is still challenging to provide an accurate sea ice field on a kilometer-scale resolution. [ABSTRACT FROM AUTHOR]

This paper describes a high-fidelity numerical model that simulates vessel stationkeeping operations in ice-rich waters. The discrete event simulation engine incorporates several novel features, including new ice floe failure models for bow and midships locations; an ice floe creation strategy that facilitates rafting of ice floes; and a vessel thruster model that takes into account physical limitations such as thruster angle slew rates and propeller ramp rates. It accommodates a wide range of ice field specifications and runs in real-time on a standard desktop personal computer (Intel® Core™ i7 Processor or equivalent). The model has been validated using physical measurements of a generic drillship model in several broken ice conditions; it predicted thruster forces and motions that were comparable to those observed during dynamic positioning operations. [ABSTRACT FROM AUTHOR]

The nature of glaciation (bipolar vs. unipolar) during the Eocene--Oligocene transition (EOT) remains unresolved. Here, we report the occurrence of frost marks, ice-rafted debris (IRD), and glendonites from the Upper Eocene to Lower Oligocene Niubao Formation (Fm.) deposited in a proglacial lake above glaciolacustrine conglomerates and diamictite facies in the Lunpola Basin, central Tibetan Plateau (CTP). Magnetostratigraphy dates these cryospheric deposits to ca. 36.2--31.8 Ma, synchronous with a stratigraphic interval containing IRD offshore of SE Greenland and in the Barents, Chukchi, and Laptev Seas, suggesting a strong continental-oceanic coupling. Our results provide robust continental evidence for intermittent cryospheric processes in the midlatitude Northern Hemisphere during the late Eocene and EOT. The global cold snap EOT-1 influenced already glacierized high-altitude mountains, lowering equilibrium line altitudes (ELAs) of glaciers and leading to local development of ice fields, ice caps, and valley glaciers with proglacial lake systems, such as the one recorded in the Niubao Fm. The record of IRD, glendonites, and frost marks before the onset of EOT-1 points to an active cryosphere on a plateau already elevated by ca. 36.2 Ma. [ABSTRACT FROM AUTHOR]

The present-day sea-level variations and vertical movements in the northern Adriatic Sea and in the highly vulnerable Venetian Lagoon result from a number of simultaneously operating contributions. These include Glacial Isostatic Adjustment (GIA), the global, long-term process arising from interactions between the cryosphere, the solid Earth and the oceans in response to the melting of continental ice sheets. Although the GIA contribution in northern Adriatic Sea has been the subject of various investigations so far, significant uncertainties still exist, especially related to the extent and chronology of the Würm Alpine ice sheet and to the rheological profile of the mantle. Here, taking advantage of the recent publication of updated deglaciation chronologies for the far field late-Pleistocene ice sheets and for the near-field alpine ice complex, we produce up-to-date estimates of the present-day rates of GIA-induced relative sea-level variations and vertical displacements in the Venetian Lagoon and in the northern Adriatic Sea, which are compared with GNSS and tide-gauge observations. From high-resolution numerical simulations, we find that GIA is responsible for a complex pattern of geodetic signals across the Po plain and the northern Adriatic Sea. The modeled GIA rates are of the order of fractions of mm yr−1, generally small – but not negligible – compared to the signals observed at local tide gauges and at GNSS sites in the Po plain and facing the Venetian Lagoon. Our results indicate that, while GIA represents a relatively small component among those responsible for present-day land movements and relative sea-level variations in the northern Adriatic Sea, its contribution needs to be taken into account for a correct interpretation of the observed geodetic variations. [ABSTRACT FROM AUTHOR]

