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Low-Level Temperature Inversions and Their Effect on Aerosol Condensation Nuclei Concentrations under Different Large-Scale Synoptic Circulations

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Advances in Atmospheric Sciences 2015年第7期32卷 898-908页

作者： LI Jun CHEN Hongbin Zhanqing LI WANG Pucai Maureen CRIBB FAN Xuehua key laboratory of Middle Atmosphere and Global Environment observation Institute of Atmospheric PhysicsChinese Academy of Sciences Collaborative Innovation Center on Forecast and Evaluation of meteorological Disasters Nanjing University of Information Science & Technology The Earth System Science Interdisciplinary Center University of MarylandCollege Park College of Global Change and Earth System Science Beijing Normal University

Knowledge of the statistical characteristics of inversions and their effects on aerosols under different large-scale synoptic circulations is important for studying and modeling the diffusion of pollutants in the boundary layer. Based on results gen- erated using the self-organizing map （SOM） weather classification method, this study compares the statistical characteristics of surface-based inversions （SBIs） and elevated inversions （EIs）, and quantitatively evaluates the effect of SBIs on aerosol condensation nuclei （CN） concentrations and the relationship between temperature gradients and aerosols for six prevailing synoptic patterns over the the Southern Great Plains （SGP） site during 2001-10. Large-scale synoptic patterns strongly influ- ence the statistical characteristics of inversions and the accumulation of aerosols in the low-level atmosphere. The activity, frequency, intensity, and vertical distribution of inversions are significantly different among these synoptic patterns. The verti- cal distribution of inversions varies diurnally and is significantly different among the different synoptic patterns. Anticyclonic patterns affect the accumulation of aerosols near the ground more strongly than cyclonic patterns. Mean aerosol CN con- centrations increase during SBIs compared to no inversion cases by 16.1%, 22.6%, 24.5%, 58.7%, 29.8% and 23.7% for the six synoptic patterns. This study confirms that there is a positive correlation between temperature gradients and aerosol CN concentrations near the ground at night under similar large-scale synoptic patterns. The relationship is different for different synoptic patterns and can be described by linear functions. These findings suggest that large-scale synoptic patterns change the static stability of the atmosphere and inversions in the lower atmosphere, thereby influencing the diffusion of aerosols near the ground.

关键词： temperature inversion aerosol condensation nuclei large-scale synoptic pattern statistical characteristics

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Estimating daily actual evapotranspiration of a rice–wheat rotation system in typical farmland in the Huai River Basin using a two-step model and two one-step models

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Journal of Integrative Agriculture 2021年第1期20卷 274-288页

作者： LI Meng CHU Rong-hao Abu Reza Md.Towfiqul ISLAM JIANG Yue-lin SHEN Shuang-he School of Resources and Environment Anhui Agricultural UniversityHefei 230036P.R.China Hefei Scientific Observing and Experimental Station of Agro-Environment Ministry of Agriculture and Rural AffairsP.R.China Anhui Public meteorological Service Center Anhui Meteorological BureauHefei 230031P.R.China department of Disaster Management Begum Rokeya UniversityRangpur 5400Bangladesh key laboratory of meteorological Disaster Ministry of Education(KLME)ZJoint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CICFEMD)/Jiangsu Key Laboratory of Agricultural MeteorologyCollege of Applied MeteorologyNanjing University of Information Science&TechnologyNanjing 210044P.R.China

