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1.
Based on the observed and NCEP reanalysis data from 1985 to 2006,the climate background and synoptic situation of fog at Great Wall Station were analyzed. It is shown that the seasonal variation of fog is controlled by the change of general circulation and local pressure field. Three favorable typical synoptic situations for fog development are found, the Front-of-A-Depression type, the Saddle-Shaped-Field type and the Passing-Weak-Cyclone type. The first one is the most important situation. Advection cooling fog is dominant at Great Wall Station, but there are other kinds of fog as well. As a result, some helpful principles for local fog forecasting are given. 相似文献
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A case of a snowstorm at the Great Wall Station was studied using data of NCEP (National Centers for Environmental Prediction) analysis, in situ observations and surface weather charts. The storm occurred on August 29th,2006, and brought high winds and poor horizontal visibility to the region.It was found that the storm occurred under the synoptic situation of a high in the south and a low in the north. A low-level easterly jet from the Antarctic continent significantly decreased the air temperature and humidity.Warm air advection at high level brought sufficient vapor from lower latitudes for the snowstorm to develop.The dynamic factors relating to strong snowfall and even the developmentof a snowstorm were deep cyclonic vorticity at middle and low levels,the configuration of divergence at high level and convergence at low level, and strong verticaluplift. There was an inversion layer in the low-level atmosphere during the later phase of the storm.This vertical structure of cold air at low levels and warm air at high levels may have been important to the longevity of the snowstorm. 相似文献
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Gravity measurement is of great importance to the height datum in Antarctica.The absolute gravity measurement was carried out at Great Wall Station, Antarctica, using FG5 absolute gravity instrument.The gravity data was processed with corrections of earth tide, ocean tide, polar motion and the atmospher, and the RMS is within +3 x 10 -s ms-2.The vertical and horizontal gravity gradients were measured using 2 LaCoaste & Romberg (LCR) gravimeters.The absolute gravity measurement provides the fundamental data for the validation and calibration of the satellite gravity projects such as CHAMP, GRACE and GOCE, and for the high accuracy geoid model. 相似文献
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TIAN Shichao JIN Haiyan GAO Shengquan ZHUANG Yanpei ZHANG Yang WANG Bin CHEN Jianfang 《极地研究(英文版)》2015,(1)
Concentrations of chlorophyll-a (Chl-a), particulate organic carbon (POC) and its stable carbon isotope composition (δ13C) were analyzed to investigate the biogeochemical characteristics and sources of... 相似文献
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The radioactive isotope——137 Cs is one of the important tracers for studying the physical processes and the human impacts on the environment. Based on the investigation results of the terrestrial ecosystem of Great Wall Station, Antarctica, it was shown that there are some artificial radioactive elements——137Cs in Antarctic terrestrial ecosystem. The sequence of 137Cs specific activities is as follows: crustaceous lichen>fruticose lichen>surface-moss>surface soil, and the crustaceous lichen is one of the most sensitive ways in monitoring the impact of the long-term diffusion of 137Cs on the environment. 相似文献
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Since 2002, we have been observing the mesosphere and lower thermosphere (MLT) region over King Sejong Station (KSS; 62.22°S, 58.78°W), Antarctica, using various instruments such as the Spectral Airglow Temperature Imager (SATI), All Sky Camera (ASC) and VHF meteor radar. The meteor radar, installed in March 2007, continuously measures neutral winds in the alti- tude region 70-110 km and neutral temperature near the mesopause 24 h.d-1, regardless of weather conditions. In this study, we present results of an analysis of the neutral wind data for gravity wave activity over the tip of the Antarctic Peninsula, where such activity is known to be very high. Also presented is temperature estimation from measurement of the decay times of meteor trails, which is compared with other temperature measurements from SATI and the Sounding of the Atmosphere using Broadband Emis- sion Radiometry (SABER) instrument onboard the Thermosphere Ionosphere Mesosphere Energy and Dynamics (TIMED) satel- lite. 相似文献
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基于影像的明长城解译与判识,可在室内获得有关长城走向与基本空间分布格局。据此,文物田野调查人员可以科学制定田野调查规划以提高长城资源田野调查效率。同时,在影像上标志长城资源的田野调查成果,能够进一步提高明长城记录的科学性、正确性与准确性,确保明长城在语义与空间位置上的统一与唯一,为测量长城、制定长城保护与管理方案等奠定... 相似文献
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由于历史的原因和技术条件所限,我国一直未能实施长城资源的综合科学调查,缺乏关于其空间分布、保存状况、实际长度等方面的科学数据资料。为了摸清明长城"家底",国家测绘局和国家文物局发挥各自优势,联合开展了长城资源调查与测量工作。按照"文物部门定性、测绘部门定量"的基本策略,提出了"影像为基、立体量测、带状建库"的总体研究思路;研究制定了明长城资源田野调查、明长城长度量测和明长城资源地理信息系统建设的技术路线;开展了技术试点、标准制定、人员培训、质量控制等方面的工作。经过来自明长城沿线10个省(市、自治区)的上百名文物专家和700多名测绘专业技术人员三年多的不懈努力,该项目在世界上首次完成了长达8 800余公里的超大型线型文化遗产的资源综合调查与测量,第一次全面获得了关于明长城资源分布与坡面长度等一系列丰硕成果,成功地拓展了地理信息在文物领域的应用,在国内外产生了重要影响。 相似文献
