Estimating winter turbulent heat fluxes over the North Water Polynya and surrounding sea ice using ERA5 and ASRv2 reanalysis data (2005–2016)

The North Water Polynya (NOW) is one of the largest and most productive polynyas in the Arctic. Compared to the surrounding sea ice, the combination of high winds and cold air, together with the thin ice or open water surface of the NOW, produces large turbulent heat fluxes (THFs). The accurate estimation of these parameters requires high-resolution atmospheric data, which can be provided by the reanalysis products from different sources. In this study, we calculated the winter latent heat flux (LHF) and sensible heat flux (SHF) over the NOW and its surrounding sea ice area from 2005/2006 to 2015/2016 using high-resolution (15 km) Arctic System Reanalysis version 2 (ASRv2) data and low-resolution (30 km) European Centre for Medium-Range Weather Forecasts ERA5 data. Results show that the LHF/SHF over the surrounding sea ice is about 82%/88% lower than over the NOW, as estimated using either dataset. Furthermore, within each area, the difference in the THFs estimated from the two datasets is small. The spatial distribution of the LHF/SHF estimated from both data sources is similar to that of sea ice concentration. The average LHF/SHF in the polynya obtained using ASRv2 data is only 5%/7% higher than that from the values obtained using ERA5 data. This is because the wind speed and air temperature from the ASRv2 data are higher than those of ERA5, and their effects on the THFs can cancel each other out. Furthermore, the estimated THFs do not necessarily improve with the refined resolution of ASRv2

Reception of Germany's new Arctic Policy Guidelines (2024)

In September 2024, the new German Arctic guidelines were published, which are likely to shape German Arctic policy for four to five years. This was preceded by interdepartmental coordination and a cabinet decision by the German government.1 The very title “Germany’s Arctic Policy Guidelines- Germany and the Arctic in the context of the climate crisis and the “Zeitenwende” gives an initial indication that the new guidelines are part of a series of guidelines and strategy documents updated after the “Zeitenwende,”2 not least the “National Security Strategy” from June 2023,3 which is referred to twice in the new guidelines.4 In addition to the Arctic guidelines, only two other regions are covered by the German government with their own strategy documents: China and Africa.5 This underlines the importance that the Federal Government attaches to the Arctic, even though Germany is not an Arctic state and, therefore, only has observer status in the Arctic Council (AC). The choice of the term “guidelines” instead of “strategy” reflects this idea as a form of de-prioritization of the subject matter, both internally and externally. Due to the foreseeable importance of the guidelines, the most important changes to the previous guidelines are presented first. The media, scientific, and expert perception of the new guidelines is then recorded. The focus is not on the actual behaviour of the federal government

Shipping decarbonization governance in Arctic waters: theoretic logic and implementation pathways

The accelerated decline of Arctic sea ice since the 1980s has paradoxically amplified greenhouse gas (GHG) emissions through increased shipping activities in this ecologically vulnerable region. This study investigates how to reconcile the decarbonization of Arctic shipping with conflicting environmental, economic, and geopolitical interests. Through systematic literature review and interest-balancing analysis, our findings identify three systemic barriers: (1) inadequate adaptation of International Maritime Organization (IMO) regulations to Arctic-specific environmental risks, (2) fragmented enforcement mechanisms among Arctic and non Arctic States, and (3) technological limitations in clean fuel adoption for ice-class vessels. To address these challenges, a tripartite governance framework is proposed. First, legally binding amendments to International Convention for the Prevention of Pollution from Ships (MARPOL) Annex VI introducing Arctic-specific Energy Efficiency eXisting ship Index (EEXI) standards and extending energy efficiency regulations to fishing vessels. Second, a phased fuel transition prioritizing liquefied natural gas (LNG) and methanol, followed by hydrogen-ammonia synthetics. Third, enhanced multilateral cooperation through an Arctic Climate Shipping Alliance to coordinate joint research and development in cold-adapted technologies and ice-route optimization. By integrating United Nations Convention on the Law of the Sea (UNCLOS) obligations with IMO Polar Code implementation, this study advances a dynamic interest-balancing framework for policymakers, offering actionable pathways to achieve Paris Agreement targets while safeguarding Arctic ecosystems

