Archive

31 March 2022, Volume 34 Issue 1 Previous Issue    Next Issue

---

For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

Select

Research progress on remote sensing retrieval of chlorophyll a and primary productivity in the Arctic Ocean 2022, 34 (1):  1-10.  DOI: 10.13679/j.jdyj.20210010 Abstract ( 906 )   PDF (7755KB) ( 532 )   As important parameters of the marine ecosystem and its functional structure, knowledge of the chlorophyll a (Chl a) concentration and phytoplankton primary production is crucial for evaluation of marine ecosystem status. Understanding of the spatiotemporal changes of both Chl a concentration and primary production in the Arctic Ocean is of great importance regarding the improvement of our knowledge of the marine ecosystem and its response to ongoing climate change. Hence, in this study, we considered the various approaches that use ocean color remote sensing to estimate the Chl a concentration and primary production in the Arctic Ocean. The variations of Chl a concentration and primary production in recent years on both temporal and spatial scales were summarized to provide perspective regarding the biogeochemical changes occurring in the Arctic Ocean and their impact on the marine ecosystem. References | Related Articles | Metrics

Select

Applied research on low-altitude wind field using coherent doppler wind lidar at Zhongshan Station, Antarctic Wang Zhangjun, Wang Rui, Li Hui, Zhuang Quanfeng, Huang Wentao, Liu Fuchao, Ban Chao, Chen Chao 2022, 34 (1):  11-19.  DOI: 10.13679/j. jdyj. 20210057 Abstract ( 968 )   PDF (6125KB) ( 1172 )   The polar atmosphere plays an important role in the global atmospheric system, and the polar wind field structure and its changes are closely related to global atmospheric dynamics. For further study of both the low-altitude atmospheric wind field properties and the characterization of its spatiotemporal variations in the Antarctic, a coherent Doppler wind lidar was developed by the Institute of Oceanographic Instrumentation at Qilu University of Technology (Shandong Academy of Sciences, China), and deployed at Zhongshan Station (Antarctica) during the summer period of the 36th Chinese National Antarctic Research Expedition. After field installation and testing, routine wind lidar observations commenced on January 8, 2020. Results showed that the high sensitivity, precision, and stability of the system ensured full-time observation of the low-altitude atmospheric wind field with high spatiotemporal resolution. In this paper, we report detailed information regarding the coherent Doppler wind lidar, including its measurement principles, structural design, technical parameters, and data inversion algorithm, together with experimental results. Specifically, the data observed by the wind lidar were compared with those from an L-band GTS1 digital radiosonde. Statistical analysis of wind speed (direction) data obtained by the two instruments showed a correlation coefficient of 0.907 (0.832) and a standard deviation of 0.565 m·s–1 (6.02°), confirming the reliability of the wind data measured by the developed lidar system. Lidar data obtained as part of a typical continuous observation series were also analyzed. By comparing parts of the lidar data with meteorological data recorded at the ground station, we further demonstrated the stability and reliability of the wind field data. Thus, the developed wind lidar system represents a novel effective approach for observing the low-altitude atmosphere in the Antarctic. References | Related Articles | Metrics

Select

Comparison of remote sensing sea ice concentration products for Arctic shipping services Huang Lin, Qiu Yubao, Zhou Jingtian, Wang Changlin, Liang Xi, Li Qun 2022, 34 (1):  20-33.  DOI: 10.13679/j.jdyj.20210018 Abstract ( 1020 )   PDF (7654KB) ( 770 )   Recent rapid warming of the Arctic has promoted extension of the Arctic navigation period. However, the reliability of spatial information regarding the edge of the sea ice area, provided by remote sensing products, is critical for safe operation of Arctic shipping and polar research vessels. We compared and analyzed nine sea ice concentration (SIC) products, and used high-resolution synthetic aperture radar (SAR) data to evaluate their accuracy in determining the sea ice edge area. Results showed that the largest daily deviations from the mean values of the nine products occurred during the summer navigable window (June–August). Average deviations of ASI products with a passive microwave high-frequency algorithm and OSI SAF products with an integrated algorithm were 0.59% and −0.65%, respectively. The greatest inconsistency in spatial distribution among the nine products was found in the sea ice marginal area. In 2018, the difference between the daily maximum and minimum sea ice extent of the nine products ranged from 2.51 × 106 to 6.26 × 106 km2. The SAR data were used for comparison with the nine products in the ice margin area. In the closed pack sea ice marginal area, apart from the three products based on the ASI and NT2 algorithms, the other products overestimated (underestimated) the low (high) SIC area. The ASI and OSI SAF products based on AMSR2 sensors produced the highest correlation with the SAR data, with R2 values of 0.85 and 0.82, respectively, and root mean square errors (RMSEs) of 12.19% and 9.70%, respectively. However, in the drift sea ice edge area, all products underestimated SIC; the OSI SAF product had the highest R2 value (0.78) and lowest RMSE (6.19%). Of the nine products tested, the analysis indicated that OSI SAF products based on AMSR2 sensors could better represent the sea ice margin and low SIC areas in Arctic navigation channels. References | Related Articles | Metrics

