Table of Content

30 June 2017, Volume 33 Issue 3 Previous Issue    Next Issue

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Diagnostic analysis of an extreme blizzard and gale weather process under different triggering conditions over Jilin province WANG Ning, QIN Yu-lin, YAO Shuai, WANG Ting-ting, NIU Li-qiang 2017, 33 (3):  1-9.  doi: 10.3969/j.issn.1673-503X.2017.03.001 Abstract ( 238 )   PDF (3578KB) ( 466 )   Save An extreme blizzard and gale weather process over Jilin province on February 21 to 22 in 2015 was diagnosed and analyzed using the conventional meteorological observation data,regional automatic station precipitation data and the NCEP (National Centers for Environmental Prediction) 1°×1° 6-hourly reanalysis data.The results show that a high-level cold eddy combining with eastern expansion of the ground Mongolia cyclone is a main factor influencing this blizzard weather event.Overlaying of temperature and pressure fields at 850 hPa in reverse phase is consistent with the typical gale weather situation over Jilin province.Corresponding snowfall process can be divided into two phases,namely,snowfall at warm and then cold areas.The first phase of snowfall is triggered by the low-level southerly jet with an abnormally abundant water vapor coming from Bohai and Yellow Sea.The dynamic conditions in this phase are relatively weak.In the second phase,the water vapor condition is weaker than in the first phase.It is mainly due to the westerly transport of water vapor converging at the Sea of Japan,which is controlled by the easterly and northerly jets in the north part of the low vortex.While its dynamic conditions are stronger than those of the first phase.During the heavy snowfall period,the dry intrusion and frontogenesis process are obvious,and the role of cold air is significant.When the heavy snowfall occurs,the echo intensity is general within 15-25 dBz,and the echo height is equal or less than 4 km.Meanwhile,the snowfall intensity in the cold area is closely related to the strengthening of shear line and the invasion of cold air. References | Related Articles | Metrics

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Analysis of the hollow structure and characteristics of landing typhoon “Matmo” GUO Da-feng, ZHOU Fang, CHEN Xiang-xiang, BAO Hui-meng 2017, 33 (3):  10-20.  doi: 10.3969/j.issn.1673-503X.2017.03.002 Abstract ( 288 )   PDF (4640KB) ( 602 )   Save The formation of hollow structure and its characteristics of typhoon "Matmo" were analyzed based on diagnostic analysis methods including the circulation situation,vertical structure of typhoon,water vapor transport and the effect of intrusion of the cold air.The conventional meteorological data,NCEP (National Centers for Environmental Prediction) reanalysis and FY-2 cloud data were used.The results show that the terrain,such as Taiwan Island,the mountains along the coast of Fujian province and Wuyi Mountains,is the main reason to influence the change of intensity and structure of typhoon "Matmo".The vorticity and divergence fields at upper and low layers,water vapor flux transport,the intrusion of the ground cold and dry air among others contribute to the formation of the "hollow" phenomenon of "Matmo".Compared with the other typhoons,it indicates that even though the tracks and influencing regions are similar,their structures are significantly different.This suggests that the structure change of landing typhoons is very complicated. References | Related Articles | Metrics

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Characteristic analysis of a tornado developing from the super-typhoon “Mujigae” XIAO Liu-si, CHEN Zhi-gang, HU Dong-ming, LIAO Fei 2017, 33 (3):  21-28.  doi: 10.3969/j.issn.1673-503X.2017.03.003 Abstract ( 313 )   PDF (5198KB) ( 557 )   Save The characteristics of a tornado developed from outside of the super-typhoon "Mujigae" (No.1522),which happened in Panyu district of Guangzhou,were analyzed using the analysis data from the LAPS (Local Analysis and Prediction System) and Doppler radar data.The results show that this tornado is ranked as F2.It is located at the front-right-hand side along the moving direction of the typhoon with about 390 km.This position is a convergence zone of strong southerly and southeasterly flows,with sufficient unstable energy,a stronger vertical wind shear,and a cold air intruding from the low layer.There is an obvious bow structure rather than hook or drape characteristics on the radar reflectivity graph,and a moderate intensity meso-cyclone existing in the low-level on the radial velocity graph.It is hard to define it as a supercell or non-supercell tornado according to the above information. References | Related Articles | Metrics

