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Comparison and Verification of Coherent Doppler Wind Lidar and Radiosonde Data in the Beijing Urban Area

Advances in Atmospheric Sciences 2024年第11期41卷 2203-2214页

作者： Zexu LUO Xiaoquan SONG Jiaping YIN Zhichao BU Yubao CHEN Yongtao YU Zhenlu ZHANG College of Marine Technology Faculty of Information Science and EngineeringOcean University of ChinaQingdao 266100China Laboratory for Regional Oceanography and Numerical Modeling Laoshan LaboratoryQingdao 266237China qingdao Leice Transient Technology Co.LTD Qingdao 266100China CMA meteorological Observation Centre Beijing 100081China Beijing Municipal meteorological Observation center Beijing 102600China qingdao meteorological comprehensive support center Qingdao 266003China

As a new type of wind field detection equipment, coherent Doppler wind lidar(CDWL) still needs more relevant observation experiments to compare and verify whether it can achieve the accuracy and precision of traditional observation equipment in urban areas. In this experiment, a self-developed CDWL provided four months of observations in the southern Beijing area. After the data acquisition time and height match, the wind profile data obtained based on a Doppler beam swinging(DBS) five-beam inversion algorithm were compared with radiosonde data released from the same location. The standard deviation(SD) of wind speed is 0.8 m s^(–1), and the coefficient of determination R~2 is 0.95. The SD of the wind direction is 17.7° with an R~2 of 0.96. Below the height of the roughness sublayer(about 400 m), the error in wind speed and wind direction is significantly greater than the error above the height of the boundary layer(about 1500 m). For the case of wind speeds less than 4 m s^(–1), the error of wind direction is more significant and is affected by the distribution of surrounding buildings. Averaging at different height levels using suitable time windows can effectively reduce the effects of turbulence and thus reduce the error caused by the different measurement methods of the two devices.

关键词： coherent Doppler wind lidar radiosonde wind measurement urban boundary layer

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Effect of Peak Power and Pulse Width on Coherent Doppler Wind Lidar’s SNR

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Instrumentation 2022年第2期9卷 26-32页

作者： REN Yong WU Xuefei TAO Fa CAO Haishuai Fujian Key Laboratory of Severe Weather Fuzhou 350001 meteorological Observation center of the China meteorological Administration Beijing 100081 Fujian Atmospheric Detection Technology support center Fuzhou 350008 qingdao Leice Transient Technology Co.Ltd Qingdao 266000

The laser device is the core component of coherent Doppler wind *** peak power and pulse width of laser transmitting pulse have important effects on *** on coherent Doppler wind pulse lidar,the peak power and pulse width influence on SNR is studied on the theoretical derivation and analysis,and the results show that the higher the peak power can realize the greater the signal-to-noise ratio of coherent Doppler wind *** when the peak power is too large,the laser pulse may appear nonlinear phenomenon,which cause the damage of the ***,the peak power must be less than the stimulated brillouin scattering power *** the pulse width can make the laser device to output more energy,but it will also make the spatial resolution lower,and the influence of turbulence on SNR will be *** a series of simulation analyses,it can be concluded that when the peak power is 650W and the pulse width is 340ns,the SNR of the system can be *** addition,the coherent Doppler wind lidar system is set up to carry out corresponding experimental *** experimental results are consistent with the theoretical analysis and simulation,which verifies the correctness of the theoretical analysis and simulation *** provides theoretical basis and practical ex-perience for the design of laser transmitting pulse in coherent Doppler wind lidar system.

关键词： Coherent Lidar Fiber Laser Peak Power Pulse Width Signal-to-Noise Ratio(SNR)

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Improving the Forecasts of Coastal Wind Speeds in Tianjin,China Based on the WRF Model with Machine Learning Algorithms

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Journal of meteorological Research 2024年第3期38卷 570-585页

作者： Weihang ZHANG Meng TIAN Shangfei HAI Fei WANG Xiadong AN Wanju LI Xiaodong LI Lifang SHENG College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao266100China Tianjin Key Laboratory for Oceanic Meteorology Tianjin Institute of Meteorological ScienceTianjin300074China CMA Earth System Modeling and Prediction Centre China Meteorological Administration(CMA)Beijing100081China qingdao meteorological Bureau Qingdao266003China

