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Dust storms and loess accumulation on the Tibetan Plateau: A case study of dust event on 4 March 2003 in Lhasa

Chinese Science Bulletin 2004年第9期49卷 953-960页

作者： FANG Xiaomin HAN Yongxiang MA Jinghui SONG Lianchun YANG Shengli zhang xiaoye Key Laboratory of Western China's Environmental Systems (Lanzhou University) Ministry of Education & College of Resources and Environment Lanzhou University Lanzhou 730000 China State Key Laboratory of Loess and Quatermary Geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710054 China Lanzhou Arid Meteorological Instiute of China Meteorological Bu-reau Lanzhou 730000 China

Whether the Tibetan Plateau is a significant dust source area is of great importance, because this is re-lated to the understanding of sources, accumulation and environmental effects of dusts on the Tibetan Plateau and in the Far East-Pacific Ocean regions as well as to the evolution of coupling of the Tibetan Plateau and atmosphere-ocean- continent exchange. Synoptic dynamics and remote sensing tracing of a dust storm on 3 to 5 March, 2003 in Lhasa on South Tibet demonstrate that the Tibetan Plateau possesses all factors and conditions of generating dust storms. Accom-panied with this dust storm is a strong ascending stream on the Plateau which has raised various sizes of dust particles into different levels. The lifted coarse particles were largely fallen down and accumulated as loess on the eastern Tibetan Plateau, and the fine particles were translated by the west-erly jet and subsided in the northern Pacific Ocean. The spa-tial-temporal distribution of dust-storms between years 1961 and 2000 on the Plateau shows that dust-storms mainly occur in winter and early spring with high frequency, and the path of dust storm moves gradually from south to north, which is closely coupled with the northward moving of the westerly jet from winter to spring over the Tibetan Plateau. Com-pared with other twelve dust source areas in China, the Ti-betan Plateau is one of the key dust source areas for the long-distance transport because its high occurring frequency and elevation cause fine particles easily to be lifted into the zone of the westerly jet.

关键词：沙尘暴黄土沉积青藏高原拉萨沙尘来源地区 2003年

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Dirac method for nonlinear and non-homogenous boundary value problems of plates

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 15-38页

作者： xiaoye MAO Jiabin WU Junning zhang Hu DING Liqun CHEN Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Frontier Science Center of MechanoinformaticsShanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200444China Shanghai Institute of Aircraft Mechanics and Control Shanghai 200092China

The boundary value problem plays a crucial role in the analytical investigation of continuum dynamics. In this paper, an analytical method based on the Dirac operator to solve the nonlinear and non-homogeneous boundary value problem of rectangular plates is proposed. The key concept behind this method is to transform the nonlinear or non-homogeneous part on the boundary into a lateral force within the governing function by the Dirac operator, which linearizes and homogenizes the original boundary, allowing one to employ the modal superposition method for obtaining solutions to reconstructive governing equations. Once projected into the modal space, the harmonic balance method(HBM) is utilized to solve coupled ordinary differential equations(ODEs)of truncated systems with nonlinearity. To validate the convergence and accuracy of the proposed Dirac method, the results of typical examples, involving nonlinearly restricted boundaries, moment excitation, and displacement excitation, are compared with those of the differential quadrature element method(DQEM). The results demonstrate that when dealing with nonlinear boundaries, the Dirac method exhibits more excellent accuracy and convergence compared with the DQEM. However, when facing displacement excitation, there exist some discrepancies between the proposed approach and simulations;nevertheless, the proposed method still accurately predicts resonant frequencies while being uniquely capable of handling nonuniform displacement excitations. Overall, this methodology offers a convenient way for addressing nonlinear and non-homogenous plate boundaries.

关键词： rectangular plate Dirac operator nonlinear boundary time-dependent boundary boundary value problem

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Advances in studying interactions between aerosols and monsoon in China

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Science China Earth Sciences 2016年第11期59卷 1-16页

作者： WU GuoXiong LI ZhanQing FU CongBin zhang xiaoye zhang RenYi zhang RenHe ZHOU TianJun LI JianPing LI JianDong ZHOU DeGang WU Liang ZHOU LianTong HE Bian HUANG RongHui LASG Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Global Change and Earth System Science Beijing Normal UniversityBeijing 100875China School of Atmospheric Sciences Nanjing UniversityNanjing 210093China Chinese Academy of Meteorological Sciences Chinese Meteorological AdministrationBeijing 100081China Department of Atmospheric Sciences Texas A&M UniversityTexas 77843USA CMSR Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Joint Center for Global Change Studies Beijing Normal UniversityBeijing 100875China