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Analysis of the precursor signal of an abnormal main mode for summer precipitation in Heilongjiang province LI Yong-sheng, WANG Yong-guang, WANG Ying 2017, 33 (3):  29-35.  doi: 10.3969/j.issn.1673-503X.2017.03.004 Abstract ( 192 )   PDF (1686KB) ( 402 )   Save The precursor signal of a main mode affecting the summer precipitation in Heilongjiang province was analyzed using the summer precipitation data from 15 meteorological stations from 1981 to 2010,NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) reanalysis data and monthly average sea surface temperature from NOAA (National Oceanic and Atmospheric Administration) from 1980 to 2015.A statistical precipitation forecasting model for summer precipitation in Heilongjiang province was established based on the principal component regression method.The results show that the abnormal precursor signals affecting the main mode of summer precipitation in Heilongjiang province mainly include the height field in south regions of Novaya Zemlya and the Kara Sea last November,the inverse variation of the sea surface temperature between the central part of North Pacific and California vicinity last winter,and the anomaly sea surface temperature in the southern Indian Ocean.Through yearly cross hindcast and every four year independent sample prediction tests from 1981 to 2010,it indicates that the precipitation forecasting model established here performs very well.It is used in operation and gets a good prediction in the summer precipitation in Heilongjiang province in 2015.It suggests that this model may have the value for the summer prediction. References | Related Articles | Metrics

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Study on a multiple urban waterlogging model in the typical areas of Tianjin CHEN Jing, XIE Yi-yang, LI Da-ming, LI Pei-yan, WANG Xue-lian, QIU Xiao-bin 2017, 33 (3):  36-44.  doi: 10.3969/j.issn.1673-503X.2017.03.005 Abstract ( 224 )   PDF (3182KB) ( 592 )   Save A typical partial section of the Jin River in Tianjin was taken as the research object in this study,and a waterlogging model was reconstructed based on urban geographic information and operational modes of drainage pipe network.Grids of river,road,sewer and community in the urban waterlogging model were partitioned by layer in order to build independent modelling systems for these grids,and then a multiple and three-dimensional urban waterlogging model with different sub-regions and layers was developed based on the established systems.The simulation results of ten rainfall events in Tianjin from 2009 to 2015 were validated using the urban seeper information and the data of river water level provided by Drainage Management Department.The results indicate that 88% of all the rainfall processes in Tianjin from 2009 to 2015 was simulated with an absolute error between the simulated and real maximum seeper depth less than 10 cm.The evolution of water level simulated by the model is consistent with the real evolution,with a statistical mean error between the simulated and measured river water level less than 10 cm and a relative error of water balance of zero.This multiple urban waterlogging model can effectively simulate the variation of river water level and urban seeper. References | Related Articles | Metrics

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Vertical distributions of aerosol during two haze events in 2015 over Ningbo,Zhejiang province HUANG Si-yuan, WANG Jie, QUAN Cai-feng 2017, 33 (3):  45-51.  doi: 10.3969/j.issn.1673-503X.2017.03.006 Abstract ( 232 )   PDF (2115KB) ( 488 )   Save Observation data from the polarized-LiDARs of Zhenhai district and Fenghua,as well as conventional surface meteorological data,wind profile radar data and atmospheric composition data were used to analyze the vertical distribution characteristics of aerosol over Ningbo during two haze events,occurring on February 12-14 and 16-18,2015,respectively.Their formation mechanisms were further evaluated by means of vertical-temporal variations of extinction and depolarized coefficients at 532 nm and 355 nm.The results show that the first event was caused by local pollutants accumulation,whereas the second event was caused by the transboundary transport,deposition and near-surface mixing of pollutants.Particulate matters appeared below 1 km and between 1-2 km during the two events,respectively.High-level wind fields from wind profile radars were in good agreement with particulate matter characteristics observed by polarized-LiDARs,which can further interpret the different formation mechanisms of the two events.Using LiDAR-network technology to observe high-level particulate matters altered the limitation of near surface observations and single site soundings,providing reasonable technological methods for the quantitative analysis of pollutant transport intensities and spatial-temporal variations.Through LiDAR network,monitoring and early warning of haze events will be further promoted. References | Related Articles | Metrics

