Volume 42,Issue 2,2014 Table of Contents
2014, 42(2):187-192.
Abstract:
Large data processing centers need to match UPS (Uninterruptible Power System) power supply systems, but in the system design of UPS, the harmonic currents from the input terminal may influence the other devices of the power distribution system. Taking the power supply system of the Beijing Meteorological Satellite Ground Station as an example, the emergency power supply situation is analyzed while the satellite receiving antenna tracking satellite, and there appeared obvious dithering in the drive motor, which was induced by the harmonic currents of UPS. The principles and the influence of UPS power supply working on the electric power distribution system are introduced, and the design of an active filter to eliminate electric power harmonic influence and the method to reduce antenna drive motor dithering are described. The expansion trends of electric power harmonic waves induced by new rectification power supply technology are discussed.
Large data processing centers need to match UPS (Uninterruptible Power System) power supply systems, but in the system design of UPS, the harmonic currents from the input terminal may influence the other devices of the power distribution system. Taking the power supply system of the Beijing Meteorological Satellite Ground Station as an example, the emergency power supply situation is analyzed while the satellite receiving antenna tracking satellite, and there appeared obvious dithering in the drive motor, which was induced by the harmonic currents of UPS. The principles and the influence of UPS power supply working on the electric power distribution system are introduced, and the design of an active filter to eliminate electric power harmonic influence and the method to reduce antenna drive motor dithering are described. The expansion trends of electric power harmonic waves induced by new rectification power supply technology are discussed.
2014, 42(2):193-197.
Abstract:
The design principles and main characteristics of the MWP967KV ground based 35 channel microwave profiling radiometer are presented. The prototype radiometer is a compact integration of dual band (K band and V band) broadband radiometry antennas, two receivers, a synthesizer local oscillator, a surface meteorological sensor, and a power supply in a cabinet. It has the capability of detecting downwelling atmospheric thermal emission continuously on a minute time scale. Several levels of observed data are composed and regulated. By using BP artificial neural network retrieval algorithms, the radiometer is capable of retrieving the vertical distributions (profiles) of atmospheric temperature, water vapor, relative humidity, and other variables in real time. The retrieved profiles range from the surface up to 10 km. The radiometer was used in atmospheric observation in Beijing in autumn to winter of 2012 for about two months. The data of 69 radiosonde cases are gathered to evaluate the radiometer’s performance. The accuracies of dual band atmospheric bright temperature values are analyzed. The retrieved temperature and humidity profiles are analyzed as well, and the mean difference, root mean square difference, and correlation are calculated. The statistical results indicate that the radiometer has the ability to support real time weather surveillance.
The design principles and main characteristics of the MWP967KV ground based 35 channel microwave profiling radiometer are presented. The prototype radiometer is a compact integration of dual band (K band and V band) broadband radiometry antennas, two receivers, a synthesizer local oscillator, a surface meteorological sensor, and a power supply in a cabinet. It has the capability of detecting downwelling atmospheric thermal emission continuously on a minute time scale. Several levels of observed data are composed and regulated. By using BP artificial neural network retrieval algorithms, the radiometer is capable of retrieving the vertical distributions (profiles) of atmospheric temperature, water vapor, relative humidity, and other variables in real time. The retrieved profiles range from the surface up to 10 km. The radiometer was used in atmospheric observation in Beijing in autumn to winter of 2012 for about two months. The data of 69 radiosonde cases are gathered to evaluate the radiometer’s performance. The accuracies of dual band atmospheric bright temperature values are analyzed. The retrieved temperature and humidity profiles are analyzed as well, and the mean difference, root mean square difference, and correlation are calculated. The statistical results indicate that the radiometer has the ability to support real time weather surveillance.
2014, 42(2):198-203.
Abstract:
To discuss the impact of the quantificated identifying index on fog and haze observation, some comparisons are conducted on fog days, mist days and haze days from 18 stations in Hubei Province from 2006 to 2012 One dataset is used as the initial records without quantificating, while the others are processed with the quantificated identifying index. The results shows that by the quantificated identifying index, the number of haze days increases obviously, while the numbers of mist and fog days moderately decrease. As for Hubei Province, there would appear fogs or light fogs when relative humidity between 80% and 94%. By the statistical analysis of hourly record humidity, visibility, and weather patterns, the homogeneous dataset of fog, mist, and haze can be obtained to realize the modification of the historical records. Nevertheless, observers should not use the quantificated identifying index only; weather situation must be well considered to avoid frequent shifts between mist and haze while mist developing, mist disappearing, as well as the value being around the critical levels.