Characterized by sudden changes in strength,complex influencing factors,and significant impacts,the wind speed in the circum-Bohai Sea area is relatively challenging to *** the western side of Bohai Bay,as the economic center of the circum-Bohai Sea,Tianjin exhibits a high demand for accurate wind *** this study,three machine learning algorithms were employed and compared as post-processing methods to correct wind speed forecasts by the Weather Research and Forecast(WRF)model for *** results showed that the random forest(RF)achieved better performance in improving the forecasts because it substantially reduced the model bias at a lower computing cost,while the support vector machine(SVM)performed slightly worse(especially for stronger winds),but it required an approximately 15 times longer computing *** back propagation(BP)neural network produced an average forecast significantly closer to the observed forecast but insufficiently reduced the *** regard to wind speed frequency forecasting,the RF method commendably corrected the forecasts of the frequency of moderate(force 3)wind speeds,while the BP method showed a desirable capability for correcting the forecasts of stronger(force>6)*** addition,the 10-m u and v components of wind(u_(10)and v_(10)),2-m relative humidity(RH_(2))and temperature(T_(2)),925-hPa u(u925),sea level pressure(SLP),and 500-hPa temperature(T_(500))were identified as the main factors leading to bias in wind speed forecasting by the WRF model in Tianjin,indicating the importance of local dynamical/thermodynamic processes in regulating the wind *** study demonstrates that the combination of numerical models and machine learning techniques has important implications for refined local wind forecasting.

关键词： machine learning Weather Research and Forecast(WRF)model wind speed forecasting coastal region

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A Deep Learning Approach for Forecasting Thunderstorm Gusts in the Beijing–Tianjin–Hebei Region

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Advances in Atmospheric Sciences 2024年第7期41卷 1342-1363页

作者： Yunqing LIU Lu YANG Mingxuan CHEN Linye SONG Lei HAN Jingfeng XU Faculty of Information Science and Engineering Ocean University of ChinaQingdao 266100China Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089China Collaborative Innovation center on Forecast and Evaluation of meteorological Disasters(CIC-FEMD) Nanjing University of Information Science&TechnologyNanjing 210044China

Thunderstorm gusts are a common form of severe convective weather in the warm season in North China,and it is of great importance to correctly forecast *** present,the forecasting of thunderstorm gusts is mainly based on traditional subjective methods,which fails to achieve high-resolution and high-frequency gridded forecasts based on multiple observation *** this paper,we propose a deep learning method called Thunderstorm Gusts TransU-net(TGTransUnet)to forecast thunderstorm gusts in North China based on multi-source gridded product data from the Institute of Urban Meteorology(IUM)with a lead time of 1 to 6 *** determine the specific range of thunderstorm gusts,we combine three meteorological variables:radar reflectivity factor,lightning location,and 1-h maximum instantaneous wind speed from automatic weather stations(AWSs),and obtain a reasonable ground truth of thunderstorm ***,we transform the forecasting problem into an image-to-image problem in deep learning under the TG-TransUnet architecture,which is based on convolutional neural networks and a *** analysis and forecast data of the enriched multi-source gridded comprehensive forecasting system for the period 2021–23 are then used as training,validation,and testing ***,the performance of TG-TransUnet is compared with other *** results show that TG-TransUnet has the best prediction results at 1–6 *** IUM is currently using this model to support the forecasting of thunderstorm gusts in North China.

关键词： thunderstorm gusts deep learning weather forecasting convolutional neural network transformer

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Variation Characteristics of Heat Resources in Liaoning Province, China in Recent 60 Years and Their Impact on meteorological Services

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Journal of Geoscience and Environment Protection 2022年第8期10卷 158-169页

作者： Yuqi Zhang Lin Ma Liaoning Provincial meteorological Service center Shenyang China Liaoning Provincial meteorological Equipment support center Shenyang China

To study the temporal and spatial changes of heat resources to serve agricultural production and economic development. The climate data from 1958 to 2017 were selected, and the temporal and spatial changes of heat resources in Liaoning, China were analyzed by using the method of climate diagnosis and analysis. The results show that: the southern coastal area of Liaoning has the most heat resources, the northwestern hilly area and the eastern mountainous area the least, and the central plain area in the middle distribution pattern;compared with 1958-1980, 1981-2017 ≥0°C, ≥10°C accumulated temperature, etc. The value line is advanced 100-160km northward. The accumulated temperature of ≥0°C and ≥10°C in Liaoning experienced abrupt changes in climate in 1993 and 1994, and the climate abrupt change in the southern coastal area was earlier than that in the inland. , the increase in the northwestern hilly area and the eastern mountainous area is less than that in the central plain area and the southern coastal area. The study on the impact on meteorological services found that the increase or decrease of heat resources has a significant impact on agro-meteorological services, which can prolong the growing season of crops, relatively reduce the damage of frost, improve comprehensive utilization of land, and increase crop yields;at the same time, with the increase of heat resources and the northward expansion of the isoline of accumulated temperature, the area affected by pests and diseases has expanded, which has aggravated the harm to agriculture economic burden.