The objective of this study is to evaluate the performance of three models for estimating daily evapotranspiration(ET) by employing flux observation data from three years(2007, 2008 and 2009) during the growing seasons of winter wheat and rice crops cultivated in a farmland ecosystem(Shouxian County) located in the Huai River Basin(HRB), China. The first model is a two-step model(PM-Kc);the other two are one-step models(e.g., Rana-Katerji(R-K) and advection-aridity(AA)). The results showed that the energy closure degrees of eddy covariance(EC) data during winter wheat and rice-growing seasons were reasonable in the HRB, with values ranging from 0.84 to 0.91 and R2 of approximately 0.80. Daily ET of winter wheat showed a slow decreasing trend followed by a rapid increase, while that of rice presented a decreasing trend after an increase. After calibrating the crop coefficient(Kc), the PM–Kc model performed better than the model using the Kc recommended by the Food and Agricultural Organization(FAO). The calibrated key parameters of the R-K model and AA model showed better universality. After calibration, the simulation performance of the PM-Kc model was satisfactory. Both the R-K model and AA model underestimated the daily ET of winter wheat and rice. Compared with that of the R-K model, the simulation result of the AA model was better, especially in the simulation of daily ET of rice. Overall, this research highlighted the consistency of the PM-Kc model to estimate the water demand for rice and wheat crops in the HRB and in similar climatic regions in the world.

关键词： daily evapotranspiration crop coefficient crop water demand rice–wheat rotation system Huai River Basin

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Ensemble Simulation of Land Evapotranspiration in China Based on a Multi-Forcing and Multi-Model Approach

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Advances in Atmospheric Sciences 2016年第6期33卷 673-684页

作者： Jianguo LIU Binghao JIA Zhenghui XIE Chunxiang SHI High Performance Computing Center School of Mathematics and Computational ScienceHuaihua University State key laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences National meteorological information Center China Meteorological Administration

In order to reduce the uncertainty of offline land surface model （LSM） simulations of land evapotranspiration （ET）, we used ensemble simulations based on three meteorological forcing datasets [Princeton, ITPCAS （Institute of Tibetan Plateau Research, Chinese Academy of Sciences）, Qian] and four LSMs （BATS, VIC, CLM3.0 and CLM3.5）, to explore the trends and spatiotemporal characteristics of ET, as well as the spatiotemporal pattern of ET in response to climate factors over China's Mainland during 1982-2007. The results showed that various simulations of each member and their arithmetic mean （EnsAVlean） could capture the spatial distribution and seasonal pattern of ET sufficiently well, where they exhibited more significant spatial and seasonal variation in the ET compared with observation-based ET estimates （Obs_MTE）. For the mean annual ET, we found that the BATS forced by Princeton forcing overestimated the annual mean ET compared with Obs_MTE for most of the basins in China, whereas the VIC forced by Princeton forcing showed underestimations. By contrast, the Ens_Mean was closer to Obs_MTE, although the results were underestimated over Southeast China. Furthermore, both the Obs_MTE and Ens_Mean exhibited a significant increasing trend during 1982-98; whereas after 1998, when the last big EI Nifio event occurred, the Ens_Mean tended to decrease significantly between 1999 and 2007, although the change was not significant for Obs_MTE. Changes in air temperature and shortwave radiation played key roles in the long-term variation in ET over the humid area of China, but precipitation mainly controlled the long-term variation in ET in arid and semi-arid areas of China.

关键词： land evapotranspiration ensemble simulations multi-forcing and multi-model approach spatiotemporal varia-tion uncertainty

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The impact of the atmospheric turbulence-development tendency on new particle formation: a common finding on three continents

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National Science Review 2021年第3期8卷 140-150页

作者： Hao Wu Zhanqing Li Hanqing Li Kun Luo Yuying Wang Peng Yan Fei Hu Fang Zhang Yele Sun Dongjie Shang Chunsheng Liang Dongmei Zhang Jing Wei Tong Wu Xiaoai Jin Xinxin Fan Maureen Cribb Marc L.Fischer Markku Kulmala Tuukka Pet?j? State key laboratory of Remote Sensing Science College of Global Change and Earth System ScienceBeijing Normal University ESSIC and department of Atmospheric Science University of MarylandCollege Park State key laboratory of Clean Energy Utilization Zhejiang University School of Atmospheric Physics Nanjing University of Information Science and Technology meteorological observation Center China Meteorological Administration State key laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences State key Joint laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University State key Joint laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Lawrence Berkeley National laboratory Institute for Atmospheric and Earth System Research/Physics Faculty of ScienceUniversity of Helsinki Aerosol and Haze laboratory Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology Joint International Research laboratory of Atmospheric and Earth System Sciences School of Atmospheric Sciences Nanjing University

