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30 March 2015, Volume 27 Issue 1 Previous Issue    Next Issue

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NEAR-SURFACE STRUCTURE AND ENERGY CHARACTERISTICS OF THE ANTARCTIC CIRCUMPOLAR CURRENT Gao Libao, Yu Weidong, Wang Haiyuan 2015, 27 (1):  1-8.  DOI: 10.13679/j.jdyj.2015.1.001 Abstract ( 1544 )   PDF (5820KB) ( 1549 )   A strong nearly zonal Antarctic Circumpolar Current (ACC), combined with complex fronts, dominates the circulation system in the Southern Ocean. In this study, historical surface drifter observations collected from the Southern Ocean were used to study the near-surface structure, variability, and energy characteristics of the ACC. Standard variance ellipses indicated that both the Agulhas Return Current and the East Australian Warm Current are stable supplements of the near-surface ACC. During austral winter, current velocity increases because of the enhanced westerly wind. Stimulated by the meridional motion of the ACC, the meridional velocity shows greater characteristics of instability than the zonal velocity does over the core current. Additionally, the ACC exhibits an eastward declining trend in core current velocity from southern Africa. The energy distribution suggests that the mean kinetic energy (MKE), eddy kinetic energy (EKE), and  are strong over the core current of the ACC. However, EKE/MKE suggests there is much less (more) eddy dissipation in regions with strong (weak) energy distribution. All energy forms other than EKE/MKE present west–east reducing trends. Furthermore, eddy dissipation has much greater effect on MKE in the northern part of the Southern Ocean. Related Articles | Metrics

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STATISTICAL EVALUATION OF THE ELEMENTAL COMPOSITION AND SOURCE ANALYSIS OF SURFACE SEDIMENTS IN PRYDZ BAY, ANTARCTICA Lan Musheng, Yu Peisong, Han Zhengbing, Hu Chuanyu, Pan Jianming, Zhang Haisheng 2015, 27 (1):  9-16.  DOI: 10.13679/j.jdyj.2015.1.009 Abstract ( 1425 )   PDF (2549KB) ( 1343 )   A number of major and trace elements including C, N, Ca, and Al were measured in 20 surface sediment samples collected from Prydz Bay, Antarctica, during the CHINARE 18–27 cruises. The distributions of these elements and their characteristics of association were used to explore the sedimentary environment and material sources within the study area. The results showed that the values of most of the elements in the surface sediments changed over a wide range. Furthermore, the elemental distribution, correlation, and clustering features presented two patterns. One represented by OC, TN, and S that indicated a source of marine organisms, and the other represented by K, Ti, and Rb that indicated a source of terrigenous clastics. The results also suggested that sedimentation at the center of Prydz Bay and the southeastern area was controlled by biological production, whereas sedimentation near the Fram Bank and continental shelf in front of the Amery Shelf, contained a large number of ice-rafted clasts. Related Articles | Metrics

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VERTICAL DISTRIBUTION OF ZOOPLANKTON COMMUNITY IN SOUTH SHETLAND ISLANDS, ANTARCTICA, DURING AUSTRAL SUMMER Yang Guang, Li Chaolun, Zhang Yongshan, Liu Qun 2015, 27 (1):  17-24.  DOI: 10.13679/j.jdyj.2015.1.017 Abstract ( 1403 )   PDF (2413KB) ( 1277 )   Research on the patterns of the vertical distribution of zooplankton could help improve understanding of the role of zooplankton in the marine food web. Based on samples collected in the South Shetland Islands during the 28th Chinese National Antarctic Research Expedition, vertical profiles of the zooplankton community structure were investigated using multivariate analysis and three communities identified. Group 1 contained samples collected in surface water (0–200 m). The average abundance of this group was 31 782.02 ind·1 000 m-3 and the indicator species were mostly copepods: Oithona similis, Ctenocalanus citer, Oncaea curvata, Calanoides acutus, Calanus propinquus,and Calyptopis I-III stages of Euphausia superba. Group 2 comprised samples from depths of 200–1 000 m. The average abundance was 22 325.59 ind·1 000 m-3 and the indicator species were mostly O. curvata, O. similis, Oithona frigida, C. citer, Aetideopsis minor, Bathycalanus bradyi, C. acutus, C. propinquus, Metridia gerlachei, Alacia spp., and Eukrohnia hamate. Group 3 comprised samples collected in deep water (1 000–2 000 m). The average abundance was only 989.27 ind·1 000 m-3 and the indicator species was Bathycalanus bradyi. Bio-Env analysis showed that chlorophyll a and salinity were the most significant factors affecting community structure and that consideration of these two factors with depth provided the best explanation for the community clustering. Related Articles | Metrics

