Volume 44,Issue 4,2016 Table of Contents
2016, 44(4):517-527.
Abstract:
From May 2013 to May 2014， the networked radar system consisting of 4 Xband weather radar in Nanjing and the surrounding areas was installed for rapid alert and fine detection of thunderstorms and heavy rainfall under the cooperation of IAPLAEGO and CETCNRT. The developing key techniques of cooperative selfadaption observation by single and multipleradar are discussed. The cooperative selfadaptation observation frame is established, and the software of the core observation control algorithm is developed. The main algorithm includes weather area selection and scan strategy. The intelligent judgment and highlight of severe weather areas are realized, and relative positions between radar and the target are also taken into consideration. The results show that the developed mode for cooperative selfadaptation observation, which could accurately find the weather areas of interest quickly, is effective. The higher spatial and temporal observations of important target areas have been acquired.
From May 2013 to May 2014， the networked radar system consisting of 4 Xband weather radar in Nanjing and the surrounding areas was installed for rapid alert and fine detection of thunderstorms and heavy rainfall under the cooperation of IAPLAEGO and CETCNRT. The developing key techniques of cooperative selfadaption observation by single and multipleradar are discussed. The cooperative selfadaptation observation frame is established, and the software of the core observation control algorithm is developed. The main algorithm includes weather area selection and scan strategy. The intelligent judgment and highlight of severe weather areas are realized, and relative positions between radar and the target are also taken into consideration. The results show that the developed mode for cooperative selfadaptation observation, which could accurately find the weather areas of interest quickly, is effective. The higher spatial and temporal observations of important target areas have been acquired.
2016, 44(4):528-534.
Abstract:
Three strategies on data quality early warning of automatic soil water observations are setup: (1) Abnormal value detection of the automatic soil observation data is conducted based on the regularity of the soil moisture evolution. (2) From the relationship between soil observations, the soil hydrological constants are calculated, which are used to determine the theoretically soil moisture boundary for the automatic soil observation data limit tests. (3) Referring to the relationships between soil water content and soil water flow trend, the water potential flow trend coefficient is set up by using the real water contents as well as its field capacity and wilting moisture, which is used to analyze the unreasonable distributions of soil water among the different soil layers. Based on the data of early warning strategies, the operatiing scheme is setup for data quality check in real time. The outputs from the early warning system shows that the relative higher detection rate implies to the suspicious soil hydrological constants, which is used in calculating the soil moisture from the instrument signals, and the inappropriate observation environment of the instrument due to the soil hole, cracks, and so on around the instrument after installation. The warning results are consistent with the conclusions from the automatic soil water observation station field investigations. The warning effects are objective, reliable, and suitable for different levels of operation sectors to use automatic soil water data in routine services.
Three strategies on data quality early warning of automatic soil water observations are setup: (1) Abnormal value detection of the automatic soil observation data is conducted based on the regularity of the soil moisture evolution. (2) From the relationship between soil observations, the soil hydrological constants are calculated, which are used to determine the theoretically soil moisture boundary for the automatic soil observation data limit tests. (3) Referring to the relationships between soil water content and soil water flow trend, the water potential flow trend coefficient is set up by using the real water contents as well as its field capacity and wilting moisture, which is used to analyze the unreasonable distributions of soil water among the different soil layers. Based on the data of early warning strategies, the operatiing scheme is setup for data quality check in real time. The outputs from the early warning system shows that the relative higher detection rate implies to the suspicious soil hydrological constants, which is used in calculating the soil moisture from the instrument signals, and the inappropriate observation environment of the instrument due to the soil hole, cracks, and so on around the instrument after installation. The warning results are consistent with the conclusions from the automatic soil water observation station field investigations. The warning effects are objective, reliable, and suitable for different levels of operation sectors to use automatic soil water data in routine services.
2016, 44(4):535-541.
Abstract:
Aiming at the problem of low data availability of FDR automatic soilmoisture station, based on the working principles of FDR automatic soil moisture sensors, combined with the data processing procedures and methods, about 450 secondarylevel calibration parameters of 60 station in Hunan and the related observation data are analyzed. It is noted that by the current calibration methods, it is difficult to conducted full scale calibration under natural conditions, and the unreasonable secondary calibration parameters are the root cause of the low data availability of FDR automatic soilmoisture data. The two calibration parameters are not reasonable, for the slope of the equation is too large, too small, or negative values, leading to such problems as too large increase amplitude, unchanging, or opposite to the reality of observation data. The suggestions of largesample undisturbed soil sampling and laboratory calibration are put forward aiming at the problems of current data calibration method. The method is verified preliminarily, and the results show that the method can effectively improve the quality of soil moisture observation data from the sources.
Aiming at the problem of low data availability of FDR automatic soilmoisture station, based on the working principles of FDR automatic soil moisture sensors, combined with the data processing procedures and methods, about 450 secondarylevel calibration parameters of 60 station in Hunan and the related observation data are analyzed. It is noted that by the current calibration methods, it is difficult to conducted full scale calibration under natural conditions, and the unreasonable secondary calibration parameters are the root cause of the low data availability of FDR automatic soilmoisture data. The two calibration parameters are not reasonable, for the slope of the equation is too large, too small, or negative values, leading to such problems as too large increase amplitude, unchanging, or opposite to the reality of observation data. The suggestions of largesample undisturbed soil sampling and laboratory calibration are put forward aiming at the problems of current data calibration method. The method is verified preliminarily, and the results show that the method can effectively improve the quality of soil moisture observation data from the sources.
2016, 44(4):542-547.
Abstract:
The realtime display system of AMDAR (Aircraft Meteorological Data Relay) data in the Meteorological Center of the China Eastern Civil Aviation Administration is introduced. The construction and working flow of the AMDAR data application systems are presented. The thunderstorm, gale, and snow weather events are analyzed by using the AMDAR data application systems. The results show that the AMDAR data application systems are visualized and practical, and can effectively improve the utilization of the data. The uneven spatialtemporal distribution of AMDAR data is mainly distributed between 00:00UTC and 15:00UTC in the midlow level under 4 km. The system can provide continuous wind and temperature distributions of upperlevels, and also be able to catch up the small and medium scale weather characteristics. In certain weather processes, it can provide useful objective bases for nowcasting and has certain practical value.