The seasonally ice-covered marine region of the European Arctic has experienced warming and sea ice loss in the last two decades. During expeditions in August 2020 and 2021, new data on size-fractioned primary production (PP), chlorophyll a concentration, phytoplankton biomass and composition and carbon fixation rates in the dark were obtained in the marginal ice zone (MIZ) of the Barents Sea, Nansen Basin and Greenland Sea to better understand the response of Arctic ecosystems to ongoing climate changes. Four different situations were observed in the study region: (i) a bloom of the large-cell diatom Podosira glacialis, whose biomass was trapped in a strong halocline at the edge of a dense ice cover; (ii) a bloom of the chain-like colonies of Thalassiosira diatoms on the shelf in mixed waters in fields of shallow ice that could be supported by "fresh" elements in the polynya condition, as well as by terrestrial run-off and drifting ices; at the late stage, this bloom was accompanied by intensive growth of Phaeocystis pouchetti; (iii) dominance of small-cell phytoplankton under weakened stratification and the significant influence of the Atlantic water, depleted of microelements and silicates; (iv) dominance of dinoflagellates of eutrophic water in the contact zone between the water masses of Arctic origin and Atlantic origin in clear water under conditions of increased light intensity. The >10 µm phytoplankton cell size group increased its relative contribution to PP as a response to stratification, light and nutrient load associated with sea ice conditions. Small phytoplankton with sizes < 2 µm formed the basis of total PP in the MIZ regardless of the state of the sea ice. [ABSTRACT FROM AUTHOR]

Touching wooden seats and plastic slides might cause pain.Use caution with cold surfaces. Wear gloves.Anti-skid warning signs and emergency rescue stations should be set up on ice and snow fields and sites where stone bricks are laid.Regularly check the insulation coating of the touch area of the iron and steel facilities in the park. ht Correction 13: Section 5 The NUTCIR of female, male, and all children are -1.3-13.4, 0.6-14.1, and 0.5-14.0 °C, respectively. Minimize exposure to cold surfaces without gloves.Wear gloves.The average temperature of the stone brick surface under sunlight (-21.1 °C) was 6.1 °C lower than the numbness threshold (-15 °C) of the fingers touching the stone surface, and 3.1 °C lower than the frostbite threshold (-18 °C). [Extracted from the article]

During escort and convoy operations, icebreakers are often required to maneuver to open up channels or adjust routes due to the prevalence of ice floe conditions in Arctic routes. This study aimed to investigate the global ice load characteristics of the maneuvering captive motions, including constant turning motion, pure yaw motion, and pure sway motion, of the icebreaker Xue Long, using a combination of the discrete element method (DEM) and drag model. First, the method was verified using simulating Araon model tests from the Korea Institute of Ocean Science and Technology (KIOST). In addition, the maneuvering captive motions of the Xue Long model were simulated at varying turning radii, drift angles, and sway and yaw periods, which are typical but currently poorly studied maneuvering motions. Overall, the results of the study showed that the method is able to reproduce the coupling effect of the ship–ice–water system by considering ship–ice interaction and ice resistance, where the mean deviation and maximum deviation of ice resistance are 9.45% and 13.3%, respectively. The influences of the turning radius, drift angle, and sway and yaw period on the ice resistance and transverse force characteristics were studied and analyzed via ship–ice interactions. The present study provides a prediction tool for the assessment of ship maneuvering performance to assist the hull line development and model testing of icebreakers. [ABSTRACT FROM AUTHOR]

Lake ice melting and breakup form a fast, nonlinear process with important mechanical, chemical, and biological consequences. The process is difficult to study in the field due to safety issues, and therefore only little is known about its details. In the present work, the field data were collected on foot, by hydrocopter, and by boat for a full time series of the evolution of ice thickness, structure, and geochemistry through the melting period. The observations were made in lake Pääjärvi in 2018 (pilot study) and 2022. In 2022, the maximum thickness of ice was 55 cm with 60 % snow ice, and in 40 d the ice melted by 33 cm from the surface and 22 cm from the bottom while the porosity increased from less than 5 % to 40 %–50 % at breakup. In 2018, the snow-ice layer was thin, and bottom and internal melting dominated the ice decay. The mean melting rates were 1.31 cm d -1 in 2022 and 1.55 cm d -1 in 2018. In 2022 the electrical conductivity (EC) of ice was 11.4 ± 5.79 µ S cm -1 , which is 1 order of magnitude lower than in the lake water, and ice pH was 6.44 ± 0.28, which is lower by 0.4 than in water. The pH and EC of ice and water decreased during the ice decay except for slight increases in ice due to flushing by lake water. Chlorophyll a was less than 0.5 µ g L -1 in porous ice, approximately one-third of that in the lake water. The results are important for understanding the process of ice decay with consequences for lake ecology, further development of numerical lake ice models, and modeling the safety of ice cover and ice loads. [ABSTRACT FROM AUTHOR]