Scientific issues relevant to interactions between aerosols and the Asian monsoon climate were discussed and evaluated at the 33 rd "Forum of Science and Technology Frontiers" sponsored by the Department of Earth Sciences at the Chinese Academy of Sciences. Major results are summarized in this paper. The East Asian monsoon directly affects aerosol transport and provides a favorable background circulation for the occurrence and development of persistent fog-haze weather. Spatial features of aerosol transport and distribution are also influenced by the East Asian monsoon on seasonal, inter-annual, and decadal scales. High moisture levels in monsoon regions also affect aerosol optical and radiative properties. Observation analyses indicate that cloud physical properties and precipitation are significantly affected by aerosols in China with aerosols likely suppressing local light and moderate rainfall, and intensifying heavy rainfall in southeast coastal regions. However, the detailed mechanisms behind this pattern still need further exploration. The decadal variation in the East Asian monsoon strongly affects aerosol concentrations and their spatial patterns. The weakening monsoon circulation in recent decades has likely helped to increase regional aerosol concentrations. The substantial increase in Chinese air pollutants has likely decreased the temperature difference between land and sea, which favors intensification of the weakening monsoon circulation. Constructive suggestions regarding future studies on aerosols and monsoons were proposed in this forum and key uncertain issues were also discussed.

关键词： Aerosol Monsoon Interaction Fog-haze

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The Significant Contribution of Small-Sized and Spherical Aerosol Particles to the Decreasing Trend in Total Aerosol Optical Depth over Land from 2003 to 2018

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Engineering 2022年第9期16卷 82-92页

作者： Ke Gui Huizheng Che Lei Li Yu Zheng Lei zhang Hujia Zhao Junting Zhong Wenrui Yao Yuanxin Liang Yaqiang Wang xiaoye zhang State Key Laboratory of Severe Weather&Key Laboratory of Atmospheric Chemistry of China Meteorological Administration Chinese Academy of Meteorological SciencesBeijing 100081China Institute of Atmospheric Environment China Meteorological AdministrationShenyang 110166China

The optical and microphysical properties of aerosols remain one of the greatest uncertainties associated with evaluating the climate forcing attributed to *** the trends in aerosol optical depth(AOD)at global and regional scales have been widely examined,little attention has been paid to the trends in type-dependent AODs related to aerosol particle ***,using the aerosol optical component dataset from the Multi-angle Imaging SpectroRadiometer(MISR)instrument,we investigate decadal-scale trends in total aerosol loading as well as AODs for five aerosol components by particle size and morphology during 2003–2018 over *** between the total AOD(TAOD)trends and type-dependent AOD changes were examined,and the relative contribution of each type-dependent AOD to the overall TAOD trends was *** dividing the TAOD values into four different aerosol pollution levels(APLs)with splits at 0.15,0.40,and 0.80,we further explored the relationships between TAOD changes and interannual variations in the frequency-of-occurrences(FoOs)of these ***-term trends in FoOs in the different APLs show that there was a significant improvement in air quality between 2003 and 2018 in most land areas,except South Asia,corresponding to a shift from lightly polluted to clean ***,the effects of different APLs on TAOD changes are regionally dependent and their extent of correlation varied ***,we observed that the annual mean TAOD has decreased by 0.47%.a^(-1)over land since 2003(P<0.05).This significant reduction was mainly attributed to the continued reduction in small-sized(<0.7 mm diameter)AOD(SAOD)(-0.74%.a^(-1))and spherical AOD(SPAOD)(-0.46%.a^(-1)).Statistical analysis shows that SAOD and SPAOD respectively accounted for 57.5%and 89.6%of the TAOD,but contributed 82.6%and 90.4%of the trend in *** study suggests that small-sized and spherical aerosols composed of sulfate,organic matter,and black carbon play a

关键词： AOD MISR Aerosol pollution levels Aerosol type Particle size and morphology

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Research Progress on Estimation of the Atmospheric Boundary Layer Height

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Journal of Meteorological Research 2020年第3期34卷 482-498页

作者： Hongsheng zhang xiaoye zhang Qianhui LI Xuhui CAI Shaojia FAN Yu SONG Fei HU Huizheng CHE Jiannong QUAN Ling KANG Tong ZHU Laboratory for Climate and Ocean–Atmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking UniversityBeijing 100871 State Key Laboratory of Severe Weather and Key Laboratory of Atmospheric Chemistry of CMA Chinese Academy of Meteorological SciencesChina Meteorological Administration(CMA)Beijing 100081 State Key Joint Laboratory of Environmental Simulation and Pollution Control Department of Environmental SciencePeking UniversityBeijing 100871 School of Atmospheric Sciences Sun Yat-sen UniversityGuangzhou 510275 State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029 Institute of Urban Meteorology China Meteorological AdministrationBeijing 100081