The realtime display system of AMDAR (Aircraft Meteorological Data Relay) data in the Meteorological Center of the China Eastern Civil Aviation Administration is introduced. The construction and working flow of the AMDAR data application systems are presented. The thunderstorm, gale, and snow weather events are analyzed by using the AMDAR data application systems. The results show that the AMDAR data application systems are visualized and practical, and can effectively improve the utilization of the data. The uneven spatialtemporal distribution of AMDAR data is mainly distributed between 00:00UTC and 15:00UTC in the midlow level under 4 km. The system can provide continuous wind and temperature distributions of upperlevels, and also be able to catch up the small and medium scale weather characteristics. In certain weather processes, it can provide useful objective bases for nowcasting and has certain practical value.
2016, 44(4):548-554.
Abstract:
To study the observing performance differences of two laser raindrop spectrometers, Parsivel and LNM, an analysis is made of the observational data from two laser raindrop spectrometers at the Beijing southern observatory from July to November 2014 (123 days under the North rainy conditions), considering manual records in the same period as standards. Comparison is conducted in the cumulative rainfall, precipitation beginning and ending time, and the particle information between the two devices. The results show that the Parsivel laser raindrop spectrometer lacks of sensitivity in timely reporting of precipitation beginning time, has more abundant classification information, and outputs larger particle diameters compared with LNM in the same precipitation process. In terms of cumulative rainfall, the results of the two devices and tippingbucket raingauges basically are comparable. When the cumulative rainfall is over 10 mm, LNM reports significantly greater cumulative rainfall than Parsivel.
To study the observing performance differences of two laser raindrop spectrometers, Parsivel and LNM, an analysis is made of the observational data from two laser raindrop spectrometers at the Beijing southern observatory from July to November 2014 (123 days under the North rainy conditions), considering manual records in the same period as standards. Comparison is conducted in the cumulative rainfall, precipitation beginning and ending time, and the particle information between the two devices. The results show that the Parsivel laser raindrop spectrometer lacks of sensitivity in timely reporting of precipitation beginning time, has more abundant classification information, and outputs larger particle diameters compared with LNM in the same precipitation process. In terms of cumulative rainfall, the results of the two devices and tippingbucket raingauges basically are comparable. When the cumulative rainfall is over 10 mm, LNM reports significantly greater cumulative rainfall than Parsivel.
2016, 44(4):555-561.
Abstract:
Aiming at the problems existing in the maintenance of observation equipment, by use of the NI PXI virtual instrument technology, and the LabVIEW graphical programming software platform, an automatic meteorological station fault diagnosis, testing, and maintenance system is designed based on the virtual instrument technology, mainly including the hardware design of the testing system, application software design, and dynamic maintenance database design, which realizes the functions of automatic meteorological station data acquisition, processing, analysis, diagnosis, file display, printing, etc. Through the test signal treatment by software programming to strengthen the function of adaptive test, using database retrieval function, the system realizes the fault similarity search function and improves the efficiency of fault testing and diagnosis.
Aiming at the problems existing in the maintenance of observation equipment, by use of the NI PXI virtual instrument technology, and the LabVIEW graphical programming software platform, an automatic meteorological station fault diagnosis, testing, and maintenance system is designed based on the virtual instrument technology, mainly including the hardware design of the testing system, application software design, and dynamic maintenance database design, which realizes the functions of automatic meteorological station data acquisition, processing, analysis, diagnosis, file display, printing, etc. Through the test signal treatment by software programming to strengthen the function of adaptive test, using database retrieval function, the system realizes the fault similarity search function and improves the efficiency of fault testing and diagnosis.
2016, 44(4):562-566.
Abstract:
Based on the Android SDK development environment， a mobile client that can be used for weather radar professional operations is designed and exploited as a small affiliated assistant application，which provides a convenient information tool of radar information to Android smartphone users. The platform not only realizes radar information display and other basic functions, but also achieves the acquisition of radar products and image display, and performs some complex operations such as checking the status of the radar system and radar operation assurance. It is convenient for users such as aviation forecasters and civil controllers, etc., to check out the latest radar echo images. It is a new approach of civil aviation security and is of practicality and reference value.
Based on the Android SDK development environment， a mobile client that can be used for weather radar professional operations is designed and exploited as a small affiliated assistant application，which provides a convenient information tool of radar information to Android smartphone users. The platform not only realizes radar information display and other basic functions, but also achieves the acquisition of radar products and image display, and performs some complex operations such as checking the status of the radar system and radar operation assurance. It is convenient for users such as aviation forecasters and civil controllers, etc., to check out the latest radar echo images. It is a new approach of civil aviation security and is of practicality and reference value.
2016, 44(4):567-570.
Abstract:
A remote maintenance and testing system for the network of lighting location finder is presented. Based on the maintenance method of lighting location finders, the proposed system produces the key information of realtime monitoring and running status of the lightning location finder and provides the assessment and the alarm of the equipment malfunction in fully automatic manner. Particularly, the system is implemented by using the current stateoftheart Web visual techniques with a friendly graphical user interface (GUI). The system provides robust realtime interaction with the hardware of the network. The proposed system overcomes the problems presented by the conventional maintenance mode, such as failing to response quickly to the malfunction of the distributed stations. The proposed system shows promising in the lightning location network maintenance, and can obtain a sound efficiency and accuracy performance.
A remote maintenance and testing system for the network of lighting location finder is presented. Based on the maintenance method of lighting location finders, the proposed system produces the key information of realtime monitoring and running status of the lightning location finder and provides the assessment and the alarm of the equipment malfunction in fully automatic manner. Particularly, the system is implemented by using the current stateoftheart Web visual techniques with a friendly graphical user interface (GUI). The system provides robust realtime interaction with the hardware of the network. The proposed system overcomes the problems presented by the conventional maintenance mode, such as failing to response quickly to the malfunction of the distributed stations. The proposed system shows promising in the lightning location network maintenance, and can obtain a sound efficiency and accuracy performance.
2016, 44(4):571-575.
Abstract:
In order to further broaden the meteorological information release channels and enhance the capability of meteorological services and the public availability of meteorological information, based on the Web server of Binhai New Area meteorological information, a public meteorological information service platform was developed by using the WeChat platform, the Java programming language, Oracle database, Hibernate, and Spring Framework technologies. In this platform, meteorological information can be gained in charts, text, GIS maps, and other different forms. The platform is taking full advantage of the new mobile media to release meteorological information, early warning message, and current weather situation to the public.
