Table of Content

30 August 2019, Volume 35 Issue 4 Previous Issue    Next Issue

ARTICLES

Select

Aircraft observations on physical properties of precipitation clouds in Hebei province KANG Zeng-mei, LI Zhong-liang, LIU Wei, DONG Xiao-bo, MAI Rong, SUN Yu-wen 2019, 35 (4):  1-7.  doi: 10.3969/j.issn.1673-503X.2019.04.001 Abstract ( 225 )   PDF (3329KB) ( 142 )   Save Based on data obtained from an airborne particle measurement system,weather radar,and Ka-band cloud radar,we analyzed the microphysical structure of mixed convective-stratiform clouds during a precipitation event caused by a low-trough cold front in Hebei province on May 22,2017.The results indicated that precipitation clouds are observed in the southwesterly flows ahead of a low trough.The mixed convective-stratiform clouds are large-scale stratiform clouds embedded with numerous convective-cloud-nuclei structures.The 0℃-layer height is about 3577-4004 m,and it decreases with the development of precipitation.The enhancement of embedded convection lifts the cloud top.The number concentration of cloud particles increases from 1.8×105 to 5.0×10-5 L-1 due to the occurrence and enhancement of convection in clouds.Meanwhile,the supercooled water content in the clouds rises significantly from 0.05 to 0.60 g·m-3.The supercooled water content in the upper layers of the cold clouds remains around 0.2 g·m-3 and accounts for 60% of the total liquid in the upper and middle layers.The growth rate of ice crystals is enhanced due to the adequate supply of supercooled liquid water.The ice crystal concentrations increase explosively in the lower layers of cold clouds in the presence of weak convection and increase rapidly in the upper and middle layers of the cold clouds in the presence of strong convection.The maximum diameter of precipitation particles increases from 8000 to more than 10000 μm and the spectral distribution of maximum precipitation particles with diameter larger than 10000 μm spans from the bottom to the upper-middle layers in the clouds. References | Related Articles | Metrics

Select

Comparisons of dynamic downscaling of the wind field in forest areas of Da-Xiao-Xing'anling Mountains MENG Ying-ying, CAO Dian-bin, WU Yan, WANG Zi-yang 2019, 35 (4):  8-15.  doi: 10.3969/j.issn.1673-503X.2019.04.002 Abstract ( 202 )   PDF (963KB) ( 78 )   Save In this study,we conducted the downscaling analysis of 10-m wind fields at 6 stations in Da-Xiao-Xing'anling Mountains during spring in 2017.We also used the observations to evaluate the 10-m wind speed and direction simulated with the Weather Research and Forecasting (WRF) model and with the CALMET downscaling model.The correlation coefficients between observed hourly wind speeds and that simulated with the two models reach 0.5-0.7.The prediction accuracy gradually increases with the increase of wind speed.The forecasting deviation of wind speed is relatively large at night and decreases during the daytime.The WRF model predicts the variability of wind speeds better than the CALMET model,and that has a higher correlation with the observations;but for the case of strong winds,the CALMET model performs better than the WRF model.The wind direction simulations of WRF and CALMET models are both in a good agreement with the observations.Wind directions with high prediction accuracy correspond to the prevailing wind directions of each station.Meanwhile,a simple-regression method is used to correct daily mean wind speed.Results indicate that the forecasting accuracy of daily mean wind speed increases by 50% on average,with good prospects in the operational application. References | Related Articles | Metrics

Select

Characteristics and causes of rare continuous rain weather event in He'nan province during autumn in 2017 ZHU Yu-zhou, LV Xiao-na, LIAO Rong-wei 2019, 35 (4):  16-24.  doi: 10.3969/j.issn.1673-503X.2019.04.003 Abstract ( 365 )   PDF (4883KB) ( 64 )   Save An event of continuous rain weather occurred from late August to mid-October in 2017 in He'nan province;such weather occurred rarely in the past 14 years.The characteristics of atmospheric circulation during this event were analyzed based on meteorological data from 1961 to 2017 in He'nan province and the National Center for Environment Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data.Different analysis methods were used in this study,including the correlation analysis method,the T-test method,the wavelet analysis method,and the band-pass filter analysis method,etc.The results show that the Wular Ridge,the Bay Lake Trough,and the Western Pacific Subtropical High are abnormally strong and maintain for a long time during this event.Eastern Europe and Caspian-Bahu areas are the key upstream regions for the continuous rainy process.The atmospheric circulation in the Eastern Europe has an oscillation period from quasi two weeks to 30 days,while the oscillation period in the Caspian-Bahu is from 4 to 8 days.The east-west span of the 200-hPa jet axis and the maximum wind speed of the jet core are abnormally larger than that on average in the same period.The divergence zone in the southwestern part of the jet zone has the suction effect over He'nan province,which is conducive to the occurrence of precipitation.The zonal wind speeds of the upper jet enhance three times,corresponding to three continuous rainy processes.The water vapor transport sources and channels are different during different continuous rainy processes;water vapor in these three rainy processes originates from the Indian Ocean,the South China Sea,and the Western Pacific Ocean,respectively. References | Related Articles | Metrics