To discuss the impact of the quantificated identifying index on fog and haze observation, some comparisons are conducted on fog days, mist days and haze days from 18 stations in Hubei Province from 2006 to 2012 One dataset is used as the initial records without quantificating, while the others are processed with the quantificated identifying index. The results shows that by the quantificated identifying index, the number of haze days increases obviously, while the numbers of mist and fog days moderately decrease. As for Hubei Province, there would appear fogs or light fogs when relative humidity between 80% and 94%. By the statistical analysis of hourly record humidity, visibility, and weather patterns, the homogeneous dataset of fog, mist, and haze can be obtained to realize the modification of the historical records. Nevertheless, observers should not use the quantificated identifying index only; weather situation must be well considered to avoid frequent shifts between mist and haze while mist developing, mist disappearing, as well as the value being around the critical levels.
2014, 42(2):204-207.
Abstract:
The Technology of Sliding Timing Window (TSTW) can define the starting and ending time of GPS data involved in data processing. Using TSTW, the latest observations can be added into the real time data processing with more actual results. Using a timing window with fixed widths, the accuracy of ambiguity resolution can be guaranteed with the least occupation of computer resources. Using TSTW and getting observations from 6 IGS (International GNSS Service) stations in China in 2008, the parameters for the troposphere at these 6 stations are calculated. Using the daily Zenith Total Delay (ZTD) of the stations that posted on the website of CODE as normal values, the standard deviations are calculated, respectively, and the influences on the accuracy and the real time properties of ZTD solution by timing windows with different widths are analyzed. The operational system of “Ground based GPS Real time Water Vapor Retrieval” using TSTW can gain the parameters in the troposphere with high accuracy and meanwhile meet the real time demands of operation. The best timing window width is about 8 hours.
The Technology of Sliding Timing Window (TSTW) can define the starting and ending time of GPS data involved in data processing. Using TSTW, the latest observations can be added into the real time data processing with more actual results. Using a timing window with fixed widths, the accuracy of ambiguity resolution can be guaranteed with the least occupation of computer resources. Using TSTW and getting observations from 6 IGS (International GNSS Service) stations in China in 2008, the parameters for the troposphere at these 6 stations are calculated. Using the daily Zenith Total Delay (ZTD) of the stations that posted on the website of CODE as normal values, the standard deviations are calculated, respectively, and the influences on the accuracy and the real time properties of ZTD solution by timing windows with different widths are analyzed. The operational system of “Ground based GPS Real time Water Vapor Retrieval” using TSTW can gain the parameters in the troposphere with high accuracy and meanwhile meet the real time demands of operation. The best timing window width is about 8 hours.
5 Calibration Method and Uncertainty Evaluation of AWS Data Acquisition Unit for Temperature Channel
2014, 42(2):208-212.
Abstract:
The accuracy of Automatic Weather Station (AWS) temperature data can be affected directly by the processing performance of the data acquisition unit for temperature channel. The Least Squares Support Vector Machine (LSSVM) method is used to establish the model with the data from the temperature calibration experiment on the data acquisition unit for temperature channel in an unattended AWS to correct measurement errors. The measurement uncertainty of the corrected temperature channel is evaluated. Results show that after correction, the measurement error of the data acquisition unit for temperature channel is less than 005 ℃ and the uncertainty is only 006 ℃, which are far less than the values before correction. This method is applicable in other meteorological data acquisition devices to guarantee the quality of AWS observation data.
The accuracy of Automatic Weather Station (AWS) temperature data can be affected directly by the processing performance of the data acquisition unit for temperature channel. The Least Squares Support Vector Machine (LSSVM) method is used to establish the model with the data from the temperature calibration experiment on the data acquisition unit for temperature channel in an unattended AWS to correct measurement errors. The measurement uncertainty of the corrected temperature channel is evaluated. Results show that after correction, the measurement error of the data acquisition unit for temperature channel is less than 005 ℃ and the uncertainty is only 006 ℃, which are far less than the values before correction. This method is applicable in other meteorological data acquisition devices to guarantee the quality of AWS observation data.
