Prydz Bay, East Antarctica, is a critical region for studying ocean–sea ice–ice shelf interactions and their role in the global climate system. This review synthesizes the advancements in numerical modeling of physical oceanographic processes in Prydz Bay, highlighting the evolution from early one-dimensional thermodynamic models to contemporary high-resolution, three-dimensional coupled ocean–sea ice–ice shelf frameworks. We discuss key milestones in understanding processes such as frazil ice dynamics and its impact on the basal mass balance of the Amery Ice Shelf, the pathways and mechanisms of Modified Circumpolar Deep Water intrusions, and the dynamic influences of large icebergs on regional circulation. Despite significant progress, challenges remain in integrating multi-component interactions and achieving long-term, high-resolution climate projections. Future efforts should focus on developing fully coupled models that incorporate atmosphere–ocean–sea ice–ice shelf–iceberg interactions, supported by enhanced observational networks and improved computational efficiency. This review underscores the importance of continued modeling advancement to better predict the responses of Antarctic ice shelves and polar climate to global change.

In the context of global warming, the ongoing reduction in Arctic sea ice and associated influences have become a focal point. Many studies have linked Arctic changes to extreme weather and climate events in the Northern Hemisphere midlatitudes, including cold spells, heatwaves, droughts, storms, and wildfires. However, the causality and physical pathways of the Arctic–midlatitude linkage remain controversial and highly uncertain, hindering the attribution of extremes to Arctic climate change. This study builds on extensive previous research and reviews recent progress in understanding the influence of Arctic amplification and sea ice loss on midlatitude climate variability, as well as the associated uncertainties. The impacts of Arctic changes on the midlatitude weather and climate are substantially mediated by the jet streams, Rossby waves, transient eddy-mean flow interactions, and the stratospheric polar vortex. Despite the enhanced comprehension of mechanisms and pathways, the aforementioned Arctic-midlatitude linkage remains debated. The ongoing prospection is attributed to the noise arising from intrinsic atmospheric variability, Arctic nonlinearities, lower latitude factors, and climate background state. The present study has sought to elucidate the intricacies of the Arctic-midlatitude linkage, with a particular focus on the ramifications for mean and extreme weather and climate conditions in Eurasia and North America. This study also specifically introduces discussions about the sources of uncertainty and possible underlying causes that need to be addressed.

The Fildes Peninsula is among the Antarctic regions most affected by human activity. As the interface between terrestrial and marine ecosystems, the intertidal is a gateway for ecological and public health risks. Antibiotic resistance genes (ARGs) and virulence factor genes (VFGs) intensify these risks by transferring pathogenic traits via horizontal gene transfer. However, a comprehensive assessment of ARGs and VFGs in Fildes Peninsula intertidal sediments is lacking. We addressed this gap by performing shotgun metagenomic sequencing on 14 intertidal sediments. We detected 20 ARG types comprising 397 subtypes. Multidrug, bacitracin, and polymyxin resistance dominated the resistome, although their overall abundance was relatively low. A total of 4,204 VFGs were identified and were primarily associated with adherence, motility, immune modulation, and effector delivery. The abundance of VFGs was also relatively low and significantly correlated with the abundance of ARGs. Additionally, we also identified 787 mobile genetic elements (MGEs) that carried 138 VFGs but found no ARGs associated with MGEs at the contig level. Host assignment implicated taxa such as Ilumatobacter as major ARG carriers and detected opportunistic pathogen Pseudomonas aeruginosa carrying CAM-1, a metallo-β-lactamase gene. In summary, our results reveal a highly diverse but generally low-abundance resistome and virulome in Fildes Peninsula intertidal sediments, with limited evidence for MGE-mediated ARG dissemination. However, they emphasize the necessity of monitoring to protect Antarctic microbial integrity.

As one of the most susceptible components of the global climate system, the Arctic undergoes rapid changes where aerosol properties play a pivotal role in modulating regional radiation budgets and climate feedbacks. Amid intensified Arctic amplification and expanding anthropogenic footprints, the chemical composition, sources, and cloud condensation nuclei activity of Arctic organic aerosols (OA) have emerged as critical research frontiers. This review synthesizes current knowledge on the seasonal dynamics and physicochemical evolution of Arctic OA, with a particular emphasis on secondary organic aerosols formation pathways. We evaluate the complex interplay between indigenous marine biogenic emissions, long-range transported pollutants, and episodic biomass burning. Emerging evidence indicates that the cloud condensation nuclei potential of Arctic OA is fundamentally governed by their molecular-level oxidation state and phase state, which collectively reshape cloud microphysics and radiative forcing. This synthesis underscores the necessity of integrating multiphase chemistry into the aerosol-cloud climate feedback loop to bolster the reliability of climate models in the context of rapid Arctic amplification.

