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We examine an algorithm for the creation of proton-disordered ice cells based on a simulated-annealing (SA) scheme for molecular orientations. Application to defect-free ice Ih, a clathrate-hydrate structure, and a random polycrystalline ice Ih sample demonstrates the SA technique to be effective, attaining maximum HB connectivity using relatively short cooling simulations, thus serving as an alternative method for those cases in which the application of topology-based methods is inhibited. [ABSTRACT FROM AUTHOR]

We investigated the structure of ice under nanoporous confinement in periodic mesoporous organosilicas (PMOs) with different organic functionalities and pore diameters between 3.4 and 4.9 nm. X-ray scattering measurements of the system were performed at temperatures between 290 and 150 K. We report the emergence of ice I with both hexagonal and cubic characteristics in different porous materials, as well as an alteration of the lattice parameters when compared to bulk ice. This effect is dependent on the pore diameter and the surface chemistry of the respective PMO. Investigations regarding the orientation of hexagonal ice crystals relative to the pore wall using x-ray cross correlation analysis reveal one or more discrete preferred orientation in most of the samples. For a pore diameter of around 3.8 nm, stronger correlation peaks are present in more hydrophilically functionalized pores and seem to be connected to stronger shifts in the lattice parameters. [ABSTRACT FROM AUTHOR]

Glaciologist Rob DeConto's research on polar climate change, specifically focusing on glaciers and ice sheets, is discussed in this article. DeConto explains the differences between Antarctica and Greenland and the challenges of understanding how the Antarctic ice sheet will behave in a warmer world. He also discusses the potential dangers of marine ice sheet instability and the impact of melting ice shelves on sea-level rise. The article emphasizes the uncertainties surrounding the rate of sea-level rise and the need for further research in this area. It highlights the term "deep uncertainty" used by the Intergovernmental Panel on Climate Change (IPCC) to describe the situation and the conservative nature of current projections. The author emphasizes the need for action to address the melting of ice sheets, as it poses a threat to infrastructure worldwide. [Extracted from the article]

Glaciers are the ambassadors of climate change. Their worldwide decline has serious impacts on natural hazards, the water cycle, and sea level rise. The monitoring of glaciers documents the increasingly rapid melting, which has culminated in a suite of extreme years—for example, 2023 in North America and the European Alps. Numerical simulations of future glacier change, supported by a large basis of observational data, allow us to understand the enormous changes ahead and prepare us for a world without glaciers. Technical approaches to reduce glacier melting have been developed and are applicable locally—for example, in connection with tourist activities—but they clearly fail at the larger scale. [ABSTRACT FROM AUTHOR]

Here, we investigate the hypothesis that despite the existence of at least two high-density amorphous ices, only one high-density liquid state exists in water. We prepared a very-high-density amorphous ice (VHDA) sample and rapidly increased its temperature to around 205 ± 10 K using laser-induced isochoric heating. This temperature falls within the so-called "no-man's land" well above the glass-liquid transition, wherein the IR laser pulse creates a metastable liquid state. Subsequently, this high-density liquid (HDL) state of water decompresses over time, and we examined the time-dependent structural changes using short x-ray pulses from a free electron laser. We observed a liquid–liquid transition to low-density liquid water (LDL) over time scales ranging from 20 ns to 3 μs, consistent with previous experimental results using expanded high-density amorphous ice (eHDA) as the initial state. In addition, the resulting LDL derived both from VHDA and eHDA displays similar density and degree of inhomogeneity. Our observation supports the idea that regardless of the initial annealing states of the high-density amorphous ices, the same HDL and final LDL states are reached at temperatures around 205 K. [ABSTRACT FROM AUTHOR]

We use molecular dynamics simulations to examine the homogeneous nucleation of ice VII from metastable liquid water. An unsupervised machine learning classification identifies two distinct local structures composing Ice VII nuclei. The seeding method, combined with the classical nucleation theory (CNT), predicts the solid–liquid interfacial free energy, consistent with the value from the mold integration method. Meanwhile, the nucleation rates estimated from the CNT framework and brute force spontaneous nucleations are inconsistent, and we discuss the reasons for this discrepancy. Structural and dynamical heterogeneities suggest that the potential birthplace for an ice VII embryo is relatively ordered, although not necessarily relatively immobile. Moreover, we demonstrate that without the formation of hydrogen-bond links, ice VII embryos do not grow. [ABSTRACT FROM AUTHOR]

In recent years, much attention has been devoted to understanding the pathways of phase transition between two equilibrium condensed phases (such as liquids and solids). However, the microscopic pathways of transition involving non-equilibrium, non-diffusive amorphous (glassy) phases still remain poorly understood. In this work, we have employed computer simulations, persistence homology (a tool rooted in topological data analysis), and machine learning to probe the microscopic pathway of pressure-induced non-equilibrium transition between the low- and high-density amorphous (LDA and HDA, respectively) ice phases of the TIP4P/2005 and ST2 water models. Using persistence homology and machine learning, we introduced a new order parameter that unambiguously identifies the LDA- and HDA-like local environments. The LDA phase transitions continuously and collectively into the corresponding HDA phase via a pre-ordered intermediate phase during the isothermal compression. The local order parameter susceptibilities show a maximum near the transition pressure (P*)—suggesting maximum structural heterogeneities near P*. The HDA-like clusters are structurally ramified and spatially delocalized inside the LDA phase near the transition pressure. We also found manifestations of the first-order low-density to high-density liquid transition in the sharpness of the order parameter change during the LDA to HDA transition. We further investigated the (geometrical) structures and topologies of the LDA and HDA ices formed via different protocols and also studied the dependence of the (microscopic) pathway of phase transition on the protocol followed to prepare the initial LDA phase. Finally, the method adopted here to study the phase transition pathways is not restricted to the system under consideration and provides a robust way of probing phase transition pathways involving any two condensed phases at both equilibrium and out-of-equilibrium conditions. [ABSTRACT FROM AUTHOR]

Water can be vitrified if it is cooled at high rates, which makes it possible to outrun crystallization in so-called no man's land, a range of deeply supercooled temperatures where water crystallizes rapidly. Here, we study the reverse process in pure water samples by flash melting amorphous ice with microsecond laser pulses. Time-resolved electron diffraction reveals that the sample transiently crystallizes despite a heating rate of more than 5 × 106 K/s, even though under the same conditions, vitrification can be achieved with a similar cooling rate of 107 K/s. Moreover, we observe different crystallization kinetics for amorphous solid water and hyperquenched glassy water. These experiments open up new avenues for elucidating the crystallization mechanism of water and studying its dynamics in no man's land. They also add important insights into the laser melting and revitrification processes that are integral to the emerging field of microsecond time-resolved cryo-electron microscopy. [ABSTRACT FROM AUTHOR]

In extreme and nanoconfinement conditions, the tetrahedral arrangement of water molecules is challenged, resulting in a rich and new phase behavior unseen in bulk phases. The unique phase behavior of water confined in hydrophobic nanoslits has been previously observed, such as the formation of a variety of two-dimensional (2D) ices below the freezing temperature. The primary identified 2D ice phase, termed square tube ice (STI), represents a unique arrangement of water molecules in 2D ice, which can be viewed as an array of 1D ice nanotubes stacked in the direction parallel to the confinement plane. In this study, we report the molecular dynamics (MD) simulations evidence of a novel 2D ice phase, namely, helical square tube ice (H-STI). H-STI is characterized by the stacking of helical ice nanotubes in the direction parallel to the confinement plane. Its structural specificity is evident in the presence of helical square ice nanotubes, a configuration unseen in both STI and single-walled ice nanotubes. A detailed analysis of the hydrogen bonding strength showed that H-STI is a 2D ice phase diverging from the Bernal–Fowler–Pauling ice rules by forming only two strong hydrogen bonds between adjacent molecules along its helical ice chain. This arrangement of strong hydrogen bonds along ice nanotube and weak bonds between the ice nanotube shows a similarity to quasi-one-dimensional van der Waals materials. Ab initio molecular dynamics simulations (over a 30 ps) were employed to further verify H-STI's stability at 1 GPa and temperature up to 200 K. [ABSTRACT FROM AUTHOR]