Select

Turbulent mixing and its relationship with water mass and circulation in the upper ocean of the Weddell-Scotia Confluence, Antarctica Lin Lijin, Shi Jiuxin, Yao Chenyang, Guo Guijun, Cheng Lingqiao, Jiao Yutian, Shi Qian 2022, 34 (1):  34-50.  DOI: 10.13679/j.jdyj.20210020 Abstract ( 927 )   PDF (16304KB) ( 514 )   Based on the turbulence microstructure, Conductivity-Temperature-Depth profiler and Lowered Acoustic Doppler Current Profiler data obtained by the 32nd Chinese National Antarctic Research Expedition in the Weddell-Scotia Confluence (WSC) from December 2015 to January 2016, the spatial distribution characteristics of turbulent mixing in the upper ocean (30–500 dbar) were analyzed. Results showed that turbulent kinetic energy dissipation (ε) and turbulent eddy diffusivity (Kρ) have regional features closely related to local characteristics of the water mass and circulation. In the region of the Powell Basin edge and South Orkney Plateau, strong surface stratification strengthened by inputs of sea ice meltwater impedes turbulent mixing, which results in diffusivity to be lower than 10–4 m2×s–1, the lowest mixing level in the studied area. In the region of Bransfield Strait, where intrusion and modification of water masses from adjacent seas result in relatively weak stratification, the spatially-averaged (30–500 dbar) Kρ is 1.2×10–4 m2×s–1. Striking diffusivity profiles with values range from 3.2×10–4 to 3.2×10–3 m2×s–1, exceeding the levels in the other subregions, were found in the Hesperides Trough, the main channel of water exchanges between Scotia Sea and Weddell Sea. Extensive interactions between the complex circulations and rough/steep topography intensify turbulent mixing and enhance the homogeneity of the vertical thermohaline structure. On the slope of the South Scotia Sea, intrusions of water with different temperature and salinity properties, cause remarkably high mixing, with an average Kρ of around 1.6×10–4 m2×s–1. Further analysis revealed that the seawater stratification, instability due to vertical shear of the flow and thermohaline intrusion are important factors influencing the turbulent mixing in the WSC area. References | Related Articles | Metrics

Select

Evolution of water structure under the influence of mCDW intrusion on the continental shelf of Vincennes Bay, Antarctica 2022, 34 (1):  51-61.  DOI: 10.13679/j.jdyj.20210014 Abstract ( 897 )   PDF (6199KB) ( 915 )   Using seal CTD data obtained in Vincennes Bay (Antarctica) during March–October 2012, this study investigated the evolution of water structure on the continental shelf under the influence of the intrusion of modified Circumpolar Deep Water (mCDW) during the freezing period. Results showed obvious mCDW intrusion in the deep layer from the bay mouth to the innermost part of the bay. Effects from cooling and brine rejection during sea ice formation extended from the upper layer into the interior; however, deep layer (>400 dbar) stratification in the innermost part of the bay remained unbroken until mid-June. Under the different influences of heat brought by mCDW, the glacier front C-Zone and the polynya D-Zone of the innermost bay exhibited different water structure characteristics. From early April to June, Ice Shelf Water (ISW) persisted at depths of 300–600 dbar in the C-Zone with warm cores (θ > −1.7°C) above and below, indicating that the heat carried by mCDW causes melting of the ice shelf within this depth range, while the meltwater of the ice shelf cools the seawater. Ocean heat content in the D-Zone was substantially higher than that in the C-Zone, and ISW was found below 400 dbar only in early April. Therefore, mCDW carries more heat into the D-Zone, and melting of the ice shelf in the D-Zone might occur over a deeper range. Additionally, during the late freezing period (September – October), the vertical characteristics of the water in polynyas tend to be homogeneous, proving the existence of deep convection for the formation and accumulation of Dense Shelf Water. References | Related Articles | Metrics