In order to further broaden the meteorological information release channels and enhance the capability of meteorological services and the public availability of meteorological information, based on the Web server of Binhai New Area meteorological information, a public meteorological information service platform was developed by using the WeChat platform, the Java programming language, Oracle database, Hibernate, and Spring Framework technologies. In this platform, meteorological information can be gained in charts, text, GIS maps, and other different forms. The platform is taking full advantage of the new mobile media to release meteorological information, early warning message, and current weather situation to the public.
2016, 44(4):576-580.
Abstract:
The measurement errors of SL3 type double tipping rainguage due to the coordination problem are analyzed through a precipitation simulation experiment. The results show: The improperly adjusted capacity of uptipping but proper capacity of downtipping make precipitation loss increase, leading to small measurement value because of the coordination problem of up and down tipping. For example, when rainfall intensity is 1 mm/min and the capacity of right up tipping is less 0.4 mL, the precipitation measurement error is -4%. In contrast, proper up tipping but improper down tipping brings the greater measurement error. When rainfall intensity is 1 mm/min and the capacity of right down tipping less 0.4 mL, the precipitation measurement error is +11%. Sometimes, the measurement error of improperly adjusted capacity of both tipping is smaller than that of one improper and the other proper. Meanwhile, the design of double tipping raingauge cannot completely solve the problem of measurement error induced by different precipitation rates, but can reduce the error obviously. The maximum deviation of precipitation measurement is 2% in the 4 mm/min and 1 mm/min condition. The solution of using siphon principle equipment to replace the up tipping is proposed, to reduce the effect of manual adjustment.
The measurement errors of SL3 type double tipping rainguage due to the coordination problem are analyzed through a precipitation simulation experiment. The results show: The improperly adjusted capacity of uptipping but proper capacity of downtipping make precipitation loss increase, leading to small measurement value because of the coordination problem of up and down tipping. For example, when rainfall intensity is 1 mm/min and the capacity of right up tipping is less 0.4 mL, the precipitation measurement error is -4%. In contrast, proper up tipping but improper down tipping brings the greater measurement error. When rainfall intensity is 1 mm/min and the capacity of right down tipping less 0.4 mL, the precipitation measurement error is +11%. Sometimes, the measurement error of improperly adjusted capacity of both tipping is smaller than that of one improper and the other proper. Meanwhile, the design of double tipping raingauge cannot completely solve the problem of measurement error induced by different precipitation rates, but can reduce the error obviously. The maximum deviation of precipitation measurement is 2% in the 4 mm/min and 1 mm/min condition. The solution of using siphon principle equipment to replace the up tipping is proposed, to reduce the effect of manual adjustment.
2016, 44(4):581-584.
Abstract:
A new subway line in Chongqing beneath a meteorological station is studied，and the requirements for vibration environment of meteorological observation instruments at the meteorological station are analyzed. The field test of vibration effect for the Chongqing metro lines has been running was conducted to assess the effect of subway vibration on the weather station. The research results show that (1) Combined with the accuracy requirements of meteorological detection instruments and with reference to the “construction allowable vibration standards,” it is proposed for the vibration environment of meteorological detection: the vibration acceleration (peak value) is less than or equal to 0.0314 m/s2; vibration velocity (peak) is less than or equal to 0.5; and vibration displacement (mean square root) is less than or equal to 1.8 μm. (2) While the trains passing, the dominated ground vibration frequency is 6 to 90 Hz, and the peak velocity of vertical vibration is 0.0188 mm/s, and the peak velocity of horizontal vibration is 0.0151 mm/s. It is suggested that the vibration of metro train operation should be controlled within the acceptable range for weather detection
A new subway line in Chongqing beneath a meteorological station is studied，and the requirements for vibration environment of meteorological observation instruments at the meteorological station are analyzed. The field test of vibration effect for the Chongqing metro lines has been running was conducted to assess the effect of subway vibration on the weather station. The research results show that (1) Combined with the accuracy requirements of meteorological detection instruments and with reference to the “construction allowable vibration standards,” it is proposed for the vibration environment of meteorological detection: the vibration acceleration (peak value) is less than or equal to 0.0314 m/s2; vibration velocity (peak) is less than or equal to 0.5; and vibration displacement (mean square root) is less than or equal to 1.8 μm. (2) While the trains passing, the dominated ground vibration frequency is 6 to 90 Hz, and the peak velocity of vertical vibration is 0.0188 mm/s, and the peak velocity of horizontal vibration is 0.0151 mm/s. It is suggested that the vibration of metro train operation should be controlled within the acceptable range for weather detection
2016, 44(4):585-595.
Abstract:
The best tracks and satellitesborne infrared cloud top temperatures (TBB) observations of the National Centers for Environmental Prediction Final Analysis are employed to examine the largescale and innercore convection and characteristics of tropical cyclones (TCs) undergoing different intensity changes in the western North Pacific (WNP) and South China Sea (SCS) ocean basins from 2000 to 2014. The mean conditions of TCs cases that undergo rapid intensification (RI) are compared to those of the nonRI cases. In addition, the nonRI cases are defined in four other intensity change bins: slow intensification (SI), intensification stable (IS), slow weakness (SW) and rapid weakness (RW). For the environmental variables, statistically significant differences are found between RI cases and nonRI samples, especially in IS, SW and RW groups. In both basins, RI events tend to form in environments with weaker environmental vertical wind shear than SI cases. In the WNP, RI events occurred in high maximum potential intensity environments characterized by warmer sea surface temperature, greater upperoceanic heat content, and stronger upperlevel divergence. RI events tend to occur in favorable environments with higher lowerlevel relative humidity, and cooler upperlevel temperatures than nonRI cases. For TBB observations, RI cases have larger cold TBB covering areas in the innercore regions, and lower average symmetry TBB within the eyewalls of the storms. The KNearest Neighbor (KNN) rule is employed to identify the RI cases using leaveoneout cross validation. The results show that the verification of forecasts is generally skillful.
