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A study on atmospheric turbulence structure and intermittency during heavy haze pollution in the Beijing area

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Science China Earth Sciences 2019年第12期62卷 2058-2068页

作者： Yan REN Hongsheng ZHANG Wei WEI xuhui cai Yu SONG Ling KANG Laboratory for Climate and Ocean-A tmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking UniversityBeijing 100871China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China tate Key Joint Laboratory of Environmental Simulation and Pollution Control Department of Environmental SciencePeking UniversityBeijing 100871China

In this study,the characteristics of turbulence transport and intermittency and the evolutionary mechanisms were studied in different pollution stages of heavy haze weather from December 2016 to January 2017 in the Beijing area using the method developed by Ren et al.(2019)as the automatic identification of atmospheric spectral gaps and the reconstruction of atmospheric turbulence *** results reveal that turbulence intermittency is the strongest in the cumulative stage(CS)of heavy haze weather,followed by in the transport stage(TS),and it is the weakest in the dissipation stage(DS).During the development and accumulation of haze pollution,buoyancy contributes negatively to turbulent kinetic energy(TKE),and horizontal wind speed is *** classical turbulent motion is often affected by submesoscale *** a result,the calculation results of turbulence parameters are affected by submesoscale motion,which causes intensified turbulence *** the dissipation of pollution,the downward momentum transfer induced by low-level jets provides kinetic energy for turbulent motion in the near surface *** turbulent mixing effect is enhanced,and intermittency is *** to the intermittency of atmospheric turbulence,turbulence parameters calculated from the original fluctuation of meteorological elements may be *** overestimation of turbulence parameters in the CS is the strongest,followed by the TS,and the DS is the *** overestimation of turbulent fluxes results in an overestimation of atmospheric dissipation capability that may cause an underestimation of pollutant concentrations in the numerical simulations of air quality.

关键词： Heavy haze weather Turbulence intermittency Eddy covariance Air quality Urban underlying surfaces

Current-dependent positive magnetoresistance in La_(0.8)Ba_(0.2)MnO_(3)ultrathin films

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Chinese Physics B 2021年第9期30卷 513-519页

作者： Guankai Lin Haoru Wang xuhui cai Wei Tong Hong Zhu Department of Physics University of Science and Technology of ChinaHefei 230026China Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field Laboratory of the Chinese Academy of SciencesHefei 230031China Key Laboratory of Strongly-Coupled Quantum Matter Physics Chinese Academy of SciencesHefei 230026China

We report an investigation into the magnetoresistance(MR)of La_(0.8)Ba_(0.2)MnO_(3)ultrathin films with various *** the 13 nm-thick film shows the commonly reported negative magnetoresistive effect,the 6 nm-and 4 nm-thick films display unconventional positive magnetoresistive(PMR)behavior under certain *** well as the dependence on the film's thickness,it has been found that the electrical resistivity and the PMR effect of the thinner films are very dependent on the test *** example,the magnetoresistive ratio of the 4 nm-thick film changes from+46%to-37%when the current is increased from 10 nA to 100 nA under 15 kOe at 40 *** addition,the two thinner films present opposite changes in electrical resistivity with respect to the test current,i.e.,the electroresistive(ER)effect,at low *** discuss the complex magnetoresistive and ER behaviors by taking account of the weak contacts at grain boundaries between ferromagnetic metallic(FMM)*** PMR effect can be attributed to the breaking of the weak contacts due to the giant magnetostriction of the FMM grains under a magnetic *** the competing effects of the conductive filament and local Joule self-heating at grain boundaries on the transport properties,the dissimilar ER effects in the two thinner films are also *** experimental findings provide an additional approach for tuning the magnetoresistive effect in manganite films.

关键词： positive magnetoresistance electroresistance Joule self-heating conductive filament

Influence of Intermittent Turbulence on Air Pollution and Its Dispersion in Winter 2016/2017 over Beijing, China

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Journal of Meteorological Research 2020年第1期34卷 176-188页

作者： Wei WEI Hongsheng ZHANG xuhui cai Yu SONG Yuxuan BIAN Kaitao XIAO He ZHANG State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081 Laboratory for Climate and Ocean–Atmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking UniversityBeijing 100871 State Key Joint Laboratory of Environmental Simulation and Pollution Control Department of Environmental SciencePeking UniversityBeijing 100871 State Key Laboratory of NBC Protection for Civilian Beijing 102205

With rapid urbanization in recent years,severe air pollution has emerged as a major issue for many regions of China,especially in some metropolises.A persistent pollution case during 6 December 2016–8 January 2017 was selected to investigate the relations between turbulent intermittency and frequent PM2.5(particulate matters with diameter less than 2.5μm)pollution events over the metropolitan region of Beijing,*** accumulation of PM2.5 near the surface frequently occurred as a combined result of strong inversion layers,stagnant winds,high ambient humidity levels,and stable stratification during this ***-order Hilbert spectral analysis indicated that steep decreases in the PM2.5 concentration were simultaneous with the occurrence of intermittent turbulence and strong vertical mixing.A wind profiler observation revealed existence of low-level jets(LLJs)at the end of the polluted periods,suggesting that the upper-level turbulent mixing accompanied by the wind shear of LLJ was transported downward and enhanced the vertical mixing near the surface,which might have caused an abrupt reduction in PM2.5 and improvement in air conditions.