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ANALYSIS OF THE STATUS AND TREND OF THE ANTARCTIC KRILL FISHERY Huang Hongliang, Chen Xuezhong, Liu Jian, Li Lingzhi, Wu Yue, Yang Jialiang, Zhou Bin, Qi Guangrui, Chen Shuai, Xu Guodong 2015, 27 (1):  25-30.  DOI: 10.13679/j.jdyj.2015.1.025 Abstract ( 1710 )   PDF (2223KB) ( 3002 )   The krill resource is very abundant in the area surrounding Antarctica and its development potential has been receiving considerable worldwide attention. Based on statistical data of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), this study analyzed the developmental status of countries involved in fishing of Antarctic krill, and studied the characteristics of structural changes of the Antarctic krill fishery. The results suggested a number of conclusions. 1) Traditional Antarctic krill fishing countries such as Poland, Japan, and Ukraine are gradually withdrawing from the development of Antarctic krill because of the limitations of krill fishing technology and fishing gear. 2) The numbers of Antarctic krill fishing vessels and size of fishing catches continue to rise because of the participation of emerging countries such as Norway, China, and Chile. 3) The fishing catch from March to September accounts for 70%—90% of the total fishing catch, although Antarctic krill can be fished all year around. 4) The fishing catch fluctuates considerably in CCAMLR districts 48.1, 48.2, 48.3, and the selection of fishing grounds is becoming increasingly difficult because of changing environmental factors and new fishery management measures. 5) Traditional modes of large-scale resource investigation are not adapted to the Antarctic krill resource and fishery management requirements and therefore, scientific investigations of the krill fishery based on fishing vessel data, will become an important reference for surveying and assessing the Antarctic krill resource. Related Articles | Metrics

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STRATEGIC THINKING BEHIND THE COMMERCIAL DEVELOPMENT OF ANTARCTIC KRILL Liu Qin, Huang Hongliang, Li Linian, Wang Qian, Zhou Yusi, Ruan Wen 2015, 27 (1):  31-37.  DOI: 10.13679/j.jdyj.2015.1.031 Abstract ( 1743 )   PDF (967KB) ( 2656 )   Regional characteristics, large quantities, and wide applications have increased the importance of Antarctic krill as a strategic resource. The characteristics of the Antarctic krill resource provide the basis for the formulation and implementation of the strategy for its commercial development, in accordance with the requirements of the development of the strategic emerging industries. Based on China’s strategy for ocean development and the characteristics of the Antarctic krill resource, this article evaluates the strategic capability of the krill resource and establishes goals regarding the development of its exploitation. Studies have shown that the primary areas of focus are the refinement of policies managing the utilization of the Antarctic krill resource, China’s Antarctic krill industrial development model and risk assessment, key technological breakthroughs in China’s development of the Antarctic krill industrialization mechanism, and China’s policies and measures considering research for safeguarding the krill resource. Related Articles | Metrics

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PATENT LAYOUT AND TREND ANALYSIS OF ANTARCTIC KRILL INDUSTRY IN CHINA Yue Dongdong, Wang Lumin, Huang Hongliang, Zheng Hanfeng, Feng Chunlei, Jiang Hang, Li Ziniu 2015, 27 (1):  38-46.  DOI: 10.13679/j.jdyj.2015.1.038 Abstract ( 1436 )   PDF (826KB) ( 1930 )   In this study, a search and statistical analysis of the patent applications in China relating to the Antarctic krill industry was performed. The overall trend, patent type, IPC category, applicant country, key areas of distribution, legal status, and life cycle as well as the freedom to operate were analyzed. In addition, the characteristics of the Antarctic krill industry patents regarding the development period of new technologies were investigated. It was determined that patent applications in China are lagging behind those of foreign applicants, and it is proposed that a strategy of innovation be implemented to avoid the patent-barrier risk to industrial development of Antarctic krill. Related Articles | Metrics

