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33篇 您的检索式:作者名="Zhanhai LI"
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1In situ experiments on width and evolution characteristics of excavation damaged zone in deeply buried tunnels显示文摘The seven long tunnels of Jinping II hydropower station are deeply buried.The width and evolution characteristics of excavation damaged zone(EDZ) are the key problem to the design of tunnels excavation and supports.In order to study this problem,several specific experimental tunnels with different overburden and geometric sizes were excavated at this site.Digital borehole camera,sliding micrometer,cross-hole acoustic wave equipment and acoustic emission apparatus were adopted.This paper introduced the comprehensive in situ experimental methods through pre-installed facilities and pre-drilled boreholes.Typical properties of the surrounding rock mass,including cracks,deformation,elastic wave and micro fractures,were measured during the whole process of the tunnel excavation.The width and characteristics of formation and evolution of tunnels EDZ were analyzed under different construction methods involving of TBM and drilling and blasting,the test tunnels were excavated by full-face or two benches.The relationships between EDZ and tunnel geometry sizes,overburden and excavation method were described as well.The results will not only contribute a great deal to the analysis of rock mass behavior in deeply buried rock mass,but also provide direct data for support design and rockburst prediction.LI ShaoJun 1,FENG XiaTing 1,LI ZhanHai 3,CHEN BingRui 1,JIANG Quan 1,WU ShiYong 2,HU Bin 2 &XU JinSong 2 1 State Key Laboratory of Geomechanics and Geotechinical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China 2 Ertan Hydropower Development Company,Ltd.,Chengdu 610051,China 3 School of Resources and Civil Engineering,Northeastern University,Shenyang 110004,China 2011Science China(Technological Sciences)2011,54,S1:13
2Intratidal and neap-spring variations of suspended sediment concentrations and sediment transport processes in the North Branch of the Changjiang Estuary显示文摘Profiles of tidal current and suspended sediment concentration(SSC) were measured in the North Branch of the Changjiang Estuary from neap tide to spring tide in April 2010. The measurement data were analyzed to determine the characteristics of intratidal and neap-spring variations of SSC and suspended sediment transport. Modulated by tidal range and current speed, the tidal mean SSC increased from 0.5 kg/m3 in neap tide to 3.5 kg/m3 in spring tide. The intratidal variation of the depth-mean SSC can be summarized into three types: V-shape variation in neap tide, M-shape and mixed M-V shape variation in medium and spring tides. The occurrence of these variation types is controlled by the relative intensity and interaction of resuspension, settling and impact of water exchange from the rise and fall of tide. In neap tide the V-shape variation is mainly due to the dominant effect of the water exchange from the rise and fall of tide. During medium and spring tides, resuspension and settling processes become dominant. The interactions of these processes, together with the sustained high ebb current and shorter duration of low-tide slack, are responsible for the M-shape and M-V shape SSC variation. Weakly consolidated mud and high current speed cause significant resuspension and remarkable flood and ebb SSC peaks. Settling occurs at the slack water periods to cause SSC troughs and formation of a thin fluff layer on the bed. Fluxes of water and suspended sediment averaged over the neap-spring cycle are all seawards, but the magnitude and direction of tidal net sediment flux is highly variable.LI Zhanhai LI Michael Z DAI Zhijun ZHAO Fangfang LI Jiufa 2015Acta Oceanologica Sinica2015,34,1:9