Application of the coherent thermodynamic model [W. Holzapfel and S. Klotz, J. Chem. Phys. 155, 024506 (2021)] for H2O ice Ih to the more detailed data for D2O ice Ih provides better insight into the contributions from quenched proton disorder and offers a new basis for understanding the apparent differences between the data for thermal expansion measured with neutron diffraction on polycrystalline samples [A. Fortes, Acta Crystallogr., Sect. B: Struct. Sci., Cryst. Eng. Mater. 74, 196 (2018) and A. Fortes, Phys. Chem. Chem. Phys 21, 8264 (2019)] and macroscopic dilatation measurements on single crystals [D. Buckingham et al., Phys. Rev. Lett. 121, 185505 (2018)]. The comparison points to contributions from defects effecting the two techniques in different ways. The uncertainties in thermodynamic data due to the contributions from proton disorder and additional defects are compared with the "reference data" [R. Feistel and W. Wagner, J. Phys. Chem. Ref. Data 35, 1021 (2006)] for H2O ice Ih. [ABSTRACT FROM AUTHOR]

Heterogeneous nucleation is the main path to ice formation on Earth. The ice nucleating ability of a certain substrate is mainly determined by both molecular interactions and the structural mismatch between the ice and the substrate lattices. We focus on the latter factor using molecular simulations of the mW model. Quantifying the effect of structural mismatch alone is challenging due to its coupling with molecular interactions. To disentangle both the factors, we use a substrate composed of water molecules in such a way that any variation on the nucleation temperature can be exclusively ascribed to the structural mismatch. We find that a 1% increase in structural mismatch leads to a decrease of ∼4 K in the nucleation temperature. We also analyze the effect of orientation of the substrate with respect to the liquid. The three main ice orientations (basal, primary prism, and secondary prism) have a similar ice nucleating ability. We finally assess the effect of lattice flexibility by comparing substrates where molecules are immobile to others where a certain freedom to fluctuate around the lattice positions is allowed. Interestingly, we find that the latter type of substrate is more efficient in nucleating ice because it can adapt its structure to that of ice. [ABSTRACT FROM AUTHOR]

Heterogeneous ice nucleation (HIN) has applications in climate science, nanotechnology, and cryopreservation. Ice nucleation on the earth's surface or in the atmosphere usually occurs heterogeneously involving foreign substrates, known as ice nucleating particles (INPs). Experiments identify good INPs but lack sufficient microscopic resolution to answer the basic question: What makes a good INP? We employ molecular dynamics (MD) simulations in combination with machine learning (ML) to address this question. Often, the large amount of computational cost required to cross the nucleation barrier and observe HIN in MD simulations is a practical limitation. We use information obtained from short MD simulations of atomistic surface and water models to predict the likelihood of HIN. We consider 153 atomistic substrates with some surfaces differing in elemental composition and others only in terms of lattice parameters, surface morphology, or surface charges. A range of water features near the surface (local) are extracted from short MD simulations over a time interval (≤ 300 ns) where ice nucleation has not initiated. Three ML classification models, Random Forest (RF), support vector machine, and Gaussian process classification are considered, and the accuracies achieved by all three approaches lie within their statistical uncertainties. Including local water features is essential for accurate prediction. The accuracy of our best RF classification model obtained including both surface and local water features is 0.89 ± 0.05. A similar accuracy can be achieved including only local water features, suggesting that the important surface properties are largely captured by the local water features. Some important features identified by ML analysis are local icelike structures, water density and polarization profiles perpendicular to the surface, and the two-dimensional lattice match to ice. We expect that this work, with its strong focus on realistic surface models, will serve as a guide to the identification or design of substrates that can promote or discourage ice nucleation. [ABSTRACT FROM AUTHOR]

Ice is different from ordinary crystals because it contains randomness, which means that statistical treatment based on ensemble averaging is essential. Ice structures are constrained by topological rules known as the ice rules, which give them unique anomalous properties. These properties become more apparent when the system size is large. For this reason, there is a need to produce a large number of sufficiently large crystals that are homogeneously random and satisfy the ice rules. We have developed an algorithm to quickly generate ice structures containing ions and defects. This algorithm is provided as an independent software module that can be incorporated into crystal structure generation software. By doing so, it becomes possible to simulate ice crystals on a previously impossible scale. [ABSTRACT FROM AUTHOR]

Amorphous ice phases are key constituents of water's complex structural landscape. This study investigates the polyamorphic nature of water, focusing on the complexities within low-density amorphous ice (LDA), high-density amorphous ice, and the recently discovered medium-density amorphous ice (MDA). We use rotationally invariant, high-dimensional order parameters to capture a wide spectrum of local symmetries for the characterization of local oxygen environments. We train a neural network to classify these local environments and investigate the distinctiveness of MDA within the structural landscape of amorphous ice. Our results highlight the difficulty in accurately differentiating MDA from LDA due to structural similarities. Beyond water, our methodology can be applied to investigate the structural properties and phases of disordered materials. [ABSTRACT FROM AUTHOR]

Forward stimulated Raman scattering and backward stimulated Raman scattering (BSRS) are measured when an intense 532 nm nanosecond pulsed laser is focused into water and heavy water. The investigation reveals a significant observation: the formation of the ice VII structure exclusively occurs in the backward direction when optical breakdown takes place, provided that the input energy falls below 90 mJ for liquid water or 75 mJ for heavy water. This phase transition is attributed to secondary shock compression, which comes from energy transfer and compression between the BSRS in plasmas with the pump laser. The optical breakdown experiment under pre-pressure reveals that the shock compression in the back direction is approximately 2.3 times that of the forward direction. This research is useful for shock compression and dynamics in plasmas. [ABSTRACT FROM AUTHOR]

The H2O and H2O2 molecules resemble each other in a multitude of ways as has been noted in the literature. Here, we present density functional theory (DFT) calculations for the H2O2(s) and H2O2·2H2O(s) crystals and make selected comparisons with ice polymorphs. The performance of a number of dispersion-corrected density functionals—both self-consistent and a posteriori ones—are assessed, and we give special attention to the D3 correction and its effects. The D3 correction to the lattice energies is large: for H2O2(s) the D3 correction constitutes about 25% of the lattice energy using PBE, much more for RPBE, much less for SCAN, and it primarily arises from non-H-bonded interactions out to about 5 Å.The large D3 corrections to the lattice energies are likely a consequence of several effects: correction for missing dispersion interaction, the ability of D3 to capture and correct various other kinds of limitations built into the underlying DFT functionals, and finally some degree of cell-contraction-induced polarization enhancement. We find that the overall best-performing functionals of the twelve examined are optPBEvdW and RPBE-D3. Comparisons with DFT assessments for ices in the literature show that where the same methods have been used, the assessments largely agree. [ABSTRACT FROM AUTHOR]

