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A Review of Atmospheric Electricity Research in China from 2011 to 2018 预览
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作者 Xiushu QIE Yijun ZHANG 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第9期994-1014,共21页
Atmospheric electricity research has been conducted actively in China,having profited from the development and application of high temporal and spatial resolution lightning detection and location technologies.This pap... Atmospheric electricity research has been conducted actively in China,having profited from the development and application of high temporal and spatial resolution lightning detection and location technologies.This paper reviews the scientific advances made in the field of atmospheric electricity in China from 2011 to 2018,covering the following five aspects:(1)lightning detection and location techniques;(2)discharge processes and parameters associated with rocket-triggered lightning;(3)physical processes in natural lightning and attachment to the ground;(4)lightning activities and charge structure in different thunderstorms;and(5)effects of thunderstorms on the upper atmosphere.In addition,some outstanding questions for future research are outlined. 展开更多
关键词 ATMOSPHERIC ELECTRICITY LIGHTNING THUNDERSTORM LIGHTNING LOCATION TECHNIQUES
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Characteristics of size distributions and sources of water-soluble ions in Lhasa during monsoon and non-monsoon seasons
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作者 Nannan Wei Zhiyou Xu +5 位作者 Junwen Liu Guanghua Wang Wei Liu Deqing Zhuoga Detao Xiao Jian Yao 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第8期155-168,共14页
To understand the physical and chemical characteristics, particle size distribution and sources of size-separated aerosols in Lhasa, which is located on the Tibetan Plateau(TP), six sizes of aerosol samples were colle... To understand the physical and chemical characteristics, particle size distribution and sources of size-separated aerosols in Lhasa, which is located on the Tibetan Plateau(TP), six sizes of aerosol samples were collected in Lhasa in 2014. Ca^2+, NH4^+, NO3^-,SO4^2-and Cl^-were the dominant ions. The ratio of cation equivalents(CE) to anion equivalents(AE) for each particle size segment indicated that the atmospheric aerosols in Lhasa were alkaline. SO4^2-and NO3-could be neutralized by Ca^2+, but could not be neutralized by NH4^+, according to the [NH4^+]/[NO3^-+ SO4^2-] and [Ca^2+]/[NO3^-+ SO4^2-] ratios. Mobile sources were dominant in PM0.95-1.5,PM1.5-3 and PM3-7.2, while stationary sources were dominant in the other three size fractions according to the [NO3^-]/[SO4^2-] ratios. The particle size distribution of all watersoluble ions during monsoon and non-monsoon periods was characterized by a bimodal distribution due to the different sources and formation mechanisms, and it was revealed that different ions had different sources in different seasons and different particle size segments by combining particle size distribution with correlation analysis. Source analysis of aerosols in Lhasa was performed using the Principal component analysis(PCA) for the first time, which revealed that combustion sources, motor vehicle exhaust, photochemical reaction sources and various types of dust were the main sources of Lhasa aerosols.Furthermore, Lhasa’s air quality was also affected by long-distance transmission, expressed as pollutants from South Asia and West Asia, which were transmitted to Lhasa according to backward trajectory analysis. 展开更多
关键词 Atmospheric AEROSOLS WATER-SOLUBLE ions(WSIs) Size distribution Principal component analysis(PCA) BACKWARD trajectory
Electrical features of radio-frequency atmospheric pressure helium discharge with and without dielectric electrodes
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作者 H ASHRAF S Z A SHAH +5 位作者 H I A QAZI M A KHAN S HUSSAIN M A BADAR S NIAZ M SHAFIQ 《等离子体科学与技术:英文版》 SCIE EI CAS CSCD 2019年第2期60-67,共8页