The best tracks and satellitesborne infrared cloud top temperatures (TBB) observations of the National Centers for Environmental Prediction Final Analysis are employed to examine the largescale and innercore convection and characteristics of tropical cyclones (TCs) undergoing different intensity changes in the western North Pacific (WNP) and South China Sea (SCS) ocean basins from 2000 to 2014. The mean conditions of TCs cases that undergo rapid intensification (RI) are compared to those of the nonRI cases. In addition, the nonRI cases are defined in four other intensity change bins: slow intensification (SI), intensification stable (IS), slow weakness (SW) and rapid weakness (RW). For the environmental variables, statistically significant differences are found between RI cases and nonRI samples, especially in IS, SW and RW groups. In both basins, RI events tend to form in environments with weaker environmental vertical wind shear than SI cases. In the WNP, RI events occurred in high maximum potential intensity environments characterized by warmer sea surface temperature, greater upperoceanic heat content, and stronger upperlevel divergence. RI events tend to occur in favorable environments with higher lowerlevel relative humidity, and cooler upperlevel temperatures than nonRI cases. For TBB observations, RI cases have larger cold TBB covering areas in the innercore regions, and lower average symmetry TBB within the eyewalls of the storms. The KNearest Neighbor (KNN) rule is employed to identify the RI cases using leaveoneout cross validation. The results show that the verification of forecasts is generally skillful.
2016, 44(4):596-604.
Abstract:
The optical flow method is an important method in motion image analysis, which is mainly used to determine the motion information of a target. The element forecast fields produced by numerical models are gridded spaces, which are also a kind of images, and the optical flow method used in image analysis can be applied to the numerical model verification. The optical flow method is used to the heavy precipitation forecast verification. The principles of the optical flow method are described by using the theoretical simulation, and then through the verification on the 24 h precipitation forecast of ECMWF and T639 models for three different types of heavy precipitation process, the practical application of the optical flow verification method in heavy precipitation forecast verification is discussed. The results show: (1) By decomposing the forecast error into intensity, displacement, and angular errors, the optical flow verification method can give an accurate quantitative analysis of the heavy precipitation forecast errors. (2) Based on the application of the optical flow verification method for three different types of heavy precipitation processes such as plum rain, southwest vortex, and typhoon, it can be found that for the same precipitation process, different numerical models usually have different performance in strength, displacement, and angular errors. The optical flow verification results have high reference value in reflecting the differences of the precipitation strength, precipitation belt deviation angle, and distance of different models.
The optical flow method is an important method in motion image analysis, which is mainly used to determine the motion information of a target. The element forecast fields produced by numerical models are gridded spaces, which are also a kind of images, and the optical flow method used in image analysis can be applied to the numerical model verification. The optical flow method is used to the heavy precipitation forecast verification. The principles of the optical flow method are described by using the theoretical simulation, and then through the verification on the 24 h precipitation forecast of ECMWF and T639 models for three different types of heavy precipitation process, the practical application of the optical flow verification method in heavy precipitation forecast verification is discussed. The results show: (1) By decomposing the forecast error into intensity, displacement, and angular errors, the optical flow verification method can give an accurate quantitative analysis of the heavy precipitation forecast errors. (2) Based on the application of the optical flow verification method for three different types of heavy precipitation processes such as plum rain, southwest vortex, and typhoon, it can be found that for the same precipitation process, different numerical models usually have different performance in strength, displacement, and angular errors. The optical flow verification results have high reference value in reflecting the differences of the precipitation strength, precipitation belt deviation angle, and distance of different models.
2016, 44(4):605-611.
Abstract:
Based on the model prediction outputs from the European Centre for MediumRange Weather Forecasts (ECMWF), Japan Meteorological Agency (JMA) and National Centers for Environmental Prediction (NCEP), the multimodel ensemble forecasts of surface temperature are carried out by methods of the Multimodel Ensemble Mean (EMN), the Running Training Period Biasremoved Ensemble Mean (RBREM) and the Running Training Period Superensemble Forecast (RSUP), for Taizhou, Jiangsu Province. Their forecasts are compared with single model forecasts by means of Root Mean Square Error (RMSE) and Anomaly Correlation Coefficient (ACC). Thus, the multimodel ensemble forecast system is established. For the surface temperature forecast at 08:00 and 20:00, it is found from the comparative analysis of forecast results that the forecast skill of RBREM is apparently superior to those of individual models, EMN, and RSUP. Its average RMSE is reduced by about 0.5 ℃ with respect to the optimal single mode, and ACC increased by about 0.16. Additionally, the RBREM is applied into the daily operational forecast of Taizhou for the temperature. The forecast accuracy rate is improved efficiently due to the RBREM multimodel ensemble forecast system.
Based on the model prediction outputs from the European Centre for MediumRange Weather Forecasts (ECMWF), Japan Meteorological Agency (JMA) and National Centers for Environmental Prediction (NCEP), the multimodel ensemble forecasts of surface temperature are carried out by methods of the Multimodel Ensemble Mean (EMN), the Running Training Period Biasremoved Ensemble Mean (RBREM) and the Running Training Period Superensemble Forecast (RSUP), for Taizhou, Jiangsu Province. Their forecasts are compared with single model forecasts by means of Root Mean Square Error (RMSE) and Anomaly Correlation Coefficient (ACC). Thus, the multimodel ensemble forecast system is established. For the surface temperature forecast at 08:00 and 20:00, it is found from the comparative analysis of forecast results that the forecast skill of RBREM is apparently superior to those of individual models, EMN, and RSUP. Its average RMSE is reduced by about 0.5 ℃ with respect to the optimal single mode, and ACC increased by about 0.16. Additionally, the RBREM is applied into the daily operational forecast of Taizhou for the temperature. The forecast accuracy rate is improved efficiently due to the RBREM multimodel ensemble forecast system.
2016, 44(4):612-621.
Abstract:
By using the NCEP/NCAR reanalyzed data, the differences of the midupper troposphere temperature in the areas of the same latitude are compared, based on the temperature variations in the midupper troposphere over the Tibetan Plateau (500 to 200 hPa). TDI (Tibetan middlehigh level temperature zonal Deviation Index) is defined by the zonal temperature deviation. Moreover, the characteristics of multiple time scale variations of the index in spring and summer are also presented. Major conclusions are: (1) From spring to summer, the Asia midupper troposphere warm center moves westward from the west Pacific to the land and controls the whole East Asia gradually, and then retreats. The disturbance temperature warm center in spring moves westward from the southeast of China to the south of the Tibetan Plateau, and reinforces gradually, but it is stable in Southern Tibetan Plateau in summer. (2) The annual variation curve of TDI shows a single maximum obviously. The thermal effect increases gradually in April and reaches the maximum in July, then decreases rapidly after September. (3) The maximum, minimum and average value of TDI in all months are high in summer and low in winter.TDI in summer changes slightly. (4) The interannual change of TDI is obvious, but the index of spring (summer) has certain (obvious) monthly variation and there is no obvious linear trend.