Atmospheric boundary layer height(ABLH)is an important parameter used to depict characteristics of the planetary boundary layer(PBL)in the lower *** ABLH is strongly associated with the vertical distributions of heat,mass,and energy in the PBL,and it is a key quantity in numerical simulation of the PBL and plays an essential role in atmospheric environmental *** this paper,various definitions and methods for deriving and estimating the ABLH are summarized,from the perspectives of turbulent motion,PBL dynamics and thermodynamics,and distributions of various substances in the *** methods for determining the ABLH by means of direct observation and remote sensing retrieval are reviewed,and comparisons of the advantages and disadvantages of these methods are *** paper also summarizes the ABLH parameterization schemes,discusses current problems in the estimation of ABLH,and finally points out the directions for possible future breakthroughs in the ABLHrelated research and application.

关键词： atmospheric boundary layer height(ABLH) turbulent boundary layer aerosol accumulation layer remote sensing retrieval parameterization

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Practical Paths towards Lowering Black Carbon Emissions

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Advances in Climate Change Research 2011年第1期2卷 12-22页

作者： Guorui Zhi xiaoye zhang Hongbing Cheng Junli Jin Fang zhang Tingting Wang Xiaochun zhang Chinese Academy of Meteorological Sciences ChiTta Meteorological Administration Bcijing 100081 China

Black carbon （BC） aerosol, accounting for a minor fraction of atmospheric aerosols, is attracting increased attentio1 due to its impact on air quality, human health, and climate change. Focusing on BC emission reduction, this paper give1 a brief introduction to the sources and global distribution of BC. Along with the decrease of BC emissions from sue1 actions as the reduction of global greenhouse gases （GHGs） and regulating local air quality, it also highlights othet BC reduction approaches such as control and improvement of combustion conditions, the elimination of open biomas burning, and the sequestration of BC by biomass pyrolysis. Finally, it is stressed that at this moment there is no enougt reason to push BC reduction into any climate change related negotiations, although BC has been included in some o so-called win-win reduction targets for the quick response to both climate and non-climate appeals.

关键词： black carbon reduction policy consideration

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Aerosol Hygroscopicity during the Haze Red-Alert Period in December 2016 at a Rural Site of the North China Plain

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Journal of Meteorological Research 2018年第1期32卷 38-48页

作者： Xuefei QI Junying SUN Lu zhang Xiaojing SHEN xiaoye zhang Yangmei zhang Yaqiang WANG Haochi CHE Zhouxiang zhang Junting ZHONG Kaiyan TAN Huarong ZHAO Sanxue REN State Key Laboratory of Severe Weather、Key Laboratory of Atmospheric Chemistry of China Meteorological Administration Chinese Academy of Meteorological Sciences Beijing 100081 Integrated Ecological-Meteorological Observation and Experimental Station Chinese Academy of Meteorological Sciences Beijing 100081

A humidification system was deployed to measure aerosol hygroscopicity at a rural site of the North China Plain during the haze red-alert period 17–22 December 2016. The aerosol scattering coefficients under dry [relative humidity（RH）〈 30%] and wet（RH in the range of 40%–85%） conditions were simultaneously measured at wavelengths of450, 550, and 700 nm. It is found that the aerosol scattering coefficient and backscattering coefficient increased by only 29% and 10%, respectively when RH went up from 40% to 80%, while the hemispheric backscatter fraction went down by 14%, implying that the aerosol hygroscopicity represented by the aerosol scattering enhancement factor f（RH） is relatively low and RH exerted little effects on the aerosol light scattering in this case. The scattering enhancement factors do not show significant differences at the three wavelengths, only with an approximate 2% variation, suggesting that the aerosol hygroscopicity is independent of the wavelength. Aerosol hygroscopicity is highly dependent on the aerosol chemical composition. When there is a large mass fraction of inorganics and a small mass fraction of organic matter, f（RH） reaches a high value. The fraction of NO3^- was strongly correlated with the aerosol scattering coefficient at RH = 80%, which suggests that NO3^- played an important role in aerosol hygroscopic growth during the heavy pollution period.