关键词： Heat Resource meteorological Service Accumulated Temperature Temporal and Spatial Evolution

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Development and Validation of a Metabolic-related Prognostic Model for Hepatocellular Carcinoma

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Journal of Clinical and Translational Hepatology 2021年第2期9卷 169-179页

作者： Junyu Huo Liqun Wu Yunjin Zang Liver Disease center The Affiliated Hospital of Qingdao UniversityQingdaoShandongChina

Background and Aims:Growing evidence suggests that metabolic-related genes have a significant impact on the occurrence and development of hepatocellular carcinoma(HCC).However,the prognostic value of metabolic-related genes for HCC has not been fully ***:mRNA sequencing and clinical data were obtained from The Cancer Genome Atlas and the GTEx Genotype-Tissue Expression comprehensive *** expressed metabolic-related genes in tumor tissues(n=374)and normal tissues(n=160)were identified by the Wilcoxon ***-dependent receiver operating characteristic curve analysis,univariate multivariate Cox regression analysis and Kaplan-Meier survival analysis were used to evaluate the predictive effectiveness and independence of the prognostic *** independent cohorts(International Cancer Genome Consortiums and GSE14520)were applied to verify the prognostic ***:Our study included a total of 793 patients with *** constructed a risk score consisting of five metabolic-genes(BDH1,RRM2,CYP2C9,PLA2G7,and TXNRD1).For the overall survival rate,the low-risk group had a considerably higher rate than the high-risk *** and multivariate Cox regression analyses indicated that the risk score was an independent predictor for the prognosis of ***:We constructed and validated a novel prognostic model,which may provide support for the precise treatment of HCC.

关键词： Hepatocellular carcinoma Metabolic Prognostic Signature

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SPECTRAL REFLECTANCE MEASUREMENTS AT THE CHINA RADIOMETRIC CALIBRATION TEST SITE FOR THE REMOTE SENSING SATELLITE SENSOR

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Acta meteorologica Sinica 2001年第3期15卷 377-382页

作者：张玉香张广顺刘志权张立军朱顺斌戎志国邱康睦 National Satellite meteorological center Beijing 100081

A comprehensive field experiment was made with the support of the project of China Radiometric Calibration Site (CRCS) during June-July *** reflectance spectra were measured at Dunhuang Calibration Test Site in the *** than two thousands of spectral curves were acquired in a 20km×20km *** spectral coverage is from 350 nm to 2500 *** measurement values show that reflectance is between 10% and 33% at the VIS- SWIR spectral *** standard deviation of reflectance is between 1.0% and 2.0% for the spectral *** characteristics and ground reflectance measurements at the Dunhuang test site,result analysis and error source were *** addition,a comparison of the reflectance obtained in 1999 with those measured in 1994 and 1996 was also made.

关键词： reflectance measurements calibration site reference panel

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Cause of PM2.5 pollution during the 2016-2017 heating season in Beijing, Tianjin, and Langfang, China

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Journal of Environmental Sciences 2020年第9期32卷 201-209页

作者： Nini Pang Jian Gao Fei Che Tong Ma Su Liu Yan Yang Pusheng Zhao Jie Yuan Jiayuan Liu Zhongjun Xu Fahe Chai Department of Environmental Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China Chinese Research Academy of Environmental Sciences Beijing 100012China qingdao Huasi Environmental Protection Technology Co. Ltd.Qingdao 266199China Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089China Tianjin Environmental Monitoring center Tianjin 300191China