Select

Accuracy validation and distribution characteristics of Arctic MODIS aerosol optical depth Yang Yanli, Chang Liang 2022, 34 (1):  62-71.  DOI: 10.13679/j.jdyj.20210028 Abstract ( 936 )   PDF (6037KB) ( 758 )   The Arctic is a highly climate-sensitive area. In recent years, the Arctic temperature has increased at twice the rate of the global average, and aerosols have a significant impact on Arctic warming. To explore the optical characteristics of aerosols over the Arctic, we analyze the characteristics of the spatial and temporal distributions of the Arctic aerosol optical depth (AOD) based on Moderate-resolution Imaging Spectroradiometer (MODIS) 10-km and 3-km AOD products from March 2000 to October 2018 and validate these products via comparisons with the ground-based Aerosol Robotic Network (AERONET). The results indicate that the correlation coefficients between the MODIS 10-km and 3-km AODs and the AERONET base station points are 0.840 and 0.853, respectively, and that the root mean square error is less than 0.1. Both the 10-km and 3-km AODs are in good agreement with the ground-based observations. The results for the correlation coefficient, root mean square error, relative mean bias, and expected error between the two AOD products and the AERONET data all show that, overall, the accuracy of MODIS 10-km AOD products in the Arctic region is higher than 3-km AOD , and both are more accurate in the Eastern Hemisphere of the Arctic than in other regions. Moreover, the accuracy of the MODIS 10-km AOD increases as the latitude increases in the Western Hemisphere of the Arctic, although no consistent pattern is observed in the 3-km AOD. Additionally, the two AOD products typically exhibit greater accuracy in May, September, and October and are slightly more accurate in spring than in summer. Moreover, remarkable AOD differences are detected between low and high latitudes in the Arctic, where AOD increases unevenly as the latitude decreases. The Arctic MODIS AOD exhibits obvious seasonal variations. Spring AOD values generally range from 0.1 to 0.3 and peak in the Nordic region in April. In summer, high AOD values extend to larger areas from June to August, while the AOD values are typically smaller than 0.1 in autumn. Moreover, the two MODIS AOD products exhibit different patterns over Arctic land and ocean areas. The MODIS 10-km AOD is usually larger over the Arctic Ocean, while the MODIS 3-km AOD is generally larger over the Arctic land areas. References | Related Articles | Metrics

Select

Analysis of the influence of liquid water content on rime and ice formation on offshore wind turbine’s blades in cold regions Cao Huiqing, Bai Xu, Yin Qun 2022, 34 (1):  72-80.  DOI: 10.13679/j.jdyj.20210021 Abstract ( 741 )   PDF (1620KB) ( 859 )   This study used Fluent and FENSAP-ICE to simulate the ice formation of offshore wind turbine blades in cold regions. The liquid water content was selected as a sensitive parameter, and the influence of the change of the liquid water content on the thickness, amount and shape of ice formation was analyzed. The results showed that when the liquid water content was in the range of 0.05–0.25 g·m–3, the amount and thickness of ice on the blade surface increased gradually. The liquid water content did not affect the type and growth trend of ice on the blade surface. Moreover, the adsorption surface between the ice and the blade did not change with the variation of the liquid water content. References | Related Articles | Metrics

Select

Study on the industrial governance of Antarctic tourism with the view of global governance Guan Song, Liu Dahai 2022, 34 (1):  81-89.  DOI: 10.13679/j.jdyj.20210061 Abstract ( 753 )   PDF (507KB) ( 897 )   The newly rising governing bodies are playing bigger roles in the global governance. The International Association of Antarctica Tour Operators (IAATO) is not only an international association, but also a new and important organization for the governance of Antarctic tourism, of which related research in China should be largely strengthened. By properly reviewing and analyzing the development of Antarctic tourism and its industrial governance, we could find that the industrial governance of Antarctic tourism has contributed a lot to the enhancement, development and implementation of the Antarctic Treaty System. The influence of IAATO in the Antarctic tourism governance should not be ignored. However, the role of China in the industrial governance of Antarctic tourism is quite weak. This unfavorable situation does not match the status of China as the second largest Antarctic tourism country. Therefore, we should pay more attention to and conduct research on the industrial governance of Antarctic tourism from the view of global governance and strengthen the role of China in the IAATO’s activities. Furthermore, we should also improve the domestic legislation in order to deal with the development trend of global governance. References | Related Articles | Metrics

Select

Shanghai’s participation in China’s polar science diplomacy Tang Yao 2022, 34 (1):  90-100.  DOI: 10.13679/j.jdyj.20210024 Abstract ( 840 )   PDF (404KB) ( 1252 )   Since the 1970s, increasing attention has been paid to subnational actors such as local government and cities in studies of international system and national foreign policy, and various theories related to city diplomacy have been proposed. Local government participates in national science diplomacy in four primary ways: twinned cities, intercity international organizations, foreign direct exchanges between cities, and city collaboration platforms. The representative event of polar science diplomacy was the conclusion of the Antarctic Treaty by 12 participating countries, which included the United States of America and the Soviet Union, during the International Geophysical Year. Subsequently, starting from nothing, China has achieved historic advances in its polar activities on small–large through polar science diplomacy. Shanghai is a gateway city via which China communicates with the Arctic and Antarctic, and it has been promoting China’s polar science diplomacy since the 1980s. The status of Shanghai as a national polar gateway city developed during the 1980s–1990s, and its foreign direct exchanges comprised mainly personnel visits. Since the beginning of 21st century, Shanghai has become an Asian polar gateway city and the forms of foreign direct exchanges have become increasingly diverse. During this transformative process, Shanghai experienced problems concerning the lack of top-level design, single form of participation and low level of foreign direct exchanges. Taking the opportunity presented by the “Fourteenth Five-Year Plan” and the preparation for the “Fifth International Polar Year”, Shanghai could further promote China’s polar science diplomacy through measures such as establishing polar twinned cities and building polar city collaboration platforms. References | Related Articles | Metrics

