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30 March 2016, Volume 28 Issue 1 Previous Issue    Next Issue

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The polar space environment observation system at Zhongshan Station, Antarctica Huang Dehong, Hu Hongqiao, Liu Ruiyuan, Yang Huigen, Zhang Beichen, Hu Zejun, Liu Jianjun, He Fang, Liu Yonghua, Han Desheng 2016, 28 (1):  1-10.  DOI: 10.13679/j.jdyj.2016.1.001 Abstract ( 990 )   PDF (4760KB) ( 1670 )   The Zhongshan Station in Antarctica is situated in the cusp region, and the rich ionospheric signatures and auroral phenomena that can be observed there mean it is well suited for undertaking polar space environment observations. The Zhongshan Polar Space Environment observation system has been developed and the observational instrumentation has been enhanced since its construction in 1989. Currently, multiple instruments are employed in the system for research on aurora, the ionosphere and geomagnetism. The system operates continuously in observing the polar space environment, and the status of the system’s instrumentation can be monitored remotely. The geomagnetism and cosmic noise absorption data are transferred to China in near real-time and the databases are available to the public. The prospects for China’s Polar Space Environment observation system are outlined. Related Articles | Metrics

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Statistical research of field-aligned currents under radical interplanetary magnetic fields Cao Xue, Liu Dingwei, Huang Tao, Zhang Kedeng 2016, 28 (1):  11-18.  DOI: 10.13679/j.jdyj.2016.1.011 Abstract ( 1047 )   PDF (3938KB) ( 1139 )   The characteristics of field-aligned currents (FACs) and the related physical quantities under radial interplanetary magnetic field (RIMF) from 2001 to 2009 were investigated. Statistical analysis and comparison with FACs under normal conditions were performed using CHAllenging Minisatellite Payload (CHAMP) data. The results showed that the intensity of noon FACs has clear dependence on the dipole tilt angle under normal conditions and that the ratio between summer and winter is about 3; however, the dependence disappears under RIMFs and the ratio decreases to 2. The magnitude of the interplanetary magnetic field (IMF), the merging electric field, solar wind dynamic pressure, and the auroral electrojet (AE) index decrease, while the disturbance storm time(Dst) index remains almost stable under RIMFs. The merging electric field is a controlling factor of FACs under normal conditions, but the control effect disappears during RIMFs. In the Northern Hemisphere, the intensity of FACs under IMF < 0 conditions is larger than that under IMF > 0 conditions (the situation is the converse in the Southern Hemisphere). Although the intensity of FACs under normal conditions is greater than that under RIMFs, the probability that the density of FACs under RIMFs is greater than the yearly average is about 0.2, and some geomagnetic disturbances, such as substorms, still occur under RIMFs. Related Articles | Metrics

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STATISTICAL PROPERTIES OF POLAR IONOSPHERIC SCINTILLATIONS AT THE SOUTH POLE AND MCMURDO STATIONS,ANTARCTICA Li Penghui, Hu Hongqiao, Fang Hanxian, Liu Ruiyuan, Yang Shenggao 2016, 28 (1):  19-24.  DOI: 10.13679/j.jdyj.2016.1.019 Abstract ( 835 )   PDF (3274KB) ( 1111 )   Based on scintillation receiver observations from December 2013 to November 2014 at the South Pole and McMurdo stations, a statistical analysis was performed on the diurnal and seasonal variations of the phase scintillation occurrence at the two stations. The statistical results indicated that the phase scintillation occurrence in spring and autumn is significantly greater than in summer and winter, and that there is a twin-peak structure to the diurnal variation. Phase scintillation occurrence is enhanced at magnetic noon and magnetic post-midnight. Ionospheric irregularities produced by soft electron precipitation and ionospheric convection on the polar cusp could lead to scintillation near magnetic noon. The enhanced occurrence of scintillation at magnetic post-midnight could be induced by a strong density gradient caused by the plasma cloud across the polar cap region. The phase scintillation occurrence at McMurdo Station is greater than at the South Pole, which might be due to the difference in their magnetic latitudes. Related Articles | Metrics