Select

Analysis of a persistent heavy air pollution event during Autumn in Harbin LI Shu-ling, HUA Cong, ZHAO Ling, XU Sheng-rong, JING Xue-yi, ZHANG Xin, JIANG Bing 2019, 35 (4):  25-32.  doi: 10.3969/j.issn.1673-503X.2019.04.004 Abstract ( 255 )   PDF (1698KB) ( 119 )   Save Using meteorological and environmental monitoring data,the backward trajectory analysis,and satellite fire-monitoring data,the characteristics of a persistent heavy air pollution event in Harbin from October 18 to 20,2017 were analyzed,including atmospheric circulation,meteorological elements,pollutant sources,and transport.The results indicate that the heavy and severely heavy air pollution periods last for 48 h,with the mean and maximum PM2.5 (primary air pollutant) concentration reaching 438 μg·m-3 and 1487 μg·m-3,respectively.This heavy pollution event can be divided into two stages where double peaks of pollutant concentrations are observed.During this heavy pollution event,atmospheric circulation at upper levels are smooth and dominated by warm advection ahead of a shallow trough,and meanwhile,the surface is controlled by a weak low pressure.The surface wind speed is low,about 1.5 m·s-1 on average,and the occurrence frequency of wind speed ≤ 1.5 m·s-1 is 71%.The convergence of wind field favored the accumulation of air pollutants.During the development of heavy pollution,the increase of relative humidity (RH) contribute to the hygroscopic growth of particulate matters and thus enhance the pollution process.The decrease of PM2.5 concentration to the minimum lags 4-5 h behind that of RH to its minimum value.A strong surface temperature inversion layer is observed in the planetary boundary layer,with the top up to about 200 m and the intensity larger than 2.0℃·(100 m)-1.The stable stratification makes poor vertical diffusion.These air pollutants dominantly come from straw burning,followed by the coal combustion for building heating.The heavy pollution event in Harbin is due to the accumulation of local pollutants under stable meteorological conditions and the long-distance transport of massive pollutants caused by straw burning. References | Related Articles | Metrics

Select

Spatiotemporal characteristics of criteria air pollutants during the critical period of straw burning in Huaihe River Basin WU Wen-yu, ZHANG Hao, HE Bin-fang, HUO Yan-feng, ZHANG Hong-qun, ZHAI Jing 2019, 35 (4):  33-39.  doi: 10.3969/j.issn.1673-503X.2019.04.005 Abstract ( 183 )   PDF (2524KB) ( 68 )   Save Based on monitoring data of satellite remote-sensing fire point,air quality and meteorological parameters during June in 2015,we used the ANUSPLIN and Kriging interpolation methods to grid air quality index (AQI) and mass concentrations of criteria air pollutants,and then we analyzed their spatiotemporal characteristics and correlations with air temperature,relative humidity,and wind speed during the critical period of straw burning in Huaihe River Basin.The results show that the AQI and mass concentrations of PM10 and PM2.5 increase significantly during the straw burning period,which corresponds to the spatiotemporal variation of satellite fire monitoring points on a certain degree.The AQI,PM10 and PM2.5 concentrations increase with fluctuations in the early and middle June and tend to decline in late June.The spatial distributions of AQI,PM10,and PM2.5 concentrations are similar to each other,and are characterized by patterns of "low in the south and high in the north" and "two high and one low".The AQI,PM10 and PM2.5 concentrations had a significantly positive correlation with air temperature,negative correlation with relative humidity,and no significant correlation with wind speed. References | Related Articles | Metrics