A new mechanism of new particle formation(NPF) is investigated using comprehensive measurements of aerosol physicochemical quantities and meteorological variables made in three continents,including Beijing,China;the Southern Great Plains site in the USA;and SMEAR Ⅱ Station in Hyytiala,Finland.D espite the considerably different emissions of chemical species among the sites,a common relationship was found between the characteristics of NPF and the stability *** stability parameter(ζ=Z/L,where Z is the height above ground and L is the Monin-Obukhov length) is found to play an important role;it drops significantly before NPF as the atmosphere becomes more unstable,which may serve as an indicator of nucleation *** the atmosphere becomes unstable,the NPF duration is closely related to the tendency for turbulence development,which influences the evolution of the condensation ***,the unstable atmosphere may dilute pre-existing particles,effectively reducing the condensation sink,especially at coarse mode to foster *** new mechanism is confirmed by model simulations using a molecular dynamic model that mimics the impact of turbulence development on nucleation by inducing and intensifying homogeneous nucleation events.

关键词： new particle formation turbulence development molecular dynamic

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Analysis of a Mesoscale Convective System that Produced a Single Sprite

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Advances in Atmospheric Sciences 2017年第2期34卷 258-271页

作者： Jing YANG Gaopeng LU Ningyu LIU Haihua CU Yu WANG Morris COHEN key laboratory of Middle Atmosphere and Global Environment observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China Geospace Physics laboratory Physics and Space Sciences DepartmentFlorida Institute of TechnologyMelbourneFL 32901USA Hebei Province meteorological Bureau Shijiazhuang 050000China State Grid Electric Power Research Institute Wuhan 430074China School of Electrical and Computer Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

Sprites are brief optical emissions occurring above thunderstorms. Features of sprites and their parent thunderstorms and lightning activities have been studied by many researchers. Here, we report a single sprite recorded over a mesoscale convective system during its life cycle in Northeast China. The results show that the sprite might have been a dancing one, with a 20 km horizontal displacement from its parent cloud-to-ground flash （CG） and a 38 ms time delay; all the sprite elements occurred during the continuing current process of the parent flash. The peak current of the parent CG was the largest during the almost one-hour time window containing the sprite, and the absolute values of all the negative flashes were smaller than 100 kA during the same time period and did not produce sprite. The sprite did not occur during the time period in which the maximum area of the thunderstorm reached. The occurrence of sprite corresponded well with the decay of the thunderstorm convection, and no significant relationship between the occurrence of sprite and the increase in the 30-35 dBZ and 35-40 dBZ interval was found. The large wind gradient in the 8-12 km region of the thunderstorm may have played an important role in the sprite production.

关键词： sprite mesoscale convective system Doppler radar lightning magnetic field

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A Review of Atmospheric Electricity Research in China from 2011 to 2018

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Advances in Atmospheric Sciences 2019年第9期36卷 994-1014页

作者： Xiushu QIE Yijun ZHANG key laboratory of Middle Atmosphere and Global Environment observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China department of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China Collaborative Innovation Centre on Forecast and Evaluation of meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China College of Earth and Planetary Science University of Chinese Academy of SciencesBeijing 100049China

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 *** 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 *** addition,some outstanding questions for future research are outlined.