A comparative study of radio-frequency atmospheric pressure glow discharge(rf APGD)generated in helium with and without dielectric electrodes to investigate the effect of electrodes insulation on electrical features o... A comparative study of radio-frequency atmospheric pressure glow discharge(rf APGD)generated in helium with and without dielectric electrodes to investigate the effect of electrodes insulation on electrical features of APGD is presented. In the α mode, both the rf APGDs remain volumetric, stable and uniform. In the γ mode, the APGD without dielectric electrodes shrinks into a constricted plasma column whereas APGD with dielectric electrodes remains stable and retains the same volume without plasma constriction even at higher densities of discharge current. A comparison of electrical features of both rf APGDs in normal and abnormal glow discharge regimes is presented. In both APGDs with and without dielectric electrodes,impedance measurements have been performed and compared with equivalent circuit models.The measured impedance data is found to be in good agreement with simulated data. 展开更多
关键词 RADIOFREQUENCY atmospheric pressure GLOW DISCHARGE DIELECTRIC ELECTRODES plasma stability control
Coastal sea level variability in the Bohai Bay: influence of atmospheric forcing and prediction 预览
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作者 Lü Xianqing WANG Daosheng +1 位作者 YAN Bing YANG Hua 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第2期486-497,共12页
The sea level variabilities, especially the atmosphere-driven sea level variabilities, which are diff erent in studies on diverse areas and timescales, need to be further documented in the Bohai Bay. Coastal sea level... The sea level variabilities, especially the atmosphere-driven sea level variabilities, which are diff erent in studies on diverse areas and timescales, need to be further documented in the Bohai Bay. Coastal sea level data and coincident meteorological data collected hourly at two observation stations (E1 and E2) in the Bohai Bay, which is a typical semi-enclosed coastal sea in China, are analyzed for the period from 19 August 2014 to 18 November 2014. The sub-sampled low-pass (<0.8 cpd) sea levels (SLSLs) at E1 and E2 are almost the same as each other, while the winds are not. On the whole, SLSLs at E1 and E2 are dominantly influenced by the across-shore wind;in detail, the dominant wind orientation at E1 is 65° measured clockwise from north, and SLSL at E2 is significantly influenced by the sub-sampled wind (SW) at 55°. Regression of SLSL onto the corresponding SW in dominant orientation and the atmospheric pressure is used to predict SLSL, which make the frequency of occurrences when the predicted total sea level is within 0.15 m from the observed values increase to 66.03% and 58.08% at E1 and E2 from original 36.71% and 34.80% without using it, respectively. The results indicate that for the prediction of the total sea level variability in the coastal shallow waters, the SLSL influenced by the atmospheric forcing, including local wind and atmospheric pressure, can be predicted using the multivariable linear regression model. 展开更多
关键词 COASTAL sea level ATMOSPHERIC FORCING Bohai BAY PREDICTION
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Perturbations in Earth’s Atmosphere over An Indian Region during the Total Solar Eclipse on 22 July 2009
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作者 S.B.Surendra PRASAD Vinay KUMAR +4 位作者 K.Krishna REDDY S.K.DHAKA Shristy MALIK M.Venkatarami REDDY U.Murali KRISHNA 《气象学报:英文版》 SCIE CSCD 2019年第4期784-796,共13页
During a total solar eclipse(TSE)on 22 July 2009,atmospheric perturbations were monitored from the surface to thermosphere to understand TSE’s impact on the meteorological(temperature,relative humidity,wind speed,and... During a total solar eclipse(TSE)on 22 July 2009,atmospheric perturbations were monitored from the surface to thermosphere to understand TSE’s impact on the meteorological(temperature,relative humidity,wind speed,and wind direction)and chemical(O3 and NOx)parameters around Kadapa(14.28°N,78.42°E),a tropical semi-arid region of India.For this purpose,an experiment was conducted at Yogi Vemana University Campus,Kadapa,India,to measure the temperature,wind speed,wind direction,and concentrations of ozone(O3),NO,NO2,and NOx by using the automatic weather station(AWS)and O3 analyzer.On the eclipse day(22 July 2009),the surface observations at Kadapa showed a reduction in temperature(about 1.1℃)because of the solar insulation.Comparison of the thermal,dynamical(wind),and chemical parameters on the TSE day with control days[preceding(21 July 2009)and succeeding(23 July 2009)the TSE]illustrated the influence of solar eclipse.During the eclipse period,the O3 mixing ratio decreased,while NO2 and NOx increased;however,NO remained unchanged.In addition,radio occultation(RO)temperature profiles from Constellation Observing System for Meteorology,Ionosphere,and Climate(COSMIC)/Formosat