Select

Characteristics of atmospheric PM10 and PM2.5 mass concentrations in Huangshi city HU Cai-jiao, LI Jin-lun, WANG Zu-wu, CHENG Hai-rong, KE Hao-hao, WU Wan-ye 2019, 35 (4):  40-46.  doi: 10.3969/j.issn.1673-503X.2019.04.006 Abstract ( 231 )   PDF (2296KB) ( 119 )   Save The characteristics of mass concentrations of PM10 and PM2.5,and their distribution and correlation with meteorological parameters in Huangshi were analyzed using the online monitoring data of inhalable particulate matter (PM10) and fine particulate matter (PM2.5) at five monitoring stations and surface meteorological elements such as wind direction,wind speed,air temperature,air pressure from January to December in 2015.The results show that the annual average concentrations of PM10 and PM2.5 at the five monitoring sites in Huangshi in 2015 range within 95.8-108.6 μg·m-3 and 64.3-68.9 μg·m-3,respectively;both exceed the National secondary standard.The seasonal mean mass concentrations of PM10 and PM2.5 are higher (143.9 ±62.2 for PM10 and 95.5 ±44.5 μg·m-3 for PM2.5) in winter,and low (75.2±24.0 for PM10 and 50.7 ±17.3 μg·m-3 for PM2.5) in summer,respectively.Among the five monitoring stations,PM pollution is heavier in the Xialu,Xisai,and Tieshan districts,and the mass concentrations of PM10 and PM2.5 have significant correlation at all sites.The concentrations of atmospheric particulate matter have a negative correlation with air temperature,positive correlation with air pressure,no significant correlation with wind speed and relative humidity,and influenced largely by wind direction. References | Related Articles | Metrics

Select

Characteristics of acid rain in the Beijing-Tianjin-Hebei region from 2012 to 2017 ZHANG Liang-yu, WEI Li-xin, ZHAO Chun-lei, ZHANG Hui, JIA Fang, XU Zhi-qing 2019, 35 (4):  47-54.  doi: 10.3969/j.issn.1673-503X.2019.04.007 Abstract ( 245 )   PDF (1732KB) ( 105 )   Save Using the observation data of 26 acid rain stations in the Beijing-Tianjin-Hebei region from 2012 to 2017,the spatial distribution characteristics of precipitation pH value and acid rain frequency were studied based on the GIS interpolation method.The variation characteristics of acid rain in different months,seasons and at different precipitation grades in the acid rain area were analyzed.The causes of acid rain formation were studied.The results show that from 2012 to 2017,the area of acid rain influencing in this region decreases.The areas with severe acid rain from 2012 to 2014 and with a high frequency of acid rain from 2012 to 2013 are both mainly distributed in the junction region of Chengde,Tangshan and Qinhuangdao cities.Compared with 2012,the acid rain area (accounting for 15% of the total region area) and the area with a high frequency of acid rain (accounting for 17% of the total region area) in 2017 decrease 63% and 52%,respectively.Generally,the frequency of relatively weak acid rain is the highest.83% of the extraordinarily strong acid rain occurs in 2012 and 2013.Compared with other seasons,the average pH value of in autumn precipitation is the lowest,its frequency of acid rain occurrence is the highest,and its pollution extent is the most serious.The increase of air pollutants in winter leads to the increase of K value in precipitation.The average pH value in the moderate-graded precipitation is the smallest.For the light-graded precipitation,the ratio of acid rain occurrence times to the total acid rain occurrence times reaches the maximum,and the corresponding K value in precipitation is the largest.After a rainstorm,acid rain pollution is reduced.After 2011,the emission of NOx exceeds that of SO2.The acid rain pollution has gradually changed from sulfuric acid-nitric acid type to nitric acid type.Reducing the emission of SO2 and NOx is an important measure to reduce the acid rain pollution in the Beijing-Tianjin-Hebei region. References | Related Articles | Metrics