By using the NCEP/NCAR reanalyzed data, the differences of the midupper troposphere temperature in the areas of the same latitude are compared, based on the temperature variations in the midupper troposphere over the Tibetan Plateau (500 to 200 hPa). TDI (Tibetan middlehigh level temperature zonal Deviation Index) is defined by the zonal temperature deviation. Moreover, the characteristics of multiple time scale variations of the index in spring and summer are also presented. Major conclusions are: (1) From spring to summer, the Asia midupper troposphere warm center moves westward from the west Pacific to the land and controls the whole East Asia gradually, and then retreats. The disturbance temperature warm center in spring moves westward from the southeast of China to the south of the Tibetan Plateau, and reinforces gradually, but it is stable in Southern Tibetan Plateau in summer. (2) The annual variation curve of TDI shows a single maximum obviously. The thermal effect increases gradually in April and reaches the maximum in July, then decreases rapidly after September. (3) The maximum, minimum and average value of TDI in all months are high in summer and low in winter.TDI in summer changes slightly. (4) The interannual change of TDI is obvious, but the index of spring (summer) has certain (obvious) monthly variation and there is no obvious linear trend.
2016, 44(4):622-630.
Abstract:
Based on the data from 12 representative stations on the Yangtze River Basin and Three Gorges River Basin, according to the 500year sequence of drought/flood grades and the precipitation data from May to September since the establishment of the stations, on the basis of drought/flood grade standards, the sequence of drought/flood grades is obtained for the Yangtze River Basin, the upper reaches, the middle reaches, the lower reaches of the Basin, and the Three Gorges Reservoir Area from 1470 to 2011. The results show that the reaches of Yangtze River and the Three Gorges reservoir area displayed the more significant alternating of droughts and floods, but the drought frequency accelerated in the 20th century and flood frequency increased from the 19th century. The frequencies of drought over years in the Yangtze River Basin and Three Gorges reservoir area had 160year periodic oscillation. The frequencies of flood and over in the Yangtze River Basin showed 140 years periodic oscillation, but after the 20th century the trend weakened, and that in three Gorges reservoir area had 100years periodic oscillation. The spatial and temporal distribution characteristics of precipitation were consistent with the decreasing trend, by using EOF. At the same time, the precipitation of the upper reaches of the Yangtze River had a downward trend, reflecting the drought trend of the upper reaches of the Yangtze River basin and three Gorges reservoir area. By using MK mutation test, there was no significant change in precipitation before and after the reservoir water storage in the upper reaches of the Yangtze River Basin and the Three Gorges reservoir area. In the context of global climate change, the drought evolution of the Three Gorges reservoir area is not an isolated event. It is inseparable with the background of the upper reaches of the Yangtze River and the whole basin.
Based on the data from 12 representative stations on the Yangtze River Basin and Three Gorges River Basin, according to the 500year sequence of drought/flood grades and the precipitation data from May to September since the establishment of the stations, on the basis of drought/flood grade standards, the sequence of drought/flood grades is obtained for the Yangtze River Basin, the upper reaches, the middle reaches, the lower reaches of the Basin, and the Three Gorges Reservoir Area from 1470 to 2011. The results show that the reaches of Yangtze River and the Three Gorges reservoir area displayed the more significant alternating of droughts and floods, but the drought frequency accelerated in the 20th century and flood frequency increased from the 19th century. The frequencies of drought over years in the Yangtze River Basin and Three Gorges reservoir area had 160year periodic oscillation. The frequencies of flood and over in the Yangtze River Basin showed 140 years periodic oscillation, but after the 20th century the trend weakened, and that in three Gorges reservoir area had 100years periodic oscillation. The spatial and temporal distribution characteristics of precipitation were consistent with the decreasing trend, by using EOF. At the same time, the precipitation of the upper reaches of the Yangtze River had a downward trend, reflecting the drought trend of the upper reaches of the Yangtze River basin and three Gorges reservoir area. By using MK mutation test, there was no significant change in precipitation before and after the reservoir water storage in the upper reaches of the Yangtze River Basin and the Three Gorges reservoir area. In the context of global climate change, the drought evolution of the Three Gorges reservoir area is not an isolated event. It is inseparable with the background of the upper reaches of the Yangtze River and the whole basin.
2016, 44(4):631-639.
Abstract:
Based on the monthly pan evaporation data of 5 meteorological stations over the Dianchi Lake basin from 1961 to 2010，the temporalspatial distributions of pan evaporation, and the correlations between the pan evaporation and the dynamical factor (wind speed), thermal factors (average temperature, average temperature diurnal range, and sunshine duration), the water factors (precipitation, relative humidity, and vapor pressure) and other factor (total cloud cover) are analyzed.The contrast of the annual variations of pan evaporation between the Chuxiong meteorological station and the Dianchi Lake basin during the same time is conducted. The results indicate that mainly 2 to 4 year period cycles can be detected in the annual variation of pan evaporation. In the recent 50 years，not only the annual pan evaporation, but also pan evaporation in spring and in summer showed a clearly downward trend in the Dianchi Lake basin. The downward trends of pan evaporation in the middle and north parts of the basin were more obvious than those in the south part of the basin and areas surrounding Kunming Station. The changes of annual, spring, autumn, and winter pan evaporation were basically similar in the Dianchi Lake basin and Chuxiong Station, but the changes of pan evaporations in summer were greatly different in the two areas. Correlation analysis between pan evaporation and meteorological factors shows that the trend of pan evaporation variation in the Dianchi lake basin was positively correlated with the heat factor and dynamic factor, and negatively correlated with water factor and total cloud cover. The effects of average temperature diurnal range， sunshine duration， vapor pressure, and wind speed were remarkable.