Comprehensive analysis of seismic activity on King George Island, Antarctica: insights from the September–October 2020 seismic swarm

A seismic swarm occurred southeast of King George Island, South Shetland Islands, Antarctica, between August 2020 and February 2021. This work intends to parameterize seismic events recorded by seismic station AM.R4DE2 from 15 September to 31 October 2020. Using the localization methodology with a single station, the record of the entire period was analyzed manually to determine the local magnitude, hypocentral distance, epicentral distance, backazimuth, and location of the epicenter for each event. We could parameterize 6362 events, although we estimate the occurrence to be around 20000 for the period. The results suggest a magmatic origin for the swarm, supporting previous studies. Seismicity exhibited a southeastward migration away from King George Island, as indicated by a progressive increase in epicentral distance over time. Most events were classified as volcanic and volcano-tectonic, supporting a magmatogenesis hypothesis linked to the opening of Bransfield Ridge

Pathways

The Arctic Council Magazine. A biennial publication of the Arctic Council Secretariat. Issue 2, May 202

The Kingdom of Denmark's Chairship - Greenland, Faroe Islands, Denmark

An overall ambition will be to have an inclusive Chairship and to bring the work of the Arctic Council close to the peoples and citizens living in the region who must have an impact on the activities in the region, particularly on how sustainable development is interpreted and advanced. Recognizing that Indigenous Knowledge and perspectives are essential to understanding and managing changes in the Arctic, strong integration of Indigenous Knowledge alongside scientific insights in the work of the Arctic Council will be a priority. A special focus will be given to advancing sustainable development in Arctic communities and economic empowerment of Indigenous Peoples

Pendulum routes in the Northeast Passage: design and economic analysis

Global warming has made the regular operation of Arctic routes possible. This study selects hub ports based on infrastructure conditions and sea ice status, and then designs two pendulum route solutions for the Northeast Passage according to the distance between hub ports and ice-covered areas. We employ an evaluation framework combining annual profit metrics with discounted net present value (NPV) analysis, conducting probabilistic economic assessments through Monte Carlo simulations (20,000 iterations). Key findings indicate that (1) both solutions demonstrate >90% probability of economic viability and (2) Solution I′, with hub ports closer to ice-covered areas than those in Solution II, yields 5.02% higher mean annual profit and 4.69% greater NPV. The results indicate that pendulum routes in the Northeast Passage can achieve economic benefits by enabling year-round regular operations. Moreover, shorter shipping distances between hub ports and ice-covered areas enhance economic viability

Design of China’s ice-class fleet scale and economic viability assessment under normalized operation of the Northeast Passage

Global warming has led to a gradual extension of the navigable window for the Arctic Route, providing a realistic possibility for the normalized commercial operation of the Northeast Passage (NEP). Based on the changes in the navigable window of the NEP, Russia’s proposed nuclear-powered icebreaker construction scheme, and China’s potential development of a moderately sized ice-class fleet, this study establishes three scenarios for the commercial operation of the NEP. These scenarios include: (a) normalized summer operational scenario (from July to October each year), (b) normalized summerautumn operational scenario (from June to January of the following year), and (c) normalized year-round operational scenario (12 months per year). The cargo transportation potential of the NEP under three normalized operational scenarios was predicted based on the grey prediction model. On this basis, construction scale plans for China’s ice-class fleet to meet cargo transportation demands under the three normalized operational scenarios were designed. The economic benefits of different plans were evaluated using a profit-maximization linear programming model. The research results show the following: (1) The cargo transportation potential of the NEP demonstrates a rapid growth trend in the future, with annual throughput under year-round normalized operations expected to exceed 100 million tonnes and reach 297 million tonnes. (2) Under different normalized operational scenarios, the fleet scale and vessel type composition vary. Under the normalized summer operational scenario, the optimal scale for China’s ice-class fleet is 20 vessels, consisting solely of ships classed as PC7 by the International Association of Classification Societies (IACS). Under the normalized summer-autumn operational scenario, the optimal fleet scale is 31 vessels, including 30 IACS PC7 ships and 1 IACS PC3 ship. Under the normalized year-round operational scenario, the optimal fleet scale is 45 vessels, composed of 30 IACS PC7 ships, 8 IACS PC3 ships, and 7 IACS PC2 ships. (3) Among the three normalized operational scenarios, the normalized year-round operational scenario yields the best economic benefits for the fleet scale, while the normalized summer operational scenario yields the lowest economic benefits