Select

Exploration of simulation and application of early summer cold vortex in Northeast China using the BCC_CSM1.1(m) model JIAO Min, LI Ji, YU Ya-xin, HU Chun-li, WANG Ying, ZHOU Bin 2019, 35 (4):  55-62.  doi: 10.3969/j.issn.1673-503X.2019.04.008 Abstract ( 257 )   PDF (2094KB) ( 71 )   Save Based on the numerical simulation data of the BCC_CSM1.1 (Beijing Climate Center Climate System Model version 1.1) (m) model and the NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) reanalysis data from 1991 to 2017,the ability of BCC_CSM1.1 (m) model to simulate the cold vortex in Northeast China in early summer was evaluated.The results demonstrate that the BCC_CSM1.1 (m) model is basically successful in simulating the climate state of 500 hPa geopotential height fields.The mean square root error shows that the simulation result of the 500 hPa geopotential height fields in the south of Northeast China is better than that in the north of Northeast China.The first EOF mode of 500 hPa geopotential height fields demonstrates that the BCC_CSM1.1 (m) model can well simulate the major temporal and spatial features.The BCC_CSM1.1 (m) model can well simulate the upward trend and interannual variability of the northeast cold vortex (NECV) index in the last 27 years,however,the simulated upward trend is stronger than the actual situation and the interannual variability is weaker than the actual situation.The BCC_CSM1.1 (m) model can also successfully reproduce the interdecadal abrupt change of the NECV index,however,the start time of abrupt change is later than that of the actual situation.It is able to successfully simulate the significant positive correlation between the NECV index and the 500 hPa geopotential height fields in Northeast China and nearby areas,however,it fails to catch the significant negative correlation between the NECV index and the early summer rainfall in Northeast China.Furthermore,the ability of the NECV index to simulate the rainfall in early summer in Northeast China is very limited. References | Related Articles | Metrics

Select

Circulation characteristics and differences of distribution modes of the early summer precipitation in the Songhua River basin LOU De-jun, WANG Ji, ZHANG Xue-mei, LIU Yu-lian, ZHOU Xian-wei 2019, 35 (4):  63-68.  doi: 10.3969/j.issn.1673-503X.2019.04.009 Abstract ( 217 )   PDF (2343KB) ( 86 )   Save Based on the early summer precipitation data from 31 meteorological stations in the Songhua River Basin and the NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) reanalysis data from 1961 to 2017,the temporal and spatial distribution of precipitation in the Songhua River Basin and the influence characteristics of circulation were discussed by statistical methods.Results show that there are mainly three modes of the precipitation in the Songhua River Basin:the consistent rainfall mode in the whole basin,the anti-phase rainfall modes from northwest to southeast and from northeast to southwest.The main circulation characteristics affecting the three distribution modes are the low pressure at the east of Lake Baikal and Okhotsk blocking high (southwest low-northeast high),Ural ridge-West Siberian trough-Stanovoy Range ridge (a two-ridges-and-one-trough type),and the Bohai Sea and North China low pressure and the high in the northeast.The local high pressure or blocking situation plays a very important role in the formation of the three modes of precipitation in the early summer over the Songhua River Basin.The East Asia-Pacific and Polar-Eurasian types are teleconnections that play an important role in the distribution of the first mode precipitation. References | Related Articles | Metrics

Select

Spatial and temporal variation of NDVI and the reason analysis in Nagqu area LA Ba, LUO Sang-qu, CI Zhen, PING Cuo-wang 2019, 35 (4):  69-76.  doi: 10.3969/j.issn.1673-503X.2019.04.010 Abstract ( 192 )   PDF (1724KB) ( 77 )   Save The remote sensing and Geographic Information System (GIS) was applied to study the temporal and spatial distribution and change tendency of the Normalized Difference Vegetation Index (NDVI) in Nagqu area from 2000 to 2014.The relationship of meteorological factors with NDVI was also analyzed.The results show that the NDVI in Nagqu area increases gradually from south to north,from west to east,and from high to low altitudes.In recent 15 years,the NDVI,in general,shows no significant decline.Compared with the time from 2006-2008,the values of NDVI in 2000-2005 and 2009-2014 are high.From 2000 to 2014,the vegetation at the most regions in the northwest of Nagqu is in a stable state.The area that vegetation has obvious change concentrates in the central and southeastern regions with a dense population.Degradation and improvement areas show staggering features.The vegetation change is mainly controlled by precipitation and heat climatic conditions.Additionally,human activities play a significant influence on it at a short-term time scale. References | Related Articles | Metrics