2014, 42(2):213-218.
Abstract:
The operational system software currently used in radiosonde stations has the function of automatic correcting, i.e., to modify the temperature pressure moisture curve automatically. But in practical applications, if only relying on the automatic correction to process the abnormal data, it maybe cause the distortion or inaccuracy of measurements. In order to avoid the shortcomings of the software and ensure the accuracy and comprehensiveness of the first hand sounding data, it is necessary to carry out human intervention in abnormal data processing. Some examples from Dongyuan Station are used to illustrate the necessity of human intervention， and the methods of human intervention and the issues that need attention in human intervention are discussed.
The operational system software currently used in radiosonde stations has the function of automatic correcting, i.e., to modify the temperature pressure moisture curve automatically. But in practical applications, if only relying on the automatic correction to process the abnormal data, it maybe cause the distortion or inaccuracy of measurements. In order to avoid the shortcomings of the software and ensure the accuracy and comprehensiveness of the first hand sounding data, it is necessary to carry out human intervention in abnormal data processing. Some examples from Dongyuan Station are used to illustrate the necessity of human intervention， and the methods of human intervention and the issues that need attention in human intervention are discussed.
2014, 42(2):219-224.
Abstract:
Using the quality control information of metadata from 25 meteorological stations over Ningxia from 1951 to 2011, an analysis is made of the various contents of the metadata, such as the temporal distribution of the stations, especially observation instruments and the number of times of station moves. The results show that the number of times of observation instrument changes accounts for 896% in the total number of changes; the annual average number of times of observation instrument changes are 30 to 140 times as many as other changes. The main causes for the frequent change of the meteorological metadata include the scarcity of observation instruments in the early 1950s, the implementation of new standards, and the change of observation instruments. There were frequent station moves from 1951 to 1960, but it had little effect on the homogeneity of temperature, while the urbanization from 2001 to 2011 had obvious effect on temperature homogeneity. After the quality control of station metadata, the errors, the revised errors, and the rate of revised errors decreased. The metadata quality is improved significantly, and the meteorological metadata can be used to provide high quality service for meteorological scientific research.
Using the quality control information of metadata from 25 meteorological stations over Ningxia from 1951 to 2011, an analysis is made of the various contents of the metadata, such as the temporal distribution of the stations, especially observation instruments and the number of times of station moves. The results show that the number of times of observation instrument changes accounts for 896% in the total number of changes; the annual average number of times of observation instrument changes are 30 to 140 times as many as other changes. The main causes for the frequent change of the meteorological metadata include the scarcity of observation instruments in the early 1950s, the implementation of new standards, and the change of observation instruments. There were frequent station moves from 1951 to 1960, but it had little effect on the homogeneity of temperature, while the urbanization from 2001 to 2011 had obvious effect on temperature homogeneity. After the quality control of station metadata, the errors, the revised errors, and the rate of revised errors decreased. The metadata quality is improved significantly, and the meteorological metadata can be used to provide high quality service for meteorological scientific research.
2014, 42(2):225-230.
Abstract:
Comparisons are conducted between wind profiler and radiosonde measurements of three years (2006 to 2008) to evaluate the detective accuracy of wind profilers. Meanwhile, comparison results at different heights, times, and speeds, are analyzed respectively, and a correlation analysis is made to calculate the average deviation and standard deviation. Results show that the two sets of wind measurements have good consistency with each other. The standard deviation of the horizontal wind component is about 23 m/s, mainly from the detecting errors in wind measurement and the differences in temporal and spatial sampling of the two systems.
Comparisons are conducted between wind profiler and radiosonde measurements of three years (2006 to 2008) to evaluate the detective accuracy of wind profilers. Meanwhile, comparison results at different heights, times, and speeds, are analyzed respectively, and a correlation analysis is made to calculate the average deviation and standard deviation. Results show that the two sets of wind measurements have good consistency with each other. The standard deviation of the horizontal wind component is about 23 m/s, mainly from the detecting errors in wind measurement and the differences in temporal and spatial sampling of the two systems.
2014, 42(2):231-239.