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Retrievals of aerosol optical depths and their spatial distributions over Jing-Jin-Ji region YANG Peng, CHEN Jing, GAO Qi, ZHI Li-hui, ZHAO Li-ping, CUI Sheng-cheng 2017, 33 (3):  52-58.  doi: 10.3969/j.issn.1673-503X.2017.03.007 Abstract ( 235 )   PDF (2106KB) ( 498 )   Save Based on Terra/MODIS MOD021KM data from September 1,2014 to May 31,2015,as well as deep blue algorithm and look-up-table methods,aerosol optical depths (AOD) over Jing-Jin-Ji region were retrieved with the spatial resolution of 1 km,the results were compared with NASA products and CE-318 measurements.The results show that the retrieved AODs have higher spatial resolution and relatively good agreements with the products of MOD 04_L2 (10 km×10 km) and MOD 04_3K (3 km×3 km) .The mean absolute error between retrieved AODs and those observed by CE-318 sun-photometer at Shijiazhuang site is about 0.07,with a high correlation coefficient of 0.98.When Terra passed the territory,mean errors of retrieved AOD compared with MOD 04_L2 and MOD 04_3K products were around 0.06 and 0.03,respectively.Further relationship analysis on the spatial contributions of retrieved AODs and the mass concentrations of PM2.5 and PM10 over Hebei province indicated that the correlation coefficients between AOD and PM2.5 and PM10 are 0.745 and 0.663,respectively,suggesting that the retrieved AODs with the resolution of 1 km could effectively reflect the mass concentrations of PM2.5 and PM10. References | Related Articles | Metrics

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Variation characteristics and meteorological influencing factors of air pollution in Shanghai CHEN Lei, MA Jing-hui, ZHEN Xin-rong, CAO Yu 2017, 33 (3):  59-67.  doi: 10.3969/j.issn.1673-503X.2017.03.008 Abstract ( 407 )   PDF (1034KB) ( 1604 )   Save Observational data of hourly concentrations and individual daily air quality indexes (IAQI) for six air pollutants during 2013 and 2014 over Shanghai were used to analyze the variation characteristics and meteorological influencing factors over Shanghai.The results show that the good to excellent rate of atmospheric environment quality was 77.0% in 2014,obviously higher than that in 2013.The air qualities in the two years varied seasonally,apparently worse in winter,especially in December with the highest AQI,while better in autumn.According to the variations of primary pollutants,PM2.5 was the dominant contributor to the air qualities of Shanghai and its pollution mostly appears in winter,whereas O3 was the major pollutant in summer.The concentrations of PM2.5,PM10,NO2 and O3 over Shanghai are all lower during the weekends than those during the weekdays,especially for PM2.5 and NO2.Haze days appeared much more frequently in the case that the PM2.5 concentrations are beyond the moderate pollution level,but there is no one-to-one relationship.Since weather patterns influence PM2.5 pollution significantly,the ground-level patterns can be divided into seven types,among which Type High Pressure Center and Type High Pressure Wedge are the dominate patterns.Due to the frequent cold air activities in winter,particles from upwind directions are transported to Shanghai under the northwest wind,leading to severe pollution.In addition,Type High Pressure Center and Type High Pressure Wedge weathers appear frequently under the control of Cold High,causing air pollution due to poor diffusion.During summer and autumn under control of the Subtropical High,the better horizontal and vertical diffusions are favorable to the removal of PM2.5 pollution,but it is favorable to the O3 pollution due to high temperature and sufficient sunlight conditions. References | Related Articles | Metrics

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Spatial-temporal characteristics of severe air pollution events in Zhejiang province LI Huai-chuan, CHEN Xuan-miao, YE Zi-xiang, WU Xian-du 2017, 33 (3):  68-79.  doi: 10.3969/j.issn.1673-503X.2017.03.009 Abstract ( 212 )   PDF (5554KB) ( 583 )   Save Daily and hourly air quality index (AQI) data from October of 2012 to May of 2015 in 11 cities of Zhejiang province were used to analyze the occurrence time,durations and temporal variations of AQI during the 61 severe air pollution events when the AQI was more than 200.Weather patterns were used to reveal the spatial-temporal variations of severe air pollution events as well.The results show that severe pollution events mainly occur in winter,especially during December and January,and PM2.5 is the primary pollutant.The number of severe pollution hours is more in the northwestern region than in the southeastern region,appearing significant regional differences.Three types of weather patterns contribute to severe pollution in Zhejiang province and they are Synchronous Change,North-south Transport and Regional Accumulation.Type North-south Transport can be further divided into Movement Transport and Diffusion Transport with the former presenting local movement and area movement patterns.Type Regional Accumulation tends to develop into severe pollution with long-hour duration. References | Related Articles | Metrics

