The peer-reviewed journal Advances in Polar Science (APS) published Issue 34(1) in March 2023. This issue covers six articles, the titles and highlights of which are presented below. All papers are available online and downloaded freely, thanks to generous funding from the Polar Research Institute of China. See more details via APS website: aps.chinare.org.cn.

(1) Constraining the timing of West Antarctic Ice Sheet changes using East Antarctic ice cores

The stability of polar ice sheets—the West Antarctic Ice Sheet (WAIS) in particular—has drawn considerable attention from not only the scientific community but also the policy-makers. Thermodynamically, ice will melt under rising ocean temperature, but the non-linear nature in the polar ice sheets means that it is challenging to constrain when and how fast those changes will happen. Looking into the past geologic history and events may inform us how WAIS responded to past warming events. In this Opinion Editorial, a trans-Antarctic ice core array that extends from the North Victoria Land to the Hercules Dome and dates back to the Last Interglacial is proposed. Because ice cores contain a wide range of proxies indicative of their adjacent environment and the timescales of ice cores can be synchronized by various geochemical markers within, it is hoped that the timing of WAIS changes in the Last Interglacial can be better constrained.

(2) Temporal and spatial variation characteristics of Antarctic sea ice and the causes of its record decline during 2015–2016: a review

Sea ice extent (SIE) anomalies in the Southern Ocean and other regions except the Amundsen-Bellingshausen Sea both increased before 2014 and decreased after 2014, while SIE anomalies in the Amundsen-Bellingshausen Sea decreased before and after 2014. The rapid decline of Antarctic SIE from 2015 to 2016 is caused by the direct thermal and dynamic effects of atmosphere and ocean, as well as by the effects of climate variabilities. Zonal wave number 3 structure in Indian Ocean, Ross Sea and Amundsen-Bellingshausen Sea from August to October 2016 generates strong meridional heat transport and favors sea ice loss. Negative Pacific Decadal Oscillation (PDO) during 2014 and 2016 strengthens westerlies, causing warmer subsurface water in the Southern Ocean upward through Ekman suction. And then the negative Southern Hemisphere Annular Mode (SAM) in late 2016 contributes to anomalously warm sea surface temperature and surface wind, producing the rapid decrease of Antarctic SIE.

(3) Physical-chemical and biological control of the zooplankton community in the Amundsen Sea, Antarctica  

Biotic/abiotic factors shaping the zooplankton community in the Amundsen Sea were studied. The zooplankton community was dominated by small copepods in abundance and large zooplankton (e.g. krill, large copepods) in biomass. The abundance and biomass of total zooplankton and most of the dominant species showed a positive correlation with those of phytoplankton and ciliates. Both biological and physical-chemical processes significantly affect the zooplankton community.

(4) The roles of phosphate in shaping the structure and dynamics of Antarctic soil microbiomes

Changes in soil geochemical factors upon phosphate addition were all relevant to the Antarctic microbiome structure. Links between geochemical factors and composition were significant, with soil pH showing the highest correlation. Some taxa, such as Sphingobacteriia, Sphingobacteriales and Chitinophagaceae, were more abundant in phosphate-treated soils. Co-occurrence network analysis revealed significantly increased levels of associations in all major network properties over time after phosphate supplementation.

(5) Development potential of the Northeast Passage based on a multinomial-logit-based stochastic user equilibrium model

This is a study on the Northeast Passage by applying a multinomial-logit-based stochastic user equilibrium (MNL SUE) model incorporating time value of cargo to investigate future proportions of cargo flow through the Northeast Passage and the Suez Canal Route between representative ports. A multidisciplinary model was used, as well as sea ice projections of the Arctic sea ice cover and future scenarios analysis to investigate the future navigability of the Northeast Passage. The result shows that the proportion of cargo flow through the NEP is estimated to be 68.5% under the scenario of year-round operation of the Northeast Passage, which represents considerable commercial potential.

(6) An assessment of China’s participation in polar subregional organizations

International cooperation is vital for the polar regions. China’s polar cooperation in the past tended to focus on intergovernmental and bilateral mechanisms rather than regional cooperation. However, regional and subregional cooperation is playing an increasing role in the polar regions with the rapid development of geopolitics and global climate change. Involvement in three subregional polar organizations—the Asian Forum for Polar Sciences (AFoPS), the Pacific Arctic Group (PAG), and the China-Nordic Arctic Research Center (CNARC)—in the last two decades reflects China’s improved skills and flexibility in participating in international polar cooperation and represents an exercise in the “win-win” principle under China’s Arctic Policy. This paper presents a review of the development of polar subregional cooperation, examines China’s participation in three subregional organizations and provides feasible suggestions for China’s future engagement with these organizations.

Citations

(1) Yan Y Z. Constraining the timing of West Antarctic Ice Sheet changes using East Antarctic ice cores. Adv Polar Sci, 34(1): 1-4, doi: 10.13679/j.advps.2023.0003

(2) Yang Y Y, Liu H L, Wang X D. Temporal and spatial variation characteristics of Antarctic sea ice and the causes of its record decline during 2015–2016: a review. Adv Polar Sci, 2023, 34(1): 5-16, doi: 10.13679/j.advps.2022.0022

(3) Chen H, Li H B, Zhao J, et al. Physical-chemical and biological control of the zooplankton community in the Amundsen Sea, Antarctica. Adv Polar Sci, 2023, 34(1): 17-27, doi: 10.13679/j.advps.2022.0055

(4) Tan J K, Cao H S, Liu L, et al. The roles of phosphate in shaping the structure and dynamics of Antarctic soil microbiomes. Adv Polar Sci, 2023, 34(1): 28-44, doi: 10.13679/j.advps.2022.0024

(5) Zhou X L, Hu M X. Development potential of the Northeast Passage based on a multinomial-logit-based stochastic user equilibrium model. Adv Polar Sci, 2023, 34(1): 45-55, doi: 10.13679/j.advps.2022.0056

(6) Shan Y Y, He J F, Guo P Q, et al. An assessment of China’s participation in polar subregional organizations. Adv Polar Sci, 2023, 34(1): 56-65, doi: 10.13679/j.advps.2022.0023