Abstract:
By means of Doppler radar and Wind Profiling radar data, along with weather reports in August, 2010 in Chengdu and July and August 2011 in Beijing, an analysis is made of the abilities of different radar to identify the corresponding weather phenomena. The comparative analysis indicates: (1) when there is weaker precipitation, the correlation between horizontal wind directions and speeds obtained by the two kinds of radar is very good within the heights of 300 to 2100 meters, and the wind direction correlation coefficient is 0596, and that of wind speeds is 0736, which should be considered together for forecasting; (2) under the condition of heavy rainfall, the correlation between horizontal wind directions and the speeds obtained by the two kinds of radar is good at different altitudes, especially from 300 to 2100 meters, and the correlation coefficient of the wind directions is 0508, and that of wind speeds is 0573The wind vector products of wind profiling radar give more details; (3) in overcast weather, the correlation between horizontal wind directions and speeds obtained by the two kinds of radar is better at lower levels than that at higher levels; (4) under sunny conditions, the wind profiling radar is more suitable for weather forecasting and monitoring.
By means of Doppler radar and Wind Profiling radar data, along with weather reports in August, 2010 in Chengdu and July and August 2011 in Beijing, an analysis is made of the abilities of different radar to identify the corresponding weather phenomena. The comparative analysis indicates: (1) when there is weaker precipitation, the correlation between horizontal wind directions and speeds obtained by the two kinds of radar is very good within the heights of 300 to 2100 meters, and the wind direction correlation coefficient is 0596, and that of wind speeds is 0736, which should be considered together for forecasting; (2) under the condition of heavy rainfall, the correlation between horizontal wind directions and the speeds obtained by the two kinds of radar is good at different altitudes, especially from 300 to 2100 meters, and the correlation coefficient of the wind directions is 0508, and that of wind speeds is 0573The wind vector products of wind profiling radar give more details; (3) in overcast weather, the correlation between horizontal wind directions and speeds obtained by the two kinds of radar is better at lower levels than that at higher levels; (4) under sunny conditions, the wind profiling radar is more suitable for weather forecasting and monitoring.
2014, 42(2):240-244.
Abstract:
With the improvement of the automation level of radiosonde sounding and its precision, the sounding data have become more accurate. In order to improve the precision and integrity of wind finding data and solve the problems caused by error data or unsuitable computing methods, a method is proposed, in which the second wind finding data can be used to judge the wind direction, together with calculating quantity wind layer, and the slope distance is calculated by using interpolation technique to reduce the man made errors. Good results are obtained in the actual work, and the phenomena of data missing reduced significantly.
With the improvement of the automation level of radiosonde sounding and its precision, the sounding data have become more accurate. In order to improve the precision and integrity of wind finding data and solve the problems caused by error data or unsuitable computing methods, a method is proposed, in which the second wind finding data can be used to judge the wind direction, together with calculating quantity wind layer, and the slope distance is calculated by using interpolation technique to reduce the man made errors. Good results are obtained in the actual work, and the phenomena of data missing reduced significantly.
2014, 42(2):245-250.
Abstract:
Based on the facts that there are no echo signals in CINRAD/CC Radar in the past few years, the faults in the antenna subsystem, launch subsystem, receiving subsystem, and signal processing subsystem are sorted and analyzed. It is found that the faults have different properties. According to the receiving flow of radar echo signals and the working principles of each subsystem, by using classification and gradual diagnostic methods, the maintenance methods for faults without echo signals for each subsystem are described through analyzing radar status parameters. Some test data and waveforms of key points are also provided as references for maintenance. Technicians can eliminate faults and maintain equipment based on these indexes in practical work. Taking Puer Station as an example, the procedures to eliminate faults are described according to the terminal parameters and the variation of parameters at monitoring points. Based on the signal flow, the fault was eliminated through the segmental measurement and analysis of key points. The process of the fault elimination is summarized, which is of reference value for the related professionals.
Based on the facts that there are no echo signals in CINRAD/CC Radar in the past few years, the faults in the antenna subsystem, launch subsystem, receiving subsystem, and signal processing subsystem are sorted and analyzed. It is found that the faults have different properties. According to the receiving flow of radar echo signals and the working principles of each subsystem, by using classification and gradual diagnostic methods, the maintenance methods for faults without echo signals for each subsystem are described through analyzing radar status parameters. Some test data and waveforms of key points are also provided as references for maintenance. Technicians can eliminate faults and maintain equipment based on these indexes in practical work. Taking Puer Station as an example, the procedures to eliminate faults are described according to the terminal parameters and the variation of parameters at monitoring points. Based on the signal flow, the fault was eliminated through the segmental measurement and analysis of key points. The process of the fault elimination is summarized, which is of reference value for the related professionals.