We develop a single-class ice and snow model embedded inside a 3D hydrodynamic model on unstructured grids and apply it to lake studies using highly variable mesh resolution. The model is able to reasonably capture the ice fields observed in both small and large lakes. For the first time, we attempt simulation of ice processes on very small scales (~ 1 m). Physically sound results are obtained at the expense of moderately increased computational cost, although more rigorous validation nearshore is needed due to lack of observation. We also outline challenges on developing new process-based capabilities for accurately simulating nearshore ice. [ABSTRACT FROM AUTHOR]

In light of the recent climate warming, monitoring of lake ice in Arctic and subarctic regions is becoming increasingly important. Many shallow Arctic lakes and ponds of thermokarst origin freeze to the bed in the winter months, maintaining the underlying permafrost in its frozen state. However, as air temperatures rise and precipitation increases, fewer lakes are expected to develop bedfast ice. In this work, we propose a novel temporal deep-learning approach to lake ice regime mapping from synthetic aperture radar (SAR) and employ it to study lake ice dynamics in the Old Crow Flats (OCF), Yukon, Canada, over the 1992/1993 to 2020/2021 period. We utilized a combination of Sentinel-1, ERS-1 and ERS-2, and RADARSAT-1 to create an extensive annotated dataset of SAR time series labeled as either bedfast ice, floating ice, or land, which was used to train a temporal convolutional neural network (TempCNN). The trained TempCNN, in turn, allowed us to automatically map lake ice regimes. The classified maps aligned well with the available field measurements and ice thickness simulations obtained with a thermodynamic lake ice model. Reaching a mean overall classification accuracy of 95 %, the TempCNN was determined to be suitable for automated lake ice regime classification. The fraction of bedfast ice in the OCF increased by 11 % over the 29-year period of analysis. Findings suggest that the OCF lake ice dynamics are dominated by lake drainage events, brought on by thermokarst processes accelerated by climate warming, and fluctuations in water level and winter snowfall. Catastrophic drainage and lowered water levels cause surface water area and lake depth to decrease and lake ice to often transition from floating to bedfast ice, while a reduction in snowfall allows for the growth of thicker ice. The proposed lake ice regime mapping approach allowed us to assess the combined impacts of warming, drainage, and changing precipitation patterns on transitions between bedfast and floating-ice regimes, which is crucial to understanding evolving permafrost dynamics beneath shallow lakes and drained basins in thermokarst lowlands such as the OCF. [ABSTRACT FROM AUTHOR]

Glacier monitoring has been internationally coordinated for more than 125 years. Despite this long history, there is no authoritative answer to the popular question: 'Which glaciers are the largest in the world?' Here, we present the first systematic assessment of this question and identify the largest glaciers in the world – distinct from the two ice sheets in Greenland and Antarctica but including the glaciers on the Antarctic Peninsula. We identify the largest glaciers in two domains: on each of the seven geographical continents and in the 19 first-order glacier regions defined by the Global Terrestrial Network for Glaciers. Ranking glaciers by area is non-trivial. It depends on how a glacier is defined and mapped and also requires differentiating between a glacier and a glacier complex, i.e. glaciers that meet at ice divides such as ice caps and icefields. It also depends on the availability of a homogenized global glacier inventory. Using separate rankings for glaciers and glacier complexes, we find that the largest glacier complexes have areas on the order of tens of thousands of square kilometers whereas the largest glaciers are several thousands of square kilometers. The world's largest glaciers and glacier complexes are located in the Antarctic, Arctic and Patagonia. [ABSTRACT FROM AUTHOR]

Accurate ice flow velocity data are essential for studying the mass balance of the Antarctic ice sheet. However, there is a lack of ice velocity maps of 1960s–80s in basin-wide regions or the entire ice sheet. In this study, an enhanced hierarchical network densification approach is developed for basin-wide Antarctic velocity mapping using historical ARGON and Landsat images. The produced multiple historical velocity maps from 1963 to 1989 in the region of the Fimbul and Jelbart ice shelves, East Antarctica, achieved an accuracy better than 29 m a−1. They revealed that the ice flow velocity had no significant changes over the period. Combining the surface mass balance estimate with the ice discharge estimated from our historical velocity maps and recently published velocity maps, we estimated a positive mass balance of 8.6 ± 3.9 Gt a−1 in the study area from 1963 and 2015. Our results indicate that the region's positive mass balance, as estimated in recently published studies, has been maintained since the 1960s. It is also in concordance with the low level of mass balance from 1992 to 2017 in East Antarctica. This suggests that the study area has been stable since the 1960s. [ABSTRACT FROM AUTHOR]