Freezing of water under nanoconfinement exhibits physical peculiarities with respect to the bulk water. However, experimental observations are extremely challenging at this scale, which limits our understanding of the effect of confinement on water properties upon freezing. In this study, we use molecular dynamic simulations to investigate how confinement affects the kinetics of growth of ice and the thermodynamic equilibrium of ice-liquid coexistence. TIP4P/Ice water model and CSH-FF model were applied to simulate ice crystallization in a confined cement system at temperatures down to 220 K. We adapted an interface detection algorithm and reparameterized the CHILL/CHILL+ algorithm to capture ice growth. The confinement leads to a shift of the maximum growth rate of ice to a higher temperature than for bulk water. Both the confinement and surface impurities contribute to slowing down the ice growth. For the ice-liquid coexistence at equilibrium, we derive a formulation of Thomson's equation adapted to statistical physics quantities accessible by molecular simulation, and we show that this adapted equation predicts accurately the melting line of bulk and confined ice Ih as a function of pressure. The confinement decreases systematically the melting temperature of ice of about 5 K compared with bulk ice Ih. A premelted water film about 1 nm thick is observed between the solid wall and ice, and its thickness is found to decrease continuously as temperature is lowered. We note that the surface impurities are key to the formation of the premelted water nanofilm when the temperature is lower than 250 K. [ABSTRACT FROM AUTHOR]

We sequenced and comprehensively analysed the genomic architecture of 98 fluorescent pseudomonads isolated from different symptomatic and asymptomatic tissues of almond and a few other Prunus spp. Phylogenomic analyses, genome mining, field pathogenicity tests, and in vitro ice nucleation and antibiotic sensitivity tests were integrated to improve knowledge of the biology and management of bacterial blast and bacterial canker of almond. We identified Pseudomonas syringae pv. syringae, P. cerasi, and P. viridiflava as almond canker pathogens. P. syringae pv. syringae caused both canker and foliar (blast) symptoms. In contrast, P. cerasi and P. viridiflava only caused cankers, and P. viridiflava appeared to be a weak pathogen of almond. Isolates belonging to P. syringae pv. syringae were the most frequently isolated among the pathogenic species/pathovars, composing 75% of all pathogenic isolates. P. cerasi and P. viridiflava isolates composed 8.3 and 16.7% of the pathogenic isolates, respectively. Laboratory leaf infiltration bioassays produced results distinct from experiments in the field with both P. cerasi and P. syringae pv. syringae, causing significant necrosis and browning of detached leaves, whereas P. viridiflava conferred moderate effects. Genome mining revealed the absence of key epiphytic fitness-related genes in P. cerasi and P. viridiflava genomic sequences, which could explain the contrasting field and laboratory bioassay results. P. syringae pv. syringae and P. cerasi isolates harboured the ice nucleation protein, which correlated with the ice nucleation phenotype. Results of sensitivity tests to copper and kasugamycin showed a strong linkage to putative resistance genes. Isolates harbouring the ctpV gene showed resistance to copper up to 600 μg/ml. In contrast, isolates without the ctpV gene could not grow on nutrient agar amended with 200 μg/ml copper, suggesting ctpV can be used to phenotype copper resistance. All isolates were sensitive to kasugamycin at the label-recommended rate of 100μg/ml.

Utilizing CloudSat/CALIPSO satellite data and ERA5 reanalysis data from 2007 to 2016, this study analyzed the distributions of optical and physical characteristics and change characteristics of ice clouds over the Tibetan Plateau (TP). The results show that the frequency of ice clouds in the cold season (November to March) on the plateau is over 80%, while in the warm season (May to September) it is around 60%. The average cloud base height of ice clouds in the warm season is 3–5 km, and mostly around 2 km in the cold season. The average cloud top height in the warm season is around 5–8 km, while in the cold season it is mainly around 4.5 km. The average thickness of ice clouds in both seasons is around 2 km. The statistical results of microphysical characteristics show that the ice water content is around 10−1 to 103 mg/m3, and the effective radius of ice clouds is mainly in the range of 10–90 μm. Both have their highest frequency in the west of the TP and lowest in the northeast. A comprehensive analysis of the change in temperature, water vapor, and ice cloud occurrence frequency shows that the rate of increase in water vapor in the warm season is greater than that in the cold season, while the rates of increase in both surface temperature and ice cloud occurrence are smaller than in the cold season. The rate of increase in temperature in the warm season is around 0.038 °C/yr, and that in the cold season is around 0.095 °C/yr. The growth rate of thin ice clouds in the warm season is around 0.15% per year, while that in the cold season is as high as 1% per year. The results suggest that the surface temperature change may be related to the occurrence frequency of thin ice clouds, with the notable increase in temperature during the cold season possibly being associated with a significant increase in the occurrence frequency of thin ice clouds. [ABSTRACT FROM AUTHOR]

This study prepared six different ice creams to investigate the effect of yeast protein (YP) on their sensory, rheological, thermal properties and fat destabilisation. Results indicated that YP could improve sensory quality, flow and viscoelastic properties. The thermal property was also positively influenced by YP with a significant decrease in frozen water percentage and an increase in glass transition temperature (P < 0.05). Additionally, the particle size and confocal laser scanning microscopy results illustrated that YP could moderately promote the fat aggregate percentage and size. Overall, YP could serve as a fat replacer to produce reduced‐fat ice cream. [ABSTRACT FROM AUTHOR]

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The operational sea ice forecasts from the Arctic Ice Ocean Prediction System (ArcIOPS) during 2021–2023 are validated against satellite-retrieved sea ice concentration and drift data, in situ and reanalyzed sea ice thickness data. The results indicate that the ArcIOPS has a reliable capacity on the Arctic sea ice forecasts for the future 7 days. Over the validation period, the root mean square error (RMSE) of the ArcIOPS sea ice concentration forecasts at a lead time of up to 168 h ranges between 8% and 20%, and the integrated ice edge error (IIEE) is lower than 1.6 × 106 km2 with respect to the Hai Yang 2B (HY-2B) sea ice concentration data. Compared to the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS), sea ice volume evolution from the ArcIOPS forecasts is closer to that derived from the CS2SMOS sea ice thickness observations, which have been assimilated into the ArcIOPS. Sea ice thickness comparisons at three locations in the Beaufort Sea between the ArcIOPS forecasts and in situ mooring observations also prove that the sea ice thickness forecasts are credible, which sets a solid basis for supporting ice-breaker navigation in the Arctic thick ice zone. The sea ice drift deviations between the ArcIOPS forecasts and the National Snow and Ice Data Center (NSIDC) data are lower than 4 cm/s in most of the months. Future work will emphasize on developing multi-variable data assimilation scheme and fully coupled air‒ice‒ocean forecasting system for the Arctic sea ice forecasts. [ABSTRACT FROM AUTHOR]