关键词： atmospheric electricity lightning thunderstorm lightning location techniques

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Current status and future directions of geoportals

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International Journal of Digital Earth 2020年第10期13卷 1093-1114页

作者： Hao Jiang John van Genderen Paolo Mazzetti Hyeongmo Koo Min Chene University of the Chinese Academy of Sciences BeijingPeople’s Republic of China Chinese Academy of Sciences Aerospace Information Research InstituteBeijingPeople’s Republic of China Faculty of Geo-information Science and Earth observation University of TwenteEnschedeThe Netherlands Institute of Atmospheric Pollution Research National Research CouncilFlorenceItaly key laboratory of Virtual Geographic Environment(Ministry of Education) Department of GeographyNanjingNanjing Normal UniversityJiangsuPeople’s Republic of China

Geoportals are a consolidated web-based solution to provide open spatial data sharing and online geo-information *** roles and possible advancements according to the Digital Earth vision and implementation require *** paper presents a review of the literature concerning geoportals and serves the following primary ***,various geoportal approaches for discovering and accessing Earth observation data and geo-information,mainly with scientific purposes,are summarized according to their characteristics and ***,current major challenges in geoportals are identified in terms of functionalities,technologies,and especially big data support,from geoportal cases of ***,based on lessons learned from the international and Chinese geoportals,solutions and recommendations for the challenges in geoportals are proposed in terms of their architectures,services,and *** results show that geoportals usually provide access to distributed data systems,offering maps,data discovery,and data *** of them are also capable of offering online analysis and processing service,enhanced semantic search engines,and dynamic visualization *** strength of geoportals could lead to a full-fledged online Digital Earth system that could provide better data sharing and dissemination solutions to the challenges posed by big data.

关键词： Geoportal(s) big Earth data Digital Earth taxonomy of geoportals geoportals in China

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In Situ observation of Crystalline Silicon Growth from SiO_(2) at Atomic Scale

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Research 2019年第1期2019卷 369-377页

作者： Kaihao Yu Tao Xu Xing Wu Wen Wang Hui Zhang Qiubo Zhang Luping Tang Litao Sun SEU-FEI Nano-Pico Center Key Laboratory of MEMS of Ministry of EducationSchool of Electronic Science and EngineeringSoutheast UniversityNanjing 210096China Shanghai key laboratory of Multidimensional information processing Department of Electronic EngineeringEast China Normal UniversityShanghai 200241China

The growth of crystalline Si(c-Si)via direct electron beam writing shows promise for fabricating Si nanomaterials due to its ultrahigh ***,to increase the writing speed is a major obstacle,due to the lack of systematic experimental explorations of the growth process and *** paper reports a systematic experimental investigation of the beaminduced formation of c-Si nanoparticles(NPs)from amorphous SiO_(2) under a range of doses and temperatures by in situ transmission electron microscopy at the atomic scale.A three-orders-of-magnitude writing speed-up is identified under 80 keV irradiation at 600℃ compared with 300 keV irradiation at room *** analysis reveals that the self-organization of c-Si NPs is driven by reduction of c-Si effective free energy under electron *** study provides new insights into the formation mechanisms of c-Si NPs during direct electron beam writing and suggests methods to improve the writing speed.

关键词： temperature writing observation

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Land-surface processes and summer-cloud-precipitation characteristics in the Tibetan Plateau and their effects on downstream weather: a review and perspective

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National Science Review 2020年第3期7卷 500-515页

作者： Yunfei Fu Yaoming Ma Lei Zhong Yuanjian Yang Xueliang Guo Chenghai Wang Xiaofeng Xu Kun Yang Xiangde Xu Liping Liu Guangzhou Fan Yueqing Li Donghai Wang School of Earth and Space Sciences University of Science and Technology of China key laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau ResearchChinese Academy of Sciences CAS Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences University of Chinese Academy of Sciences CAS Center for Excellence in Comparative Planetology School of Atmospheric Physics Nanjing University of Information Science and Technology State key laboratory of Severe Weather Chinese Academy of Meteorological Sciences China Meteorological Administration School of Atmospheric Sciences Lanzhou University Ministry of Education key laboratory for Earth System Modeling Department of Earth System Science Tsinghua University Chengdu University of information Technology Institute of Plateau Meteorology CMA School of Atmospheric Sciences Sun Yat-sen University