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PACK ICE COMMUNITY STRUCTURE IN THE ARCTIC OCEAN DURING SUMMER 2012 Jia Shulei, Zhang Fang, Lin Ling, Jia Rui, He Peimin, He Jianfeng 2016, 28 (1):  25-33.  DOI: 10.13679/j.jdyj.2016.1.025 Abstract ( 963 )   PDF (2885KB) ( 1225 )   As a part of the Arctic Ocean ecosystem, the sea ice community plays important roles in primary production and the carbon cycle. In this study, we used the fluorescence microscopy technique to analyze samples of the pack ice community, collected from the central Arctic Ocean in summer 2012. The results showed that the average integrated biomass was （105.85±53.41） mg C•m−2, of which heterotrophic bacteria comprised 47.2%, followed by diatoms (26.7%), heterotrophic flagellates (18.2%), autotrophic flagellates (6.9%), and ciliates (1.0%). An autotrophic flagellate bloom was observed at the bottom of the high-latitude station (87°39.598′N, 123°43.454′E). The community of this station was in the late period of diatom algal bloom and there was considerable melting of the upper sea ice layer, which could have led to a suitable habitat at the bottom for autotrophic flagellate growth (the higher ratios of N/P). It is suggested that the melting of sea ice in recent years has had obvious influence on the pack ice community in the Arctic Ocean. For example, the biomass of the heterotrophic taxa has increased and heterotrophic bacteria have replaced diatoms as the dominant group. Related Articles | Metrics

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DIVERSITY OF CULTURABLE BACTERIA IN SOIL FROM FILDES PENINSULA, ANTARCTIC Yang Xiao Ding Hui, Zang Jiaye, Zhang Botao, Zhao Qian, Cong Bailin, Dong Longlong, Yue Tonghui, Zhang Bin, Wang Nengfei 2016, 28 (1):  34-41.  DOI: 10.13679/j.jdyj.2016.1.034 Abstract ( 880 )   PDF (3184KB) ( 1052 )   Culturable bacteria were isolated from 16 soil samples collected from Fildes Peninsula during the 29th Chinese Antarctic Scientific Expedition. Classification and phylogenetic analysis based on 16S rDNA showed that the 67 bacteria belonged to 3 classes and 13 genera. The predominant phyla were Actinobacteria and Proteobacteria and the predominant genera were Arthrobacter and Pseudomonas. The soil properties at four typical sites influenced by humans, seals, and penguins were analyzed. Preliminary analyses of the relationships between soil properties and bacterial diversity and community were conducted. The results showed that bacterial diversity and community were affected by humans, seals, and penguins at different levels. Overall, eight amylase-producing bacteria were found in this study. Related Articles | Metrics

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DISTRIBUTION OF N2O in PRYDZ BAY AND ADJACENT SOUTHERN OCEAN Wu Man, Zhan Liyang, Chen Liqi 2016, 28 (1):  42-48.  DOI: 10.13679/j.jdyj.2016.1.042 Abstract ( 1029 )   PDF (1935KB) ( 1353 )   Water samples collected from Prydz Bay and the adjacent Southern Ocean during the 25th and 26th Chinese Antarctic Research Expeditions were analyzed for N2O concentration using the static headspace gas chromatography method. The concentration of N2O over the Prydz Bay continental shelf was found to be relatively low, with a range of 13.2—17.4 nmol·L−1, and it was undersaturated compared with the current atmospheric mixing ratio, with saturation anomaly centers at −7%. However, higher concentrations of N2O, with a range of 15.5—23.3 nmol·L−1, were found in the Southern Ocean. The subsurface to bottom waters all showed oversaturation against the atmospheric mixing ratio prior to the industrial revolution. It was established that the distribution pattern of N2O within the study area was related to the complex hydrographic characteristics of the region. Prydz Bay shelf water with undersaturated N2O might mix with Circumpolar Deep Water and sink to the bottom of the Southern Ocean, forming Antarctic Bottom Water. This could act as a pathway for N2O transportation into deep water, providing a sink for atmospheric N2O. Related Articles | Metrics