2014, 42(2):248-352.
Abstract:
Selecting the ∑CI (CI: Comprehensive meteorological drought Index) of the summer autumn, March, and the previous 20 days of the previous year as forest fire CI to represent the long term, medium term, and current meteorological drought conditions, by means of the comprehensive meteorological drought index and forest fire information from 1980 to 1999, forest fire warning service is provided with 〖WTBX〗H〖WTBZ〗c (forest fire CI). The analysis concludes: (1) in the whole year, the minimum forest fire factor was in June; ∑CI in May was greater than those in April and June except the previous summer autumn (∑CI was lower than that in April). (2) 89% of the samples occurred in April and June when 〖WTBX〗H〖WTBZ〗c>1, and in May there were 84% of the samples with 〖WTBX〗H〖WTBZ〗c>1 When 〖WTBX〗H〖WTBZ〗c≥2, there occurred a forest fire in ten days in 76% of years, on average 4 times per year; when 〖WTBX〗H〖WTBZ〗c<2, there occurred a fire only 45% of years, on average 23 times per year. Therefore, it can be seen that when 〖WTBX〗H〖WTBZ〗c≥2, it has high fire risk, when 1≤〖WTBX〗H〖WTBZ〗c＜2, it has moderate fire risk and when 〖WTBX〗H〖WTBZ〗c<1, it has low fire risk in spring forest fire warning service.
Selecting the ∑CI (CI: Comprehensive meteorological drought Index) of the summer autumn, March, and the previous 20 days of the previous year as forest fire CI to represent the long term, medium term, and current meteorological drought conditions, by means of the comprehensive meteorological drought index and forest fire information from 1980 to 1999, forest fire warning service is provided with 〖WTBX〗H〖WTBZ〗c (forest fire CI). The analysis concludes: (1) in the whole year, the minimum forest fire factor was in June; ∑CI in May was greater than those in April and June except the previous summer autumn (∑CI was lower than that in April). (2) 89% of the samples occurred in April and June when 〖WTBX〗H〖WTBZ〗c>1, and in May there were 84% of the samples with 〖WTBX〗H〖WTBZ〗c>1 When 〖WTBX〗H〖WTBZ〗c≥2, there occurred a forest fire in ten days in 76% of years, on average 4 times per year; when 〖WTBX〗H〖WTBZ〗c<2, there occurred a fire only 45% of years, on average 23 times per year. Therefore, it can be seen that when 〖WTBX〗H〖WTBZ〗c≥2, it has high fire risk, when 1≤〖WTBX〗H〖WTBZ〗c＜2, it has moderate fire risk and when 〖WTBX〗H〖WTBZ〗c<1, it has low fire risk in spring forest fire warning service.
2014, 42(2):251-255.
Abstract:
The malfunction of SPD can incur many problems. The most hazardous problem is the fire and explosion resulted from the failure of MOV (Metal Oxide Varistor). The reasons for the fire are analyzed and the working mechanisms of thermal fuses are described. The method using thermal fuses to protect SPDs from excessive heating and MOV fire is introduced. In order to test the characteristics of thermal fuses, the tolerance impulse overcurrent, the voltage limiting, and thermal stability experiments are designed. The results indicate that using a thermal fuse as the arrester disconnector can stand the impulses of thunders. The change rate of the residual voltage is only 22% and the switching voltage is within 10% after the experiment. It shows that thermal fuses do not affect the voltage limiting performance of MOV. When the MOV is over heating, the thermal fuse can rapidly blow out and turn off the circuit to inhibit current to protect working systems. Comparison is conducted between thermal fuse and low temperature soldering tin through thermal stability experiments. It is discovered that thermal fuses have certain advantages when the operating temperature is blow 130 ℃.