关键词： intermittent turbulence PM2.5 stable stratification Beijing

Characteristics of Turbulent Transfer during Episodes of Heavy Haze Pollution in Beijing in Winter 2016/17

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Journal of Meteorological Research 2018年第1期32卷 69-80页

作者： Yan REN Shuwen ZHENG Wei WEI Bingui WU Hongsheng ZHANG xuhui cai Yu SONG Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic Sciences School of Physics Peking University Beijing 100871 State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 Tianjin Meteorological Bureau Tianjin 300074 State Key Joint Laboratory of Environmental Simulation and Pollution Control Department of Environmental Science Peking University Beijing 100871

We analyzed the structure and evolution of turbulent transfer and the wind profile in the atmospheric boundary layer in relation to aerosol concentrations during an episode of heavy haze pollution from 6 December 2016 to 9 January 2017. The turbulence data were recorded at Peking University＇s atmospheric science and environment observation station. The results showed a negative correlation between the wind speed and the PM2.5 concentration. The turbulence kinetic energy was large and showed obvious diurnal variations during unpolluted（clean） weather, but was small during episodes of heavy haze pollution. Under both clean and heavy haze conditions, the relation between the non-dimensional wind components and the stability parameter z/L followed a 1/3 power law, but the normalized standard deviations of the wind speed were smaller during heavy pollution events than during clean periods under near-neutral conditions. Under unstable conditions, the normalized standard deviation of the potential temperatureσθ/｜θ＊｜ was related to z/L, roughly following a –1/3 power law, and the ratio during pollution days was greater than that during clean days. The three-dimensional turbulence energy spectra satisfied a –2/3 power exponent rate in the high-frequency band. In the low-frequency band, the wind velocity spectrum curve was related to the stability parameters under clear conditions, but was not related to atmospheric stratification under polluted conditions. In the dissipation stage of the heavy pollution episode, the horizontal wind speed first started to increase at high altitudes and then gradually decreased at lower altitudes. The strong upward motion during this stage was an important dynamic factor in the dissipation of the heavy haze.

关键词： haze turbulence wind profile atmospheric boundary layer Beijing metropolitan area

COATS:Comprehensive observation on the atmospheric boundary layer three-dimensional structure during haze pollution in the North China Plain

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Science China Earth Sciences 2023年第5期66卷 939-958页

作者： Qianhui LI Hongsheng ZHANG Xiaoye ZHANG xuhui cai Xipeng JIN Lu ZHANG Yu SONG Ling KANG Fei HU Tong ZHU Tianjin Key Laboratory for Oceanic Meteorology Tianjin Meteorological Service CenterTianjin Meteorological BureauTianjin 300074China Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking UniversityBeijing 100871China State Key Laboratory of Severe Weather and Key Laboratory of Atmospheric Chemistry of CMA Chinese Academy of Meteorological SciencesChina Meteorological Administration(CMA)Beijing 100081China State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

The North China Plain(NCP)is troubled by severe haze pollution and the evolution of haze pollution is closely related to the atmospheric boundary layer(ABL).However,experimental and theoretical studies on the physical-chemical processes of the ABL in the NCP are lacking,with many scientific problems to be *** solve these problems,the Comprehensive Observation on the Atmospheric boundary layer Three-dimensional Structure(COATS)during haze pollution was carried out in the NCP from 2016 to *** COATS experiment adopted a"point-line-surface"spatial layout,obtaining both spatial-temporal profiles of the meteorological and environmental elements in the ABL and the turbulent transport data of fine particulate matter(PM_(2.5))in winter and *** research achievements are as *** spatial-temporal distribution characteristics of the ABL structure and PM_(2.5)concentrations in NCP were *** typical thermal structure of persistent heavy haze events and the pollutant removal mechanism by low-level jets were *** was determined that the spatial structure of the ABL adjusted by the Taihang Mountains is responsible for the heterogeneous distribution of haze pollution in the NCP,and that mountain-induced vertical circulations can promote the formation of elevated pollution *** restraints of the atmospheric internal boundaries on horizontal diffusion of pollutants were *** contribution of the ABL to haze pollution in winter and summer was qualitatively compared and quantitatively *** turbulent transport nature behind the relationship between the atmospheric boundary layer height(ABLH)and surface PM_(2.5)concentrations was *** concept of"aerosol accumulation layer"was defined,and the applicability of the material method in determining ABLH was clarified.A measurement system for obtaining the turbulent flux of PM_(2.5)concentrations was developed,and the turbulence characteristics of PM_(2.5)concentrations w