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Impact of the indo-pacific warm pool SST anomaly on Arctic sea ice variation Chen Di, Gao Shanhong, Chen Jinnian 2016, 28 (1):  49-57.  DOI: 10.13679/j.jdyj.2016.1.049 Abstract ( 1043 )   PDF (6591KB) ( 1399 )   The characteristics of the long-term variation of SST anomaly (SSTA), globally and in the Indo–Pacific warm pool (IPWP), were analyzed using statistical methods. A possible relationship between the SSTA of the IPWP and the rapid decline in the rate of Arctic sea ice coverage was considered. It was found that the global SSTA has increased slowly over the last 100 years but with interannual fluctuations. The decadal variation reflected a decelerating tendency, and the long-term variations of the global and IPWP SSTAs were similar. The rate of Arctic sea ice coverage before the early 1980s showed a positive anomaly, whereas it was negative afterwards. The linear rate of decline was established as −1.5% per decade and it was largest during the months of July–October (2.6%, 2.8%, 3.0%, and 2.5% per decade, respectively). Correlation analysis showed the relation between the rapid decline in the rate of Arctic sea ice coverage and the IPWP SSTA variation was close but lagged by about 30 months. The Arctic oscillation might be important in the communication of this relationship. Regression analysis was used to establish a prediction equation relating Arctic sea ice change and the IPWP SSTA, and the variation in the rate of Arctic sea ice coverage for the coming two years was predicted. The results indicated that the anomaly in the rate of Arctic sea ice coverage would be −6.16% in 2015 and 2016. This work provides a theoretical basis for the evaluation of the effects of global climate change. Related Articles | Metrics

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SEA ICE ALBEDO OBSERVATIONS DURING  NAVIGATIONS THROUGH PRYDZ BAY, ANTARCTICA, IN THE AUSTRAL SUMMER OF 2013-2014 Li Mingguang, Lei Ruibo, Li Zhijun, Han Hongwei,Tian Zhongxiang 2016, 28 (1):  58-66.  DOI: 10.13679/j.jdyj.2016.1.058 Abstract ( 850 )   PDF (3767KB) ( 1132 )   Underway incident and reflected solar irradiance were measured onboard the R/V Xuelong during its navigations in Prydz Bay, Eastern Antarctica, during the Australian summer of 2013–2014. The albedo of seawater and sea ice was calculated from the observed data. Albedo obtained from different navigational segments from late November to early March was compared. This period spanned the seasons of sea ice melt to growth. Landfast ice covered by snow had the largest albedo (~0.70). The second highest was pack ice with snow (~0.55—0.65), while, the albedo of pack ice without snow cover could decrease to about 0.40. The albedo of new ice was very low (~0.15—0.30). However, snow cover would increase it to about 0.40, which was comparable with second-year ice without snow cover. The observed albedo was linked to sea ice concentration derived from AMSR2 data and visual observations from the bridge of the R/V Xuelong. Regional average albedo depended mainly on sea ice concentration, although it was also affected by the physics of the underlying surface. For example, the albedo of new ice formed from late February to early March was only 30%—50% that of second-year pack ice. Therefore, the contribution of new ice to the regional average albedo is not as great as to regional ice concentration. During the melt season, the relatively large water content within the snow cover can reduce near-infrared spectral reflection. Thus, ice concentration alone is insufficient to establish a reasonable albedo parameterization for the mixing zone of sea ice and water. Instead, the influences of ice and snow types should also be considered. Related Articles | Metrics

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Water masses and exchanges in the region around the northern tip of Antarctic Peninsula observed in summer of 2011/2012 Shi Jiuxin, Sun Yongming, Jiao Yutian, Hao Guanghua, Wang Miao 2016, 28 (1):  67-79.  DOI: 10.13679/j.jdyj.2016.1.067 Abstract ( 916 )   PDF (7565KB) ( 765 )   Water masses and exchanges in the region around the northern tip of the Antarctic Peninsula were analyzed based on CTD (Conductivity-Temperature-Depth profiler) and XCTD (eXpendable CTD) data observed during the 28th Chinese National Antarctic Research Expedition in December 2011 to January 2012. The Weddell Deep Water (WDW) with significant warm core, the Weddell Sea Deep Water(WSDW) and Weddell Sea Bottom Water(WSBW, with potential temperature less than -0.7℃) with neutral density greater than 28.27 kg·m-3 were found in the southern deep area of observing region, especially in Powell Basin. The WDW on the surrounding slope showed relative weaker core characteristics because of mixing with peripheral waters. In some locations with complex bottom topography, such as the Philip Ridge and Hesperides Trough, stronger mixing and a thermohaline intrusion occurred at the WDW layer. WDW with a deeper saline core at 1 500 db, overlaid by warm water with vertically uniform temperature and salinity, was observed to the northeast of Elephant Island, indicating that the WDW might have come from different sources and undergone different modifications. No Circumpolar Deep Water was found in the Bransfield Strait; however, some mesoscale processes, such as eddies on the shelf near King George Island, could influence exchange between the Drake Passage and Bransfied Strait. Related Articles | Metrics