Satellite Mission(FORMOSAT-3)and Thermosphere,Ionosphere,and Mesosphere Energetics and Dynamics(TIMED)satellites were utilized to understand the impact of TSE on dynamics of the middle and upper atmosphere from tropopause to the thermosphere.High vertical resolution COSMIC observations revealed that during the solar eclipse,tropopause was cooler with twin peaks(double tropopause).The lower thermosphere between 110 and 130 km became warmer during the TSE,which might be caused by the dynamical response of the atmosphere in this region to the solar eclipse.The experimental data have provided very fine-scale variations of the atmospheric parameters both in time and height and also constituted a new set of results on TSE for further research. 展开更多
关键词 total solar eclipse (TSE) atmospheric perturbations tropopause dynamics COSMIC/FORMOSAT-3satellite radio occultation (RO) observations
Synergistic Effect of NaCl and SO2 on the Initial Atmospheric Corrosion of Zinc Under Wet–Dry Cyclic Conditions
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作者 Qi Yin Zhen-Yao Wang +1 位作者 Miao-Ran Liu Chen Pan 《金属学报:英文版》 SCIE EI CAS CSCD 2019年第6期780-796,共17页
The synergistic eff ect of NaCl and SO2 on the atmospheric corrosion of zinc has been studied at equivalent total but different ratios of molar deposition rate under wet–dry cyclic conditions.The results show that th... The synergistic eff ect of NaCl and SO2 on the atmospheric corrosion of zinc has been studied at equivalent total but different ratios of molar deposition rate under wet–dry cyclic conditions.The results show that the corrosion rates,corrosion morphologies and the composition of the corrosion products are strongly infl uenced by the molar deposition rate ratio of NaCl and SO2(NaCl/SO2).The corrosivity of NaCl and SO2 toward zinc increases in order of SO2<1:3<3:1<NaCl<1:1.The corrosion morphology is patchy corrosion for Group 1:1,while it is pocking corrosion for the other four experimental groups.The corrosion product containing sulfur and chlorine detected on zinc is Gordaite(NaZn4SO4(OH)6Cl·6H2O),which has quite porous structure and was supposed to cause the patchy corrosion tendency of zinc in Group 1:1.In addition,soluble zinc corrosion products,which can inhibit the atmospheric corrosion process of zinc,were found on zinc samples in Groups 1:3 and SO2 and connected to the lower corrosion rates of zinc in these two groups. 展开更多
关键词 Atmospheric CORROSION ZINC SYNERGISTIC effect CORROSIVITY CORROSION morphology Gordaite
Response of the Dominant Modes of Atmospheric Circulation in the Northern Hemisphere to a Projected Arctic Sea Ice Loss in 2007 预览
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作者 FAN Tingting HUANG Fei ZHOU Xiao 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第3期589-595,共7页
This study revisits the Arctic sea ice extent(SIE) for the extended period of 1979-2015 based on satellite measurements and finds that the Arctic SIE experienced three different periods: a moderate sea ice decline per... This study revisits the Arctic sea ice extent(SIE) for the extended period of 1979-2015 based on satellite measurements and finds that the Arctic SIE experienced three different periods: a moderate sea ice decline period for 1979-1996, an accelerated sea ice decline period from 1997 to 2006, and large interannual variation period after 2007, when Arctic sea ice reached its tipping point reported by Livina and Lenton(2013). To address the response of atmospheric circulation to the lowest sea ice conditions with a large interannual variation, we investigated the dominant modes for large atmospheric circulation responses to the projected 2007 Arctic sea ice loss using an atmospheric general circulation model(ECHAM5). The response was obtained from two 50-yr simulations: one with a repeating seasonal cycle of specified sea ice concentration for the period of 1979-1996 and one with that of sea ice conditions in 2007. The results suggest more occurrences of a negative Arctic Oscillation(AO) response to the 2007 Arctic sea ice conditions, accompanied by an North Atlantic Oscillation(NAO)-type atmospheric circulation response under the largest sea ice loss, and more occurrences of the positive Arctic Dipole(AD) mode under the 2007 sea ice conditions, with an across-Arctic wave train pattern response to the largest sea ice loss in the Arctic. This study offers a new perspective for addressing the response of atmospheric circulation to sea ice changes after the Arctic reached the tipping point in 2007. 展开更多