3Flood-ebb asymmetry in current velocity and suspended sediment transport in the Changjiang Estuary显示文摘Time series measurements were conducted on suspended sediment and current velocity from neap tide to spring tide in the South Branch of the upper Changjiang Estuary in the summer of 2011. Strong flood-ebb asymmetry in the current velocity was observed in the South Branch as a result of high river runoff and tide deformation, in which the magnitude and duration of ebb currents were significantly greater than those of flood currents. The suspended sediment concentration(SSC) and suspended median grain size also exhibited remarkable flood-ebb variation; these variables were considerably larger during the ebb than during the flood and increased from neap to spring tide. Affected by the strong asymmetry in the current velocity and SSC between the flood and ebb,suspended sediment flux during the ebb was notably larger than during the flood, and a seaward tidal net flux was observed in each tidal cycle. The balance of sediment flux illustrates that the seaward sediment transport was dominated by river flow and tidal trapping and the landward sediment transport was dominated by the Stokes drift and the shear effect. Notable resuspension occurred during the spring and moderate tides. The critical velocity for the resuspension of bed sediments was estimated based on the correlation between current velocity with SSC and suspended median grain size. The results show that the critical velocity was approximately 40 cm/s during the flood phases and approximately 80 cm/s during the ebb phases because the surficial flood bed sediments located in the lower reach are much finer than the surficial ebb bed sediments located in the upper reach. The flood-ebb variation in the critical erosion velocity has significant effect on the intratidal variation of SSC and sediment transport process, and it is a common phenomenon in many estuaries of the world due to the complicated spatial distribution of bed sediments.LI Zhanhai WANG Yaping CHENG Peng ZHANG Guoan LI Jiufa 2016Acta Oceanologica Sinica2016,35,10:7
4Albedo of Coastal Landfast Sea Ice in Prydz Bay,Antarctica:Observations and Parameterization显示文摘The snow/sea-ice albedo was measured over coastal landfast sea ice in Prydz Bay, East Antarctica(off Zhongshan Station)during the austral spring and summer of 2010 and 2011. The variation of the observed albedo was a combination of a gradual seasonal transition from spring to summer and abrupt changes resulting from synoptic events, including snowfall, blowing snow, and overcast skies. The measured albedo ranged from 0.94 over thick fresh snow to 0.36 over melting sea ice. It was found that snow thickness was the most important factor influencing the albedo variation, while synoptic events and overcast skies could increase the albedo by about 0.18 and 0.06, respectively. The in-situ measured albedo and related physical parameters(e.g., snow thickness, ice thickness, surface temperature, and air temperature) were then used to evaluate four different snow/ice albedo parameterizations used in a variety of climate models. The parameterized albedos showed substantial discrepancies compared to the observed albedo, particularly during the summer melt period, even though more complex parameterizations yielded more realistic variations than simple ones. A modified parameterization was developed,which further considered synoptic events, cloud cover, and the local landfast sea-ice surface characteristics. The resulting parameterized albedo showed very good agreement with the observed albedo.Qinghua YANG Jiping LIU Matti LEPPRANTA Qizhen SUN Rongbin LI Lin ZHANG Thomas JUNG Ruibo LEI Zhanhai ZHANG Ming LI Jiechen ZHAO Jingjing CHENG 2016Advances in Atmospheric Sciences2016,33,5:7
5Structure of the internal isochronous layers at Dome A,East Antarctica显示文摘Dome A (Kunlun Station) is considered a likely place for finding an ice core record reaching back to one million years. The internal isochronous layering of the Antarctic Ice Sheet, revealed by ice radar, is a prerequisite for selecting sites for deep ice core drilling that can be used for studying the paleoclimatic record. In 2004/2005, during the 21st Chinese National Antarctic Research Expedition (CHINARE 21), a 200-km long, continuous radar profile was obtained across Dome A. The internal layers along the profile were derived from the stratigraphy detected by the radar. The morphology of the isochronous layers shows that: (1) The internal layers in the shallow ice sheet (0-500 m) are generally flat, with no more than 50 m of layer intervals, and have typical synclines and anticlines in some localized regions. (2) At 500-2000 m below the surface of the ice sheet, the layers appear as 'bright layers', and the width of the layer intervals expands to 50-100 m. (3) When the