关键词： COATS experiment Haze pollution ABL three-dimensional structure Aerosol accumulation layer Turbulent flux of PM_(2.5)concentrations North China Plain

Ionospheric electromagnetic perturbations observed on DEMETER satellite before Chile M7.9 earthquake

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Earthquake Science 2009年第3期22卷 251-255页

作者： Xuemin Zhang Jiadong Qian Xinyan Ouyang xuhui Shen Jin'an cai Shufan Zhao Institute of Earthquake Science China Earthquake Administration Beijing 100036 China

Based on the ionospheric electromagnetic data observed on DEMETER satellite of France, the ionospheric electromagnetic signals were analyzed within 10 days before Chile M7.9 earthquake on November 14, 2007. It is found that, low frequency electromagnetic disturbances began to increase in a large scale of latitude, and reached to a maximum one week prior to the earthquake, and at about three days before the quake, the peak values shifted to lower latitude. Taking three days as a group, spatial images of a few parameters were analyzed, from which it can be seen during the five days prior to this earthquake, the amplitude and scale of anomalies are enlarged, while the epicenter is located at the boundary of anomalous region. The anomalous tempo-spatial variation in electron density prior to the earthquake were also obtained in terms of tracing the data from revisited orbits in half a year prior to the quake.

关键词： DEMETER satellite ionosphere electromagnetic disturbance electron density

Estimation for ammonia emissions at county level in China from 2013 to 2018

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Science China Earth Sciences 2022年第6期65卷 1116-1127页

作者： Wenling LIAO Mingxu LIU Xin HUANG Tiantian WANG Zhenying XU Fang SHANG Yu SONG xuhui cai Hongsheng ZHANG Ling KANG Tong ZHU State Key Joint Laboratory of Environmental Simulation and Pollution Control Department of Environmental SciencePeking UniversityBeijing 100871China Joint International Research Laboratory of Atmospheric and Earth System Sciences School of Atmospheric SciencesNanjing UniversityNanjing 210023China Laboratory for Atmosphere-Ocean Studies Department of Atmospheric and Oceanic ScienceSchool of PhysicsPeking UniversityBeijing 100871China

Ammonia (NH_(3)) can interact with other trace chemicals in the atmosphere,significantly impacting atmospheric chemistry and global climate *** is a largely agricultural country with high consumption of nitrogen fertilizer and large livestock herds,resulting in high NH_(3) *** this study,a comprehensive county-level inventory of Chinese NH_(3) emissions from 2013 to 2018 was *** on previous research,an estimate of NH_(3) emissions from household coal combustion was added to the *** estimation of emissions from open biomass burning was improved by using a method based on fire radiative energy (FRE).The total NH_(3) emissions in China increased from 2013 (9.64 Tg) to 2015 (9.75 Tg),and then decreased to 9.12 Tg in *** from fossil fuels reached a peak value in 2018,accounting for 8.4%of total emissions,while fertilizer application and livestock waste were responsible for fewer emissions than in previous years,accounting for 27.7%and 49.9%of the total from non-fossil fuel sources,*** highest emission rates were in central and southwestern ***,NH_(3) emissions peaked in spring and *** inventory had a 1-km spatial resolution and a monthly temporal resolution,which confirmed its suitability for global and regional air quality simulations.

关键词： Ammonia emission Seasonal variations Spatial distribution Policy Suggestions China

同方期刊数据库

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

Significant effects of transport on nanoparticles during new particle formation events in the atmosphere of Beijing

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Particuology 2023年第9期80卷 1-10页

作者： Dongjie Shang Min Hu Lizi Tang Xin Fang Ying Liu Yusheng Wu Zhuofei Du xuhui cai Zhijun Wu Shengrong Lou Mattias Hallquist Song Guo Yuanhang Zhang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringInternational JointLaboratory for Regional Pollution ControlMinistry of Education(IJRC)Peking UniversityBeijing100871China Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Nanjing University of Information Science&TechnologyNanjing210044China Department of Chemistry and Molecular Biology University of GothenburgGothenburg41296Sweden Shanghai Academy of Environmental Sciences Shanghai200233China

The mechanisms of new particle formation(NPF)events that occurred under high aerosol loadings(“polluted”NPF)in the atmosphere have been unclear,which has inhibited the precision of particlepollution *** deepen the understanding of how the“polluted”NPF events occur,a one-monthcomprehensive measurement was conducted in the atmosphere of Beijing during the summer ***“clean”NPF events(frequency=22%)(condensation sink,CS0.015 s^(-1))were influenced by both local nucleation-growth and regional transport,and the contributions from thetwo factors to 6e25 nm particle number concentration were 60%and 40%,*** studyemphasized the importance of the transport for nanoparticles in relatively polluted atmospheres,and forthat the regional joint particle pollution control would be an essential policy.

关键词： New particle formation Transport Nanoparticles Sulfuric acid