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    30 September 2023, Volume 35 Issue 3 Previous Issue    Next Issue

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    The main characteristics of Antarctic total column ozone during the depletion and recovery periods and their relationship with stratospheric circulation
    Li Jiayao, Zhou Shunwu, Yang Cheng, Deng Zhongren, Yao Yao, Sun Yang
    2023, 35 (3):  337-351.  DOI: 10.13679/j.jdyj.20220430
    Abstract ( 801 )   PDF (2290KB) ( 511 )  

    In the 21st century, total column ozone (TCO) over Antarctica has been recovering. Based on the Bodeker Scientific Filled TCO (BS-TCO) datasets and ERA5 reanalysis datasets covered by 41 years (1979–2019), the main characteristics of Antarctic TCO and stratospheric circulation during the austral spring (September–November) are analyzed separately in the late 20th century (1979–1999, depletion period) and the early 21st century (2000–2019, recovery period). The relationship between stratospheric circulation anomalies and TCO and the possible effect of planetary waves on TCO variations are discussed in each period. Results indicate that (1) Antarctic TCO has strongly decreased during the depletion period, at a rate of 51.5 Du×(10 a)−1, and continuously increased during the recovery period, by 14.2 Du×(10 a)−1. Significant correlations are calculated between TCO and stratospheric each factor: polar stratospheric clouds (PSC) area, lower-stratospheric temperature, mid-stratospheric geopotential height, and mid-stratospheric zonal-mean zonal wind at 60°S, which all experience rapid variations during the depletion period and slow variations during the recovery period. (2) Over the total analysis period, relationships between TCO and temperature, geopotential height, and zonal wind are significant and consistent, with stronger correlations in the recovery period. (3) The stratospheric Eliassen-Palm (EP) flux, associated with EP flux convergence and large negative eddy heat flux in the middle and upper stratosphere, is stronger than in the depletion period and induces the increased temperatures, lower geopotential heights, lower zonal wind, and the smaller PSC area, thereby explaining the Antarctic TCO recovery.

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    Enrichment characteristics and source analysis of heavy metals in Prydz Bay sediments, East Antarctica
    Jiang Wenxuan, Yu Peisong, Zhang Haifeng, Zhao Jun, Zhang Huijuan, Pan Jianming
    2023, 35 (3):  352-361.  DOI: 10.13679/j.jdyj.20220402
    Abstract ( 738 )   PDF (956KB) ( 540 )  
    Based on the analysis of heavy metal contents in the core ANT30/P1-02, collected in Prydz Bay, East Antarctica during the 30th Chinese National Antarctic Research Expedition, variations in their enrichment characteristics and sources since the last interglacial period are discussed. The results show that the change trend of heavy metal enrichment coefficient was consistent with that of the heavy metal content. Several clear differences in the heavy metal content trend were observed, and can be used to characterize the glacial cycle. Notable enrichments were measured for Pb, Zn and particularly for Ba. Conversely, Ge, Cd and Fe elements were not enriched, or not noticeable, with relatively little difference in enrichment coefficient is not obvious in the glacial period. Moreover, Ca enrichment was observed in the last interglacial period. By estimating heavy metal inputs from different sources, five sources with large differences were identified. During the last glacial period, sources of Fe and Ge exhibited notable variations. Marked source variations were also measured for Ba, Ca, and Zn, but during the last interglacial period. Fe and Ca were more affected by inputs from rocks, whereas Ge, Ba and Zn were more affected by biogenic material inputs. The large source variations observed for Fe, Ge, Ba, Zn and Ca were consistent with the measured enrichment coefficient variations.
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    Effects of two inorganic carbon removal methods for determination of reactive-iron-bound organic carbon in Antarctic marine sediments
    Huang Wenhao, Zhao Jun, Guo Xiaoze, Guo Jiaying, Li Dong, Pan Jianming
    2023, 35 (3):  362-370.  DOI: 10.13679/j.jdyj.20220403
    Abstract ( 769 )   PDF (1672KB) ( 617 )  
    The reactive-iron (FeR)-bound organic carbon (OC-Fe) in marine sediments has long-term preservation potential. Accurate determination of OC-Fe content is essential to evaluate its contribution to carbon sequestration (fOC-Fe) and to global warming. Quantitative differences between the fumigation and rinse methods, applied to estimate the OC-Fe and fOC-Fe, have not previously been assessed. In this study, the fumigation and rinse methods were used respectively to remove inorganic carbon of the original samples, after reduction experiment and control experiment for which samples are from 5 surface sediments in Prydz Bay, Antarctica. Then, the OC content was measured, and the OC-Fe content and fOC-Fe were calculated. The OC content measured with the rinse method was 34.82%±12.92%, 32.80%±15.11% and 26.15%±20.51% lower than with the fumigation method in the raw, control and after reduction samples, respectively. This implies notable dissolution of acid-soluble and water-soluble OC with rinse method, resulting in an ineffective of the control experiment. The OC-Fe content and the fOC-Fe values range obtained were significantly different between the two methods, indicating that the rinse method can partially dissolves OC bound with highly crystallized iron oxide or to low-activity iron silicate, thereby amplifying the fOC-Fe differences, and preventing accurate assessment of the OC-Fe contribution to OC in marine sediment. Therefore, fumigation method is the recommended method to remove inorganic carbon in the study of OC-Fe.
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    Numerical simulation of Marie Byrd Land ice sheet, West Antarctica,using constrained Elmer/Ice parameters