basal topographic wavelengths are approximate to the thickness of the ice (3 km), the traced internal layers, with localized bumps or concave folds, are asymptotic parallel to the subglacial topography. For the longer topographic wavelengths (~20 km) wider than the thickness of the ice, the layers do not rise and fall with the basal topography. The internal layers surrounding some mountain peaks representing the most extreme variation in the terrain are sharply disturbed by the subglacial topography. (4) Layer discontinuity and fracture were detected in the basal ice sheet. Finally, by combining this new information with that derived from existing data regarding ice thickness, we were able to select three potential sites for reconstructing the age-depth relationship of the ice core.TANG XueYuan SUN Bo ZHANG ZhanHai ZHANG XiangPei CUI XiangBin LI Xin 2011Science China Earth Sciences2011,54,3:6
6Molecular and serological surveillance of Getah virus in the Xinjiang Uygur Autonomous Region,China,2017–2020显示文摘The Getah virus(GETV),a mosquito-borne RNA virus,is widely distributed in Oceania and Asia.GETV is not the only pathogenic to horses,pigs,cattle,foxes and boars,but it can also cause fever in humans.Since its first reported case in Chinese mainland in 2017,the number of GETV-affected provinces has increased to seventeen till now.Therefore,we performed an epidemiologic investigation of GETV in the Xinjiang region,located in northwestern China,during the period of 2017-2020.ELISA was used to analyze 3299 serum samples collected from thoroughbred horse,local horse,sheep,goat,cattle,and pigs,with thoroughbred horse(74.8%),local horse(67.3%),goat(11.7%),sheep(10.0%),cattle(25.1%)and pigs(51.1%)being positive for anti-GETV antibodies.Interestingly,the neutralizing antibody titer in horses was much higher than in other species.Four samples from horses and pigs were positive for GETV according to RT-PCR.Furthermore,from the serum of a local horse,we isolated GETV which was designated as strain XJ-2019-07,and determined its complete genome sequence.From the phylogenetic relationships,it belongs to the Group III lineage.This is the first evidence of GETV associated to domestic animals in Xinjiang.Overall,GETV is prevalent in Xinjiang and probably has been for several years.Since no vaccine against GETV is available in China,detection and monitoring strategies should be improved in horses and pigs,especially imported and farmed,in order to prevent economic losses.Ning Shi Xiangshu Qiu Xinyu Cao Zhanhai Mai Xiangyu Zhu Nan Li He Zhang Jinyong Zhang Zhuoxin Li Nuerlan Shaya Huijun Lu Ningyi Jin 2022Virologica Sinica2022,37,2:5
7Snow and sea ice thermodynamics in the Arctic:Model validation and sensitivity study against SHEBA data显示文摘Evolution of the Arctic sea ice and its snow cover during the SHEBA year were simulated by applying a high-resolution thermodynamic snow/ice model (HIGHTSI).Attention was paid to the impact of albedo on snow and sea ice mass balance,effect of snow on total ice mass balance,and the model vertical resolution. The SHEBA annual simulation was made applying the best possible external forcing data set created by the Sea Ice Model Intercomparison Project.The HIGHTSI control run reasonably reproduced the observed snow and ice thickness.A number of albedo schemes were incorporated into HIGHTSI to study the feedback processes between the albedo and snow and ice thickness.The snow thickness turned out to be an essential variable in the albedo parameterization.Albedo schemes dependent on the surface temperature were liable to excessive positive feedback effects generated by errors in the modelled surface temperature.The superimposed ice formation should be taken into account for the annual Arctic sea ice mass balance.Cheng Bin Timo Vihma Zhang Zhanhai Li Zhijun Wu Huiding 2008Chinese Journal of Polar Science2008,19,2:5