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ANALYSIS OF SURFACE CURRENT FEATURES IN PRYDZ BAY AND ADJACENT SEA Ji Huifeng, Deng Xiaodong, Cao Bing, Xu Changsan, Wu Huiming 2016, 28 (1):  80-86.  DOI: 10.13679/j.jdyj.2016.1.080 Abstract ( 849 )   PDF (2274KB) ( 1265 )   Based on data obtained during the 29th Antarctic expedition from 8 Argos drifting buoys near Prydz Bay, this study analyzed the surface current features of the sea and compared them with previous findings. The results revealed a surface current flowing westward in western and northern parts of Prydz Bay, showing that in this region, the surface current was a counterclockwise flow along the coast of Antarctica. In eastern parts, the current direction was first south and then west or north, and in the northwest, the current direction was south. The average velocity of the 8 buoys was 0.02–0.20 m·s−1 and the maximum velocity was 1.57 m·s−1. Areas with velocity >1.0 m·s−1 were concentrated in Prydz Bay and beyond Cape Klose and Cape Darnley. Areas with velocity >1.5 m·s−1 were found only in Prydz Bay and the outer region of Cape Klose. Related Articles | Metrics

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Analysis on sea ice conditions in the Arctic Northeast Passage in summer 2014 Li Xinqing, Cheng Xiao, Hui Fengming, Zhai Mengxi, Zhang Yuanyuan 2016, 28 (1):  87-94.  DOI: 10.13679/j.jdyj.2016.1.087 Abstract ( 1368 )   PDF (6094KB) ( 1521 )   Data obtained from AMSR-E and AMSR-2 were used to calculate the extent of Arctic sea ice and to determine sea ice distributions for June–September from 2003 to 2014. Little difference was found between the extent of sea ice in 2014 and the mean 2003–2013 distribution. However, two apparent differences were found between the spatial distribution of sea ice in 2014 and the median 2003–2013 extent. (1) Sea ice in the Laptev Sea was obviously less than the median extent, and the sea ice boundary was higher than 85°N in September. (2) Sea ice extent in the northern Barents Sea was greater than the median extent, and the sea ice boundary expanded during summer 2014. The air pressure field in summer 2014 caused southerly winds over the Laptev Sea and northerly winds over the Barents Sea. The southerly winds brought warmer air, which promoted sea ice melting and forced the sea ice boundary to retreat northward. The northerly winds brought colder air, which reduced sea ice melting and forced the sea ice to drift southward. This resulted in a greater amount of sea ice in the northern Barents Sea. The Northeast Passage is generally navigable from early August to early October in Severnaya Zemlya. The time of opening of the Northeast Passage in the New Siberian Islands and adjacent sea regions is earlier than in Severnaya Zemlya and it closes later. Therefore, the navigability of the entire Northeast Passage depends on sea ice conditions around Severnaya Zemlya. Related Articles | Metrics