    Yang Shuhu, Lyu Jinlei, Niu Lihang, Zhang Yun, Han Yanling, Hong Zhonghua
    2023, 35 (3):  371-382.  DOI: 10.13679/j.jdyj.20220412
    Abstract ( 713 )   PDF (10853KB) ( 163 )  
    Remaining uncertainties considerably limit the simulation accuracy when evaluating the geothermal flux at the bottom of the Marie Byrd Land ice sheet, West Antarctica, and its temporal evolution. Investigating the influence of the geothermal flux on the ice sheet temperature and velocity field is essential. In this study, based on the bedrock elevation and surface elevation data from BedMachine Antarctica V2 updated in 2021, the surface temperature, surface mass balance and geothermal flux were added as boundary conditions, the diagnostic simulations of the part of the West Antarctic Marie Byrd Land (76.8°S–77.3°S, 138°W– 142°W) were conducted with the Full-Stokes, three-dimensional Elmer/Ice model. The parameters of the basal slip coefficient and Glen enhancement factor in Elmer/Ice were constrained by the remote sensing surface ice flow data from the MEaSUREs project (MEaSUREs In-SAR-Based Antarctica Ice Velocity Map) updated in 2020 by the National Snow and Ice Data Center. The root-mean-square error (RMSE) between the simulated and remotely-sensed surface ice flow velocities was used as an evaluation index to optimize model parameters for regional simulations. The minimum RMSE (4.140 m·a–1) was obtained for a basal friction coefficient of 0.1 and a Glen enhancement factor of 0.26. The ice-sheet velocity, temperature, and stress field were derived using these parameter values and several estimates of the geothermal flux. Experimental results show that the temperature field variations at the base of the ice sheet were greatly related to geothermal flux variations.
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    A 1-km digital elevation model of the Antarctic ice sheet inferred from ICESat-2 altimetry
    Fan Yipei, Wang Zemin, Zhang Baojun
    2023, 35 (3):  383-391.  DOI: 10.13679/j.jdyj.20220413
    Abstract ( 857 )   PDF (4798KB) ( 787 )  
    A digital elevation model (DEM) describes the shape of an ice sheet. It is a particularly essential data to study the Antarctic ice sheet. However, because of climate change, the West Antarctic ice sheet has suffered drastic melting that induced marked modifications of its DEM changes. Ice, Cloud and land Elevation Satellite-2 (ICESat-2) is the latest-generation satellite laser altimetry. It was launched in 2018 by the National Aeronautics and Space Administration (NASA). The onboard Advanced Topographical Laser Altimeter System (ATLAS) acquires high-density, high accuracy observations of the Antarctic ice sheet. In this study, a new DEM of the Antarctic ice sheet established by spatio-temporal fitting of ICESat-2 elevation measurements onto a high-resolution grid with a cell size of 1 km×1 km. The median, root-mean-square and decile interval of the differences between the ICESat-2 DEM derived in this study and IceBridge elevation data were –0.45 m, 17.51 m, and 17.93 m, respectively. In different slope bands, the ICESat-2 DEM accuracy was higher than that of a previous DEM also derivedo from ICESat-2 data.
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    Application of a heuristic path planning algorithm for mobile sensing units in Zhongshan Station based on a federated learning mechanism

    Wang Yuchen, Zhu Biao, Guo Jingxue, Dou Yinke, Yao Xu, Sun Yang
    2023, 35 (3):  392-404.  DOI: 10.13679/j.jdyj.20220428
    Abstract ( 791 )   PDF (12391KB) ( 554 )  