Select

Applicability evaluation of the GLIGEN weather generator on the simulation of temperature in three provinces of Northeast China GAO Shu-xin, SONG Xiao-wei, LI Lin-lin, XUE Yi, CHEN Peng-xin, QI Wen-chuan 2019, 35 (4):  77-84.  doi: 10.3969/j.issn.1673-503X.2019.04.011 Abstract ( 240 )   PDF (1238KB) ( 243 )   Save The CLIGEN (Climate Generator) is a model developed by the U.S.Department of Agriculture to provide daily meteorology data with long sequences.Whether it is applicable to the three provinces i.e.Heilongjiang,Jilin,and Liaoning of Northeast China has not been evaluated.In this paper,the temperature simulated by the CLIGEN was evaluated by daily meteorological data from 15 weather stations in Northeast China from 1981 to 2015.The extreme maximum and minimum temperatures,the numbers of days with temperature ≥ 35℃ and temperature ≤ 0℃ were evaluated at 72 sites in Northeast China.The results show that the CLIGEN performs very well in the simulations of daily average maximum and minimum temperatures,and the MAPE (mean absolute percent error) and effective coefficient (E) of 12 months range from 0.33% to 14.74%.The MAPE of the minimum temperature is basically within 10%.The effective coefficient E value is also very close ranging from 0.9880 to 0.9999.The CLIGEN has a good simulation effect on the mean value of daily temperature range,but not on the standard deviation of the daily temperature range.The features of continuity and gradual change in temperature fail to be simulated by the CLIGEN.In the aspects of simulation of extreme temperature and the number of days,only the number of days with the temperatures lower than 0℃ is simulated well.From the spatial distribution of temperature difference,it shows that the larger and more values are distributed in western parts of Jilin and Liaoning provinces.This paper provides a preliminary study to evaluate the application of the CLIGEN on the simulation of temperature over three provinces in Northeast China to meet relevant research needs. References | Related Articles | Metrics

Select

Study on the accumulated temperature of cucumber growth in greenhouse MA Feng-lian, WEI Rui-jiang, WANG Xin, WU Xian-chun, SUN Qing-chuan 2019, 35 (4):  85-92.  doi: 10.3969/j.issn.1673-503X.2019.04.012 Abstract ( 216 )   PDF (871KB) ( 171 )   Save In order to study the demand of accumulated temperature for cucumber growth to improve the prediction ability and planting efficiency in greenhouse,this paper analyzed the growth regulation of leaves and fruits of cucumber and their relationships with the effective accumulated temperature in different years and stubbles and determined the dead accumulated temperature of plant,using the long-term observation data in greenhouse and the mathematical statistics method.The results show that the leaf number of cucumbers develops in an S-shaped curve during the whole growth period,following the regulation of growing slow first and then fast.The effective accumulated temperature required to grow an additional leaf during different periods presents an asymmetric "U" shape,that is,the effective accumulated temperature required to grow an additional leaf in the early and middle-late stages of leaf growth is greater than that in the middle stage.The average effective accumulated temperature of 8-40℃ required to grow an additional leaf during the whole growth period is 33-37℃·d,and that of 15-35℃ needed from fruit set to harvest is 110-130℃·d.If the temperature conditions below 10℃ and above 5℃ occur repeatedly in the greenhouse,and the accumulated effective accumulated temperature of 5-10℃ reaches about 8℃·d during the repeated process,the cucumber plants will die.The above accumulated temperature index has a practical guiding significance in the production of cucumber in the greenhouse. References | Related Articles | Metrics

Select

Change characteristics of shallow ground temperature and its prediction during the sowing period in Shenyang SONG Xiao-wei, LI Lin-lin, LI Shi, LIU Qing, GAO Shu-xin, JIANG Shan, ZHANG Jing, ZHANG Jing-xuan 2019, 35 (4):  93-99.  doi: 10.3969/j.issn.1673-503X.2019.04.013 Abstract ( 198 )   PDF (1257KB) ( 78 )   Save For understanding the change rule of ground temperature in Shenyang area,providing better forecast service on field temperature,reducing the risk of sowing and improving grain production safety,based on the data of air and ground temperature from the seven meteorological stations in Shenyang area from 1981 to 2015, the change rules of air and ground temperature in recent 35 years were analyzed using mathematical statistics methods and a ground temperature forecasting model for the spring sowing period (April and May) was established.The results show that from 1981 to 2010,the decadal temperature shows an increasing trend and the change of air temperature results in an obvious change of ground temperature.The climate tendency rates of air and ground temperature are between 0.426℃/10 a and 0.549℃/10 a.In the past 35 years,the differences of ground temperature at the soil depth of 0-5 cm,5-10 cm,and 10-20 cm are 1.5℃,0.5℃,and 0.5℃ during April and October,respectively.The ground temperature at the soil depth of 0-20 cm and air temperature undergo a climate abrupt change in 1996,affecting the changing trend of temperature.During the spring sowing period,the differences between air temperature and ground temperature at the soil depth of 0 cm,5 cm and 10 cm in the western region change respectively from the low value in April to the high value in May.The t-test of the ground temperature forecast model doesn't show significant difference at P=0.01 level,and the relative error is within ±10%,indicating that the model can be applied for the prediction of ground temperature during the spring sowing period (April and May) in Shenyang area. References | Related Articles | Metrics