Select

Practice voyage and exploration of the Northwest Passage by the R/V Xuelong in Arctic Zhu Bing, Yuan Dongfang, Xia Yinyue 2022, 34 (1):  101-113.  DOI: 10.13679/j.jdyj.20210019 Abstract ( 999 )   PDF (13149KB) ( 560 )   During China’s 8th scientific expedition to the Arctic, the R/V Xuelong completed a crossing of the Northwest Passage, marking another feat that will go down in the annals of Chinese maritime history. The successful crossing of the Northwest Passage by the R/V Xuelong accumulated valuable navigational experience for Chinese shipping, and assessment of the current navigational situation of the Northwest Passage together with details of related policies and regulations are discussed in this paper. The practical experience gained during the voyage of the R/V Xuelong regarding the fundamental requirements for navigation in polar seas, including channel access and navigation methods, navigational safety, and the prevention of marine pollution, could provide reference for other shipping attempting a crossing of the Northwest Passage. References | Related Articles | Metrics

Select

Design and application of a surface water multielement real-time observation system for the R/V Xuelong 2 Chen Qingman, Xia Yinyue, Yuan Dongfang, Shen Yue, Liao Zhouxin 2022, 34 (1):  114-120.  DOI: 10.13679/j.jdyj.20210023 Abstract ( 839 )   PDF (1711KB) ( 843 )   The continuous real-time observations of multiple elements on the sea surface of seawater is the basis of marine investigation and research, especially in the case of polar icebreakers. Its often make repeated voyages over the Pacific Ocean, Indian Ocean, Southern Ocean, and Arctic Ocean, which is long-term and fixed. It is of great significance for marine investigation and research on many major scientific issues. The continuous real-time observation of multiple elements on the surface of seawater is the basis of marine investigation and research. Based on the surface water navigation observation system deployed on the R/V Xuelong, a surface water multielement real-time acquisition system, suitable for China’s modern polar scientific investigation, has been designed for the R/V Xuelong 2. The new system incorporates improved data accuracy, enhanced system integration, improved degree of automation equipment system aspects. After several polar field tests, the system was shown capable of meeting the needs of China’s ongoing polar investigations, providing stable operation, accurate observational data and low maintenance costs. The successful application of the new system will be of considerable benefit to field observation and survey campaigns conducted in the polar regions, and also provide reference significance for the construction of continuous observation systems for deployment on future scientific research ships. References | Related Articles | Metrics

Select

Design and application of integrated management system for scientific research on the R/V Xuelong Xia Yinyue, Chen Qingman, Zhu Bing, Chen Jiyu 2022, 34 (1):  121-129.  DOI: 10.13679/j.jdyj.20210007 Abstract ( 740 )   PDF (1468KB) ( 999 )   This paper describes the development of an integrated management system for scientific research, oriented to China’s strategic polar objectives, specific to the R/V Xuelong scientific research vessel. In accordance with the requirements of the navigational and scientific operations of the R/V Xuelong, and through conducting design and application research in relation to operations in regions of floating polar ice, the integrated management system is designed to improve and guarantee the level of China’s polar scientific research capability. Following analysis of the characteristics of the primary tasks of polar scientific research, the core expedition site security requirements are identified, on the basis of which, the integrated management system is proposed. Finally, the integrated system for monitoring and management of the scientific research tasks conducted onboard the R/V Xuelong is established. References | Related Articles | Metrics

Select

Exploration and research on recovery of polar anchored submersible buoy system 2022, 34 (1):  130-138.  DOI: 10.13679/j.jdyj.20210017 Abstract ( 797 )   PDF (5610KB) ( 975 )   With the further development of the Arctic and Antarctica, the deployment and recovery of the anchorage observation system has become the normal operation content of the scientific research icebreakers.In the process of polar exploration, the placement of anchorage system is relatively simple, but the recovery operation is often affected by weather, sea conditions, floating ice, etc., which makes it impossible to recover the anchorage system successfully. In this paper, the new technical scheme of anchorage system recovery in floating ice area is discussed, and the suggestions and measures of anchorage system recovery in north and south polar areas are put forward, which can be used for reference in the future placement and recovery of polar anchorage system. References | Related Articles | Metrics