Using data from the T69 and T70 snow and ice mass balance buoys deployed during the MOSAiC expedition from October 2019 to August 2020, this study investigates the characteristics of Arctic sea ice movement and their relationships with atmospheric and oceanic conditions by combining with reanalysis wind velocity data, ocean current data, and satellite-derived sea ice concentration (SIC) data. The results show that sea ice movement responds sharply to the wind field, with the wind factor reaching a maximum of 0.12. Furthermore, due to the reduced consolidation of sea ice after June 2020, the wind factor varied across a range of 0.02 to 0.12. Compared to wind velocity, ocean currents were slower, with the ice-to-current velocity ratio ranging primarily from 1 to 2. Using a SIC threshold of 80% in a piecewise multiple regression model, we find that the regression coefficients of wind velocity and ocean current velocity with respect to ice velocity depend strongly on SIC. For SIC≤80%, the regression coefficients are 0.0012 (wind) and 0.837 (current); for SIC > 80%, they are 0.017 (wind) and 0.646 (current). The results align well with established theoretical models. This study offers a theoretical basis for parameterizing the coupling of the wind–ice–ocean current velocity in sea ice dynamics.

Fine-scale structures can be observed in small field-of-view (FOV) auroral observations, but they are often overlooked because they appear only sporadically in all-sky observations. Such forms are of great interest because they may embody specific magnetosphere-ionosphere coupling processes, reveal localized energy deposition pathways, and provide new insights into cross-scale plasma dynamics and instabilities. However, their limited spatial extent, transient occurrence, and scarcity in wide-FOV observations make systematic investigation challenging. Traditional manual analysis struggles to capture these subtle structures within vast all-sky datasets, while automated detection faces severe data imbalance and morphological ambiguity. To address these challenges, we propose a synthetic-to-real progressive learning framework for cross-FOV retrieval of rare auroral forms. A Generative Adversarial Network (GAN) is employed to perform cross-FOV transformation between unpaired small-FOV images containing rare aurora forms and all-sky images (ASI) without such structures, thereby generating large numbers of synthetic ASI with rare auroral morphology. These synthetic samples are used to train an initial detection model, which subsequently undergoes iterative fine-tuning through feedback-guided learning: The model performs inference on new all-sky data, and the progressively accumulated real detections are incorporated into the training set. Experimental results demonstrate that the proposed method achieves over 92% detection accuracy on ASI, enabling high-precision retrieval of small-scale auroral structures across large-scale observations. This framework provides a scalable and effective approach to rediscovering rare auroral phenomena in continuous all-sky monitoring, offering new opportunities for exploring the fine-scale dynamics of the upper atmosphere.

Against the background of global warming, especially the “Arctic amplification”, there has been a tension between the availability and economics of Arctic oil and gas resources and the extreme environmentality stipulated by the carbon neutrality goal. The research object is the interactions between China and Arctic oil and gas resources under the carbon neutrality goal. And China’s carbon neutrality process is proposed to be divided into four periods: 2020–2030, 2030–2040, 2040–2050, 2050–2060. The study finds as follows. First, the conflict between Russia and Ukraine has disrupted the existing interdependence between Russia and Europe in energy. Meanwhile, China and India both have uninterrupted demand for Arctic oil and gas resources from Russia. All has led to a new narrative on global energy security. Second, the possibility of ice-free Arctic Ocean in summertime makes the expansion of the navigation period of the Arctic shipping lanes possible. It has both advantages and disadvantages for China in Arctic energy consumption. Third, as the proportion of clean energy increases in China’s final energy consumption structure, China’s total demand for Arctic oil and gas resources declines correspondingly. Hence, China plays an independent role in the co-opetition with the United States and Russia. Fourth, by 2060, the co-opetition relationship between China, the United States, and Russia will undergo almost fundamental changes in the Arctic region. Those changes will be reflected in China’s increasing influence in Arctic energy distribution. Compared to typical research articles solely focused on the energy, this study has obviously theoretical, practical and methodological values.