Select

The study case of NorESM1-M on the estimation of spring maize climate potential productivity in northeast China in 2050s HOU Yi-ling, XU Han-qing, YANG Xuan, ZHAO Chun-yu 2019, 35 (4):  100-105.  doi: 10.3969/j.issn.1673-503X.2019.04.014 Abstract ( 162 )   PDF (2573KB) ( 42 )   Save Based on the climate scenarios materials outputted from the NorESM1-M model,the agro-ecological zones model was driven for analyzing the spring maize climate potential productivity in northeast China under RCP2.6 and RCP8.5 scenarios in the mid-21st century.The results show that compared with the baseline period during 1981-2010,the heat condition is improved under RCP2.6 scenario with annual mean temperature and accumulated temperature ≥ 10℃ increasing 1.72℃ and 359.6℃·d,respectively.The precipitation slightly shows an increasing trend with an averaged increase of 56.9 mm over the studied area and the trend is larger in the south than in the north,while evapotranspiration increases by 10.0 mm.Meanwhile,the area with the largest climate potential productivity is distributed in the east Liaoning.The yield per unit area in Liaoning increases by 1100 kg/ha or more relative to the baseline period.Under RCP8.5 scenario,the heat resource in northeast China is further improved.More specifically,the accumulated temperatures ≥ 10℃ in Liaoning,Jilin and Heilongjiang provinces increase by 652.7℃·d,636.3℃·d,and 683.9℃·d,respectively.In addition,compared with RCP2.6 scenario,the precipitation increases and demonstrates a large spatial variability and the production maintains an increasing trend and increases by 3.3%,8.1% and 20.0% in Liaoning,Jilin and Heilongjiang provinces,respectively. References | Related Articles | Metrics

Select

Simulation of basin water balance controlled by Fuchunjiang Reservoir watershed based on SWAT model driven by CMADS LUO Yue-zhen, GU Ting-ting, PAN Ya-ying, ZHANG Qing 2019, 35 (4):  106-112.  doi: 10.3969/j.issn.1673-503X.2019.04.015 Abstract ( 166 )   PDF (1633KB) ( 78 )   Save The runoff distribution and water balance process in Fuchunjiang Reservoir watershed basin regarded as the studied area from 2008 to 2016 were investigated based on the daily runoff simulated by SWAT model driven with the China Meteorological Assimilation Datasets (CMADS).The results show that the SWAT model using CMADS as meteorological forcing data has a good performance in simulating the variation of runoff in Fuchunjiang Basin.During the verification period,the Nash-Sutcliffe efficiency coefficient and the coefficient of determination for the daily runoff simulation are respectively above 0.70 and 0.75,which reaches the model evaluation criteria.Among the water balance elements of the basin,the main output items of the surface runoff i.e.the surface runoff and the actual evapotranspiration account for 57.2% and 36.2% of annual precipitation,respectively.Compared with the precipitation,the interannual variation of actual evapotranspiration is small.In addition,the maximums of the precipitation,the surface runoff,the soil water supply,the lateral flow,and the actual evapotranspiration appear in June,and their minimums appear in January.The surface runoff is the dominant component of the basin runoff,and its monthly change trend is consistent with that of precipitation.Whereas the base flow is much less than surface runoff,and the response of the monthly base flow to precipitation is not sensitive. References | Related Articles | Metrics