关键词 ARCTIC sea ice LOSS ARCTIC OSCILLATION ARCTIC DIPOLE atmospheric RESPONSE
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Recent Progress in Numerical Atmospheric Modeling in China 预览
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作者 Rucong YU Yi ZHANG +4 位作者 Jianjie WANG Jian LI Haoming CHEN Jiandong GONG Jing CHEN 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第9期938-960,共23页
This review summarizes the scientific and technical progress in atmospheric modeling in China since 2011,including the dynamical core,model physics,data assimilation,ensemble forecasting,and model evaluation strategie... This review summarizes the scientific and technical progress in atmospheric modeling in China since 2011,including the dynamical core,model physics,data assimilation,ensemble forecasting,and model evaluation strategies.In terms of the dynamical core,important efforts have been made in the improvement of the existing model formulations and in exploring new modeling approaches that can better adapt to massively parallel computers and global multiscale modeling.With regard to model physics,various achievements in physical representations have been made,especially a trend toward scale-aware parameterization for accommodating the increase of model resolution.In the field of data assimilation,a 4D-Var system has been developed and is operationally used by the National Meteorological Center of China,and its performance is promising.Furthermore,ensemble forecasting has played a more important role in operational forecast systems and progressed in many fundamental techniques.Model evaluation strategies,including key performance metrics and standardized experimental protocols,have been proposed and widely applied to better understand the strengths and weaknesses of the systems,offering key routes for model improvement.The paper concludes with a concise summary of the status quo and a brief outlook in terms of future development. 展开更多
关键词 NUMERICAL MODELING ATMOSPHERIC MODELING WEATHER and CLIMATE MODELING
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Climatology of Winter Extratropical Cyclones over the Coastal Waters of China 预览
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作者 Naru Xie Meng Gao Zhiqiang Gao 《大气科学研究(英文)》 2019年第2期37-45,共9页
The East China coast is one major cyclogenesis region of extratropical cyclones (ETCs) in boreal winter. In this study, the climatological characteristics of winter ETCs passing over the coastal water of China are ana... The East China coast is one major cyclogenesis region of extratropical cyclones (ETCs) in boreal winter. In this study, the climatological characteristics of winter ETCs passing over the coastal water of China are analyzed by using clustering and composite analysis. Automated cyclone detection and tracking algorithm are used to identify the ETCs, which are further classified into subgroups according to their trajectory features by using the probabilistic clustering algorithm. Six distinct types of straight moving or recurving trajectories with different climatological characteristics are identified in the clustering analysis. Accordingly, the composite analyses also present six distinct synoptic patterns corresponding to cyclogenesis as well as the impact of ETCs on terrestrial precipitation. The spatio-temporal characteristics of winter ETCs’ origination, movement, and impact are revealed by the clustering and composite analyses. 展开更多
关键词 Extratropical CYCLONES ATMOSPHERIC CIRCULATION CLUSTER analysis Precipitation
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OES diagnostic of radicals in 33MHz radio-frequency Ar/C2H5OH atmospheric pressure plasma jet
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作者 袁强华 任佩 +2 位作者 周永杰 殷桂琴 董晨钟 《等离子体科学与技术:英文版》 SCIE EI CAS CSCD 2019年第2期52-59,共8页
Ar/C2H5OH plasma jet is generated at atmospheric pressure by 33 MHz radio-frequency power source. This RF excitation frequencies which are higher than 13.56 MHz had rarely been used in atmospheric pressure plasma. The... Ar/C2H5OH plasma jet is generated at atmospheric pressure by 33 MHz radio-frequency power source. This RF excitation frequencies which are higher than 13.56 MHz had rarely been used in atmospheric pressure plasma. The plasma characteristics of ethanol are investigated. The introduction of ethanol leads to the generation of four excited carbonaceous species C, CN, CH and C2 in plasma, respectively. Optical emission intensities of four carbonaceous species were strengthened with ethanol content increasing in the range of 0-4600 ppm. The ethanol content increase results in all the Ar spectra lines decrease. The reason is that the electron temperature decreases when ethanol content is high. The emission intensity ratios of C/C2, CN/C2 and CH/C2 decrease with the increase of ethanol content, showing that the relative amount of C2 is increasing by increasing the ethanol flow. The emission intensity ratios of excited species did not change much with the increase of RF power in stable discharge mode. 展开更多