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PERFORMANCE ANALYSIS OF ARCTIC SEA ICE SIMULATION IN CLIMATE SYSTEM MODELS Qiu Bo1,2, Zhang Lujun1,2, Chu Min3, Wu Tongwen3, Tan Huihui1,2 2015, 27 (1):  47-55.  DOI: 10.13679/j.jdyj.2015.1.047 Abstract ( 1505 )   PDF (5079KB) ( 1520 )   We evaluated the capability of simulation of Arctic sea ice for the 5th phase of the Coupled Model Inter-comparison Project (CMIP5) models in comparison with satellite data. The results showed that the spatial distribution of sea ice and the seasonal change characteristics are captured well by most of the models. Observations from 1979 to 2005 have revealed a decrease in the extent of Arctic sea ice and this was simulated by all the models, but with large differences in magnitude. In response to a 1.0°C increase in surface air temperature, the extent of Arctic sea ice reduces by 0.4 × 106 km2, whereas the uncertainties of the climate models indicate a decrease of ice extent ranging from 0.62–1.68 × 106 km2for a similartemperature rise. Related Articles | Metrics

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EVALUATION OF FOUR REANALYSIS RADIATION DATASETS FROM THE EAST ANTARCTIC PLATEAU Fu Liang, Bian Linggen, Xiao Cunde, Ding Minghu 2015, 27 (1):  56-64.  DOI: 10.13679/j.jdyj.2015.1.056 Abstract ( 1305 )   PDF (3157KB) ( 1354 )   We assessed the correspondence of reanalysis radiation from NCEP-1, NCEP-2, ERA interim, and JCDAS with observational data from the Panda-1 station on the east Antarctic plateau for February 2011 to January 2012. Results indicate that the applicability of ERA interim radiation data at Panda-1 was significantly better than for the other three datasets. This could be attributed mainly to the application of a four-dimensional variational data assimilation system: a new cloud prediction equation, an improved Parameterization scheme, and greater assimilation of satellite and radar data. For downward shortwave radiation, the maximum bias (18.7 W·m-2) was found between NCEP-1 and the observations. One possible cause could be model overestimation of atmospheric transparency and underestimation of cloud coverage. Net shortwave radiation bias is caused mainly by the bias of albedo. NCEP-1 and JCDAS underestimated the surface albedo in the Panda-1 area, which meant greater ground absorption of downward shortwave radiation and overestimation of net shortwave radiation. All reanalysis datasets overestimated downward longwave radiation to some degree and the bias in winter was larger than in summer; the largest bias was found in NCEP-1 and NCEP-2 (−62.6 W·m-2 and -37.3 W·m-2, respectively). None of the reanalysis datasets could reflect the annual variation of net radiation, i.e., smaller bias in summer, larger bias in winter. Even though the reanalysis datasets have obvious shortcomings, the lack of observation stations on the Antarctica plateau means that observational data cannot satisfy research requirements and thus, reanalysis datasets remain effective tools in Antarctic climate research. Related Articles | Metrics

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POTENTIAL FOR CONTAINER TRANSPORT THROUGH THE ARCTIC NORTHERN SEA ROUTE Shou Jianmin, Feng Yuan 2015, 27 (1):  65-73.  DOI: 10.13679/j.jdyj.2015.1.065 Abstract ( 1429 )   PDF (998KB) ( 2067 )   This study analyzed the technical requirements and potential economy of ships navigating the northern sea route through the Arctic. The development of a container-shipping network through the Northeast Passage was considered based on an analysis of container trade volume between China and Europe. The scheme for analyzing the economics of the technical requirements necessary for shipping to use the Northeast Passage in the Arctic was established, and the model for the analysis of shipping costs constructed. The cost of container transportation via the Northeast Passage was compared with the Suez Canal by varying the size of the container ships. Based on the assumption that Bergen in Norway would act as a hub–spoke harbor, it was concluded that the construction of such a facility in Europe would increase the comparative power of the Arctic passage. It was concluded that under current navigational environments, voyage time through the Arctic passage would not be reduced much in comparison with the passage through the Suez Canal, but voyage costs would be reduced by 10% and fuel consumption reduced by about 35%. Related Articles | Metrics