    Heuristic algorithms are widely used in path planning for mobile units. However, in specific situations (e.g., Zhongshan Station in Antarctic), restrictions in communication bandwidth, available energy, and computing power require more efficiency and independence from the mobile units to achieve their path-planning tasks. This paper proposes an improved grey wolf-optimized path-planning algorithm and a federated learning mechanism to improve the path-planning task efficiency and reduce resource consumption. A design solution for a network-switching and distributed communication facility is presented, then used as the basis for a digital twin-sensing network. Experimental results show that the hardware platform functioned in compliance with the actual task requirements, that the new heuristic path planning algorithm outperformed other algorithms in its class, and that the federated learning mechanism improved the parameter setting efficiency in the planning algorithm. The proposed model demonstrably improved the path-planning efficiency of mobile units at the Antarctic research stations. Moreover, a series of simulations and field experiments at Zhongshan Station confirmed that the proposed algorithm achieved good performance in global heuristic path planning, planning cost evaluation, and regional dynamic path planning.

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    Microbial diversity in colored snow of Ny-Ålesund, Arctic

    Han Wei, Yuan Yiyang, Li Taiyu, Zeng Yinxin, Li Huirong, Luo Wei
    2023, 35 (3):  405-414.  DOI: 10.13679/j.jdyj.20220422
    Abstract ( 797 )   PDF (822KB) ( 403 )  
    The extreme environment of the Arctic region is inhabited by numerous independent stress-resistant microbial communities. During snowmelt, algae at the snow ice interface multiply to form colored snow. To understand this specifc ecosystem, this study isolated and cultured bacteria from colored snow and white snow of Ny-Ålesund in the Arctic, sequenced their 16S rRNA genes, and analyzed algal diversity in snow samples. In total, we isolated 272 bacterial strains, belonging to Proteobacteria, Actinobacteria, Bacteriodetes and Firmicutes in 32 genera and 74 species, including 16 strains belonging to potentially new species. Actinobacteria and Bacteroidetes were successfully isolated and cultured from colored snow, but not from white snow. In colored snow, the algal communities were dominated by Sanguina nivaloides and Chloromonas nivalis, whereas the white snow communities were dominated by Monochrysis sp. and Sanguina nivaloides. The dominant betaproteobacteria in orange snow mainly related to Chlamydomonas and mutually promoted the growth of the other communities. The results showed that microbial diversity in colored snowed from the Ny-Ålesund region was high, which provided fundamental information on algal-bacterial association in colored-snow habitats.
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    Pathways of non-governmental organizations influence on Antarctic environmental decision-making and China’s response

    Liu Huirong, Xie Xinchi
    2023, 35 (3):  415-427.  DOI: 10.13679/j.jdyj.20230004
    Abstract ( 760 )   PDF (412KB) ( 613 )  
    Environmental governance is both a core issue in Antarctic international governance and one of the key goals for countries to anchor their participation in Antarctic affairs. Looking at the decision-making mechanisms for the Antarctic environment, there are leading institutions which developed the Antarctic Treaty system such as the Antarctic Treaty Consultative Meeting (ATCM), the Committee for Environmental Protection (CEP), and the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). Additionally, there is active participation from non-governmental organizations (NGOs) such as the International Association of Antarctica Tour Operators (IAATO) operating in Antarctica. NGOs have played a unique role in setting industry standards, providing scientific knowledge, participating in agenda-setting, and strengthening public opinion guidance, leveraging their advantages as non-governmental, non-profit, and international actors, further promoting the transparency and democratization of the Antarctic environmental decision-making mechanisms. As a Consultative Party to the Antarctic Treaty, China should adopt a dialectical view of the role played by NGOs in Antarctic environmental governance. While recognizing the important contributions of NGOs in Antarctica’s law-making process, we must also be mindful of the risks posed by the “governmentalization” and “capitalization” of NGOs. Moreover, China should leverage the Scientific Committee on Antarctic Research (SCAR) as a channel for strengthening scientific cooperation with NGOs, and actively encourage and guide domestic social organizations to participate in Antarctic affairs, thus enhancing Antarctic discourse power and international status in Antarctic governance.
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    Advances in stable oxygen isotopes ratio in ocean surface seawater

    Heng Fuxin, Tian Biao, Sun Weijun, Wu Xuemei, Ding Minghu
    2023, 35 (3):  428-439.  DOI: 10.13679/j.jdyj.20220410
    Abstract ( 669 )   PDF (4364KB) ( 896 )  
    Stable oxygen isotope ratio (δ18O) in ocean surface seawater is an accurate indicator of oceanic circulations. It can also be used to reconstruct paleoclimates. With the recent expansion of the sampling range and improvement in analytical techniques, research on δ18O in surface seawater has progressed markedly, yielding mainly improved knowledge of the δ18O distribution and source attribution. However, because of constraints on the range of oceanographic surveys, the spatio-temporal variations of oceanic δ18O remain incompletely characterized. In this study, the current research methods and recent progress pertaining to δ18O in ocean surface seawater were summarized, providing a reference for further research on oxygen stable isotope ratios in ocean surface seawater.
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    Study of short term forecast and medium-long term prediction of Arctic sea ice: A review