关键词 ATMOSPHERIC pressure plasma optical emission spectroscopy RADICAL analysis
Temperature effects on atmospheric continuous-variable quantum key distribution
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作者 张淑静 马鸿鑫 +3 位作者 汪翔 周淳 鲍皖苏 张海龙 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第8期56-61,共6页
Compared with the fiber channel,the atmospheric channel offers the possibility of a broader geographical coverage and more flexible transmission for continuous-variable quantum key distribution(CVQKD).However,the fluc... Compared with the fiber channel,the atmospheric channel offers the possibility of a broader geographical coverage and more flexible transmission for continuous-variable quantum key distribution(CVQKD).However,the fluctuation of atmospheric conditions will lead to the loss of performance in atmospheric quantum communication.In this paper,we study how temperature affects atmospheric CVQKD.We mainly consider the temperature effects on the transmittance and interruption probability.From the numerical simulation analysis,it can be shown that the performance of atmospheric CVQKD is improved as temperature increases,with the other factors fixed.Moreover,the results in this work can be used to evaluate the feasibility of the experimental implementation of the atmospheric CVQKD protocols. 展开更多
关键词 ATMOSPHERIC continuous-variable QUANTUM KEY distribution temperature effects performance SECRET KEY rate
Leaf water potential and gas exchange of eucalypt clonal seedlings to leaf solar protectant 预览
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作者 Talita Miranda Teixeira Xavier Jose Eduardo Macedo Pezzopane +1 位作者 Ricardo Miguel Penchel Jose Ricardo Macedo Pezzopane 《林业研究:英文版》 CAS CSCD 2019年第1期57-64,共8页
This experiment was carried out in acclimatized greenhouses with seedlings of two hybrid clones of Eucalyptus urophylla×Eucalyptus grandis.A sunscreen protector consisting of 62.5%calcium carbonate was sprayed on... This experiment was carried out in acclimatized greenhouses with seedlings of two hybrid clones of Eucalyptus urophylla×Eucalyptus grandis.A sunscreen protector consisting of 62.5%calcium carbonate was sprayed on the seedlings at weekly intervals.Water stress was induced by suspending irrigation until the soil reached 30%available water and water was then replaced so that it returned to field capacity.Gas exchange and leaf water status were measured after 50 days.The experiment was set up in a 4×2 factorial randomized block design in four distinct environments:(1)temperatures less than 21.2℃and vapor pressure deficit of 0.15 kPa;(2)intermediate temperatures of 24.2℃and vapor pressure deficit of 0.69 kPa;(3)high temperatures of 27.0℃and high vapor pressure deficit of 1.4 kPa;and,(4)high temperature of 27.0℃and vapor pressure deficit below 1.10 kPa.Two leaf sun protector treatments were used,with five replications each.High atmospheric demand acted as a stress factor for the seedlings during the initial growth phase.Applications of leaf sunscreen protector provided beneficial effects in maintaining optimum water status and gas exchanges of the plants under water stress. 展开更多
关键词 EUCALYPTUS urophylla×Eucalyptus grandis Calcium CARBONATE Water stress ATMOSPHERIC DEMAND
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DEVELOPMENT AND ASSESSMENT OF QUANTITATIVE PRECIPITATION ESTIMATION ALGORITHMS FOR S-,C-, AND X-BAND DUAL-POLARIZATION RADARS BASED ON DISDROMETER DATA FROM THREE REGIONS OF CHINA
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作者 张扬 刘黎平 +3 位作者 文浩 陈超 王晗 席宝珠 《热带气象学报:英文版》 SCIE 2019年第2期269-292,共24页