To investigate the use of the three-point bending method and supplement the corresponding strength data of compacted snow for transportation-related applications in cold regions, compacted snow beams with an average density of 592?kg·m^?3 were fabricated and tested at three distinct flexural strain rates. Each strain rate corresponded to the ductile, transitional, and brittle behavior of compacted snow, respectively. The flexural strength, ranging from 0.518 to 0.933 MPa, peaks at the ductile-to-brittle transition, while the flexural modulus, varying between 48.97 and 287.72 MPa, increases with strain rate within the tested range. At the same strain rate corresponding to brittle failure, both mechanical properties of compacted snow exhibit higher values than those of natural snow tested by the authors. Notably, the flexural strain rate at the ductile-to-brittle transition for compacted snow identified in this study is comparable to those previously reported for natural snow under uniaxial tension. Additionally, the obtained strength data are thoroughly compared with existing literature, with detailed discussions provided. The loading rates associated with typical failure modes of compacted snow under bending, together with the obtained strength values, provide methodological guidance and reference data for future in situ testing of compacted snow structures.

The correlation between the Soil Moisture and Ocean Salinity (SMOS) L-band brightness temperature and thin sea ice thickness has been widely exploited using semi-empirical retrieval approaches based on a single-tie point (STP). However, due to pronounced spatial heterogeneity in seawater and sea ice properties across the Arctic, the use of an STP often leads to regionally biased. To address this limitation, this study proposes a multi-tie point (MTP) sea ice thickness retrieval method based on SMOS brightness temperature and sea ice concentration time series. Multiple seawater and sea ice tie-point values are identified through point-by-point time series analysis, quality control, and statistical hypothesis testing, allowing spatial variability in radiometric properties to be explicitly considered. The MTP-based retrieval is applied to Arctic freeze-up conditions. Validation against independent SMOS thin sea ice thickness products shows that the MTP approach yields significantly reduced bias and root mean square error compared with the conventional STP method, with statistically significant improvements confirmed by paired t-tests. While retrieval accuracy stabilizes beyond a certain number of tie points, the preprocessing cost associated with tie-point selection increases substantially. Considering both accuracy and efficiency, the MTP framework provides a practical and robust approach for large-scale Arctic thin sea ice thickness retrieval and enables improved characterization of regional freezing processes and maximum ice thickness.

Research on Antarctic microbial diversity has primarily focused on 3 areas: freshwater lake sediments, penguin colonies, and seawater in ice-free regions. There is a scarcity of research on the impact of slopes on microbial community structure, and this study effectively fills this gap. This study focused on the soil in the sparse vegetated tundra on a hillside near the southern coastline of the Antarctic Great Wall Station. The influence of slope position, soil physicochemical properties, and vegetated area on soil bacterial community structure was analyzed. High-throughput sequencing technology was employed to characterize a 16S rRNA gene fragment in soil samples from 5 slope areas and estimate bacterial abundance. Calculation of α-diversity and β-diversity indices, and community structure analysis were used to compare the species richness among sampling points, analyze similarities in soil bacterial community structure and composition, and identify the core bacterial population. In the non-vegetated area, the soil on the mountaintop, hillside, and at the foot of the slope showed similar physicochemical properties. In the vegetated area, the soil physicochemical properties were highly similar on the mountaintop, hillside, the foot of the slope, and the foot of the mountain. Weighted Gene Co-expression Network Analysis showed that total organic carbon, pH, and PO₄^3–-P might affect the structure of bacterial communities at the sampling point by changing the relative abundance of Chthoniobacterales, Sediminibacterium, and Actinobacteria. We hypothesize that slope-driven nutrient transport, amplified by vegetated areas (in the tundra), is a primary driver of bacterial community structure in the Antarctic tundra soil. These results provide insights into the impact of slope on microbial community structure in Antarctica.

The Arctic tundra permafrost region is a critical zone for mercury (Hg) biogeochemical cycling. This review systematically synthesizes the sources, transport, and transformation of Hg in Arctic tundra permafrost environments and their responses to climate change. Vegetation uptake of atmospheric gaseous elemental mercury and subsequent litterfall deposition constitute the dominant Hg input pathway, accounting for approximately 70% of total ecosystem Hg deposition. Arctic permafrost stores vast amounts of Hg bound to organic matter, representing a globally significant Hg reservoir. Satellite observations reveal accelerated permafrost thaw and a sustained increase in the normalized difference vegetation index over the past four decades. Active layer deepening and thermokarst development remobilize previously sequestered Hg, delivering it via riverine transport and coastal erosion to aquatic ecosystems, where microbial methylation produces toxic methylmercury, thereby increasing Hg exposure risks for Arctic indigenous communities and wildlife. The complex feedbacks between vegetation succession and permafrost degradation may jointly regulate terrestrial–atmosphere Hg exchange and the subsequent transport and transformation of Hg. However, the response of vegetation-mediated Hg sequestration to environmental change and the mechanisms of Hg remobilization during permafrost thaw remain poorly understood. Future research should prioritize long-term continuous Hg flux observations coupled with isotope tracing to elucidate coupled vegetation–permafrost Hg dynamics, identify microbial drivers of methylation and demethylation in thermokarst wetlands and lakes, and integrate modeling to assess regional- to global-scale impacts of permafrost Hg release.