The solubility of the components in the CH3COOH - CO(NH2)2 - H2O system was studied by the visual-polythermal method in the temperature range from -28.0°C to 20.0°C. The phase diagram delimits the crystallization fields of ice, CH3COOH, CH3COOH·CO(NH2)2 and CO(NH2)2. A solubility diagram has been constructed, a new urea acetate compound has been isolated and identified by chemical, X-ray phase and thermogravimetric methods of analysis. [ABSTRACT FROM AUTHOR]

The Patagonian Icefields (Northern and Southern Patagonian Icefield) are the largest ice masses in the Andes Cordillera. Despite its importance, little is known about the main mechanisms that underpin the interaction between these ice masses and climate. Furthermore, the nature of large-scale climatic control over the surface mass variations of the Patagonian Icefields still remains unclear. The main aim of this study is to understand the present-day climatic control of the surface mass balance (SMB) of the Patagonian Icefields at interannual timescales, especially considering large-scale processes. We modeled the present-day (1980–2015) glacioclimatic surface conditions for the southern Andes Cordillera by statistically downscaling the output from a regional climate model (RegCMv4) from a 10 km spatial resolution to a 450 m resolution grid and then using the downscaled fields as input for a simplified SMB model. Series of spatially averaged modeled fields over the Patagonian Icefields were used to derive regression and correlation maps against fields of climate variables from the ERA-Interim reanalysis. Years of relatively high SMB are associated with the establishment of an anomalous low-pressure center near the Drake Passage, the Drake low, that induces an anomalous cyclonic circulation accompanied with enhanced westerlies impinging on the Patagonian Icefields, which in turn leads to increases in the precipitation and the accumulation over the icefields. Also, the Drake low is thermodynamically maintained by a core of cold air that tends to reduce the ablation. Years of relatively low SMB are associated with the opposite conditions. We found low dependence of the SMB on main atmospheric modes of variability (El Niño–Southern Oscillation, Southern Annular Mode), revealing a poor ability of the associated indices to reproduce the interannual variability of the SMB. Instead, this study highlights the Drake Passage as a key region that has the potential to influence the SMB variability of the Patagonian Icefields. [ABSTRACT FROM AUTHOR]

An asthenospheric window underneath much of the South American continent increases the heat flow in the Southern Patagonian Andes, where glacial-interglacial cycles drive the building and melting of the Patagonian Icefields since the latest Miocene. The Last Glacial Maximum (LGM) was reached ~20000 years ago, and an acceleration of the deglaciation rate is recorded since the Little Ice Age (LIA), ~400 years ago. Fast uplift rates of up to 41±3 mm/yr are measured by GNSS around the Southern Patagonian Icefield and currently ascribed to post-LIA lithospheric rebound, but the possible longer-term post-LGM rebound is poorly constrained. These uplift rates, in addition, are one order of magnitude higher than those measured on other glaciated orogens (e.g., the European Alps), which raises questions about the role of the asthenospheric window in affecting the vertical surface displacement rates. Here, we perform geodynamic thermo-mechanical numerical modelling to estimate the surface uplift rates induced by post-LIA and post-LGM deglaciation accounting for temperature dependent rheologies and different thermal regimes in the asthenosphere. Our modelled maximum postglacial rebound matches the observed uplift ratebudget only when both post-LIA and post-LGM deglaciation are accounted for and if a standard continental mantle potential temperature is increased by 150–200 °C. The asthenospheric window thus play a key role in controlling the magnitude of presently observed uplift rates in the Southern Patagonian Andes. [ABSTRACT FROM AUTHOR]