REVIEW

Select

Review of the research on ecological carrying capacity evaluation methods QU Xiu-qi, LIU Miao, LI Chun-lin, HU Yuan-man, YIN Hong-yan, QI Li 2019, 35 (4):  113-119.  doi: 10.3969/j.issn.1673-503X.2019.04.016 Abstract ( 238 )   PDF (606KB) ( 181 )   Save Human activities are increasingly affecting sustainable development.Therefore,the study of ecological carrying capacity has been attracted more and more attention.In this paper,we summarize the evolution of the concept of ecological carrying capacity and introduce the main research methods of ecological carrying capacity including primary productivity method (NPP),ecological footprint method,energy value ecological footprint method,ecosystem-service-based method,carbon and oxygen balance method,state space method,the comprehensive evaluation method and the model method.The advantages and disadvantages of the above-mentioned methods are reviewed separately.At last,the shortcomings of current ecological carrying capacity researches and its future possible development directions are discussed. References | Related Articles | Metrics

SCIENTIFIC NOTES

Select

Influence of environmental conditions on temperature observation from the weather station in Beijing LI Lin, SUN He-min, QIAO Xiao-yan, FAN Xue-bo, SUN Xue-qi, DU Chuan-yao, YU Li-ping 2019, 35 (4):  120-126.  doi: 10.3969/j.issn.1673-503X.2019.04.017 Abstract ( 165 )   PDF (1884KB) ( 46 )   Save In order to gain insights into the influence of environmental conditions on air temperature observation,the difference of temperature between the two stations and its response to the sunshine,wind speed and precipitation caused by different observation circumstances were investigated using the ground-based meteorological data of Beijing (54511) and Nanhaizi (A1274) weather stations in 2017.The results suggest that the significant difference in air temperature in 2017 is attributed to the differences in environmental conditions.The annual average temperature at the 54511 station is 0.75℃ higher than that at A1274 station,and the monthly average air temperature at the 54511 station is higher than that at A1274 station for each month.In addition,the smallest and largest differences of monthly mean air temperature between two stations are 0.60℃ in July and 1.09℃ in September,respectively.Moreover,the difference of mean daily maximum air temperatures between two stations is small,while that of mean daily minimum air temperature (MINT) is large and the MINT of 54511 station is 1.24℃ higher than that of A1274 station.Besides,the diurnal variations of air temperature at the two stations are similar and both show a single peak distribution,while diurnal temperature range and MINT of 54511 stations are smaller and larger than those of A1274 station,respectively.The difference in hourly air temperature (TD) between the two stations increases with duration and intensity of sunshine increasing.TDs during 10-14 o'clock and 19-23 o'clock when short-wave and long-wave effects are respectively strongest are significantly related to direct radiation in the daytime with relationship coefficients of 0.459 and 0.601.Also,horizontal wind speed has a great influence on the difference in temperature between the two stations.At the same time,the differences of the annual average temperature between the two stations are below 0.1℃ and above 1.28℃ when the wind speed exceeds 5 m·s-1 and is less than 1 m·s-1,respectively.The temperature difference between the two stations is smaller in the rainy day than in the non-rainy day.Specifically,air temperature in 54511 station is only 0.2℃ higher than that in A11274 station.The distance between the two stations is about 4.3 km,which indicates the climatological temperature of the two stations is homogeneous.The proportions of construction land,vegetation and water body in the 2 km area around the 54511 station are about 30% higher and 28% lower as well as similar relative to those of the A1274 station,respectively.In addition,the Fifth Ring Road near the 54511 station is of the characteristics of low reflectivity and high heat capacity and is able to absorb solar radiation and store more heat in the daytime,and then releases this heat in the nighttime.Altogether,the temperature difference between the two stations is greatly affected by solar radiation and wind speed,but less affected by precipitation,owing to the difference in environmental conditions. References | Related Articles | Metrics