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Research on the variation of drought in the middle of Shandong province based on different drought indices HUAN Hai-jun, YAO Dan-dan, LIU Yan, XIA Fu-hua 2017, 33 (3):  80-87.  doi: 10.3969/j.issn.1673-503X.2017.03.010 Abstract ( 193 )   PDF (1153KB) ( 482 )   Save Based on the daily meteorological data from 8 representative weather stations in the middle of Shandong province during 1980 to 2014,a cumulative frequency method was adopted to correct the thresholds of five drought indices.The temporal-spatial variation characteristics of drought and the applicability of each drought index in the studied area were analyzed.The results show that mean annual drought days calculated using the five indexes are about 92 to 106 days.It has a decreasing trend with decadal decreasing rates ranging between 2 and 6 days per decade.The center of drought area is located in the middle part of the central Shandong province.The compound drought index is the best indicator among the five indices for recognizing severe and long-duration drought years.The suitable drought index varies with seasons in the research area.Drought days in spring,summer and winter are declining during the 35 years and spatial change characteristics of drought days are different among four seasons.In addition,the most and the least droughts occurs respectively in May and August.Annual pattern of monthly drought days appears to be an approximate cosine rule.Besides,the drought indices which work most effectively in recognizing drought days vary from one month to another. References | Related Articles | Metrics

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Assessments of biomass and yield of spring maize in the west of Liaoning province base on actual evapotranspiration ZHANG Hui, SHI Kui-qiao, CHANG Song, YANG Yang, LI Shuang, JIA Ning, ZHAO Jia 2017, 33 (3):  88-94.  doi: 10.3969/j.issn.1673-503X.2017.03.011 Abstract ( 300 )   PDF (768KB) ( 513 )   Save To determine the assessement method of growth condition in different growth periods and yield of spring maize in the west the Liaoning province,based on weather,maize phenology,biomass and yield data from different sowing date experiment in Jinzhou from 2011 to 2015,the relationships between above-ground biomass of maize (AGB) in different growth periods,meteorological yield (MY) and actual evapotranspiration (AET) were investigated with Penman-Monteith and mathematical statistics methods.At the same time,a model evaluating growth conditions of different growth stages and final output of maize was established.The results show that linear relationships between AGB,MY and AET are significant,respectively.More specifically,the relationships between AGB in different growth periods and corresponding AET are significant at 5% level in sowing to seven-leaf stage and at 1% level in sowing to jointing,sowing to tasseling and sowing to milk stage.The forecast accuracies of the developed model for different maize growth periods range from 77.8% to 94.5%.In addition,the floor levels of water supplies for maize normally growing in the west of Liaoning province are 333.2 mm,23.3 mm,83.4 mm,118.9 mm and 57.7 mm during the whole growth period,sowing to seven leaf,seven leaf to jointing,jointing to tasseling and tasseling to milk stages,respectively.Meanwhile,for the stages when maize suffers drought stress,the influence of drought stress on yield in an order of heavy to light ranges at jointing-tasseling,tasseling-milky ripening,seven leaf-jointing,sowing-seven leaf and milk-maturation stage.In general,the method established in this paper can meet the demand on agrometerological yield forecast service and has realistic value in drought impact assessment operation. References | Related Articles | Metrics

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Cause analysis of anomalous more precipitation over Dalian area in July 2013 WANG Xiu-ping, JIN Wei, SAI Han, LIU Wei-hua 2017, 33 (3):  95-100.  doi: 10.3969/j.issn.1673-503X.2017.03.012 Abstract ( 223 )   PDF (1957KB) ( 383 )   Save Based on the daily precipitation observations in Dalian and the NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) monthly mean reanalysis data from 1971 to 2016,diagnostic analysis of causes of anomalous more precipitation over Dalian during July of 2013 was conducted.The results show that a "two ridge and one trough" circulation pattern retains in the middle and high latitudes over the Eurasian Continent.The high pressure over the Ural Mountains and Okhotsk Sea is abnormally stronger,and the low trough maintains steadily near the Baikal Lake,which results in the frequent movements of cold airs to the south.Meanwhile,the more northern and stronger subtropical westerly jets,the more western and northern Western Pacific Subtropical High,and the stronger summer monsoon over the East Asia favor the transport of warm,moist water vapor to Dalian from the Bay of Bengal,the South China Sea and the northwest Pacific Ocean,along the periphery of the subtropical high.Warm and cold airs converge over Dalian,and an abnormal converging area of water vapor formed,leading to anomalous more precipitation in Dalian.Moreover,a high energy tongue,the unstable atmospheric stratification,abnormally stronger upward motions,and the divergence at upper levels and convergence in lower levels provide favorable thermal and dynamic conditions for the anomalous rainfall in Dalian area. References | Related Articles | Metrics