Evaluating the impact of the BBNJ Agreement on regulatory gaps in a competent IFB: a case study of MGRs management in the Antarctic Treaty Area

On 19 June 2023, the Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction (BBNJ Agreement) was adopted. The BBNJ Agreement aims to regulate the conservation and sustainable use of marine biodiversity in areas beyond national jurisdiction, including the high seas and the international seabed area. The BBNJ Agreement enters into an already crowded institutional landscape as a global authority with broad objectives, inevitably interacting with existing institutions, frameworks, and bodies (IFBs). Existing research has primarily focused on two areas: the first examines the impact of the institutions established by the BBNJ Agreement on existing marine governance IFBs; the second explores its influence on issues currently lacking institutional arrangements. However, comparatively little attention has been given to the Agreement’s potential impact on governance gaps within established systems. This paper takes the case of marine genetic resource (MGRs) management in the Antarctic Treaty Area to explore how the BBNJ Agreement may address regulatory gaps in a competent governance framework. Due to shortcomings in addressing core issues, concerning the legal status of MGRs access regulations, benefit-sharing mechanisms, and disclosure of origin, the Agreement is unlikely to have a significant impact on the governance of MGRs in the Antarctic Treaty System (ATS) in the short term. On the other hand, the ATS, as an effective governance framework for the Antarctic Treaty Area, has mature regulations and practical experience in Antarctic governance. Over the years, the ATS has focused on regulating bioprospecting activities as scientific research ones and strict environmental impact assessment procedures. However, there has not been an effective consensus on the regulation of commercial biological prospecting. This paper further explores the coordination issue between the BBNJ Agreement and the ATS, suggesting that in the future, MGRs governance in the Antarctic Treaty Area may evolve into a polycentric governance system

Spatiotemporal characteristics of population structure for Antarctic krill (Euphausia superba) during austral summer in Amundsen Sea

This paper was based on data collected during the 38th and 39th Chinese National Antarctic Research Expeditions in the Amundsen Sea. The spatiotemporal distribution patterns of length (total length, AT) and sexual maturity stages of Antarctic krill (Euphausia superba) were examined. The age structure and geographic distribution of cluster groups also were studied. The results reveal significant diurnal variations in the length and maturity stages of Antarctic krill during the morning (MRN) to morning twilight (MTW) period, with mean lengths ranging from 28.92 to 45.87 mm. Two cyclical patterns were observed. Regarding maturity stages, the krill were composed of juveniles, adult males, and adult females in increasing order of proportion, with a notably higher proportion of non-gravid females compared to gravid females, and mainly distributed in evening twilight (ETW) to dawn (DWN), MTW to day (DAY), MRN to MTW, MRN to MTW and night (NIT) to DAY periods, respectively. Significant spatial variations in krill length and maturity stages occur, with a marked regional boundary around 130°W. K-means clustering analysis of krill length identified Group I, Group II, and Group III, with dominant age classes of 3+, 0 and 3+, and 3+ to 4+, respectively. Group II was widely distributed in the surveyed waters, whereas Group I and Group III were distributed only in waters west of 130°W. The study area features a significant continental slope, where adults and gravid females were primarily distributed on its slopes and to the south. This spatial pattern also profoundly influenced the distribution of different cluster groups