8Review of research on Arctic sea ice physics based on the Chinese National Arctic Research Expedition显示文摘China launched its Arctic research program and organized the first Chinese National Arctic Research Expedition(CHINARE-Arctic) in 1999. By 2016, six further expeditions had been conducted using the R/V Xuelong. The main region of the expeditions has focused on the Pacific sector of the Arctic Ocean for sea ice observations. The expeditions have used icebreaker, helicopter, boat, floe, and buoy platforms to perform these observations. Some new technologies have been developed, in particular, the underway auto-observing system for sea ice thickness using an electromagnetic instrument. The long-term measurement systems, e.g., the sea ice mass balance buoy, allow observations to extend from summer to winter. Some international cooperation projects have been involved in CHINARE-Arctic, especially the 'Developing Arctic Modeling and Observing Capabilities for Long-Term Environmental Studies' project funded by the European Union during the International Polar Year. Arctic sea ice observations have been used to verify remote sensing products, identify changes in Arctic sea ice, optimize the parameterizations of sea ice physical processes, and assess the accessibility of ice-covered waters, especially around the Northeast Passage. Recommendations are provided as guidance to future CHINARE-Arctic projects. For example, a standardized operation system of sea ice observations should be contracted, and the observations of sea ice dynamics should be enhanced. The upcoming launch of a new Chinese icebreaker will allow increased ship time in support of future CHINARE Arctic oceanographic investigations.LEI Ruibo ZHANG Zhanhai LI Zhijun YANG Qinghua LI Bingrui LI Tao 2017Advances in Polar Science2017,28,2:5
9Sensitivity of the Arctic sea ice concentration forecasts to different atmospheric forcing: a case study显示文摘A regional Arctic configuration of the Massachusetts Institute of Technology general circulation model(MITgcm) is used as the coupled ice-ocean model for forecasting sea ice conditions in the Arctic Ocean at the National Marine Environmental Forecasting Center of China(NMEFC), and the numerical weather prediction from the National Center for Environmental Prediction Global Forecast System(NCEP GFS) is used as the atmospheric forcing. To improve the sea ice forecasting, a recently developed Polar Weather Research and Forecasting model(Polar WRF) model prediction is also tested as the atmospheric forcing. Their forecasting performances are evaluated with two different satellite-derived sea ice concentration products as initializations:(1) the Special Sensor Microwave Imager/Sounder(SSMIS) and(2) the Advanced Microwave Scanning Radiometer for EOS(AMSR-E). Three synoptic cases, which represent the typical atmospheric circulations over the Arctic Ocean in summer 2010, are selected to carry out the Arctic sea ice numerical forecasting experiments. The evaluations suggest that the forecasts of sea ice concentrations using the Polar WRF atmospheric forcing show some improvements as compared with that of the NCEP GFS.YANG Qinghua LIU Jiping ZHANG Zhanhai SUI Cuijuan XING Jianyong LI Ming LI Chunhua ZHAO Jiechen ZHANG Lin 2014Acta Oceanologica Sinica2014,33,12:5
10Antarctic ice sheet GLIMMER model test and its simplified model on 2-dimensional ice flow显示文摘The 3-dimensional finite difference thermodynamic coupled model on Antarctic ice sheet,GLIMMER model,is described. An ide-alized ice sheet numerical test was conducted under the EISMINT-1 benchmark,and the characteristic curves of ice sheets under steady state were obtained. Based on this,this model was simplified from a 3-dimensional one to 2-dimensional one. Improvement of the dif-ference method and coordinate system was proposed. Evolution of the 2-dimensional ice flow was simulated under coupled temperature field conditions. The results showed that the characteristic curves deriving from the conservation of the mass,momentum and energy agree with the results of ice sheet profile simulated with GLIMMER model and with the theoretical results. The application prospect of the simplified 2-dimensional ice flow model to simulate the relation of age-depth-accumulation in Dome A region was discussed.Xueyuan Tang Zhanhai Zhang Bo Sun Yuansheng Li Na Li Bangbing Wang Xiangpei Zhang 2008Progress in Natural Science:Materials International2008,18,2:3
