CONTENTS

Opinion Editorial 

A new paradigm of internal wave in the Arctic Ocean

Review 

Climate-relevant gases and their impact on the climate and environment of polar oceans

Adaptations, cultivation and commercial prospects of polar microalgae 

Articles 

Modulation of dominant thermodynamic processes and relay dynamic processes in Arctic sea ice rapid melting 

Conception and first results of the Russian National System of Background Permafrost Monitoring

Transformer-based skeleton extraction from all-sky images for estimating the number of auroral arcs

Trends & Letters 

Technologies and applications of polar air–ice–sea synergistic cooperative monitoring

XIV International Symposium on Antarctic Earth Sciences: an opportunity to share and increase our knowledge of polar geoscience research

Annoucement 

Call for papers: Special Issue “New Horizons in the Exploration of Polar Biodiversity, Ecosystem and Genetic Resources”

In the Arctic Ocean, turbulent mixing drives vertical heat flux, thereby affecting the sea ice variability. Internal wave is regarded as one of the important energy sources of mixing in this region. The high latitude and sea ice cover make internal wave in the Arctic Ocean apparently differs from that in mid- and low-latitude oceans. However, the internal wave and its underlying mechanism are less understood due to the lack of observations. This paper briefly reviews the recent studies and unresolved questions on the internal wave in the Arctic Ocean, including wind-driven near-inertial wave, internal tide, and high-frequency internal wave. The aim is to provide new insights for in-depth research in the future, with a focus on the mechanisms responsible for the evolution of internal wave under the rapidly changing Arctic climate.

Because of their effect on climate, carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and dimethylsulfide (DMS) are collectively designated as climate-relevant gases (CRGs). CO₂, CH₄, and N₂O are greenhouse gases contributing to global warming (positive climate feedback). Conversely, DMS is involved in the generation of cloud condensation nuclei, thus in the formation of clouds that cool the boundary layer by reflecting incoming solar radiation (negative climate feedback). Despite their scarcity, field observations and model results have demonstrated the essential role of polar oceans in the budget of CRGs. For example, the Southern Ocean represents a substantial CO₂ sink but a source of N₂O and DMS, thereby exerting variable feedback on climate change. Unfortunately, because of the severe environmental conditions at polar latitudes, substantial knowledge gaps remain, for example on the mechanisms underlying CRGs formation or on the strength and distribution of their sources and sinks in the Southern and Arctic Oceans. Here, we review the most recent research results on the distribution, production–loss processes, and abundance variations of CRGs in the polar oceans. We list the remaining knowledge gaps and propose future directions of research on CRGs in the polar oceans, as a useful reference for future studies.

Polar microalgae are microscopic organisms adapted to survive in cold and extreme habitats such as sea-ice, glaciers, lakes and snow. These microorganisms provide an essential basis as primary food sources in polar ecosystems. Despite their ecological importance, polar microalgae remain relatively unexplored compared to their tropical and temperate counterparts, largely due to the practical challenges of obtaining and maintaining material from the harsh polar environments. However, interest has recently surged due to their specific adaptations and potential for utilization in various fields. This review explores the survival strategies of polar microalgae and their commercial applications in healthcare and other fields. We also consider the processes involved in processing polar microalgae, from cultivation to extraction of bioactive compounds. Our findings highlight a growing need for research in this rapidly evolving field to unlock the potential of polar microalgae in multiple fields.

Thermodynamic and dynamic processes (TDP) significantly modulate the rapid variability of Arctic sea ice, with complex interactions between them. This study quantifies the Arctic sea ice budget of volume from 1989 to 2021 using data from NSIDC and PIOMAS. Results show that thermodynamic processes dominate seasonal Arctic sea ice budget variation, covering 40% of the sea ice zone, strongest at the margins and in the seasonal ice zone. Dynamic processes play a relay role, contributing less than half of that from thermodynamic processes. Their influence is strongest in winter and weakest in summer, closely linked to sea ice drift circulation. TDP exhibit opposite seasonal cycles, with thermodynamic processes inversely correlated with sea ice volume changes. Dynamic processes are most negatively correlated with thermodynamic processes when they precede by 21 d. After strong thermodynamic processes, dynamic processes become more pronounced, peaking 76 d later, indicating a seasonal coupled effect where dynamic processes sustain and amplify the sea ice changes initiated by thermodynamic processes. Significant long-term trends in TDP are identified. Thermodynamic processes have increased over the past three decades, particularly in June to July and October to November. Dynamic processes decreases from June to August but increases in September. This study enhances understanding of the complex interplay between TDP modulate Arctic sea ice changes and highlights potential decadal trends under climate change.

In 2022, the Russian Federation commenced development of a national system for permafrost monitoring. The conceptual design of this system reflects three objectives: (1) to collect data on the impact of climate change on permafrost, (2) to provide data for evaluation of climate–permafrost feedback, and (3) to provide input to a model-based permafrost data assimilation system. It is intended that the system will eventually consist of 30 active layer monitoring sites and 140 boreholes situated near existing weather stations. As of October 2024, the network comprised 38 sites spanning from the High Arctic islands to the Altai Mountains and across western and eastern Siberia. Among these sites, the lowest recorded temperature at the depth of zero annual amplitude is −11.3℃ and the minimum active layer thickness is 0.3 m, as observed on the New Siberian Archipelago. In most boreholes, a positive vertical temperature gradient exists below the depth of zero annual amplitude, indicative of ongoing warming of the upper permafrost layer attributable to climate change. The annual maximum active layer thickness is observed in September with only two exceptions: at the High Arctic sites on Franz Josef Land and Wiese Island and in the low-latitude Sayan Mountain region, where maximum thawing is observed at the end of August. Talik was found in boreholes in Salekhard and Altai where the upper boundary of the permafrost is located at depth of 6–10 m.

Studying various aurora morphology helps us understand space’s physical processes and the mechanisms behind these patterns. Auroral arcs are the brightest and most prominent auroral patterns. Due to the difficulty in precisely defining auroral shape edges, auroral arc skeleton extraction is expected as an alternative representation for studying auroral morphology, resorting skeletons extract key morphological features from complex auroral shapes. Transformer models provide a better understanding of the relationship between the overall morphology and the details when processing image data, so we proposed a Transformer-based method for auroral arc skeleton extraction. Combined with ridge-guided annotation on all-sky images, a Transformer-based skeleton extractor is trained and used to estimate the number of auroral arcs. Experiments demonstrate that the Transformer-based model can more effectively capture structural information and local details of auroral arcs, which is suitable for complex auroral morphologies.

The Arctic and Antarctic regions are sensitive to global climate change. Monitoring climatological and ecological changes in such areas has become urgently necessary to address climate change and ensure sustainable human development. Therefore, it is important to develop automatic monitoring technology for polar regions and to produce air–ice–sea long-period, multiscale, and unmanned monitoring equipment. This paper describes an unmanned ice station observation system, the autonomous observation platform of a polar unmanned aerial vehicle, dual-use ice–sea buoys, temperature chain buoys, and a wind–solar–hydrogen storage clean energy system suitable for use in the extreme polar environment. Additionally, a coupled air–ice–sea autonomous observation station currently under development is also introduced.

The SCAR XIV International Symposium on Antarctic Earth Sciences (ISAES), which has been held every four years, will be held in Punta Arenas, Chile from 18 to 25 August 2025. ISAES aims to provide a comprehensive overview of the current state of Antarctic Earth Sciences. The XIV ISAES calls for researchers from around the globe to share their latest research and insights on the Antarctic region’s geology, climate, and ecosystems.