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STUDY OF ARCTIC WATERWAY TRANSIT POLICY AND ITS DEVELOPMENT ON CIRCUMPOLAR NATIONS AND REGIONS Wang Dan, Wang Jie, Zhang Hao 2015, 27 (1):  74-82.  DOI: 10.13679/j.jdyj.2015.1.074 Abstract ( 1415 )   PDF (670KB) ( 2907 )   Global warming has accelerated and the speed of melting of the Arctic sea ice has increased, which means that the Arctic’s waterways will be opened much earlier than originally expected. Therefore, the transportation value of Arctic waterways has become increasingly prominent, which has prompted Circumpolar Nations to propose various policies and claims regarding Arctic waterway transit. Although China is not an Arctic state, the availability of an Arctic waterway could shorten international shipping routes, reducing the time and cost of foreign trade, and decreasing the risks of piracy and terrorism. Therefore, to maintain the potential benefits of Arctic waterways to China, attention should be given to this problem. In this paper, the origins of the problems pertaining to the Arctic waterway are introduced, the policies proposed by Russia, Canada, the United States, and the European Union regarding Arctic waterway transit are elaborated, and the trend of development of Arctic waterway transit policy is analyzed. Related Articles | Metrics

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GENERATION AND COMPARISON OF ASTER DEM AND INSAR DEM OF THE GROVE MOUNTAINS AREA Wan Lei, Zhou Chunxia, E Dongchen 2015, 27 (1):  83-90.  DOI: 10.13679/j.jdyj.2015.1.083 Abstract ( 1397 )   PDF (3042KB) ( 1430 )   A 15-m ASTER Digital Elevation Model (DEM) of the Grove Mountains area which is located at 72°45′S, 75°00′E was generated by optical stereo technique and an InSAR DEM with resolution of 20 m was derived. ICESat data were introduced in the process of the ASTER DEM construction, and utilized to correct the InSAR DEM. ICESat footprints were used as elevation control points during the ASTER DEM generation to reduce mismatching points. Finally, the vertical accuracy of the DEM was improved. The InSAR DEM was corrected using the quadratic polynomial with ICESat footprints as control points. And this correction has been designed to eliminate errors introduced by inaccurate estimations of the baseline. The accuracies of the ASTER and InSAR DEMs were evaluated using another set of ICESat data and the major error sources were discussed. Furthermore, the two DEMs were compared and analyzed. The specific advantages and disadvantages of these two techniques in DEM construction of the ice sheet in Antarctica were elaborated, and the advantages of both DEMs were combined to generate a high-accuracy DEM of the Grove Mountains area. Related Articles | Metrics

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POSITIONING ANALYSIS OF BEIDOU NAVIGATION SATELLITE SYSTEM OVER OCEAN AND ANTARCTIC REGIONS Du Yujun, Wang Zemin, An Jiachun, Xie Surui 2015, 27 (1):  91-97.  DOI: 10.13679/j.jdyj.2015.1.091 Abstract ( 1397 )   PDF (3306KB) ( 1859 )   Using the BeiDou/GPS dual-system four-frequency receiver, BeiDou and GPS data were collected from Tianjin in China to Kunlun Station in Antarctica, along the route of the 28th Chinese National Antarctic Research Expedition. Based on the signal-to-noise ratio and multipath of the C/A code (Coarse/Acquisition code), visible satellites, PDOP (Position Dilution of Precision), and single-frequency point positioning using the C/A code, the navigational and positioning features of BeiDou and GPS were analyzed during different parts of the voyage, especially in the ocean and Antarctic regions, under different movement modes. Results showed that the signal quality of BeiDou is generally as good as that of GPS. At 45°, the precision of BeiDou kinematic positioning is consistent with GPS, i.e., 10 and 20 m in the horizontal and vertical directions, respectively. The precision of static positioning reaches several meters in the horizontal direction, which is comparable with GPS, and about 10 m in the vertical direction, which is worse than GPS. In mid- and high latitudes, because of the lack of visible satellites, positioning accuracy is poor and even positioning failed. Related Articles | Metrics