11Interpreting grain-size trends associated with bedload transport on the intertidal fiats at Dafeng,central Jiangsu coast显示文摘A MIDAS-400 customized data acquisi- tion system has been used for the high-resolution sediment dynamic measurements over the Dafeng intertidal flats of northern Jiangsu during 6 tidal cy- cles from July 3 to July 10, 2003. The bed shear stress and bedload transport rates, in response to wave-current interactions, are calculated, which in- dicate that wind waves enhance the bottom shear stress and bedload transport rates. At the station for measurements, bedload transport was directed to seaward, with a sediment discharge of 30—150 kg·m?1 per tidal cycle. The surficial sediment samples were collected from a grid with 10 m spatial intervals over a rectangle 2×104 m2 experimental area, near the MIDAS-400 during the spring tide of July 4, 2003, and the neap tide of July 9, 2003. In addition, leveling survey was undertaken to obtain the detailed topog- raphy of the sampling area. Grain-size trend analysis of the sediment samples shows that the bedload transport patterns are complex, mainly controlled by the hydrodynamics and local geomorphology (e.g. tidal creeks) over the intertidal flats. Furthermore, the grain-size trends pattern during the neap tide rather than during the spring tide is consistent with the cal- culated bedload transport, and the grain-size trend vectors for the spring tide are larger than those forthe neap tide, indicating that the sampling thickness of surficial sediment during the neap tide may contain the information on the geomorphological evolution (or sediment deposition/erosion) from the spring to the neap tide.JIA Jianjun WANG Yaping GAO Shu WANG Aijun LI Zhanhai 2006Chinese Science Bulletin2006,51,3:3
12Observed and modelled snow and ice thickness in the Arctic Ocean with CHINARE buoy data显示文摘Sea ice and the snow pack on top of it were investigated using Chinese National Arctic Research Expedition(CHINARE) buoy data.Two polar hydrometeorological drifters,known as Zeno? ice stations,were deployed during CHINARE 2003.A new type of high-resolution Snow and Ice Mass Balance Arrays,known as SIMBA buoys,were deployed during CHINARE 2014.Data from those buoys were applied to investigate the thickness of sea ice and snow in the CHINARE domain.A simple approach was applied to estimate the average snow thickness on the basis of Zeno~ temperature data.Snow and ice thicknesses were also derived from vertical temperature profile data based on the SIMBA buoys.A one-dimensional snow and ice thermodynamic model(HIGHTSI) was applied to calculate the snow and ice thickness along the buoy drift trajectories.The model forcing was based on forecasts and analyses of the European Centre for Medium-Range Weather Forecasts(ECMWF).The Zeno~ buoys drifted in a confined area during 2003–2004.The snow thickness modelled applying HIGHTSI was consistent with results based on Zeno~ buoy data.The SIMBA buoys drifted from 81.1°N,157.4°W to 73.5°N,134.9°W in 15 months during2014–2015.The total ice thickness increased from an initial August 2014 value of 1.97 m to a maximum value of2.45 m before the onset of snow melt in May 2015;the last observation was approximately 1 m in late November2015.The ice thickness based on HIGHTSI agreed with SIMBA measurements,in particular when the seasonal variation of oceanic heat flux was taken into account,but the modelled snow thickness differed from the observed one.Sea ice thickness derived from SIMBA data was reasonably good in cold conditions,but challenges remain in both snow and ice thickness in summer.TIAN Zhongxiang CHENG Bin ZHAO liechen VIHMA Timo ZHANG Wenliang LI Zhijun ZHANG Zhanhai 2017Acta Oceanologica Sinica2017,36,8:3
13Evolution and breaking of a propagating internal wave in stratified ocean显示文摘The evolution and breaking of a propagating internal wave are directly numerically simulated using a pseudo-spectral method. The mechanism of PSI (parametric subharmonic instability) involved in the evolution is testified clearly. It dominates gradually in nonlinear resonant interactions. As a consequence,the energy cascades to a second plant wave packet which has lower frequencies and higher wavenumbers than that of the primary wave. With the growth of this wave packet,wave breaking occurs and causes strongly nonlinear regime,i.e. stratified turbulence. The strong mixing and intermittent of the turbulence can be learned from the evolution of the total energy and kurtosis of vorticity vs. time. Some statistic properties of the stratified turbulence are also analyzed,including the spectra of KE (kinetic energy) and PE (potential energy). The results show that the PE spectra display a