Correct understanding of the land-surface processes and cloud-precipitation processes in the Tibetan Plateau(TP) is an important prerequisite for the study and forecast of the downstream activities of weather systems and one of the key points for understanding the global atmospheric movement. In order to show the achievements that have been made, this paper reviews the progress on the observations for the atmospheric boundary layer, land-surface heat fluxes, cloud-precipitation distributions and vertical structures by using ground-and space-based multiplatform, multisensor instruments and the effect of the cloud system in the TP on the downstream weather. The results show that the form drag related to the topography, land–atmosphere momentum and scalar fluxes is an important part of the parameterization process. The sensible heat flux decreased especially in the central and northern TP caused by the decrease in wind speeds and the differences in the ground-air temperatures. observations show that the cloud and precipitation over the TP have a strong diurnal variation. Studies also show the compressed-air column in the troposphere by the higher-altitude terrain of the TP makes particles inside clouds vary at a shorter distance in the vertical direction than those in the non-plateau area so that precipitation intensity over the TP is usually small with short duration, and the vertical structure of the convective precipitation over the TP is obviously different from that in other regions. In addition, the influence of the TP on severe weather downstream is preliminarily understood from the mechanism. It is necessary to use model simulations and observation techniques to reveal the difference between cloud precipitation in the TP and non-plateau areas in order to understand the cloud microphysical parameters over the TP and the processes of the land boundary layer affecting cloud, precipitation and weather in the downstream regions.

关键词： Tibetan Plateau land-surface processes cloud-precipitation characteristics downstream effects

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Variational Quality Control of Non-Gaussian Innovations in the GRAPES m3DVAR System: Mass Field Evaluation of Assimilation Experiments

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Advances in Atmospheric Sciences 2021年第9期38卷 1510-1524页

作者： Jie HE Xulin MA Xuyang GE Juanjuan LIU Wei CHENG Man-Yau CHAN Ziniu XIAO Collaborative Innovation Center on Forecast and Evaluation of meteorological Disasters Key Laboratory of Meteorological DisasterNanjing University of Information Science and TechnologyNanjing 210044China State key laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Beijing Institute of Applied Meteorology Beijing 100029China department of Meteorology and Atmospheric Science and Center for Advanced Data Assimilation and Predictability TechniquesThe Pennsylvania State UniversityUniversity ParkPA 16801USA

The existence of outliers can seriously influence the analysis of variational data *** control allows us to effectively eliminate or absorb these outliers to produce better analysis *** particular,variational quality control(VarQC) can process gray zone outliers and is thus broadly used in variational data assimilation *** this study,governing equations are derived for two VarQC algorithms that utilize different contaminated Gaussian distributions(CGDs): Gaussian plus flat distribution and Huber norm *** such,these VarQC algorithms can handle outliers that have non-Gaussian ***,these VarQC algorithms are implemented in the Global/Regional Assimilation and PrEdiction System(GRAPES) model-level three-dimensional variational data assimilation(m3 DVAR) *** using artificial observations indicate that the VarQC method using the Huber distribution has stronger robustness for including outliers to improve posterior analysis than the VarQC method using the Gaussian plus flat ***,real observation experiments show that the distribution of observation analysis weights conform well with theory,indicating that the application of VarQC is effective in the GRAPES m3 DVAR *** case study and longperiod data assimilation experiments show that the spatial distribution and amplitude of the observation analysis weights are related to the analysis increments of the mass field(geopotential height and temperature).Compared to the control experiment,VarQC experiments have noticeably better posterior mass ***,the VarQC method using the Huber distribution is superior to the VarQC method using the Gaussian plus flat distribution,especially at the middle and lower levels.

关键词： variational quality control non-Gaussian distribution innovation outlier data assimilation

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