To investigate the cause of fine particulate matter(particles with an aerodynamic diameter less than 2.5 um,PM2.5) pollution in the heating season in the North China Plain(specifically Beijing,Tianjin,and Langfang),water-soluble ions and carbonaceous components in PM2.5were simultaneously measured by online instruments with 1-hr resolution,from November 15,2016 to March 15,*** results showed extreme severity of PM2.5 pollution on a regional *** inorganic ions(SNA,i.e.,NO3-+So42+NH4+) dominated the water-soluble ions,accounting for 30%-40% of PM2.5,while the total carbon(TC,i.e.,OC+EC) contributed to 26.5%-30.1% of PM2.5 IN the three *** were mainly responsible for the increasing PM2.5 pollution compared with organic matter(OM).NO3-was the most abundant species among water-soluble ions,but SO42- played a much more important role in driving the elevated PM2.5 *** relative humidity(RH) and its precursor SO2 were the key factors affecting the formation of *** reactions dominated the formation of nitrate which was mainly limited by HNO3 in ammonia-rich *** formation and regional transport from the heavily polluted region promoted the growth of PM2.5 concentrations in the formation stage of PM2.5 pollution in Beijing and *** transport or local emissions,along with secondary formation,made great contributions to the PM2.5 pollution in the evolution stage of PM2.5 pollution in Beijing and *** favourable meteorological conditions and regional transport from a relatively clean region both favored the diffusion of pollutants in all three cities.

关键词： pollution season driving

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On Spatiotemporal Characteristics of Sea Fog Occurrence over the Northern Atlantic from 1909 to 2008

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Journal of Ocean University of China 2016年第6期15卷 958-966页

作者： LI Pengyuan WANG Guanlan FU Gang LU Chungu Laboratory of Physical Oceanography Ocean-Atmosphere Interaction and Climate Department of Marine Meteorology Ocean University of China Qingdao 266100 P. R. China National meteorological center Chinese Meteorological Administration Beijing 100081 P. R. China National Science Foundation Arlington VA 22230 ~USA

In this paper, the International comprehensive Ocean and Atmosphere Data Set(ICOADS) is utilized to investigate the horizontal distribution of sea fog occurrence frequency over the Northern Atlantic as well as the meteorological and oceanic conditions for sea fog formation. Sea fog over the Northern Atlantic mainly occurs over middle and high latitudes. Sea fog occurrence frequency over the western region of the Northern Atlantic is higher than that over the eastern region. The season for sea fog occurrence over the Northern Atlantic is generally from April to August. When sea fogs occur, the prevailing wind direction in the study area is from southerly to southwesterly and the favorable wind speed is around 8 m s-1. It is most favorable for the formation of sea fogs when sea surface temperature(SST) is 5℃ to 15℃. When SST is higher than 25℃, it is difficult for the air to get saturated, and there is almost no report of sea fog. When sea fogs form, the difference between sea surface temperature and air temperature is mainly-1 to 3℃, and the difference of 0℃ to 2℃ is the most favorable conditions for fog formation. There are two types of sea fogs prevailing in this region: advection cooling fog and advection evaporating fog.

关键词： atmospheric visibility sea fog occurrence frequency the Northern Atlantic

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A novel Cu-doped high entropy alloy with excellent comprehensive performances for marine application

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Journal of Materials Science & Technology 2021年第10期69卷 48-59页

作者： Yuan Yu Nannan Xu Shengyu Zhu Zhuhui Qjao Jianbin Zhang Jun Yang Weimin Liu State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China qingdao center of Resource Chemistry and New Materials Qingdao 266000China School of Public Health Qingdao UniversityQingdao266000China

High entropy alloy(HEA)has attracted great interests as one of the promising multifunctional materials in marine ***,Cu as an effective biocide tends to form segregation in HEA,which could deteriorate corrosion and induce brittle ***,we report a strategy to tailor the existing form of Cu in HEA from undesired large-scale segregation to uniform distribution with dispersed nanoscale precipitation,while retaining the unique structure characteristics of *** Cu segregation improves toughness and avoids serious corrosion in the grain *** distribution with dispersed nanoscale precipitation of Cu further enhances the antifouling and lubricating abilities of Cu-doped *** AlCoCrFeNiCu_(0.5)HEA in this work has excellent comprehensive properties combining good mechanical properties,outstanding antifouling abilities,superior resistance to corrosion and ***,the corresponded mechanisms are discussed in terms of Cu-segregation-eliminated,nanoscale-Cu-precipitate-forming and comprehensive properties.

关键词： High entropy alloys Copper Nanoscale precipitate comprehensive properties Ocean

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