wavenumber range scaling as 0.2 N4k-3y (N is the Brunt-Visl frequency,ky is the vertical wavenumber),which is called buoyancy sub-range. However,the KE spectra cannot satisfy the negative cubic law of vertical wavenumber,which have a much larger downtrend than that of the PE spectra,for the potential energy is transferred more efficiently toward small scales than the kinetic energy. The Cox number of diapycnal diffusivity is also calculated,and it shows a good consistency with the observations and deductions in the ocean interior,during the stage of the stratified turbulence maintaining a fairly active level.LI Bingrui FAN Haimei TIAN Jiwei SUN Bo ZHANG Zhanhai 2008Acta Oceanologica Sinica2008,27,1:3
14Some parameters in arctic sea ice dynamics from an expedition in the summer of 2003显示文摘On the basis of the investigated data for sea ice physical processes during the Second Chinese National Arctic Research Expedition (CHINARE-2003) in the summer of 2003, the sea ice dynamical characteristics were analyzed and the parameters describing these characteristics were given. The new findings discovered from these parameters are:(1) The ice concentration obtained from the investigation is two tenths to three tenths lower compared with that from the NOAA Ice Chart; and the ice thickness in the summer is 2 m less compared with the results obtained during the First Chinese National Arctic Research Expedition in 1999 (CHINARE-1999), (2) the standard deviation of the ice bottom fluctuation is 3.8 times that of the snow surface on the ice sheet; (3) the maximum speed of the ice floe on which camp CHIS7 is located (CHIS7 floe) is 1 300 m/h with rotation and oscillation. The rotation angle increased stepwise, the maximum being 37.8°, while the CHIS7 floe moved toward the north-east, and its rotation angle decreased stepwise.While the CHIS7 floe moved south-eastward. The oscillation period of CHIS7 floe is 12.45 h, which is consistent with that of the inertial current at the same latitude, showing the contribution of the inertial current to the ice floe movement.LI Zhijun ZHANG Zhanhai LU Peng DONG Xilu CHENG Bin CHEN Zhi 2005Acta Oceanologica Sinica2005,24,6:3
15Arctic sea ice distribution in summer based on aerial photos显示文摘On the basis of aerial photos of sea ice in the Second Chinese National Arctic Research Expdition during July and September 2003 in the area of74.11°~79.56°N and 144.17°~169.95°W, image processing techniques are used to acquire some geometric parameters of floes, such as fractal dimension, roundness and mean caliper diameter. Latitudinal variation of morphology of arctic ice floes is then obtained, after comparing fractal dimension and roundness which represent geometry of floe edge, the latter is found to show a more obvious tendency with latitude but still not enough to describe floe abrasion. Then mean caliper diameter of ice floe is used as charac-teristic size to analyze floe size distribution, the result reveals that cumulative probabilities of floe sizes agree well with a power-law function, and distribution dimension is generally in the range of 1.05~1.25 and slightly increases as the latitude increases. However slight curvatures are still observed in the plots of cumulative probabilities as in former researches, which can be attributed to both the limitation of sampling area and effect of thermodynamic process.LU Peng LI Zhijun ZHANG Zhanhai DONG Xilu 2005Acta Oceanologica Sinica2005,24,6:3
16Grain-size distribution patterns of suspended sediment in response to hydrodynamics on the Dafeng intertidal flat, Jiangsu, China显示文摘在关系的推迟的沉积的谷物尺寸分布的模式撕了暂停,安定,并且潮汐的过程被调查基于在在 theDafeng 上的 situ 大小内部潮滩在江苏海岸上,在 2002 和 2003 的夏天。这里的推迟的沉积被罚款并且很统治细粉粒,与 7 ~的一种吝啬的谷物尺寸 13 μ m。推迟的沉积的谷物尺寸分布的 Thepatterns 被二种类型在一个潮汐的周期期间描绘:代表不足道的空间、时间的变化的一种稳定的类型;并且另外的双性人有重要变化的形式的类型。影响thegrain尺寸分布的主要因素包括暂停,安定,进口 intointertidal 公寓在洪水期间分阶段执行的推迟的沉积,和海床 sediment.Resuspension 的谷物尺寸分发增加粗糙的粒子内容,提高推迟的沉积的吝啬的谷物尺寸,并且为海床沉积的类似于那些的推迟的沉积导致谷物尺寸分布;安定过程在推迟的沉积上有相反的效果。Whenresuspension 发生,在水列的更低的部分的推迟的沉积的获得尺寸分布对临显著地作出回应。在暂停和安定过程的影响是弱的的地方,推迟的沉积的谷物尺寸分布看起来为各种各样的部分稳定、几乎相同内部潮滩在不同测量时期期间。如此的分布被指背景谷物尺寸分发,为哪个在 Dafeng 上的 meangrain 尺寸内部潮滩在 7 μ m 附近。LI Zhanhai GAO Shu CHEN Shenliang WANG Yaping 2006Acta Oceanologica Sinica2006,25,6:2
17In situ monitoring of rockburst nucleation and evolution in the deeply buried tunnels of Jinping II hydropower station显示文摘Shaojun Li Xia-Ting Feng Zhanhai Li Bingrui Chen Chuanqing Zhang Hui Zhou 2012Engineering Geology2012,,:2