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Influence of human body comfort degree on natural mortality in Hangzhou ZHANG Qing, LI Ying, LUO Yue-zhen, ZHENG Wen-tao 2017, 33 (3):  101-106.  doi: 10.3969/j.issn.1673-503X.2017.03.013 Abstract ( 265 )   PDF (1418KB) ( 482 )   Save Based on a computational approach of apparent temperature involving influence factors such as temperature,humidity and precipitation,and a classification method of human body comfortableness level,the influence of human body comfort degree on the whole natural mortality as well as on the natural mortality of different genders,ages and typical diseases in Hangzhou from August of 1998 to July of 2007 were analyzed.The purpose of this study is to provide a reference to meteorological health services in Hangzhou.The results show that the relationship between apparent temperature and natural mortality can be expressed as a quadric polynomial function.When apparent temperature is about 25.5 ℃,the number of daily mean mortality reaches a minimum but has a most significant lag correlation with apparent temperature of 3-5 d lag time.If we define daily mortality rate 36.51 as a threshold,the mortality peak days occur most frequently in winter and occasionally in summer.The human body comfortableness level is the highest in May and October.Both male and female mortality have significantly negative correlations with apparent temperature.The daily mean mortality of male is just slightly higher than that of female,and the cold uncomfortableness has greater influence on the mortality rate than the hot uncomfortableness.A significantly negative correlation of apparent temperature is observed with both of natural mortality of middle and old ages,particularly for the latter.The variation of apparent temperature has little effect on infants,teenagers and youths.The daily mean mortality is the largest for the old,followed by the middle-age,youth,infant,and teenager.Deaths owing to the respiratory and circulatory system diseases have a significantly negative correlation with apparent temperature,whereas deaths owing to cancer disease show an obviously positive correlation with apparent temperature.The daily mean mortality is mostly caused by cancer,followed by circulatory system diseases and respiratory system diseases.The respiratory system diseases are more sensitive to the temperature variation. References | Related Articles | Metrics

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Study on gas load forecast in Hangzhou based on meteorological factors GU Ting-ting, LUO Yue-zhen, ZHANG Qing, ZHU Zhan-yun 2017, 33 (3):  107-112.  doi: 10.3969/j.issn.1673-503X.2017.03.014 Abstract ( 215 )   PDF (739KB) ( 421 )   Save Using the daily and hourly data of gas load and simultaneous meteorological observational data in Hangzhou from 2008 to 2013,the variation of gas load in Hangzhou and its relationship with meteorological factors were statistically analyzed.A gas load forecasting model was established based on a SVM (Support Vector Machines) method.The results show that the gas load in Hangzhou from 2008 to 2013 exhibits obvious seasonal variation,with the highest daily mean meteorological load rate in winter and the lowest in summer.Diurnal variation of gas load,with a single peak,is similar among different seasons.The daily meteorological load rate has a negative correlation with daily air temperature in all months except for June and September,with the largest correlation coefficient in December.The daily meteorological load rate has positive values under the conditions of daily average temperature ≤ 13 ℃,and it reaches a maximum value with daily average temperature of about 3 ℃.A positive correlation between daily mean air pressure and daily meteorological load rate is observed from January to April and from October to December.The hourly meteorological load rate correlates negatively to daily air temperature in all seasons except for summer,and the best correlation occurs in autumn.Considering the main meteorological influencing factors,a gas load daily/hourly forecasting model is established based on a SVM regression method.This model has good performance,with a mean error of daily gas load forecasting of 4.36% and a mean error of hourly gas load forecasting of 4.18%. References | Related Articles | Metrics