Based on the monthly pan evaporation data of 5 meteorological stations over the Dianchi Lake basin from 1961 to 2010，the temporalspatial distributions of pan evaporation, and the correlations between the pan evaporation and the dynamical factor (wind speed), thermal factors (average temperature, average temperature diurnal range, and sunshine duration), the water factors (precipitation, relative humidity, and vapor pressure) and other factor (total cloud cover) are analyzed.The contrast of the annual variations of pan evaporation between the Chuxiong meteorological station and the Dianchi Lake basin during the same time is conducted. The results indicate that mainly 2 to 4 year period cycles can be detected in the annual variation of pan evaporation. In the recent 50 years，not only the annual pan evaporation, but also pan evaporation in spring and in summer showed a clearly downward trend in the Dianchi Lake basin. The downward trends of pan evaporation in the middle and north parts of the basin were more obvious than those in the south part of the basin and areas surrounding Kunming Station. The changes of annual, spring, autumn, and winter pan evaporation were basically similar in the Dianchi Lake basin and Chuxiong Station, but the changes of pan evaporations in summer were greatly different in the two areas. Correlation analysis between pan evaporation and meteorological factors shows that the trend of pan evaporation variation in the Dianchi lake basin was positively correlated with the heat factor and dynamic factor, and negatively correlated with water factor and total cloud cover. The effects of average temperature diurnal range， sunshine duration， vapor pressure, and wind speed were remarkable.
2016, 44(4):640-646.
Abstract:
A comparative analysis is made of the droughts over the Urumqi River basin using the observation data from the Yingxiongqiao hydro station and Urumqi meteorological station. The data series from 1960 to 2010 is used to calculate the Standardized Precipitation Index (SPI) and Z index both in the mountainous and plain areas of the Urumqi River basin, and the data of historical drought events are used to validate the results. Results indicate that for the plain area drought indexes calculated by the data of the Urumqi meteorological station from 1960 to 1978, the values of SPI and Z index are negative, meaning that the drought condition stayed in a near normal or dry level; after the year of 1978, the values of SPI and Z index began to grow with a fluctuation, with the trend of a nondrought or near normal level. For the Yingxiongqiao hydro station, the values of SPI and Z index from 1960 to 2010 showed a fluctuation with the near normal level as a main characteristic. The consistency of SPI and Z indexes indicates that drought levels changed in a very same pattern and the two curves of SPI and Z index matched very well. In terms of the mountainous and plain areas, before the year of 1978, the drought level of mountainous area was less than that of the plain areas, and after the 1978, the mountains areas had higher levels of droughts than the plain areas. The seasonal change of droughts is mainly characterized by moderate dry and occurred in summer and fall, and the severe and extreme droughts had less occurrence probability than moderate droughts, mainly happening in spring and fall. Validation shows that SPI and Z indexes are applicable to the investigation of drought patterns in the study area.
A comparative analysis is made of the droughts over the Urumqi River basin using the observation data from the Yingxiongqiao hydro station and Urumqi meteorological station. The data series from 1960 to 2010 is used to calculate the Standardized Precipitation Index (SPI) and Z index both in the mountainous and plain areas of the Urumqi River basin, and the data of historical drought events are used to validate the results. Results indicate that for the plain area drought indexes calculated by the data of the Urumqi meteorological station from 1960 to 1978, the values of SPI and Z index are negative, meaning that the drought condition stayed in a near normal or dry level; after the year of 1978, the values of SPI and Z index began to grow with a fluctuation, with the trend of a nondrought or near normal level. For the Yingxiongqiao hydro station, the values of SPI and Z index from 1960 to 2010 showed a fluctuation with the near normal level as a main characteristic. The consistency of SPI and Z indexes indicates that drought levels changed in a very same pattern and the two curves of SPI and Z index matched very well. In terms of the mountainous and plain areas, before the year of 1978, the drought level of mountainous area was less than that of the plain areas, and after the 1978, the mountains areas had higher levels of droughts than the plain areas. The seasonal change of droughts is mainly characterized by moderate dry and occurred in summer and fall, and the severe and extreme droughts had less occurrence probability than moderate droughts, mainly happening in spring and fall. Validation shows that SPI and Z indexes are applicable to the investigation of drought patterns in the study area.
2016, 44(4):647-652.
Abstract:
Aiming to adjust measures to local conditions, reasonably adjust planting structure and layout, and effectively utilize agricultural climate resources, based on the observation dates of first frost day and last frost day (the minimum ground temperature less than 0 ℃) of 4 meteorological stations in from 1961 to 2014 over Wuwei, the spatial and temporal variation characteristics of the dates of first and last frost days are analyzed systematically with the climate diagnosis analysis method. The results show that the spatial distribution of the first frost date is the earliest in mountain regions, earlier in desert regions, and the latest in oasis plains in Wuwei; that of the last frost date is the latest in mountain regions, later in deserts and the earliest in oasis plains, because of the influence of altitude, topography, and vegetation cover. First and the last frost dates have certain abnormality in various regions. The occurrence possibility of normal first and the last frost dates is about 60%, and that of the abnormal cases such as the earlier and early frost, later and late frost dates that may cause hazards on agricultural production is all about 20%. First frost date assumes a significantly delayed trend, and last frost date assumes a significantly early trend. Frost period assumes a significantly short trend, and the advanced magnitude of last frost date is greater than the delayed magnitude of first frost date. The time series of first and last frost dates have the quasiperiodic variation of 8 to 10 years and 9 to 11 years, respectively. First frost date and last frost date have a climate abrupt change in 1998 and in 1996, respectively.
Aiming to adjust measures to local conditions, reasonably adjust planting structure and layout, and effectively utilize agricultural climate resources, based on the observation dates of first frost day and last frost day (the minimum ground temperature less than 0 ℃) of 4 meteorological stations in from 1961 to 2014 over Wuwei, the spatial and temporal variation characteristics of the dates of first and last frost days are analyzed systematically with the climate diagnosis analysis method. The results show that the spatial distribution of the first frost date is the earliest in mountain regions, earlier in desert regions, and the latest in oasis plains in Wuwei; that of the last frost date is the latest in mountain regions, later in deserts and the earliest in oasis plains, because of the influence of altitude, topography, and vegetation cover. First and the last frost dates have certain abnormality in various regions. The occurrence possibility of normal first and the last frost dates is about 60%, and that of the abnormal cases such as the earlier and early frost, later and late frost dates that may cause hazards on agricultural production is all about 20%. First frost date assumes a significantly delayed trend, and last frost date assumes a significantly early trend. Frost period assumes a significantly short trend, and the advanced magnitude of last frost date is greater than the delayed magnitude of first frost date. The time series of first and last frost dates have the quasiperiodic variation of 8 to 10 years and 9 to 11 years, respectively. First frost date and last frost date have a climate abrupt change in 1998 and in 1996, respectively.
2016, 44(4):653-658.