AbstractAtmospheric freeze-drying (AFD) is a relatively new freeze-drying technology without the need for a vacuum, making it easy to operate and cost-effective. Although there have been studies using AFD to dehydrate solid foods, there is currently no research on using AFD to dehydrate frozen liquids in pharmaceutical vials. In this study, several approaches were evaluated to enhance the atmospheric sublimation of water in pharmaceutical vials. Using −4 °C impinging jet airflow to dry frozen water samples in the vial, it was found that convective action significantly affected the sublimation rate. On this basis, a 3D-printed air-guide model was designed to improve airflow circulation in the vial, and it was found that the drying rate was highest when airflow energy loss was minimized, and airflow velocity at the sample surface was maximized. Additionally, the geometric characteristics of the vial also influenced the sublimation rate; vials with a larger bottom area and shorter height showed the highest sublimation rate. Increasing the vial’s bottom radius from 11 mm to 13 mm, under atmospheric pressure and using cold air at approximately −5 °C, reduced the drying time of 1 g of frozen water from 8.5 h to 6 h; each 5 mm height increase added 0.5 h to the drying time. Using cold air at −10 °C to dry 1 g of frozen water in a 5 mL vial, the combination of ultrasonic-induced energy (at a frequency of 39.46 kHz) and the air-guide model effectively reduced the sublimation time from 7 h to 5 h, compared to using only the air-guide model. However, this technique may be vulnerable to melting at the vial-transducer contact point, should the transducer be directly attached to the vials. [ABSTRACT FROM AUTHOR]

The sea ice extent in the Weddell Sea exhibited a positive trend from the start of satellite observations in 1978 until 2016 but has shown a decreasing trend since then. This study analyzes seasonal and interannual variations in sea ice thickness using ICESat-2 laser altimetry data over the Weddell Sea from 2019 to 2022. Sea ice thickness was calculated from ICESat-2's ATL10 freeboard product using the Improved Buoyancy Equation. Seasonal variability in ice thickness, characterized by an increase from February to September, is more pronounced in the eastern Weddell sector, while interannual variability is more evident in the western Weddell sector. The results were compared with field data obtained between 2019 and 2022, showing a general agreement in ice thickness distributions around predominantly level ice. A decreasing trend in sea ice thickness was observed when compared to measurements from 2003 to 2017. Notably, the spring of 2021 and summer of 2022 saw significant decreases in Sea Ice Extent (SIE). Although the overall mean sea ice thickness remained unchanged, the northwestern Weddell region experienced a noticeable decrease in ice thickness. [ABSTRACT FROM AUTHOR]

We use digital elevation models (DEMs) and ICESat‐2 data to study the filling and outflow from a large subglacial lake under Manson Icefield in the Canadian Arctic. When full, the lake is ∼17 × 3 km with an area of 52 km2. Early in 2021 the ice surface over the center of the lake sank by >140 m implying a subglacial outburst flood of ∼4 km3. Rapid outflow occurred over ∼30 days at an average rate of ∼1,500 m3s−1 resulting in the formation of a single ∼15 km subglacial outflow path detectable from post‐outflow surface depression. The shape of the surface depression, 600–800 m wide by 2–4 m deep, reflects the shape of the subglacial channel prior to closure. Downstream ice movement appears unaffected by the outflow. After outflow ends the surface depression persisted over weeks, apparently dependent on the difference between water and overburden pressures. Plain Language Summary: Using satellite observations, we discovered a large lake under the Manson Icefield in the Canadian Arctic. Early in 2021 the ice surface over the center of the lake sank by around 140 m implying a total subglacial water outflow of around 4 km3, the largest reported outside of Iceland and Antarctica. Most of this water drained from the subglacial lake within 30 days melting some of the ice along the outflow path. For the first time we map the position and size of the subglacial output channel between the downstream end of the lake and the ocean using post‐outflow surface depression as the ice sank downward to close the channel after the water outflow. These results help in understanding the ways in which the presence, movement, and volume of water beneath glaciers influence ice movement and climate related glacial ice loss. Key Points: Using satellite height change data we document the discovery of a 52 km2 subglacial lake under the Manson Icefield, Nunavut, CanadaThe lake filled for around 14 years until early 2021 when the level in the center of the lake dropped by 130 m over 30 daysThe outflow volume was around 4 cubic kilometers and created a wide and shallow subglacial channel that could be tracked for over 15 km [ABSTRACT FROM AUTHOR]

We aimed to investigate the fluid–solid–ice coupling mechanism as structures break through ice into water. Using LS–DYNA finite element software, a numerical simulation method is established, based on the ALE flow–solid coupling method, and the penalty function contact algorithm, which describes the structure–ice–water coupling interaction. The Eulerian algorithm is used to describe the air and water domains, while the Lagrange method is applied to the wedge and ice structure. The mechanical properties of ice are characterized using the elastic–plastic failure strain model. The feasibility of simulating the entry of structures into water via the ALE method is demonstrated by comparing the experimental and simulation results of wedges entering into water. The applicability of the ice material model in simulating collision–induced breakup is verified by comparing a simulation of a rigid plate hitting a spherical head of ice, with results from the ISO standard. The effects of water during icebreaking are assessed by simulating a wedge breaking through ice into water, as well as through ice without water. Additionally, the ice breakup and motion response of the wedge under different working conditions are compared by varying the wedge mass and icebreaking speed. [ABSTRACT FROM AUTHOR]

This study presents the first three-dimensional discrete element method simulations of pressure ridge formation. Pressure ridges are an important feature of the sea-ice cover, as they contribute to the mechanical thickening of ice and likely limit the strength of sea ice at large scales. We validate the simulations against laboratory-scale experiments, confirming their accuracy in predicting ridging forces and ridge geometries. Then we demonstrate that Cauchy–Froude scaling applies for translating laboratory-scale results on ridging to full-scale scenarios. We show that non-simultaneous failure, where an ice floe fails at distinct locations across the ridge length, is required for an accurate representation of the ridging process. This process cannot be described by two-dimensional simulations. We also find a linear relationship between the ridging forces and the ice thickness, contrasting with earlier results in the literature obtained by two-dimensional simulations. [ABSTRACT FROM AUTHOR]

CryoSat‐2 has been successful in observing sea ice thickness from space by providing ice freeboard information. The initial estimate of the ice freeboard, called radar freeboard, is obtained by analyzing the observed waveform using a retracker. A series of corrections are needed to convert the radar freeboard to the ice freeboard. Those are the physical effects (e.g., changes in wave propagation speed and the distribution of scattering at snow and ice surfaces, etc.) and the bias of the retracker; however, traditionally, only the wave speed correction has been applied due to lack of enough information to perform the complete correction. Here, an alternative correction method for the CryoSat‐2 radar freeboard derived using the Threshold First‐Maximum Retracker Algorithm with a 50% threshold (TFMRA50) is proposed. Snow depth was used as a predictor for the correction, similar to the traditional wave speed correction, but the coefficients were empirically determined by performing a direct comparison of the radar freeboard from CryoSat‐2 and the ice freeboard from airborne observations. Consequently, this new empirical correction treats the physical effects and the retracker bias as a whole, which have been difficult to separate in the retrieval process. In this paper, we demonstrate that the retrieval accuracy of snow and ice variables and the consistency of the two independent retrieval methods are improved when the new correction is applied. The result of this study emphasizes the importance of compatibility between the retracker and the freeboard correction method. Plain Language Summary: Sea ice thickness and snow depth are considered essential climate variables because they are crucial for understanding climate change. The satellite CryoSat‐2 has successfully contributed to obtaining those variables by estimating the elevation of the sea ice surface from space. However, the estimation of the sea ice elevation can be affected by several error sources related to snow and ice conditions. Traditionally, it was challenging to perform a complete correction because there has not been enough detailed information on the snow and ice conditions. Considering the complex nature of sea ice, an alternative simple empirical correction method is proposed based on actual CryoSat‐2 and reference airborne observations. Accordingly, the proposed correction doesn't require detailed information on the surface conditions. We verify that the estimation of the snow and ice variables is improved when the new correction is applied. Additionally, the new correction also increases the consistency of two independent products. Based on its robustness and simplicity, we expect this new method to enhance our understanding of climate change by improving the quality of satellite snow and sea ice data. Key Points: The behavior of the CryoSat‐2 radar freeboard from the widely used retracker was found to be incompatible with conventional correctionAn alternative empirical method for improving the CryoSat‐2 radar‐to‐ice freeboard correction for a threshold retracker was developedThe new method can be generally applied to existing retrieval methods to improve the quality of snow depth and ice thickness retrievals [ABSTRACT FROM AUTHOR]