The accuracy of quantitative precipitation estimation(QPE) for dual-polarization radars can be improved by using a localized rainfall estimation algorithm derived from the raindrop size distribution(DSD). In the prese... The accuracy of quantitative precipitation estimation(QPE) for dual-polarization radars can be improved by using a localized rainfall estimation algorithm derived from the raindrop size distribution(DSD). In the present study,DSDs observed at Suzhou City, Jiangsu province;Yangjiang City, Guangdong province;and Naqu City, Tibet are analyzed during the rainy season together with the corresponding polarimetric variables for the above three regions.Most importantly, these DSD data are used to develop optimal 'synthetic' QPE algorithms for S-, C-, and X-band dual-polarization radars, which will be built or upgraded in the three regions. Meanwhile, a new piecewise fitting method(PFM) is proposed. It has been found that the number concentration N(D) of small raindrops(D<1 mm) is the highest in Suzhou, while that of larger raindrops(D>1 mm) is the highest in Yangjiang. The characteristics of the differential reflectivity(ZDR) and specific differential phase(KDP) are significantly different in the three locations,suggesting that different rainfall estimators are needed for different locations. Further performance assessment of the QPE based on DSD data indicates that the PFM QPE algorithm(LDSD) performs better than the conventional fitting method(CFM), and the localized QPE algorithm can improve the QPE accuracy. Observations from S-band dual-polarization radars and rain gauges in the Southern China Monsoon Rainfall Experiment are implemented to verify the performances of the QPE algorithms proposed in the present study. It is found that compared with non-localized algorithms, the localized LDSD algorithm yields the best results with at least 7.66% and 8.43% reductions in the RMSE and NE, respectively, which implies that while polarimetric variables can reflect DSD characteristics, the localized QPE algorithm remains necessary. 展开更多
关键词 atmospheric SOUNDING QUANTITATIVE PRECIPITATION estimation PIECEWISE fitting method drop size distribution localized QPE algorithm
Quantitative climatic reconstruction of the Last Glacial Maximum in China
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作者 Haibin WU Qin LI +4 位作者 Yanyan YU Aizhi SUN Yating LIN Wenqi JIANG Yunli LUO 《中国科学:地球科学英文版》 SCIE EI CAS CSCD 2019年第8期1269-1278,共10页
Quantitative paleoclimatic reconstruction is crucial for understanding the operation and evolution of the global climate system.For example,a quantitative paleoclimatic reconstruction for the Last Glacial Maximum(18&#... Quantitative paleoclimatic reconstruction is crucial for understanding the operation and evolution of the global climate system.For example,a quantitative paleoclimatic reconstruction for the Last Glacial Maximum(18±2 ka14C,LGM)is fundamental to understanding the evolution of Earth’s climate during the last glacial-interglacial cycle.Previous quantitative palaeoclimate reconstructions in China are generally based on statistical comparison of modern pollen assemblages and modern climate data.These methods are based on the premise that vegetation-climate interactions remain the same through time,and implicitly assume that the interactions are independent of changes in seasonality and atmospheric CO2concentration.However,these assumptions may not always be valid,which may affect the reconstructions.Here,we present the results of a quantitative study of the LGM climate of China based on an improved inverse vegetation model which incorporates physiological processes combined with a new China Quaternary Pollen Database.The results indicate that during the LGM,mean annual temperature(ANNT),mean temperature of the coldest month(MTCO)and mean temperature of the warmest month in China were lower by~5.6±0.8,~11.0±1.6 and~2.6±0.9°C,respectively,compared to today,and that the changes in ANNT were mainly due to the decrease of MTCO.The ANNT decrease in southern China was~5.5±0.5°C.Mean annual precipitation was lower by~46.3±17.8 mm compared to today and was especially low in northern China(~51.2±21.4 mm)due to the decrease in summer rainfall.Comparison of our results with recent outputs from paleoclimatic modelling reveals that while the latter are broadly consistent with our estimated changes in mean annual climatic parameters,there are substantial differences in the seasonal climatic parameters.Our results highlight the crucial importance of developing seasonal simulation on paleoclimatic models,as well as the need to improve the quality of paleoclimatic reconstructions based on proxy records from geological archi 展开更多
关键词 QUANTITATIVE PALEOCLIMATIC reconstruction INVERSE VEGETATION model BIOME SEASONAL climate changes Atmospheric CO2 concentration
Changes in sea ice kinematics in the Arctic outflow region and their associations with Arctic Northeast Passage accessibility 预览