The malfunction of SPD can incur many problems. The most hazardous problem is the fire and explosion resulted from the failure of MOV (Metal Oxide Varistor). The reasons for the fire are analyzed and the working mechanisms of thermal fuses are described. The method using thermal fuses to protect SPDs from excessive heating and MOV fire is introduced. In order to test the characteristics of thermal fuses, the tolerance impulse overcurrent, the voltage limiting, and thermal stability experiments are designed. The results indicate that using a thermal fuse as the arrester disconnector can stand the impulses of thunders. The change rate of the residual voltage is only 22% and the switching voltage is within 10% after the experiment. It shows that thermal fuses do not affect the voltage limiting performance of MOV. When the MOV is over heating, the thermal fuse can rapidly blow out and turn off the circuit to inhibit current to protect working systems. Comparison is conducted between thermal fuse and low temperature soldering tin through thermal stability experiments. It is discovered that thermal fuses have certain advantages when the operating temperature is blow 130 ℃.
2014, 42(2):256-260.
Abstract:
TV weather programs are the main channels of public weather information service. The Graphics making technology is the key factor in the quality improving of TV weather programs. In the recent decades, as the development of computer processing technology, the geographic information system, image rendering technology, the TV weather graphics making technology have experienced a leap from analog to digital technology, stand alone to network development, standard definition to high definition transition, and one dimensional to three dimensional. By integrating meteorological, television, information technology, a review is made of the development course of TV weather graphics making technology, and its future development direction is discussed.
TV weather programs are the main channels of public weather information service. The Graphics making technology is the key factor in the quality improving of TV weather programs. In the recent decades, as the development of computer processing technology, the geographic information system, image rendering technology, the TV weather graphics making technology have experienced a leap from analog to digital technology, stand alone to network development, standard definition to high definition transition, and one dimensional to three dimensional. By integrating meteorological, television, information technology, a review is made of the development course of TV weather graphics making technology, and its future development direction is discussed.
2014, 42(2):261-265.
Abstract:
Based on the researches on the real time sharing technology of meteorological data, which uses the concept of data market, a meteorological data sharing platform for Yangtze river area between Shanghai, Zhejiang, Jiangsu and Anhui provinces is first built. The platform is designed by the standard system and distributed data management model, which makes use of the multi layer system architecture. The sharing and organization of meteorological data show unification in both physical distribution and logical inference. The platform can effectively support weather nowcasting for real time data and mobile observation. It also can improve the efficiency of meteorological data sharing in real time and reduce the difficulty of data transfer.
Based on the researches on the real time sharing technology of meteorological data, which uses the concept of data market, a meteorological data sharing platform for Yangtze river area between Shanghai, Zhejiang, Jiangsu and Anhui provinces is first built. The platform is designed by the standard system and distributed data management model, which makes use of the multi layer system architecture. The sharing and organization of meteorological data show unification in both physical distribution and logical inference. The platform can effectively support weather nowcasting for real time data and mobile observation. It also can improve the efficiency of meteorological data sharing in real time and reduce the difficulty of data transfer.
2014, 42(2):266-272.
Abstract:
Focused on the comprehensive, efficient, and convenient management of numerical weather prediction operation, a variety of monitoring systems of the national and regional centers are integrated，on the basis of NMIC_SMS，to build a unitary monitoring platform for numerical weather prediction operation, which is designed with the B/S multi layer structure, developed by Java, JSP and Oracle technology. It can achieve such functions as hierarchical monitoring, statistical query, and short message warning. Experiments are conducted on various models of the Numerical Weather Prediction Center, Liaoning and Sichuan regional centers, as well as the high performance computer systems of the National Meteorological Administration. The platform has completed comprehensive testing and works stably. The application of the platform can discover faults without delay， shorten processing， thus to ensure the stable running of the numerical weather forecast system.
Focused on the comprehensive, efficient, and convenient management of numerical weather prediction operation, a variety of monitoring systems of the national and regional centers are integrated，on the basis of NMIC_SMS，to build a unitary monitoring platform for numerical weather prediction operation, which is designed with the B/S multi layer structure, developed by Java, JSP and Oracle technology. It can achieve such functions as hierarchical monitoring, statistical query, and short message warning. Experiments are conducted on various models of the Numerical Weather Prediction Center, Liaoning and Sichuan regional centers, as well as the high performance computer systems of the National Meteorological Administration. The platform has completed comprehensive testing and works stably. The application of the platform can discover faults without delay， shorten processing， thus to ensure the stable running of the numerical weather forecast system.
2014, 42(2):273-277.