Abstract:
Using the MICAPS routine data, mesoscale automatic station data and the products of ECMWF and NCEP numerical forecasts, by means of the weather diagnosis analysis method, the causes of the super typhoon “Rammasun” intensification in the near sea and its leading severe weather disaster in Guangxi are analyzed. The results show: (1) the “Rammasun” intensification in the near sea is related to the following factors: the anomaly higher sea temperature in the area where it passed, the strengthened southwest monsoon jet, and the small vertical wind shear; (2) Rammasun met the monsoon jet near the offshore of Wenchang in Hainan, which made the latent heat enlarged near the typhoon and the warm heart structure of the typhoon became completed, which is an important reason for Rammasun intensification; (3) the abundant water vapor transport and convergence and strong ascending motion were the important reasons for the abnormal rainstorm.
Using the MICAPS routine data, mesoscale automatic station data and the products of ECMWF and NCEP numerical forecasts, by means of the weather diagnosis analysis method, the causes of the super typhoon “Rammasun” intensification in the near sea and its leading severe weather disaster in Guangxi are analyzed. The results show: (1) the “Rammasun” intensification in the near sea is related to the following factors: the anomaly higher sea temperature in the area where it passed, the strengthened southwest monsoon jet, and the small vertical wind shear; (2) Rammasun met the monsoon jet near the offshore of Wenchang in Hainan, which made the latent heat enlarged near the typhoon and the warm heart structure of the typhoon became completed, which is an important reason for Rammasun intensification; (3) the abundant water vapor transport and convergence and strong ascending motion were the important reasons for the abnormal rainstorm.
2016, 44(4):659-668.
Abstract:
By using the data of conventional meteorological observation, GPS precipitable water, lightning location, and NCEP 1° ×1 ° reanalysis grid point data on 4 and 5 July 2013, a heavy rain event occurred in the central and southern Shandong is analyzed from the characteristics of different stages and formation mechanisms. The results show that the vapor sources of the torrential rain came from the South China Sea; the strength of the lowlevel jet was positively related with that of the water vapor flux; the rainfall intensity, influence scope, and duration of warm shear line storms are bigger than these of cold shear line storms; the GPS precipitable water of cold and warm shear line storms is different. The positive and negative ground lightning activities of precipitation clouds show the antiphase relationship, and the change of the positive and negative ground lightning can well reflect the change of the heavy rain. The dynamical structures of cold and warm shear line storms are different: the physical quantity field of the former tilted to the north from low to high levels, and that of the latter distributed vertically. The upward movement area of cold shear line storm was deeper than that of warmer type shear line storms.
By using the data of conventional meteorological observation, GPS precipitable water, lightning location, and NCEP 1° ×1 ° reanalysis grid point data on 4 and 5 July 2013, a heavy rain event occurred in the central and southern Shandong is analyzed from the characteristics of different stages and formation mechanisms. The results show that the vapor sources of the torrential rain came from the South China Sea; the strength of the lowlevel jet was positively related with that of the water vapor flux; the rainfall intensity, influence scope, and duration of warm shear line storms are bigger than these of cold shear line storms; the GPS precipitable water of cold and warm shear line storms is different. The positive and negative ground lightning activities of precipitation clouds show the antiphase relationship, and the change of the positive and negative ground lightning can well reflect the change of the heavy rain. The dynamical structures of cold and warm shear line storms are different: the physical quantity field of the former tilted to the north from low to high levels, and that of the latter distributed vertically. The upward movement area of cold shear line storm was deeper than that of warmer type shear line storms.
2016, 44(4):669-674.
Abstract:
In order to study the effects of temperature and precipitation on the growth of red cartridge kiwifruit in enlargement period at Houchang Village (Shuicheng County, the Guizhou Province), by means of the daytoday temperature and precipitation data from May to July, 2009 to 2014 and the data at the same time of red cartridge kiwifruit diameters in the enlargement period, an analysis is made of the responses of red cartridge kiwifruit enlargement to temperature and precipitation. The results show that in the 6 years, June is the key time for red cartridge kiwifruit enlargement, and followed by May. For fruit enlargement, the most suitable temperature is 18 ℃ to 24 ℃, with the average horizontal fruit enlargement speed being 0.48 mm/d and the average longitudinal enlargement speed being 0.61 mm/d, and the most suitable precipitation is 1.1 mm to 20.0 mm, with an average fruit horizontal enlargement velocity of 0.54 mm/d and an average longitudinal enlargement speed of 0.60 mm/d, with the correlation being significant levels (〖WTBX〗P〖WTBZ〗< 0.05). The accumulated temperature in the fruit enlargement period and the yields of red cartridge kiwifruit are negatively correlated with an extremely significant level (〖WTBX〗P〖WTBZ〗 = 0.000) and precipitation and the yields are positively related with also an extremely significant level (〖WTBX〗P〖WTBZ〗 = 0.001). When the accumulated temperature in the enlargement period of red cartridge kiwifruit is below 2100 ℃ and precipitation is more than 670 mm, the yield is above 2.3 kg/m2, and when the accumulated temperature enlargement period is higher than 2100 ℃ and the precipitation is less than 410 mm, its yield is below 2.0 kg/m2. In order to provide evidences for yield increase, the upper and lower limit indexes of temperature and precipitation for red cartridge kiwifruit enlargement are established.
In order to study the effects of temperature and precipitation on the growth of red cartridge kiwifruit in enlargement period at Houchang Village (Shuicheng County, the Guizhou Province), by means of the daytoday temperature and precipitation data from May to July, 2009 to 2014 and the data at the same time of red cartridge kiwifruit diameters in the enlargement period, an analysis is made of the responses of red cartridge kiwifruit enlargement to temperature and precipitation. The results show that in the 6 years, June is the key time for red cartridge kiwifruit enlargement, and followed by May. For fruit enlargement, the most suitable temperature is 18 ℃ to 24 ℃, with the average horizontal fruit enlargement speed being 0.48 mm/d and the average longitudinal enlargement speed being 0.61 mm/d, and the most suitable precipitation is 1.1 mm to 20.0 mm, with an average fruit horizontal enlargement velocity of 0.54 mm/d and an average longitudinal enlargement speed of 0.60 mm/d, with the correlation being significant levels (〖WTBX〗P〖WTBZ〗< 0.05). The accumulated temperature in the fruit enlargement period and the yields of red cartridge kiwifruit are negatively correlated with an extremely significant level (〖WTBX〗P〖WTBZ〗 = 0.000) and precipitation and the yields are positively related with also an extremely significant level (〖WTBX〗P〖WTBZ〗 = 0.001). When the accumulated temperature in the enlargement period of red cartridge kiwifruit is below 2100 ℃ and precipitation is more than 670 mm, the yield is above 2.3 kg/m2, and when the accumulated temperature enlargement period is higher than 2100 ℃ and the precipitation is less than 410 mm, its yield is below 2.0 kg/m2. In order to provide evidences for yield increase, the upper and lower limit indexes of temperature and precipitation for red cartridge kiwifruit enlargement are established.