Purpose: Healthcare workers (HCWs) wearing personal protective equipment (PPE) experience physiological strain that can impair motor and psychological functions, potentially affecting patient care. We assessed the effects of heat exposure on maximal strength and risk-taking behavior among PPE-wearing HCWs and the efficacy of ice slurry to alleviate adverse effects. Methods: Seventeen HCWS completed two experimental trials in a crossover design, consuming 5 g·kg−1 of body mass of ambient drink (AMB) or ice slurry (ICE) before donning PPE and undergoing 2 h of simulated decontamination exercise (wet-bulb globe temperature (WBGT): 25.9° C ± 0.8°C, PPE microenvironment WBGT: 29.1°C ± 2.1°C). Body core temperature (Tc), heart rate (HR), chest skin temperature (Tsk), ratings of perceived exertion (RPE), thermal sensation (RTS), maximal voluntary contraction (MVC), risk-taking behavior (balloon analogue risk-taking task (BART)), and salivary cortisol were assessed. Results: Predrinking to postdrinking ΔTc was greater in ICE (−0.2°C ± 0.1°C) than AMB (−0.0°C ± 0.1°C, P = 0.003). Post-drinking RTS was lower in ICE (2.7 ± 1.2) than AMB (4.1 ± 0.4, P < 0.001). ICE and AMB had similar Tc and HR (both P > 0.05), but Tsk was lower in ICE than AMB (P = 0.049). A lower MVC (30.3 ± 6.7 vs 27.4 ± 4.9 kg, P = 0.001) and higher BART-adjusted total pump count (472 ± 170 vs 615 ± 174 pumps, P = 0.017) was observed pretrial to posttrial in AMB but absent in ICE (both P > 0.05). Salivary cortisol was similar between trials (P = 0.42). Conclusions: Heat-exposed PPE-wearing HCWs had impaired maximal strength and elevated risk-taking behavior. This may increase the risk of avoidable workplace accidents that can jeopardize HCWs and patient care. Ice slurry ingestion alleviated these heat-related impairments, suggesting its potential as an ergogenic aid. [ABSTRACT FROM AUTHOR]

The Ice Cloud Imager (ICI) aboard the second generation of the EUMETSAT Polar System (EPS-SG) will provide novel measurements of ice hydrometeors. ICI is a passive conically scanning radiometer that will operate within a frequency range of 183 to 664 GHz , helping to cover the present wavelength gap between microwave and infrared observations. Reliable global data will be produced on a daily basis. This paper presents the retrieval database to be used operationally and performs a final pre-launch assessment of ICI retrievals. Simulations are performed within atmospheric states that are consistent with radar reflectivities and represent the three-dimensional (3D) variability of clouds. The radiative transfer calculations use empirically based hydrometeor models. Azimuthal orientation of particles is mimicked, allowing for the consideration of polarisation. The degrees of freedom (DoFs) of the ICI retrieval database are shown to vary according to cloud type. The simulations are considered to be the most detailed performed to this date. Simulated radiances are shown to be statistically consistent with real observations. Machine learning is applied to perform inversions of the simulated ICI observations. The method used allows for the estimation of non-Gaussian uncertainties for each retrieved case. Retrievals of ice water path (IWP), mean mass height (Zm), and mean mass diameter (Dm) are presented. Distributions and zonal means of both database and retrieved IWP show agreement with DARDAR. Retrieval tests indicate that ICI will be sensitive to IWP between 10 -2 and 10 1 kgm-2. Retrieval performance is shown to vary with climatic region and surface type, with the best performance achieved over tropical regions and over ocean. As a consequence of this study, retrievals from real observations will be possible from day one of the ICI operational phase. [ABSTRACT FROM AUTHOR]

Regional subsurface mapping of glacial depositional systems preserved in buried bedrock paleovalleys, and quantitative analysis of new LiDAR imagery of surface glacial landforms using machine learning techniques, when combined, are powerful tools for assessing the dynamics of the Laurentide Ice Sheet (LIS) during the last (Wisconsinan) glaciation in southern Ontario. While age dating of deposits preserved below Last Glacial Maximum tills (LGM: marine isotope stage (MIS) 2 < c.24 000 years B.P. (ybp)) is still sparse, newly available sedimentological data derived by cored drilling, combined with legacy outcrop data, identify thick (100 m+) successions of glaciolacustrine sediments and a lack of till(s), indicating that the ice sheet margin did not extend beyond the Niagara Escarpment at the western end of Lake Ontario, during the earliest phases of the glaciation (MIS 4) or the ensuing mid-Wisconsinan (MIS 3). Ice was able to extend into New York State blocking the Rome outlet to the Hudson Valley ponding deep proglacial lakes in the glacio-isostatically depressed Huron–Ontario–Erie basins recorded by thick glaciolacustrine sediments in paleovalleys. These were cannibalized by an expanding Late Wisconsinan ice sheet after ∼24 000 ybp recorded by extensive till sheets resting on a marked erosional unconformity, with drumlinized surfaces. Analysis and visualization of LiDAR data identifies discrete statistically validated flow sets of highly elongated streamlined bedforms (mega-scale glacial lineations (MSGLs)). These provide key evidence of a major reorganization of the ice sheet margin during deglaciation into lobate paleo ice streams shortly after 17 400 ybp. MSGLs are cut across earlier LGM drumlinized tills creating widespread "palimpsest" surfaces. At least two principal phases of fast ice flow can be identified, marked by large fluxes of sediment and the rapid building of large gravel and sand-dominated moraine complexes within interlobate depocentres, the largest glacial landforms in southern Ontario. Analysis of LiDAR data further reveals the common presence of DeGeer moraines where ice margins retreated in water, and iceberg scours. Future work using LiDAR mapping has the objective of fully documenting the number, extent, and timing of ice streams to enhance glaciological modelling when the ice sheet rapidly lost mass. [ABSTRACT FROM AUTHOR]

Hailstones in the clouds develop under various environmental conditions (temperature, humidity, wind, etc.), which impact the size and texture of the ice composing the hail. The stratified structures within a hailstone provide direct insight into the stages it underwent during its growth. In each region, the grains grow with numerous bubbles both inside them and along the grain boundaries (GBs). As hail takes shape, its grain size gradually increases while within the storm cloud and this growth continues even after it falls to the ground. Grain growth is a thermally activated process that modifies the structure of hail, influenced by the presence of bubbles and atmospheric contaminants accumulated within the cloud. This study examines the evolution of grain size in a cylindrical hailstone containing bubbles, employing theoretical equations and a Monte Carlo-based growth model. The computational results contribute to a better understanding of the interaction between GBs and pre-existing bubbles, thereby elucidating the grain size evolution in hailstone containing bubbles near the melting point. Additionally, the study assesses the significance of bubbles in retaining information about a storm within hailstones. [ABSTRACT FROM AUTHOR]