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USE OF CONTRAST RATIO TO DETECT MULTI-YEAR ICE USING AMSR-E PASSIVE MICOWAVE DATA Zhang Shugang, Guo Fadong, Zhang Jinming, Liu Lei, Bai Xuejiao 2016, 28 (1):  95-102.  DOI: 10.13679/j.jdyj.2016.1.095 Abstract ( 1004 )   PDF (4903KB) ( 1061 )   This study found that the ratio of vertically polarized brightness temperature of AMSR-E passive microwave data at 18.7 and 36.5 is the ratio of sea ice microwave emissivity for first-year ice. However, for multi-year ice, this ratio is also affected by sea ice temperature. Furthermore, the ratio for older ice is larger than for younger ice. The contrast ratio is a suitable parameter with which to ascertain the threshold between first-year and multi-year ice because the maximum gradient of the contrast ratio appears at the threshold. This threshold varies seasonally; it is relatively steady during winter but changes considerably during summer because of the influence of meltwater. Little difference was found in the multi-year ice coverage of the Arctic section of the Atlantic Ocean when ascertained by the contrast ratio and NASA Team2 (NT2) algorithm; however, large differences were found in the Arctic section of the Pacific Ocean. In comparison to the NT2, the coverage of multi-year ice is commonly found to be larger when ascertained using the contrast ratio. Related Articles | Metrics

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STUDY OF SNOWMELT DETECTION ON THE ANTARCTIC PENINSULA ICE SHEET DERIVED FROM RADARSAT-2 DUAL-POL DATA Wang Meng, Li Xinwu, Liang Lei, Lu Wanyu 2016, 28 (1):  103-112.  DOI: 10.13679/j.jdyj.2016.1.103 Abstract ( 1070 )   PDF (7235KB) ( 657 )   Snowmelt in Antarctica has considerable impact on sea level rise and climate change. We investigated the detection of snowmelt on the Antarctic Peninsula using C-band spaceborne synthetic aperture radar imagery. Based on an analysis of the backscatter characteristics of dry, percolation, and wet snow, we used a decision tree classification to divide the ice sheet into zones. The statistical analysis demonstrated that the backscatter coefficients of snow zones, especially the wet snow zone, depend mainly upon melt level and do not have a centralized distribution. The wet snow zone in drastic melt is too similar to the dry snow zone to be distinguished using the backscatter coefficient alone. Therefore, we introduced the dry snow distribution and elevation into the classification, and compared the two decision tree methods. We verified the detection results using microwave radiometer and automatic weather station data. The results showed that the two presented decision tree classifications, derived from Radarsat-2 dual-pol data, were both efficient in determining glacier zone division and distinguishing snowmelt status and thus, are shown capable of achieving high-resolution snowmelt detection in Antarctica. Related Articles | Metrics

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Geological Conditions and petroleum resource potential in the Ross Sea Basin, Antarctica Du Min, Deng Xiguang, Yang Yong, Liu Jinping, Wang Gaiyun 2016, 28 (1):  113-122.  DOI: 10.13679/j.jdyj.2016.1.113 Abstract ( 853 )   PDF (9127KB) ( 719 )   The Ross Sea is a deep bay located in the Pacific sector of the Antarctic. The Ross Sea Basin, which is divided into the Victoria Land Basin, Northern Basin, Central Trough, and Eastern Basin, constitutes one of the areas in the region with the most significant hydrocarbon potential. This study examined the regional stratigraphic and seismic characteristics, analyzed the conditions of the structures, deposition, temperature, pressure, and hydrocarbon geochemistry, and concluded that the hydrocarbon geological conditions are good. Based on two-dimensional seismic and borehole data, the maturity and hydrocarbon generating quantity were simulated. It is suggested that the oil and gas generation areas in the Eastern Basin and Victoria Land Basin are extensive, and that the thermal evolution gradation of the latter is slightly higher than the former. In comparison, the oil and gas generation areas and thermal evolution gradation of the Northern Basin and Central Trough are rather poorer. According to the simulation results of hydrocarbon generating quantity, and considering a reasonable accumulation coefficient, it is supposed that the potential hydrocarbon resources in the Ross Sea Basin are about 9.15 billion tons. Related Articles | Metrics

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AUSTRALIA ANTARCTIC INTERESTS: ACTUAL CHALLENGE AND POLICY RESPONSE Wu Ningbo, Chen Li 2016, 28 (1):  123-132.  DOI: 10.13679/j.jdyj.2016.1.123 Abstract ( 789 )   PDF (597KB) ( 2010 )   Antarctica is one of the most important strategic focuses of Australia because of its relative geographic proximity and Australia has claimed areas of this vast territory. In the process of positive participation in Antarctic affairs, Australia has established a series of integrated policy systems by its definite and specific realization of Antarctic interests and challenges. Consequently, Australia has adopted the maintenance of sovereignty, increase of scientific funding, protection of the environment, and delivery of economic benefits as its current principal targets. Related Articles | Metrics