    Zha Yufan, Zhang Yu, Chen Changsheng, Xu Danya
    2023, 35 (3):  440-459.  DOI: 10.13679/j.jdyj.20220416
    Abstract ( 845 )   PDF (1958KB) ( 593 )  
    In the current global warming context, rapid changes in Arctic sea ice have a significant impact on the environment, the hydrological conditions and ecosystems of the Arctic Ocean. As an important indicator of global climate change, accurate predictions of future changes in Arctic sea ice contribute to the understanding and awareness of climate change trends in the Arctic and even globally. At present, numerical models are one of the most important means to effectively estimate future changes in sea ice, but due to the many factors affecting the accuracy of the patterns, the estimated results between the models vary greatly. Therefore, this paper sorted out the current research progress on short term forecast and medium-long term prediction models of the Arctic Ocean at home and abroad, focusing on the simulation accuracy of the key elements in the Arctic sea ice such as the concentration, extent and area, thickness and drift speed of various models. It analyzed the prediction of the future change trend of Arctic sea ice in the current stage of the model. In addition, on the basis of previous research, the research and application of future numerical models in the prediction of Arctic Ocean sea ice are prospected.
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    Review of the impacts of Arctic climate and terrestrial environment changes on industries

    Guo Hongxiang, Zhu Wenquan, Zhao Cenliang, Chen Liyuan, Xie Zhiying
    2023, 35 (3):  460-478.  DOI: 10.13679/j.jdyj.20220404
    Abstract ( 743 )   PDF (763KB) ( 620 )  
    The Arctic amplification phenomenon of global warming has aggravated the changes of climate and terrestrial environment at high latitudes, with strong impacts on industries in the Arctic and at the global scale. In this work, impacts of climate and terrestrial environment changes in the arctic region were discussed on four main industrial sectors: mining, manufacturing, construction, and production and supply. These sectors’ economic sizes in Arctic were analyzed, and the status of recent research on the impacts of environmental changes on production factors was summarized. The existing research challenges were analyzed and an outlook on research directions was provided in five dimensions: (1) impact ways of climatic and environmental changes on each industrial sector, (2) impact mechanisms of environmental changes on each industrial sector and the global industry, (3) adoption and implementation of adaptation strategies, (4) diversification of essential environmental data and improvement of fundamental analysis methods, and (5) inspirations for China to contribute to industrial activities in the Arctic. The review provides directions to improve global understanding of the Arctic and to support Chinese participation to international initiatives related to environmental protection, industrial investment, and construction in the Arctic region.
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    Design analysis for winterization of polar vessels

    Liu Zhibing, Pu Jun, Huang Jinjin, Chen Yanzhen
    2023, 35 (3):  479-489.  DOI: 10.13679/j.jdyj.20220418
    Abstract ( 929 )   PDF (4592KB) ( 1475 )  
    Freezing is the most common problem and serious for vessels operating in polar waters, because it affects ship safety and equipment operability. Therefore, ship systems and equipment exposed to cold weather must comply with the appropriate cold protection policies to achieve the required anti-icing and de-icing effects. In this study, we conducted a thorough review of the relevant winterization rules and guidelines established by the China Classification Society (CCS). We analyzed the winterization requirements pertaining to specific areas of the ship, to assess the optimal winterization technology of equipment and systems, such as engine room ventilation, ice sea chest, ballast water tank anti freezing systems and products, and deck machinery. Finally, we summarized the main anti-freezing measures to provide design guidance for ships sailing in cold areas.
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    Recent progress in the characterization of multidimensional activities of antifreeze proteins

    Shan Yanyan, Liao Li, Xu Yi, Chen Bo
    2023, 35 (3):  490-497.  DOI: 10.13679/j.jdyj.20220424
    Abstract ( 791 )   PDF (4349KB) ( 514 )  
    Antifreeze proteins (AFPs) are proteins with a variety of activities that inhibit ice crystal growth and protect organisms from low-temperature damage. In this review, we described several activities of AFPs including ice adsorption, thermal retardation, recrystallization inhibition, ice crystal morphology modification and ice adhesion activities. Furthermore, we summarized specific methodologies and current advances in AFP characterization. Finally, we discussed remaining issues, challenges, and future directions in AFP research.
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