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DEVELOPMENT OF POLAR MOBILE INFORMATION PLATFORM BASED ON ANDROID AND iOS Liu Peng, Pang Xiaoping, Ai Songtao 2015, 27 (1):  98-103.  DOI: 10.13679/j.jdyj.2015.1.098 Abstract ( 1318 )   PDF (2367KB) ( 1382 )   Mobile Internet is developing rapidly because of smart phones, the majority of which are Android and iOS. This paper presents the design and strategy for the implementation of a mobile information platform named Mobile Polar. It is based on the Android and iOS platforms and it enables the browsing of and interaction with polar investigation data. The platform has been approved by experts and officially released in the App Store and Android markets. It provides a new channel for polar management departments, researchers, and the public to obtain easy and fast access to polar-related information. Related Articles | Metrics

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REVIEW OF RESEARCH PROGRESS OF INTERNAL RADAR ISOCHRONOUS LAYERS IN ANTARCTIC ICE SHEET Tang Xueyuan, Sun Bo, Cui Xiangbin 2015, 27 (1):  104-114.  DOI: 10.13679/j.jdyj.2015.1.104 Abstract ( 1411 )   PDF (2834KB) ( 1522 )   Radar isochronous layers, reflect the surface characteristics of ice of different periods and their variation within the Antarctic ice sheet, and contain a wealth of subglacial environmental information. Isochronous layers have increasingly been used as proxies in investigations into the evolution and subglacial environment of the Antarctic ice sheet over considerable spatiotemporal scales. The integration of geophysical observations and numerical simulation technology has enabled the visualization of these layers over the continental scale. Using these internal isochronous layers, glaciology research has achieved a number of quantitative results by relating millennial-timescale subglacial geomorphology with the paleo-ice stream. In this review concerning the Antarctic ice sheet, we summarize the physical mechanism of the internal layer and its benefit to glaciology, and evaluate its application to the following: (1) siting and dating of deep ice cores, (2) ice sheet dynamics, (3) ice sheet mass balance, (4) ice sheet stability, and (5) the subglacial environment. In addition, based on our understanding of internal isochronous layers, we outline a number of challenges to be addressed in the future. (1) The development and testing of numerical ice-sheet models with more elaborate frameworks that include the structure of internal layers, such as their temporal and spatial variations. (2) The identification of ice mass change based on the internal layers using the current Antarctic ice sheet as the initial conditions. (3) The increase of observations of the subglacial environment, to obtain higher resolution quantitative images of the isochronous layer structure and ice deformation. Related Articles | Metrics

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RESEARCH PROGRESS ON ICE VELOCITY OF ANTARCTIC ICE SHEET Chen Jun, Ke Changqing 2015, 27 (1):  115-124.  DOI: 10.13679/j.jdyj.2015.1.115 Abstract ( 1564 )   PDF (1801KB) ( 2551 )   The ice flow velocity of glaciers is important for estimating the Antarctic ice sheet mass balance, and it is of great significance for studies into rising sea level under the background of global warming. Traditional methods of monitoring Antarctic ice flow velocity, such as stake measurements and edge measurements based on optical instruments, have been replaced by GPS and remote sensing measurements. Thus, it has been established that the general characteristics of Antarctic ice flow velocity are that ice flow velocity in coastal zones is faster than inland, the ice flow velocity of the ice shelf is faster than that on the continent, and the ice flow velocity in western Antarctica is faster than in the east. Therefore, it is predicted that with increased monitoring of ice velocity over longer periods in data sparse regions, and the development of new approaches to the study of ice velocity, models of the interrelation between ice velocity and global climate change shall become a new hot topic of research. Related Articles | Metrics