Select

Identification of hydrometeors based on S-band dual-polarimetric radar measurement YANG Lei, HE Hong-bing, YANG Bo, MENG Xin 2019, 35 (4):  127-132.  doi: 10.3969/j.issn.1673-503X.2019.04.018 Abstract ( 255 )   PDF (1191KB) ( 228 )   Save In order to improve the hydrometeor types identification ability of S-band dual-polarimetric weather radar,the ambient temperature parameter considered as the recognition factor is introduced to improve the conventional fuzzy logic hydrometeor classification.Five measurements have been used as input variables to the algorithm,namely,horizontal reflectivity (ZH),differential reflectivity (ZDR),differential propagation phase shift (KDP),correlation coefficient(ρhv (0)) and height transformed with temperature closely related to hydrometeor phase,by using the empirical formula.Beta function (β) is chosen as the membership function,and the membership function threshold of each parameter is given.On this basis,this paper takes a study about hydrometeor type identification using the domestic first S-band dual-polarization weather radar data and sounding temperature data.The results show that the results of hydrometeor type identification are more reasonable because of the introduction of ambient temperature parameter.The set of parameters threshold for hydrometeor classification are feasible.In addition,the results of hydrometeor type identification are basically in an agreement with the cloud microphysics evolution law,which can be used as a reference for further research.In general,it is still necessary to verify the identification results by accumulating radar data and measured data,to select suitable radar parameters,and to fix the membership function parameters for improving the accuracy of the hydrometeor type identification results. References | Related Articles | Metrics

BULLETINS

Select

Assessment on meteorological parameters designed for the Heating,Ventilation and Air Conditioning (HVAC) systems in super high-rise buildings in Tianjin CAO Jing-fu, YANG Yan-juan, CHEN Yue-hao, WANG Min, HAO Li-sheng 2019, 35 (4):  133-138.  doi: 10.3969/j.issn.1673-503X.2019.04.019 Abstract ( 216 )   PDF (1068KB) ( 219 )   Save The vertical variations of meteorological parameters designed for the Heating,Ventilation and Air Conditioning (HVAC) systems and their impact on the design load were analyzed using temperature data obtained from a 255-m meteorological tower in Tianjin.A vertical temperature model was established and it can be used to calculate outdoor air temperature of super high-rise buildings and then to determine the values of meteorological parameters of the HVAC system.The results indicated that design outdoor temperatures for heating and air-conditioning in winter and summer all decrease with height from 5 m to 200 m above the ground,by 2.0℃,1.0℃,and 2.8℃,respectively.Such variations of outdoor design temperatures lead to the increase in design load for heating and wintertime air-conditioning by 5.78% and 1.36%,respectively,and the decrease in design load for summertime air-conditioning by 5.85%.Using the vertical temperature model,the meteorological parameters for the HVAC systems between 200 m and 500 m were calculated.Outdoor design temperatures for heating and air-conditioning in winter and summer also exhibit a decreasing trend with height in a rate of 0.52℃/100 m,0.50℃/100 m,and 0.66℃/100 m from 200 m to 500 m,respectively.It is improper to only use the 2-m observational data to calculate the outdoor design meteorological parameters of HVAC systems for super high-rise buildings.The changes in these meteorological parameters with height should be fully considered in the design for super high-rise buildings,to improve the indoor thermal comfort and building energy efficiency. References | Related Articles | Metrics

Select

Homogeneity test and variation characteristics of wind speed at two typical high mountainous meteorological stations in Central China PENG Jia-dong, YE Cheng-zhi, ZHANG Jian-ming, CHEN De-qiao 2019, 35 (4):  139-144.  doi: 10.3969/j.issn.1673-503X.2019.03.020 Abstract ( 144 )   PDF (738KB) ( 173 )   Save Based on the two-phase regression model and the historical information of meteorological station,the wind speed data from the two typical high mountainous stations of Nanyue and Lushan in Central China during 1960-2017 were tested for their homogeneity and then were corrected.After that,variations of annual-averaged wind speed and their differences relative to the surrounding low altitude stations were analyzed and verified by the NCEP/NCAR reanalysis data.The results indicate that the wind speed series of Nanyue has an inhomogeneous point which caused by wind instrument changes,while no inhomogeneous point is identified in Lushan.The annual and seasonal averaged wind speed in Nanyue and Lushan are significantly higher than that in the surrounding low altitude stations.For the high mountainous stations,the maximum wind speed occurs in spring and summer,and the seasonal differences are small for the low altitude stations.The annual and seasonal averaged wind speed show significant decreasing trends during 1960-2017 at the high mountainous stations and low altitude stations,with the decreasing rates in the mountainous stations much higher than that at the low altitude stations.The difference of mean wind speed variations between 850 hPa and 1000 hPa from NCEP/NCAR in the same area is basically consistent with the difference between the high mountainous stations and low altitude stations,which suggests that the difference of wind speed between the mid-low altitude and surface has universality in Central China. References | Related Articles | Metrics