2016, 44(4):675-679.
Abstract:
Considering the needs of lowcost, high precision, and convenient in measuring crop leaf area, using a computer and a scanner, choosing different scan modes, by means of the measurement methods of with and without Baseplate, with and without PET FILM, and different shaped samples, it is concluded that the measurement methods of without baseplate and without PET FILM 300 dpi gray scale are better than others, with the measurement error is 0.4‰. Based on computer image processing technology, the software of measuring crop leaf area is developed by scanner, which achieves such functions as parameter selection, displaying, storing and invoking image and data, data processing, leaf area index calculation and so on.
Considering the needs of lowcost, high precision, and convenient in measuring crop leaf area, using a computer and a scanner, choosing different scan modes, by means of the measurement methods of with and without Baseplate, with and without PET FILM, and different shaped samples, it is concluded that the measurement methods of without baseplate and without PET FILM 300 dpi gray scale are better than others, with the measurement error is 0.4‰. Based on computer image processing technology, the software of measuring crop leaf area is developed by scanner, which achieves such functions as parameter selection, displaying, storing and invoking image and data, data processing, leaf area index calculation and so on.
2016, 44(4):680-685.
Abstract:
Using the hourly precipitation data from automatic meteorological stations and meteorological observation stations corresponding to 61 landslides from 2010 to 2014 in Tongren, the eastern Guizhou, the types of rainfall before and after landslide are analyzed by using statistical analysis. The prediction method of landslides is discussed by using different combinations between cumulative rainfall and triggering rainfall. It is found that the forecast accuracy of the model is the best, and the false alarm rate is the smallest when using cumulative rainfall from two days before the day landslide occurred and the triggering maximum rainfall in 3 hours of the day landslide occurred. The model using the cumulative rainfall of the day landslide occurred and the triggering maximum rainfall in 3 hours of the day landslide occurred takes the second place. The discriminate curve whether the landslide occurred can be obtained in both cases. A landslide can be predicted according to the discriminate curve and precipitation forecasts for the next 24 hours or 3 hours.
Using the hourly precipitation data from automatic meteorological stations and meteorological observation stations corresponding to 61 landslides from 2010 to 2014 in Tongren, the eastern Guizhou, the types of rainfall before and after landslide are analyzed by using statistical analysis. The prediction method of landslides is discussed by using different combinations between cumulative rainfall and triggering rainfall. It is found that the forecast accuracy of the model is the best, and the false alarm rate is the smallest when using cumulative rainfall from two days before the day landslide occurred and the triggering maximum rainfall in 3 hours of the day landslide occurred. The model using the cumulative rainfall of the day landslide occurred and the triggering maximum rainfall in 3 hours of the day landslide occurred takes the second place. The discriminate curve whether the landslide occurred can be obtained in both cases. A landslide can be predicted according to the discriminate curve and precipitation forecasts for the next 24 hours or 3 hours.
2016, 44(4):686-691.
Abstract:
Based on the features of lightning, design drawings, and site survey data, the risk assessment is conducted for the case of a buildingcomplex according to the theories and methods of the Risk Management of Lightning Protection IEC623052. It is concluded that the major lightening hazards of a buildingcomplex are casualties and property losses. To improve the accuracy of the risk assessment, the methods of average number and area weighting factor are adopted to determine the values of some characteristic factors and parameters. By analysis and calculation, the results indicate that under the condition of direct lightning flashes and good protection measures of earthing and potential equalization, the major lightning hazard is property loss because of the high values of risk components of the inner system malfunction caused by the lightning strikes on the lightning electric pulse. Reasonable allocation, shielding and wiring of surge protectors are suggested to reduce lightning hazards of building complexes.
Based on the features of lightning, design drawings, and site survey data, the risk assessment is conducted for the case of a buildingcomplex according to the theories and methods of the Risk Management of Lightning Protection IEC623052. It is concluded that the major lightening hazards of a buildingcomplex are casualties and property losses. To improve the accuracy of the risk assessment, the methods of average number and area weighting factor are adopted to determine the values of some characteristic factors and parameters. By analysis and calculation, the results indicate that under the condition of direct lightning flashes and good protection measures of earthing and potential equalization, the major lightning hazard is property loss because of the high values of risk components of the inner system malfunction caused by the lightning strikes on the lightning electric pulse. Reasonable allocation, shielding and wiring of surge protectors are suggested to reduce lightning hazards of building complexes.
2016, 44(4):692-696.
Abstract:
Concerning the assessment of Fengyun satellite data service satisfaction, a review is made on the status of Fengyun satellite data service and meteorological service benefit assessment. The evaluation indexes of Fengyun satellite data service are designed based on AHP, which consist of 6 firstgrade evaluation indexes and 19 secondgrade evaluation indexes. A Fengyun satellite data service evaluation scale is designed based on it. Through the reliability and validity analysis on the evaluation scale by the splithalf reliability and factor analysis methods, the Fengyun satellite data service evaluation indexes have adequate reliability and validity, including 6 aspects of applicability, service procedure, service response, content integrity, service initiative, and service cognition.
Concerning the assessment of Fengyun satellite data service satisfaction, a review is made on the status of Fengyun satellite data service and meteorological service benefit assessment. The evaluation indexes of Fengyun satellite data service are designed based on AHP, which consist of 6 firstgrade evaluation indexes and 19 secondgrade evaluation indexes. A Fengyun satellite data service evaluation scale is designed based on it. Through the reliability and validity analysis on the evaluation scale by the splithalf reliability and factor analysis methods, the Fengyun satellite data service evaluation indexes have adequate reliability and validity, including 6 aspects of applicability, service procedure, service response, content integrity, service initiative, and service cognition.
External LinksChina Meteorological AdministrationCMA Meteorological Observation CentreChinese Academy of Meteorological SciencesBeijing Meteorological ServiceNational Satellite Meteorological Center
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Supported by:Beijing E-Tiller Technology Development Co., Ltd.
Supported by:Beijing E-Tiller Technology Development Co., Ltd.