This study aimed to explore how air pollution and green space influence ICE recurrence and whether they might interact with each other. A case-cross design was used in this study, which was carried out in Tianjin, China. A total of 8306 patients with recurrent ICE were collected from 2019 to 2020. The maximum effects of PM2.5, PM10, SO2, NO2, CO were 1.012 (95%CI: 1.004, 1.019), 1.010 (95%CI: 1.004, 1.016), 1.035 (95%CI: 0.982, 1.091), 1.067 (95%CI: 1.043, 1.091) and 1.012 (95%CI: 1.004, 1.021) , respectively, and the risk was higher in males and in the 50–60 age group. In the stratification of greening, it was found that air pollution except O3 had the highest risk of ICE recurrence for those with lower green space. Our study found that air pollution (except O3) can increase the risk of ICE recurrence, and this risk can be reduced by increasing green space. [ABSTRACT FROM AUTHOR]

Determining water concentrations in the polar regions of the Moon is one of the priority tasks of a number of space missions and, in particular, the Luna-27 mission. The complex of scientific equipment of the Luna-27 spacecraft includes time-of-flight laser ionization mass spectrometer LASMA-LR, the main task of which is to analyze the elemental composition of the regolith at the landing site. The design and configuration of the flight instrument is adapted for the analysis of regolith and was not originally intended for the study of volatile compounds. However, due to the importance of determining the water content in regolith, we reviewed some approaches to analyzing samples during lunar missions and assessed the applicability of LASMA-LR and the laser ionization mass spectrometry method in general for identifying water in regolith. It has been established that using this instrument it is possible to detect water in regolith, including determining its state (chemically bound and unbound water). Moreover, the conditions for sampling the regolith and delivering it to the soil receiving device of the instrument are critically important for the analysis, since under the conditions of the lunar surface, sublimation of ice is possible before the samples are analyzed. This technique has advantages over some other methods of analyzing water and/or ice used in space experiments, and can be used in the study of a number of planets and bodies of the Solar System. [ABSTRACT FROM AUTHOR]

Thirst is one of the most bothersome symptoms experienced by surgical patients. Effective thirst intervention and management in the Post Anesthesia Care Unit (PACU) and hospital wards is critical because patients are less sedated and more aware than in the past. There is a need to review the literature on the identification and management of thirst in the inpatient and PACU settings. The aim of this systematic review was to examine the available evidence on the effectiveness of oral cold applications on thirst in postoperative patients. This was a systematic review study. Articles in PUBMED, Web of Science, ScienceDirect, TÜBİTAK-ULAKBİM, and TRDizin databases between January 2008 and January 2023 that included oral cold applications to relieve the thirst of patients in the postoperative period were included. The PICOT-SD (Patients Interventions Comparison Outcome Time-Study Design) method was used as an eligibility criterion for inclusion in the study. The eligibility criteria included that the articles were written in English-Turkish and within the target dates, the studies included nursing interventions, the primary outcome of the studies was thirst, and the study sample included postoperative patients. The risk of bias was assessed using the RoB2 tool developed by Cochrane. A total of 254 articles were retrieved from the databases using the specified keywords. 244 articles did not meet the study criteria: 30 were excluded because they were not interventional studies, 61 were not conducted in a postoperative population, 56 were duplicates, and 79 were not on a related topic. A total of 10 studies consisting of randomized controlled trials and quasi-experimental articles met the criteria for our review. Oral cold applications effectively reduced the thirst rate of postoperative patients and improved their health-related quality of life. The intervention has also been shown to reduce other anesthesia-related complications. This systematic review concluded that cold oral applications have promising effects on thirst, dry mouth, and health-related quality of life. Cold oral applications are cost-effective and suitable for large-scale health care applications. [ABSTRACT FROM AUTHOR]

Differential interferometric synthetic aperture radar (InSAR) is a remote sensing technique for measuring surface displacements with precision down to millimeters, most commonly from satellites. In permafrost landscapes, InSAR measurements can provide valuable information on geomorphic processes and hazards, including thaw subsidence and frost heave, thermokarst, and permafrost creep. We first review recent progress in InSAR data availability, InSAR processing and uncertainty analysis methods relevant to permafrost studies. These technical advances have contributed to our understanding of surface deformation in flat and sloping terrain in polar and mountainous regions. We emphasize two emerging trends. First, InSAR increasingly enables insight into the mechanisms, controls, and drivers of permafrost landscape dynamics on subseasonal to decadal time scales. Second, InSAR observations in conjunction with models enable novel ways to infer subsurface parameters, such as near‐surface ground ice content and active layer thickness. We anticipate that in the coming decade, InSAR will mature into a widely used operational tool for monitoring, modeling, and planning across rapidly changing permafrost landscapes. [ABSTRACT FROM AUTHOR]

The stability of bridge foundations is affected by local scour, and the formation of ice jams exacerbates local scour around bridge piers. These processes, particularly the evolution of ice jams and local scour around piers, are more complex in curved sections than in straight sections. This study, based on experiments in an S-shaped channel, investigates how various factors—the flow Froude number, ice–water discharge rate, median particle diameter, pier spacing, and pier diameter—affect the maximum local scour depth around double piers in tandem and the distribution of ice jam thickness. The results indicate that under ice-jammed flow conditions, the maximum local scour depth around double piers in tandem is positively correlated with the ice–water discharge rate, pier spacing, and pier diameter and negatively correlated with median particle diameter. The maximum local scour depth is positively correlated with the flow Froude number when it ranges from 0.1 to 0.114, peaking at 0.114. Above this value, the correlation becomes negative. In curved channels, the arrangement of double piers in tandem substantially influences ice jam thickness distribution, with increases in pier diameter and spacing directly correlating with greater ice jam thickness at each cross-section. Furthermore, ice jam thickness is responsive to flow conditions, escalating with higher ice–water discharge rates and decreasing flow Froude numbers. [ABSTRACT FROM AUTHOR]

The presence of ice cover on temperate lakes is a crucial factor in determining the functioning of these ecosystems. The isolation of water from atmospheric influences significantly alters physical, chemical, and biological processes, and the intensity of this impact depends on the duration of the ice cover. This study analyzed the basic parameters of ice cover on several dozen lakes in Northeastern Poland. The aim of this study is to investigate the influence of morphometric parameters, alongside environmental factors, on the variation of ice cover characteristics in lakes located within the Eastern Baltic Lakeland. Characterization of ice conditions in the analyzed lakes was based on basic statistics such as minimum and maximum values, mean, standard deviation, coefficients of variation, skewness, and kurtosis. Given that the dataset contains variables describing ice phenomena in the studied lakes and data describing location, morphometric parameters, and land cover directly adjacent to the lake (treated as independent variables), a method of Spearman's rank correlations and constrained ordination method were decided upon. Despite the relatively small study area, significant variability was observed, with average differences as follows: 26 days for the onset of ice cover, 17 days for the end date, 15 cm for ice thickness, and a 30-day difference in the average duration of ice cover. Key factors included parameters such as lake volume, average depth, and land use (urbanized and agricultural areas). Understanding parameters such as the onset and end of ice cover is essential for lake ecosystems, both from an ecological and economic perspective. This knowledge is crucial for interpreting the behavior of living organisms, water quality, and economic considerations. [ABSTRACT FROM AUTHOR]