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作者 Dawei Gui Xiaoping Pang +2 位作者 Ruibo Lei Xi Zhao Jia Wang 《海洋学报:英文版》 SCIE CAS CSCD 2019年第8期101-110,共10页
Amplification of climate warming in the Arctic is causing a dramatic retreat of sea ice, which means the Arctic sea routes are becoming increasingly accessible. This study used a satellite-derived sea ice motion produ... Amplification of climate warming in the Arctic is causing a dramatic retreat of sea ice, which means the Arctic sea routes are becoming increasingly accessible. This study used a satellite-derived sea ice motion product to quantify the kinematic features of sea ice in the Arctic outflow region which specially referred to the Fram Strait and to the north of the Northeast Passage(NEP). An observed trend of increased southward sea ice displacement from the central Arctic to the Fram Strait indicated enhancement of the Transpolar Drift Stream(TDS). In the regions to the north of the NEP, the long-term trend of northward sea ice speed in the Kara sector was +0.04 cm/s per year in spring. A significant statistical relationship was found between the NEP open period and the northward speed of the sea ice to the north of the NEP. The offshore advection of sea ice could account for the opening of sea routes by 33% and 15% in the Kara and Laptev sectors, respectively. The difference in sea level pressure across the TDS,i.e., the Central Arctic Index(CAI), presented more significant correlation than for the Arctic atmospheric Dipole Anomaly index with the open period of the NEP, and the CAI could explain the southward displacement of sea ice toward the Fram Strait by more than 45%. The impact from the summer positive CAI reinforces the thinning and mechanical weakening of the sea ice in the NEP region, which improves the navigability of the NEP. 展开更多
关键词 sea ice ARCTIC NORTHEAST PASSAGE Transpolar Drift Stream atmospheric circulation indices
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Harnessing Crowdsourced Data and Prevalent Technologies for Atmospheric Research 预览
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作者 Noam DAVID 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第7期766-769,共4页
The knowledge garnered in environmental science takes a crucial part in informing decision-making in various fields,including agriculture, transportation, energy, public health and safety, and more. Understanding the ... The knowledge garnered in environmental science takes a crucial part in informing decision-making in various fields,including agriculture, transportation, energy, public health and safety, and more. Understanding the basic processes in each of these fields relies greatly on progress being made in conceptual, observational and technological approaches. However,existing instruments for environmental observations are often limited as a result of technical and practical constraints. Current technologies, including remote sensing systems and ground-level measuring means, may suffer from obstacles such as low spatial representativity or a lack of precision when measuring near ground-level. These constraints often limit the ability to carry out extensive meteorological observations and, as a result, the capacity to deepen the existing understanding of atmospheric phenomena and processes. Multi-system informatics and sensing technology have become increasingly distributed as they are embedded into our environment. As they become more widely deployed, these technologies create unprecedented data streams with extraordinary levels of coverage and immediacy, providing a growing opportunity to complement traditional observation techniques using the large volumes of data created. Commercial microwave links that comprise the data transfer infrastructure of cellular communication networks are an example of these types of systems. This viewpoint letter briefly reviews various works on the subject and presents aspects concerning the added value that may be obtained as a result of the integration of these new means, which are becoming available for the first time in this era, for studying and monitoring atmospheric phenomena. 展开更多
关键词 ATMOSPHERIC science IoT(Internet of Things) crowdsourced DATA commercial MICROWAVE LINKS
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Multi-aperture seeing profiler with multiple guide stars
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作者 Feng Yang Gang Zhao De-Qing Ren 《天文和天体物理学研究:英文版》 SCIE CAS CSCD 2019年第4期53-62,共10页