关键词： aerosol hygroscopicity scattering enhancement factor chemical composition

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Validating a dust production model by field experiment in Mu Us Desert, China

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Chinese Science Bulletin 2006年第7期51卷 878-884页

作者： MEI Fanmin J. Rajot S. Alfaro L. Gomes zhang xiaoye WANG Tao Key Laboratory of Desert and Desertification Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China Department of Environmental Science and Technology Xi'an University of Engineering and Technology Xi'an 710048 China Center of Monitoring and Forecasting of Chemical Components of Atmosphere State Key Laboratory of Atmospheric Chemistry Institute of National Meteorology Research Beijing 100081 China Laboratoire lnteruniversitaire des Systemes Atmospheriques Universite de Paris 12 Paris 94010 France

Field experiments of dust production have been seldom performed in Chinese deserts that are identified as one of main dust sources in the world, and such an experiment to validate a dust production model (DPM) has not been made in China until now. Saltation flux, dust emission flux, surface features and meteorological parameters (U*, Z0, Ri, etc.) were investigated in Mu Us Desert of China to verify the DPM model and accumulate dust emission data during the spring of 2002. It indicates that observed saltation fluxes from 0.07 to 8.00 g·m?1·s?1 are in good agreement with the ones predicted by the DPM model when the constant of the saltation flux equation is tuned to about 2.61, which corresponds to wind fric- tion velocities from 0.26 to 0.35 m·s?1. Unfortunately, during three local dust emission events, the observed dust fluxes are from 1 to 3 μg· m?2· s?1, lower than the modeled ones, implying that the model needs to be improved further under lower wind velocity. In comparison with data from a sandy soil with physical crust and a loam soil, saltation fluxes of the loose sandy soil in Mu Us Desert are obviously higher, which suggests that deserts and sandy land with desertification are major dust sources in northern China.

关键词：沙漠尘埃模拟野外试验

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Aerosol characteristics and impacts on weather and climate over the Tibetan Plateau

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National Science Review 2020年第3期7卷 492-495页

作者： Chuanfeng Zhao Yikun Yang Hao Fan Jianping Huang Yunfei Fu xiaoye zhang Shichang Kang Zhiyuan Cong Husi Letu Massimo Menenti State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science Beijing Normal University Collaborative Innovation Center for Western Ecological Safety College of Atmospheric Sciences Lanzhou University School of Earth and Space Sciences University of Science and Technology of China Institute of Atmospheric Composition Chinese Academy of Meteorological Sciences State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences

With the most massive snow and ice globally between 60°S and 60°N, the Tibetan Plateau (TP), also called the third pole of the world, plays significant roles in the weather, climate and lives in South Asia and East Asia and even the world [1–3].Investigating the variation of weather and the climate system over the TP has long been carried out, which is signif-

关键词： Aerosol characteristics and impacts on weather and climate over the Tibetan Plateau

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Influence of High Relative Humidity on Secondary Organic Carbon: Observations at a Background Site in East China

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Journal of Meteorological Research 2019年第5期33卷 905-913页

作者： Linlin LIANG Guenter ENGLING Yuan CHENG xiaoye zhang Junying SUN Wanyun XU Chang LIU Gen zhang Hui XU Xuyan LIU Qianli MA State Key Laboratory of Severe Weather&Key Laboratory for Atmospheric Chemistry Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084China Division of Atmospheric Sciences Desert Research InstituteRenoNV 89512USA California Air Resources Board CA 91731USA School of Environment Harbin Institute of TechnologyHarbin 150001China National Satellite Meteorological Center China Meteorological AdministrationBeijing 100081China Lin'an Regional Atmosphere Background Station Lin'an 311307China

To investigate the impacts of relative humidity(RH) on secondary organic aerosol(SOA) concentrations and chemical reactions, the carbonaceous aerosol components [i.e., organic carbon(OC) and element carbon(EC)] were quantified in daily PM2.5 samples collected at a background site in East China during summer 2015. Based on the method of EC-tracer, the concentration of secondary organic carbon(SOC) demonstrated an obvious negative relationship with RH higher than 60%. Moreover, the ratio of SOC/EC also exhibited obvious decreasing trends with increasing RH, indicating negative effects for chemical production of SOA under high RH conditions. Due to high RH,photochemistry was weakened, gaseous oxidant concentrations was lowered(e.g., significantly decreased O3 levels),and the production rates of SOA were relatively low. On the other hand, because of more water uptake under higher RH conditions, the aerosol droplet acidity was reduced and enhancement of SOA formation by acidity was accordingly absent. In addition, high RH also plays an important role in changing viscosity of pre-existing aerosol coatings,which can affect reactive uptake yield of SOA. Overall, the results from this study imply that SOA production may be more associated with photochemical processes, while aqueous-phase chemistry is not very important for some SOA formation in a moist ambient environment. In the ambient atmosphere, oxidant concentrations, reaction rates,airborne species, etc., are highly variable. How do these factors affect SOA yields under given ambient environment warrants further detailed investigations.

关键词： relative humidity organic aerosol secondary organic carbon(SOC) photochemistry aqueous-phase

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