18Interaction of an anticyclonic eddy with sea ice in the western Arctic Ocean:an eddy-resolving model study显示文摘The dramatic decline of summer sea ice extent and thickness has been witnessed in the western Arctic Ocean in recent decades,which has motivated scientists to search for possible factors driving the sea ice variability.An eddy-resolving,ice-ocean coupled model covering the entire Arctic Ocean is implemented,with focus on the western Arctic Ocean.Special attention is paid to the summer Alaskan coastal current(ACC),which has a high temperature(up to 5 C or more) in the upper layer due to the solar radiation over the open water at the lower latitude.Downstream of the ACC after Barrow Point,a surface-intensified anticyclonic eddy is frequently generated and propagate towards the Canada Basin during the summer season when sea ice has retreated away from the coast.Such an eddy has a warm core,and its source is high-temperature ACC water.A typical warm-core eddy is traced.It is trapped just below summer sea ice melt water and has a thickness about 60 m.Temperature in the eddy core reaches 2-3 C,and most water inside the eddy has a temperature over 1 C.With a definition of the eddy boundary,an eddy heat is calculated,which can melt 1 600 km 2 of 1 m thick sea ice under extreme conditions.LI Qun ZHANG Zhanhai WU Huiding 2013Acta Oceanologica Sinica2013,32,3:2
19Dominant climate factors influencing the Arctic runoff and association between the Arctic runoff and sea ice显示文摘By using the Arctic runoff data from R-ArcticNET V4.0 and ArcticRIMS,trends of four major rivers flowing into the Arctic Ocean,whose climate factor plays an important role in determining the variability of the Arctic runoff,are investigated.The results show that for the past 30 years,the trend of the Arctic runoff is seasonally dependent.There is a significant trend in spring and winter and a significant decreasing trend in summer,leading to the reduced seasonal cycle.In spring,surface air temperature is the dominant factor influencing the four rivers.In summer,precipitation is the most important factor for Lena and Mackenzie,while snow cover is the most important factor for Yenisei and Ob.For Mackenzie,atmospheric circulation does play an important role for all the seasons,which is not the case for the Eurasian rivers.The authors further discuss the relationships between the Arctic runoff and sea ice.Significant negative correlation is found at the mouth of the rivers into the Arctic Ocean in spring,while significant positive correlation is observed just at the north of the mouths of the rivers into the Arctic in summer.In addition,each river has different relationship with sea ice in the eastern Greenland Sea.LI Pixue ZHANG Zhanhai LIU Jiping 2010Acta Oceanologica Sinica2010,29,5:2
20Sensitivity and nonlinearity of Eurasian winter temperature response to recent Arctic sea ice loss显示文摘The recent decline in the Arctic sea ice has coincided with more cold winters in Eurasia.It has been hypothesized that the Arctic sea ice loss is causing more mid-latitude cold extremes and cold winters,yet there is lack of consensus in modeling studies on the impact of Arctic sea ice loss.Here we conducted modeling experiments with Community Atmosphere Model Version 5(CAM5) to investigate the sensitivity and linearity of Eurasian winter temperature response to the Atlantic sector and Pacific sector of the Arctic sea ice loss.Our experiments indicate that the Arctic sea ice reduction can significantly affect the atmospheric circulation by strengthening the Siberian High,exciting the stationary Rossby wave train,and weakening the polar jet stream,which in turn induce the cooling in Eurasia.The temperature decreases by more than 1°C in response to the ice loss in the Atlantic sector and the cooling is less and more shifts southward in response to the ice loss in the Pacific sector.More interestingly,sea ice loss in the Atlantic and Pacific sectors together barely induces cold temperatures in Eurasia,suggesting the nonlinearity of the atmospheric response to the Arctic sea ice loss.SUI Cuijuan ZHANG Zhanhai YU Lejiang LI Yi SONG Mirong 2017Acta Oceanologica Sinica2017,36,8:2
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