The determination of ice loads on polar vessels and offshore structures is important for ice-resistant design, safe operation, and management of structural integrity in ice-infested waters. Physical model testing carried out in an ice tank/basin is usually an important technical approach for evaluating the ice loads. However, the high cost and time consumption make it difficult to perform multiple repetitions or numerous trials. Recently, the rapid development of high-performance computation techniques provides a usable alternative where the numerical methods represented by the discrete element method (DEM) have made remarkable contributions to the ice load predictions. Based on DEM simulations validated by physical model tests, numerical ice tanks can be developed as an effective complement to their counterparts. In this paper, a numerical ice tank based on 3D spherical DEM was established with respect to the small ice model basin of China Ship Scientific Research Center (CSSRC-SIMB). Based on spherical DEM with parallel bond model, the model tests of typical structures (vertical cylinder and inclined plate) in level ice sheets were established in the numerical ice tank, and the ice–structure interaction process under the same initial conditions was simulated. The accuracy of the simulations is verified by comparing the simulated ice loads with the measured ice loads from the model tests in the CSSRC-SIMB. Furthermore, the application of the numerical ice tank was extended to simulate the navigation of a Wass bow in level ice and broken ice conditions. The value of the break resistance of the Wass bow in level ice was evaluated, and the numerical ice tank produced results that were found to be consistent with those obtained from Lindqvist's formula. The statistical properties of the bow load for different broken ice fields with the same initial physical conditions are analyzed by performing a repeatability test on the broken ice fields. [ABSTRACT FROM AUTHOR]

Atmospheric ice nucleation plays an important role in modifying the global hydrological cycle and atmospheric radiation balance. To date, few comprehensive field observations of ice nuclei have been carried out at high-altitude sites, which is close to the height of mixed-phase cloud formation. In this study, we measured the concentrations of ice-nucleating particles (INPs) in the immersion freezing mode at the summit of Changbai Mountain (2623 m above sea level), Northeast Asia, in summer 2021. The cumulative number concentration of INPs varied from 3.8 × 10−3 L−1 to 2.3 L−1 over the temperature range from −20.5 °C to −5.5 °C. Proteinaceous-based biological materials accounted for the majority of INPs, with the proportion of biological INPs (bio-INPs) exceeding 75 % across the entire freezing temperature range, with this proportion even exceeding 90 % above −13.0 °C. At freezing temperatures ranging from −11 °C to −8 °C, bio-INPs were found to significantly correlate with wind speed and Ca2+, and weakly correlate with isoprene and its oxidation products (isoprene × O3), suggesting that biological aerosols may attach to soil dust surfaces and contribute to INPs. During the daytime, bio-INPs showed a positive correlation with the planetary boundary layer height, with the valley breezes from southwestern mountainous regions also influencing the concentration of INPs. Moreover, the long-distance transport of air mass from the Japan Sea and South Korea significantly contributed to the high concentrations of bio-INPs. Our study emphasizes the important role of biological sources of INPs in the high-altitude atmosphere of northeastern Asia, as well as the significant contribution of long-range transport to the INPs concentrations in this region. [ABSTRACT FROM AUTHOR]

This study presents a fatigue analysis procedure for inclined structures operated in level ice fields. Three methods for calculating the local ice load causing fatigue damage, namely the direct method, simplified method, and semi-analytical method, were introduced and compared. The direct method uses finite element analysis to simulate the continuous breaking of ice, while the simplified method and the semi-analytical method estimate the probability distribution of local ice loads based on theoretical equations and empirical data. The fatigue damage ratio at the target location was calculated by applying the ice load calculated by each method to a deformable finite element model of the structure. The results obtained from each method indicate that they provide a reasonable estimation of the local ice load causing fatigue damage in level ice fields. The direct method offers high accuracy but requires significant computational time, while the simplified method and semi-analytical method offer a faster analysis time and are more suitable for long-term time domain analysis. The semi-analytical method requires empirical data to supplement theoretical formulas due to the complex natural phenomena involving various environmental conditions that must be modeled. The findings of this study provide valuable insights into the prediction of fatigue damage in ice-going ships due to long-term ice impacts. The methods proposed in this study can aid in the design of Arctic ships exposed to various conditions and provide a more cost-effective and time-efficient approach to evaluating fatigue damage compared to field measurement. Future research in this field could investigate the application of these methods to other types of structures and further refine the methodology to improve accuracy and reduce computational costs. [ABSTRACT FROM AUTHOR]