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The ice algal and phytoplankton assemblages were studied from Nella Fjord near Zhongshan Station, East Antarctica from April 12 to December 30, 1992. Algal blooms occurred about 3 cm thick on the bottom of sea ice in late April and mid November to early December respectively, and a phytoplankton bloom appeared in the underlying surface water in mid December following the spring ice algal bloom. The biomass in ice bottom was 1 to 3 orders of magnitude higher than that of surface water. Amphiprora kjellmanii, Berkeleya sp., Navicula glaciei, Nitzschia barkelyi, N. cylindrus /N. curta, N. lecointei and Nitzschia sp. were common in the sea ice temporarily or throughout the study period. The biomass in a certain ice segment was decreased gradually and the dominant species were usually succeeded as the season went on. Nitzschia sublineata and Dactyliosolen antarctica were two seasonal dominant species only observed in underlying water column. The assemblages between bottom of ice and underlying surface water were different except when spring ice algae bloomed. The evidence shows that the ice algal blooms occurred mainly by in situ growth of ice algae, and the phytoplankton bloom was mostly caused by the release of ice algae. 相似文献
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1 Introduction Thestudyonthefeaturesofatmosphericenvironmentbyglaciochemistryisthemajor contentofsnow iceandglobalchangeresearch.Antarcticicesheetisfarfromtheregions pollutedbyhumanactivities,andsurroundedbyocean,andtheAntarcticCircumpolarCur rentisthewideseawaterandatmospherebarrierbetweenAntarcticaandtheoutsideworld. AlloftheuniquegeographicalfeaturesmaketheimpuritiesinsnowandiceinAntarcticice sheetissimple.Therefore,itissignificanttostudytheorigins,transmissionpathsanddep ositionalst… 相似文献
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Instrumental neutron activation analysis (INAA) was applied to analyze the bulk, high-volume aerosol samples, collected at Zhongshan Station in the Eastern Antarctica, during 1998-2001, to study the chemical species. .A graphical technique was applied to the INAA data. Results showed that Na, Cl, Mg, Ca, Sr, Br, I, Sr and Rb were marine elements while Al, Sc, Fe and Mn were crustal elements. Compared to marine and crustal elements, five elements (Se、Co、Sb、Zn、Cr) were highly abundant in the aerosols collected at Zhongshan station, which indicated that they might come from the petroleum burning, heating and equipment operation. The presence of pollutant elements suggested that human activities have affected the local environments in Antarctica. 相似文献
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Toshitaka Suzuki Yoshinori Iizuka Teruo Furukawa Kenichi Matsuoka Kokichi Kamiyama Okitsugu Watanabe 《极地研究(英文版)》2003,14(1)
1 IntroductionAntarcticicesheetisaburialgroundforatmosphericdeposition .Sincethereiscon tinuousinteractionbetweentheicesheetandtheatmosphere,variousatmosphericsub stancesareinjectedtotheicesheetsequentiallyintimeandspace.Therefore,verticalanalysesoftheicesheetprovideuswithinformationaboutpastclimaticchange (Delmas1 992 ;LegrandandMayewski 1 997)andhorizontalanalysesoftheicesheetprovideuswithknowledgeregardinglong rangetransportofairbornematerials (Kamiyamaetal.1 989;KreutzandMayewski 1 999)… 相似文献
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The thermodynamic properties of snow cover on sea ice play a key role in the ice-ocean-atmosphere system and have been a focus of recent scientific research. In this study, we investigated the thermodynamic properties of snow cover on sea ice in the Nella Fjord, Prydz Bay, East Antarctica(69°20′S, 76°07′E), near the Chinese Antarctic Zhongshan Station. Our observations were carried out during the 29th Chinese National Antarctic Research Expedition. We found that the vertical temperature profile of snow cover changed considerably in response to changes in air temperature and solar radiation during the summer. Associated with the changes in the temperature profile were fluctuations in the temperature gradient within the upper 10 cm of the snow cover. Results of previous research have shown that the thermal conductivity of snow is strongly correlated with snow density. To calculate the thermal conductivity in this study, we measured densities in three snow pits. The calculated thermal conductivity ranged from 0.258–0.569 W?m-1?K-1. We present these datasets to show how involved parameters changed, and to contribute to a better understanding of melting processes in the snow cover on sea ice. 相似文献
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1 IntroductionTheafternoonregion (approximately 1 4 0 0to 1 60 0MLT)hasaspecialsignificanceforavarietyofmagnetosphericphenomena.Itsproximitytomagneticnoonsuggeststhattheauroralphenomenaobservedmayberelatedtodaysidemagnetosphericprocesses ,andindeedavarietyofstu… 相似文献
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1 IntroductionAlongwiththearrivalof2 3rdsolaractivepeakandthedevelopmentofthespacesci ence ,thescientistsaremoreandmoreinterestedintopicsofgeospaceeffectscausedbytheintensesolaractivities.Thegeospaceeffectsofseveralextremesolaractiveevents,suchasthe 1 993No… 相似文献
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Dome A is the highest ice feature in the Antarctica,up to now,little is known about surface topography at Dome A.The first Chinese ITASE expedition was carried out from Zhongshan station to Dome A during the 1996/1997 austral summer. During the 2004/2005 austral summer,the traverse was extended to the summit of Dome A which is 1228 km from Zhongshan Station by 21st Chinese National Antarctic Research Expedition (CHINARE).The real-time kinematic (RTK) GPS survey was carried out in the summit of Dome A dur... 相似文献
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Meiofaunal communities of three small, shallow freshwater habitats sampled during the austral summer of 2013 in Greenwich Island, South Shetland Islands, Antarctica, are reported. Communities are domin... 相似文献