Antarctic krill (Euphausia superba), widely distributes around Antarctica, is a key species supporting the biodiversity of the Southern Ocean ecosystem. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) has thus managed the krill fishery according to a precautionary way. Currently, CCAMLR is making effort to develop a refined krill fishery management approach based on more solid science, which requires accurate predictions of krill distribution. To address this need, this study investigated the effects of algorithm and spatial resolution on the performance of Antarctic krill distribution modelling. We integrated acoustic data from 4 surveys conducted in the waters adjacent to the Antarctic Peninsula with 11 environmental variables characterizing krill prey conditions, water mass properties, and seafloor topography. These data were processed at 4 spatial resolutions (5, 10, 15, and 20 km) to fit distribution models using 4 algorithms: Random Forests (RF), Generalized Additive Models (GAM), Extreme Gradient Boosting (XGBoost), and Artificial Neural Networks (ANN). Model performance was assessed and compared in terms of goodness-of-fit and predictive accuracy. The results showed that RF achieved the highest predictive performance at most resolutions, whereas GAM performed best at the coarsest resolution (20 km). XGBoost closely following RF in accuracy and demonstrated robustness as evidenced by the highly consistent partial dependence curves across resolutions. In contrast, ANN exhibited limitations with smaller sample sizes, resulting in comparatively poorer predictive performance. The analysis revealed a trade-off whereby reducing spatial resolution improved model fit and mitigated zero-inflation at the expense of fine-scale information and overall predictive accuracy. Ensemble models, integrating RF, GAM, and XGBoost, are proposed as potential balanced solutions to improve predictive stability, offering a more robust scientific basis for the refinement of krill management.

A polyketide synthase–nonribosomal peptide synthetase gene cluster?twn?in?Talaromyces sp. HDN1820200?was activated by overexpression of the pathway-specific transcriptional factor TwnD. Large-scale fermentation and chemical investigation of the mutant strain?HDN1820200/TwnD led to the discovery of one new polyketide–amino acid conjugate, bipolamide C and one new polyketide compound, variotin A. The structures of the new compounds were determined by nuclear magnetic resonance (NMR) analysis, high-resolution electrospray ionization mass spectrometry, feeding experiments, NMR calculation and DP4⁺ analysis. This study revealed that the overexpression of the pathway-specific transcriptional factor represents a promising approach for the discovery of new natural products in fungi within specialized habitat.

Understanding microbial responses to polycyclic aromatic hydrocarbon (PAH) pollution is crucial for assessing the current status of PAH contamination in polar regions. In this study, intertidal and marine sediments were enriched with a mixture of PAHs (naphthalene, phenanthrene, fluorene, pyrene, and fluoranthene). Isolation of culturable bacteria, high-throughput sequencing, and functional prediction were combined to systematically analyze bacterial structural and predicted functional responses to PAH exposure. High-throughput sequencing results showed that the relative abundance of Proteobacteria was significantly increased after enrichment, and Pseudomonas and Acinetobacter were identified as dominant genera under PAH exposure. These findings were consistent with the 19 potential PAH-degrading strains (mainly Pseudomonas) that were successfully isolated from enrichment cultures. Distinct bacterial taxa between enriched marine and intertidal sediments indicated the existence of distinct PAH-degrading groups. PICRUSt2-based functional predictions suggested higher predicted abundances of PAH-degradation pathways in polar sediments, likely through the preferential degradation of parent PAH compounds in response to elevated concentrations. This study provides valuable data on microbial responses to PAH pollution in polar regions and offers new insights for evaluating ecological hazards induced by PAHs.