Substantial seafloor morphological changes are rapidly occurring along the Canadian Arctic shelf edge. Five multibeam bathymetric mapping surveys, each partially covering a 15 km2 study area between 120‐ and 200‐m water depth, were conducted over a 12‐year time period. These surveys reveal that 65 new craters have developed between 2010 and 2022, averaging 6.5 m and reaching up to 30 m deep. Remotely operated vehicle investigations revealed massive ice outcrops exposed on two newly formed crater flanks. This ice is not relict subaerially formed Pleistocene permafrost because it is hosted in sediments which were deposited in a submarine setting post‐deglaciation. Low salinity porewater and sediment core ice samples with depleted oxygen isotopic compositions indicate waters with a meteoric signature are discharging and freezing in this area. These ascending brackish groundwaters are likely derived in part from thawed relict permafrost hundreds of meters under the continental shelf. They refreeze as they approach the −1.4°C seafloor, leading to the development of widespread, near seafloor, sub‐bottom ice layers. Conditions appropriate for ice melting also exist nearby where ice is exposed to seawater or warmed by ascending groundwater. Small variations in temperature and salinity lead to shifts between freezing of ascending brackish groundwater or melting of near seafloor ice layers. These conditions have produced a dramatic submarine thermokarst morphology riddled with multi‐aged depressions. Thermokarst geohazards may exist, unmapped, on other Arctic margins with groundwater channeled toward the shelf edge by a relict permafrost cap, and sufficiently cold shelf edge bottom water temperatures. Plain Language Summary: Significant seafloor changes are rapidly happening along the Canadian Arctic shelf edge, where numerous craters and mounds occur. Five seafloor mapping surveys collected over 12 years covering the same area reveal 65 new craters, reaching up to 30 m but averaging 6.5 m deep, were formed between 2010 and 2022. Observations from a remotely operated vehicle showed massive ice outcrops along the flanks of two newly formed craters. Chemical analyses of the ice show that the source of the frozen water is ascending brackish groundwaters that refreeze near the −1.4°C seafloor, forming widespread sub‐bottom ice layers that blister the seafloor producing ice‐cored mounds. The source of the groundwaters is likely melted relict permafrost from beneath the continental shelf. Where ice is exposed to seawater salinity or warmer groundwater, ice melting causes seafloor collapses. Minor temperature and salinity variations cause shifts between freezing of ascending brackish groundwater and melting of near‐seafloor ice layers. These ongoing processes create a dramatic submarine landscape composed of numerous depression and ice‐filled mounds of varying ages. This discovery of sub‐seafloor ice with a groundwater origin significantly expands our understanding of submarine permafrost within the Arctic continental shelves. Key Points: Massive outcrops of submarine ice layers were found within recently formed seafloor craters along the edge of the Arctic continental shelfOn‐going ice growth and decomposition is occurring around seafloor seepages to produce a distinctive submarine thermokarst topographyThermokarst geohazards may exist on other Arctic margins where sub‐zero water temperatures and submarine groundwater seepage occur [ABSTRACT FROM AUTHOR]

Much of the Antarctic coast is covered by seasonal landfast sea ice (fast ice), which serves as an important habitat for ice algae. Fast‐ice algae provide a key early season food source for pelagic and benthic food webs, and contribute to biogeochemical cycling in Antarctic coastal ecosystems. Summertime fast ice is undergoing a decline, leading to more seasonal fast ice with unknown impacts on interconnected Earth system processes. Our understanding of the spatiotemporal variability of Antarctic fast ice, and its impact on polar ecosystems is currently limited. Evaluating the overall productivity of fast‐ice algae has historically been hampered by limitations in observations and models. By linking new fast‐ice extent maps with a one‐dimensional sea‐ice biogeochemical model, we provide the first estimate of the spatio‐seasonal variability of Antarctic fast‐ice algal gross primary production (GPP) and its annual primary production on a circum‐Antarctic scale. Experiments conducted for the 2005–2006 season provide a mean fast ice‐algal production estimate of 2.8 Tg C/y. This estimate represents about 12% of overall Southern Ocean sea‐ice algae production (estimated in a previous study), with the mean fast‐ice algal production per area being 3.3 times higher than that of pack ice. Our Antarctic fast‐ice GPP estimates are probably underestimated in the Ross Sea and Weddell Sea sectors because the sub‐ice platelet layer habitats and their high biomass are not considered. Plain Language Summary: Antarctic landfast sea ice (fast ice) is sea ice fastened to the coastline of Antarctica and provides a prolific habitat for microalgae. These ice algae are ecologically important because their production takes place early in the season when water column primary production is low. By combining a new satellite data set and a biogeochemical sea‐ice algal growth model, this study provides the first estimate of circum‐Antarctic fast‐ice algal production: 2.8 million tonnes of carbon per year, which is about 12% of the total Antarctic sea‐ice algal production. The mean algal primary production per area in fast ice is 3.3 times higher than that of pack ice. Key Points: First estimate of circum‐Antarctic landfast sea‐ice annual gross primary production, with a focus on the 2005–2006 seasonMean landfast sea‐ice algal primary production is 2.8 TgC/y, representing 12% (range 5%–19%) of total Southern Ocean ice algal productivityMean modeled landfast sea‐ice algal production per area is 3.3 times higher than that of pack ice [ABSTRACT FROM AUTHOR]

Mass loss from the Greenland ice sheet has contributed to global sea-level rise over the past 20 years. Yet direct observations from the 79 North Glacier (79NG) calving front reveal decreasing Atlantic Intermediate Water (AIW) temperatures below the ice tongue from 2018 to 2021, leading to reduced ocean heat transport. This is linked to a concurrent decrease in basal melt and thinning rates at the grounding line. The origin of this AIW cooling is traced to a slowdown of the large-scale ocean circulation in the Nordic Seas, driven by European atmospheric blocking that strengthens cold air advection from the central Arctic through the Fram Strait. Blocking has driven major ocean cooling events over the last 50 years and will remain crucial in affecting Northeast GreenlandÕs glaciers. [ABSTRACT FROM AUTHOR]

We apply the Canny edge algorithm to imagery from the Utqiaġvik coastal sea ice radar system (CSIRS) to identify regions of open water and sea ice and quantify ice concentration. The radar-derived sea ice concentration (SIC) is compared against the (closest to the radar field of view) 25 km resolution NSIDC Climate Data Record (CDR) and the 1 km merged MODIS-AMSR2 sea ice concentrations within the ∼11 km field of view for the year 2022–2023, when improved image contrast was first implemented. The algorithm was first optimized using sea ice concentration from 14 different images and 10 ice analysts (140 analyses in total) covering a range of ice conditions with landfast ice, drifting ice, and open water. The algorithm is also validated quantitatively against high-resolution MODIS-Terra in the visible range. Results show a correlation coefficient and mean bias error between the optimized algorithm, the CDR and MODIS-AMSR2 daily SIC of 0.18 and 0.54, and ∼−1.0 and 0.7%, respectively, with an averaged inter-analyst error of ±3%. In general, the CDR captures the melt period correctly and overestimates the SIC during the winter and freeze-up period, while the merged MODIS-AMSR2 better captures the punctual break-out events in winter, including those during the freeze-up events (reduction in SIC). Remnant issues with the detection algorithm include the false detection of sea ice in the presence of fog or precipitation (up to 20%), quantified from the summer reconstruction with known open water conditions. The proposed technique allows for the derivation of the SIC from CSIRS data at spatial and temporal scales that coincide with those at which coastal communities members interact with sea ice. Moreover, by measuring the SIC in nearshore waters adjacent to the shoreline, we can quantify the effect of land contamination that detracts from the usefulness of satellite-derived SIC for coastal communities. [ABSTRACT FROM AUTHOR]