The daytime atmospheric turbulence profile is crucial for the design of both optical systems and the control algorithm of a solar Multi-Conjugate Adaptive Optics(MCAO) system. The Multi-Aperture Seeing Profiler(MASP) ... The daytime atmospheric turbulence profile is crucial for the design of both optical systems and the control algorithm of a solar Multi-Conjugate Adaptive Optics(MCAO) system. The Multi-Aperture Seeing Profiler(MASP) is a portable instrument which can measure the daytime turbulence profile up to~30 km. It consists of two portable small telescopes that can deliver performance similar to a SolarDifferential Image Motion Monitor +(S-DIMM+) on a 1.0 m solar telescope. In the original design of MASP, only two guide stars are used to retrieve the turbulence profile. In this paper, we studied the usage of multiple guide stars in MASP using numerical simulation, and found that there are three main advantages.Firstly, the precision of the turbulence profile can be increased, especially at a height of about 15 km, which is important for characterizing turbulence at the tropopause. Secondly, the equivalent diameter of MASP can be increased up to 30%, which will reduce the cost and weight of the instruments. Thirdly, the vertical resolution of the turbulence profile near the ground increases with the help of multiple guide stars. 展开更多
关键词 atmospheric effects site testing methods:numerical
2015年春节成都市郊大气PM1污染特征分析
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作者 林瑜 叶芝祥 +2 位作者 杨怀金 张菊 王碧菡 《环境化学》 CAS CSCD 北大核心 2019年第4期721-728,共8页
为研究西南郊区春节期间气象条件和燃放烟花爆竹对大气PM1的影响,本文于2015年2月1日至28日期间,对大气PM1进行了膜样品采集,并分析了化学成分.结果表明,采样期间大气PM1质量浓度的平均值为76.67μg·m-3,大气PM1中无机元素平均占比... 为研究西南郊区春节期间气象条件和燃放烟花爆竹对大气PM1的影响,本文于2015年2月1日至28日期间,对大气PM1进行了膜样品采集,并分析了化学成分.结果表明,采样期间大气PM1质量浓度的平均值为76.67μg·m-3,大气PM1中无机元素平均占比为19.9%.2月1日至17日期间,大气PM1中无机元素平均占比为12%,2月18日至28日期间,大气PM1中无机元素平均占比为28%,说明烟花爆竹的燃放大幅度增加了大气PM1中的无机元素.2月9日至14日期间的重污染现象表明,高空500 hPa受弱高压脊控制,高空形势稳定,850 hPa的较高温度(8℃)对逆温层的形成和维持有重要作用,且四川盆地无明显变压,均不利于污染物扩散.后向轨迹分析表明,PM1浓度累积与来自东南和东北低空气团有关. 展开更多
关键词 成都 春节 大气 PM1 无机元素 重污染 后向轨迹
Delineating the Source of Lead in the Urban Atmospheric Dust Based on Stable Isotopic Ratio:A Case Study from Panzhihua City of Southwest China 预览
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作者 WANG Jinjin HUANG Yi +2 位作者 LIU Rui CHENG Xin LONG Zhijie 《地质学报:英文版》 SCIE CAS CSCD 2019年第3期774-775,共2页
Atmospheric lead pollution is a global problem.Mining,coal mining,iron and steel smelting,and chemical and coal-fired power plants are major industries in Panzhihua City of southwest China.Many toxic and harmful heavy... Atmospheric lead pollution is a global problem.Mining,coal mining,iron and steel smelting,and chemical and coal-fired power plants are major industries in Panzhihua City of southwest China.Many toxic and harmful heavy metals,including Pb,are emitted in production activities.Pb seriously affects human health and natural ecosystems.Thus,Pb source tracing is important for Pb pollution control(Souto-Oliveira et al.,2018;Zhao et al.,2015). 展开更多
关键词 URBAN ATMOSPHERIC DUST STABLE ISOTOPIC Ratio
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Study on the Perturbation Characteristics of Two-Channel Laser Propagation in Atmospheric Turbulence
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作者 杨晓东 高明 《理论物理通讯:英文版》 SCIE CAS CSCD 2019年第6期731-735,共5页
In order to study the influence factors of acquisition detection target information by lidar and understand the influence degree of each factor, the two-channel phase perturbation model and the two-channel eikonal var... In order to study the influence factors of acquisition detection target information by lidar and understand the influence degree of each factor, the two-channel phase perturbation model and the two-channel eikonal variance model are derived in detail by using the geometrical optics method in this paper, and each factor is discussed in detail. The results show that the transmission distance is the main factor to affect the two-channel perturbation. With the increase of the transmission distance, the disturbing degree will gradually weaken. With the increase of transverse coordinates,the disturbing of two channels will also be weakened. In order to further weaken the disturbing degree, the feature dimension should be far larger than the wavelength, but far less than the transmission distance. 展开更多
关键词 atmospheric TURBULENCE two-channel phase PERTURBATION EIKONAL variance
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