The Antarctic geodetic datum constitutes a specialized implementation of the modern geodetic reference system within the extreme polar environment. A high-precision, unified, and dynamic Antarctic geodetic datum serves as critical infrastructure for polar scientific research and engineering safety. This study reviews the composition, current status, and implementation pathways of the Antarctic geodetic datum through four dimensions: coordinate datum, height datum, gravity datum and sounding datum. Preliminary analysis reveals that the development of the Antarctic geodetic datum framework is severely lagging, thereby failing to meet the demands of both scientific expeditions and polar research. To address these challenges, this study proposes an implementation pathway leveraging the 5th International Polar Year (IPY-5) to pioneer regional high-precision geodetic datum in the China’s key research sector covering the area between Amery Ice Shelf and Princess Elizabeth Land, specially highlighting the Prydz Bay–Amery Ice Shelf–Lambert Glacier–Dome A (PANDA) transect, by deploying multi-technique stations and μGal-level superconducting gravimeter networks; and then to integrate multinational observation resources to ultimately establish a high-precision, unified, and dynamic geodetic datum framework. This framework will deliver a spatiotemporal infrastructure for Antarctica to advance the strategic goals of “understanding, protecting, and utilizing Antarctica”.

This study investigates the potential formation of subglacial lakes beneath the glaciers of the Franz Josef Land archipelago, Russian Arctic, under current and future climatic conditions. Using a one-dimensional heat and mass transfer model, the research evaluates the influence of geothermal heat flow, ice thickness, and surface temperature on basal melting. The model incorporates enthalpy formulation and boundary conditions derived from field data, including temperature profiles and geothermal measurements. Results indicate that subglacial lakes could form under ice masses exceeding 300 m thickness, driven by geothermal heating, though current basal temperatures remain below the melting point. Simulations under the IPCC SSP1-2.6 scenario suggest a gradual warming trend, highlighting the long-term thermal inertia of Arctic glaciers. The study underscores the need for enhanced observational data to validate models and improve predictions of glacial dynamics in response to climate change.

Small RNAs (sRNAs) are important non-coding RNAs that usually play crucial roles in gene expression at the post-transcriptional level. The sRNAs have mostly been investigated in model microorganisms such as Escherichia coli and some pathogens. Nevertheless, microbial sRNAs from extreme environments such as the polar regions and deep sea have recently been discovered and analyzed for their unique roles in stress response, metabolic regulation and adaptation to extreme environments. These sRNAs fine-tune gene expression during oxidative and radiation stress, and modulate temperature and osmotic pressure responses. Representative sRNAs and their functions in thermophilic, psychrophilic, halophilic and radiation-tolerant bacteria are summarized in this review. Despite challenges in sample collection, RNA isolation, and functional annotation, the study of sRNAs in extreme environments provides opportunities for discovering novel regulatory mechanisms, applying them to biotechnology, and advancing our understanding of evolutionary adaptations. Looking ahead, high-throughput sequencing, synthetic biology, and multi-omics integration will bring new breakthroughs in discovering novel sRNAs and their functions and regulatory mechanisms. Such advancements are poised to enable comprehensive characterization of sRNA-mediated regulatory networks in extremophiles and unlock their biotechnological potential through mechanism-driven applications.

Icy moons such as Europa and Enceladus are, beyond Earth, our solar system’s planetary bodies most conducive to support life and to contain the remnants of past life. Earth’s polar analogs prove that life can thrive in niche-specific conditions similar to those of subsurface oceans on the icy moons. Still, key microbiological questions remain that must guide our next steps in probing for life in future space missions. Research in polar microbiology can further illuminate or define possibilities of life in icy worlds.

Phytoplankton play a pivotal role in the Southern Ocean ecosystem. This study examines the phytoplankton community structure and the environmental factors driving it in the Cosmonaut Sea, based on samples collected using a net during the summer of 2020/2021. We identified 99 phytoplankton species, predominantly comprising diatoms and dinoflagellates. Among these, diatoms—notably Pseudo-nitzschia, Chaetoceros, and Fragilariopsis, dominated the community in terms of species richness, abundance, and biomass. Endemic species of the Southern Ocean, such as Corethron pennatum, Proboscia alata, and Cylindrotheca closterium, also made significant contributions. Phytoplankton abundance and biomass showed similar spatial distribution patterns, with hotspots in the northern section of the survey area that gradually diminished towards the coastal regions. The oceanic area exhibited low phytoplankton diversity but pronounced regional variations in community distribution, with the northern region emerging as a key zone for abundance, biomass, and diversity. Nutrient distribution was identified as the primary environmental driver shaping the phytoplankton community, with silicate levels having a significant negative impact on overall phytoplankton abundance and the dominant species.