Cryopreservation is a crucial technique for the long-term ex situ conservation of plant genetic resources, particularly in the context of global biodiversity decline. This process entails freezing biological material at ultra-low temperatures using liquid nitrogen, which effectively halts metabolic activities and preserves plant tissues over extended periods. Over the past seven decades, a plethora of techniques for cryopreserving plant materials have been developed. These include slow freezing, vitrification, encapsulation dehydration, encapsulation–vitrification, droplet vitrification, cryo-plates, and cryo-mesh techniques. A key challenge in the advancement of cryopreservation lies in our ability to understand the molecular processes underlying plant freezing tolerance. These mechanisms include cold acclimatization, the activation of cold-responsive genes through pathways such as the ICE–CBF–COR cascade, and the protective roles of transcription factors, non-coding RNAs, and epigenetic modifications. Furthermore, specialized proteins, such as antifreeze proteins (AFPs) and late embryogenesis abundant (LEA) proteins, play crucial roles in protecting plant cells during freezing and thawing. Despite its potential, cryopreservation faces significant challenges, particularly in standardizing protocols for a wide range of plant species, especially those from tropical and subtropical regions. This review highlights the importance of ongoing research and the integration of omics technologies to improve cryopreservation techniques, ensuring their effectiveness across diverse plant species and contributing to global efforts regarding biodiversity conservation. [ABSTRACT FROM AUTHOR]

Introduction: In the field of sports and exercise science researchers are exploring methods to enhance recovery after training sessions. One popular approach that has gained attention is the use of ice baths. Purpose: This review examines how ice baths impact muscle recovery time following high intensity workouts looking at both the effects and practical considerations with a focus, on Delayed Onset Muscle Soreness (DOMS). The PubMed database was used in this study. A literature review was conducted using the keywords: "cold water", "muscle regeneration", "muscle soreness", "DOMS" and "ice bathing". State of Knowledge: Ice baths have been found to trigger vasoconstriction reduce inflammation and alleviate muscle soreness. However, their effectiveness in reducing exercise-induced inflammation and muscle soreness remains uncertain. The impact on DOMS varies among individuals due to factors like genetics, age, gender and health conditions. This variability highlights the challenges of incorporating ice baths into workout recovery routines. Summary: The use of ice baths in post-exercise recovery presents a complex landscape with diverse physiological responses and variable outcomes. While practical guidelines exist for the application of ice baths in high-intensity training, debates persist regarding their efficacy on DOMS compared to active recovery. While ice baths are incorporated into holistic recovery strategies conflicting research casts doubt on their standalone effectiveness prompting further exploration of how they complement other recovery methods. Moreover, potential drawbacks and conflicting evidence regarding their influence on long-term training adaptations raise questions about the overall costs and benefits. [ABSTRACT FROM AUTHOR]

Mixed-phase clouds affect precipitation and radiation differently from liquid and ice clouds, posing greater challenges to their representation in numerical simulations. Recent laboratory experiments using the Pi Cloud Chamber explored cloud glaciation conditions based on increased injection of ice-nucleating particles. In this study, we use two approaches to reproduce the results of the laboratory experiments: a bulk scalar mixing model and large-eddy simulation (LES) with bin microphysics. The first approach assumes a well-mixed domain to provide an efficient assessment of the mean cloud properties for a wide range of conditions. The second approach resolves the energy-carrying turbulence, the particle size distribution, and their spatial distribution to provide more details. These modeling approaches enable a separate and detailed examination of liquid and ice properties, which is challenging in the laboratory. Both approaches demonstrate that, with an increased ice number concentration, the flow and microphysical properties exhibit the same changes in trends. Additionally, both approaches show that the ice integral radius reaches the theoretical glaciation threshold when the cloud is subsaturated with respect to liquid water. The main difference between the results of the two approaches is that the bulk model allows for the complete glaciation of the cloud. However, LES reveals that, in a dynamic system, the cloud is not completely glaciated as liquid water droplets are continuously produced near the warm lower boundary and subsequently mixed into the chamber interior. These results highlight the importance of the ice mass fraction in distinguishing the mixed-phase clouds and ice clouds. [ABSTRACT FROM AUTHOR]

In the context of glacier retreat and increased precipitations, Arctic glacier basin slopes are subject to stress leading to visible transformations. In this work, subsurface features of a small Arctic glacier basin slopes are mapped using ground‐penetrating RADAR. In combination with surface topography data, eight transects were surveyed ranging from the areas furthest from the current glacier extent to the areas still in contact with the glacier. This allowed for a reconstitution of the successive stages ice‐cored slopes go through when glaciers retreat. It appears that slopes evolve from thick debris‐covered ice bodies connected with the glacier, to residual ice and ice/debris mixes covered in debris. At the same time, surface morphology of the slopes shifts from homogeneous ice‐cored slope gradients to more complex talus‐type slopes at the end of the process. The stages of these evolutions are in compliance with former glacier extents. The main driving factors of the slopes successive stages are the constant slope adjustments linked to debris movements, and the melting of ice cores. All these factors are exacerbated by the warmer and wetter conditions they are subject to. [ABSTRACT FROM AUTHOR]

Aircraft icing seriously threatens flight safety. This paper describes a modified shallow-water icing thermodynamic model that is applicable to unstructured grids and considers the effects of changes in water physical parameters and sublimation on icing. An icing calculation method enables the automatic determination of whether freezing occurs and the type of icing. An autonomous icing calculation program is developed to extract the geometric coordinates and mesh information of the icing surface and combine this information with the multiphase flow field of air-supercooled water droplets. The icing equations in the Godnov format are discretized to produce a large-scale sparse matrix that is solved iteratively using the biconjugate gradient stabilized method. The output includes parameter distributions for the ice thickness, water film thickness, and equilibrium temperature. Taking the National Advisory Committee for Aeronautic 0012 airfoil as the study object, the results of icing simulations are compared with experimental data from an ice wind tunnel and the ice shapes calculated by the FENSAP-ICE software. The results are found to be in good agreement with the experimental data, and the ice height errors at stagnation points are less than 15%. In the case of rime ice, single-horned ice shapes are simulated for both conventional and large supercooled droplets. For mixed ice and glaze ice, double-horned ice shapes are simulated for both droplet conditions. FENSAP-ICE fails to simulate the ice horns and produces large errors in ice thickness and ice range. [ABSTRACT FROM AUTHOR]

In the present study, we experimentally investigated the oblique impinging process of an ice particle on a water film. A parameter study of the impact velocity, impact angle, and water film thickness was carefully carried out. The results showed that three impact categories occurred, namely uprising liquid sheet, crown with a notch, and complete crown. The uprising liquid sheet only occurred in the case when the dimensionless water film thickness was 0.1, which appeared to be independent of the impact velocity and the impact angle. The crown with a notch only occurred in the case when the impact velocity was 23.0 m/s. The left tilt angles of uprising liquid sheet, crown with a notch, and complete crown all increased first and then decreased with the dimensionless time. Among the three experimental parameters investigated in the present study, the dimensionless water film thickness had the most significant effect on the evolutions of the left tilt angles. The dimensionless spreading lengths in x- and y-direction all increased with the increase in dimensionless water film thickness. In addition, the correlations of dimensionless spreading lengths in x- and y-direction were proposed. In addition, the lifetime of complete crown generally increased with the increase in the impact velocity and the dimensionless water film thickness. Within the scope of the present study, the dimensionless maximum height of uprising liquid sheet generally ranged from 3.0 to 3.5. When the impact angle was 30.0°, the dimensionless maximum height of the crown with a notch increased with the increasing dimensionless water film thickness. The present work not only provides a new insight into the study of the ice crystal icing but also offers effective support for the development of efficient anti/de-icing methods. [ABSTRACT FROM AUTHOR]