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REVIEW ON ARCITC CEPHALOPOD SPECIES AND DISTRIBUTIONS Jiao Min,Chen Xinjun,Gao Guoping,Liu Bilin 2016, 28 (1):  133-144.  DOI: 10.13679/j.jdyj.2016.1.133 Abstract ( 818 )   PDF (3455KB) ( 1426 )   Cephalopods are distributed widely around the world and they represent one of the most promising species of marine organisms in terms of the development of fishery resources, especially in the Arctic. This review collates information on the distributions of cephalopod species in Arctic waters, provides basic data on the scale of the Arctic cephalopod resources with regard to reasonable development, and researches the Arctic marine ecosystem. Cephalopods in Arctic waters belong mainly to the orders Sepioidea, Octopoda, and Teuthoidea and they can be sorted into about 14 families, 26 genera, and 43 species, of which these species Rossia palpebrosa, Rossia moelleri, Gonatus fabricii, Cirroteuthis muelleri, Bathypolypus arcticus, Benthoctopus piscatorum, and Benthoctopus sibiricus are typical types. Cephalopods are distributed primarily in the Greenland, Norwegian, and Barents seas, and they are often obtained from exploratory fishing, bycatch, or from the stomachs of other animals. Of all the cephalopods in the Arctic, Gonatus. fabricii is the most abundant; however, currently, there is no commercial development of this resource. Related Articles | Metrics

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PROGRESS OF THE POLAR METHANOGENS COMMUNITY STUDIES Yang Peng, He Jianfeng, Zhang Fang, Lin Ling, Cao Shunan 2016, 28 (1):  145-151.  DOI: 10.13679/j.jdyj.2016.1.145 Abstract ( 1187 )   PDF (602KB) ( 1653 )   Methane is one of the principal greenhouse gases. The methanogenic community is an important group of microorganisms that has the capability of producing methane, which plays a significant role in the carbon cycle. Studies of the methanogenic community in both the Arctic and the Antarctic have found ubiquitous distributions in habitats of wetlands, peatlands, lakes, tundra, permafrost, and the basal ice layer of glaciers. In this paper, the composition and diversity of the methanogenic community, its relationship with environmental change (temperature, nutrients, and pH), and the main analysis techniques used in its study are summarized, and the prospects for future research in this field are discussed. Related Articles | Metrics

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STUDY OF ULTRASONIC TEST IN THE MEASUREMENTS OF MECHANICAL PROPERTIES OF ICE Guo Yao, Li Gang, Jia Chengyan, Chang Tianying, Cui Hongliang, Markov Alexey 2016, 28 (1):  152-157.  Abstract ( 756 )   PDF (2692KB) ( 1164 )   Nonlinear high-energy ultrasonic testing equipment and the relationship between ultrasonic wave velocity (longitudinal and shear waves) and mechanical parameters of objects were used to study the mechanical parameters (Young’s modulus, Poisson’s factor, shear modulus, bulk modulus) of artificial ice samples under varying temperatures. Using MATLAB for data processing, the relationship between the velocity of ultrasonic waves in the artificial ice samples and the variation of ice temperature was obtained. Then, using a theoretical formula, the relationship between the variations of the mechanical parameters of the artificial ice samples with temperature was determined. The results showed that both the longitudinal and the shear waves displayed an increasing trend with decreasing temperature. Furthermore, the Young’s modulus, Poisson’s factor, shear modulus, and bulk modulus, calculated from the experimental data of the artificial ice samples, were also found to increase with decreasing temperature. This research promotes the application of ultrasonic detection techniques for the measurements of the physical and mechanical properties of ice, and it provides theoretical models and experimental data for undertaking research into the mechanical and flow characteristics of the Antarctic ice sheet, sea ice, and permafrost. Related Articles | Metrics