Samples for this study were collected from Geologists Island and Prydz Bay in different seasons. Otolith sections were analyzed for elemental composition in the nucleus, juvenile, and edge areas. Elements including Mg, Sr, P, K, Fe, and Zn, normalized to calcium (C_Me/C_Ca), were selected for analysis. To explore population structure, we studied factors influencing population dynamics during life stage, and regional distribution characteristics. For identified individual origins and explored the distribution and migration between regions and migration from hatching to adulthood provide a basis. So as to understand the distribution and migration pattern of Pagothenia borchgrevinki across various life history stages. Results indicated a consistent P. borchgrevinki population spawning across various regions of Southern Ocean, with eggs distributed at the bottom. Coastal slope topography changes and water compensation facilitated egg transportation from the bottom to under sea ice during hatching to juvenile stages. Long-distance migration was facilitated by the Antarctic Circumpolar Current and regional currents during development to adulthood. Multiple spawning grounds and ocean currents contributed to diverse distribution environments during the hatching period. Differences in individual development were important factors during the juvenile period, while ocean currents and autonomous behaviors influenced regional transportation patterns in the post development stages. Therefore, the research holds that differences in distribution environment and behavior during each period led to distinct factors influencing C_Me/C_Ca variations.

The cryosphere on the Qinghai-Tibet Plateau (QTP) is undergoing continuous and rapid shrinkage due to rapid climate warming. Such retreating has resulted the massive release of toxic pollutants (e.g., mercury, microplastics, halogenated organic compounds) and pathogenic microorganisms previously “frozen” in glaciers and permafrost. The releasing pollutants play an important role on regional water security, ecosystem stability, and sustainable development. Studies have revealed toxic pollutants (e.g., mercury) and new contaminants (e.g., microplastics) in the glaciers, soils, and rivers and lakes of the QTP. The total mercury export flux from glacial runoff is approximately 50 kg·a^?1, with microplastic release reaching around 10¹⁴ items·a^?1. The mercury storage amounts to be about 86.6 Gg in the upper soil layer (0–3 m) of the plateau’s permafrost. The reserve of halogenated organic compounds is estimated to be about 176 Gg (0–3 m soil layer), over 85% of these non-extractable residual halogenated organic compounds are physically sequestered, exhibiting higher release potential compared to chemically bound forms. Permafrost thaw slumping can result in an estimated 2,900 kg of mercury release, which may also increase the risk of releasing “dormant” pathogenic microorganisms. These processes pose potential threats to the water quality security of some rivers and lakes on the plateau. In the future, the QTP will continue to warm, leading to cryosphere shrinking. Consequently, the release of toxic pollutants from the retreating cryosphere will enhance, and their transport to downstream water system will exacerbate potential risks to water resource and ecological environment. It is therefore urgent to establish a comprehensive monitoring network for cryosphere-associated pollutants across the QTP, coupled with modeling framework. This will enable to characterize the distribution, migration and environmental effects of released pollutants, further providing scientific and technological support for estimating the potential environmental risks arising from cryosphere melting.

Antarctic waters are vital feeding grounds for many cetacean species, and their use is closely tied to broader ecosystem health, with whale distribution reflecting prey abundance and climate-driven changes in sea ice cover. Photo-identification studies, which rely on identifying individual whales through their distinctive markings, help to understand distribution patterns, migration routes, and habitat preferences. This study summarizes whale sightings along the Western Antarctic Peninsula (WAP) and re-sighting patterns of humpback whales (Megaptera novaeangliae). Results from the cruise conducted in summer 2023 indicate that baleen whales (Balaenopteridae) were the most abundant, with encounter rates of 0.33 individuals per nautical mile for humpback whales and 0.027-0.029 individuals per nautical mile for Balaenoptera spp. Group size of the sighted baleen whales varied between 1 and 8 individuals. Over 30,000 images were taken and 35 humpback whales identified. Comparison of these identified individuals with the images of whales from Happywhale web-based platform resulted in 12 matches, providing information on intra- and inter-annual site fidelity and migratory patterns. Intra-annual matches revealed an average residence time of 20 days, while several individuals were re-sighted across different years, indicating recurring presence within the Western Antarctic feeding grounds. These results underline the importance of continuous monitoring to better understand whale behaviour and population dynamics and to inform conservation efforts in the Southern Ocean.

permafrost丨monitoring丨GPR丨Antarctic oases丨Queen Maud Land丨 Novolazarevskaya Station