Abstract:
The Crustal Movement Observation Network of China (CMONOC) is one of the major national scientific projects, which is a GPS based integrated application network, consisting of 260 stations over the whole country. The China Meteorological Administration uses CMONOC data to conduct the real time monitoring of total water vapor. Aiming at GPS data management issues of the CMONOC.GNSS data sharing system, based on the B/S structure system and the open source WebGIS layout, a data management system of ground based navigation satellite remote sensing water vapor is developed by using Flex, JSP and Applet technology, and the real time monitoring of GPS station data transmission, the unified management of the station information, etc., are achieved, so to meet the needs of the current monitoring and safeguard of ground based GPS stations.
The Crustal Movement Observation Network of China (CMONOC) is one of the major national scientific projects, which is a GPS based integrated application network, consisting of 260 stations over the whole country. The China Meteorological Administration uses CMONOC data to conduct the real time monitoring of total water vapor. Aiming at GPS data management issues of the CMONOC.GNSS data sharing system, based on the B/S structure system and the open source WebGIS layout, a data management system of ground based navigation satellite remote sensing water vapor is developed by using Flex, JSP and Applet technology, and the real time monitoring of GPS station data transmission, the unified management of the station information, etc., are achieved, so to meet the needs of the current monitoring and safeguard of ground based GPS stations.
18 Construction of Operation Monitoring System of Automatic Soil Moisture Observation Network in China
2014, 42(2):278-282.
Abstract:
The operation monitoring system is the real time operation platform of the national automatic soil moisture observation network for observation data analysis and equipment maintenance. It is one important part of the construction of the automatic soil moisture observation network.The system structure is designed by means of C/S (Client/Server) and B/S (Browser/Server), which contains six modules: system running status monitoring, observation data quality monitoring, product analysis and display, maintenance and logistics management, observation network site database, and comprehensive analysis and assessment. The construction structure, the main functions, and the key technical methods of the operations monitoring system are described in detail.
The operation monitoring system is the real time operation platform of the national automatic soil moisture observation network for observation data analysis and equipment maintenance. It is one important part of the construction of the automatic soil moisture observation network.The system structure is designed by means of C/S (Client/Server) and B/S (Browser/Server), which contains six modules: system running status monitoring, observation data quality monitoring, product analysis and display, maintenance and logistics management, observation network site database, and comprehensive analysis and assessment. The construction structure, the main functions, and the key technical methods of the operations monitoring system are described in detail.
2014, 42(2):283-286.
Abstract:
According to the demands for meteorological information of local meteorological service, the CMACast Inner Mongolia Meteorological Information Web Platform is designed and developed based on the China Meteorological Administration satellite broadcasting system station data receiving server and meteorological data. The platform combines a variety of Web techniques, Android and NCL, etc., processes, visualizes, and dumps the CMACast station receiving data. The platform has also achieved such functions as meteorological data visualizing on Linux, cross platform access on Web and mobile terminals, common weather and forecast information display, and localization setting. The platform can provide a decision support system with a Web platform and a smartphone client for local meteorological stations, and has solved the problem of meteorological data acquisition in the working site of weather service and weather modification.
According to the demands for meteorological information of local meteorological service, the CMACast Inner Mongolia Meteorological Information Web Platform is designed and developed based on the China Meteorological Administration satellite broadcasting system station data receiving server and meteorological data. The platform combines a variety of Web techniques, Android and NCL, etc., processes, visualizes, and dumps the CMACast station receiving data. The platform has also achieved such functions as meteorological data visualizing on Linux, cross platform access on Web and mobile terminals, common weather and forecast information display, and localization setting. The platform can provide a decision support system with a Web platform and a smartphone client for local meteorological stations, and has solved the problem of meteorological data acquisition in the working site of weather service and weather modification.
2014, 42(2):287-293.
Abstract:
Based on the principle of threshold method with daily precipitation data from 1980 to 2009, observed by 20 rain gauges over the Yangtze Huaihe region, a investigation is conducted on the characteristics of precipitation over the Yangtze Huaihe region, with emphasis on the highly correlative relation between the monthly mean daily rainfall and the ratio of the number of rainy days with rainfall exceeding a certain threshold to the number of days of the month when the rainfall thresholds being 01, 10, 50, 100, 240, and 480 mm/d, respectively. A high correlation is found between the monthly mean daily rainfall and the ratio of the number of rainy days with rainfall exceeding a certain threshold to the number of days of the month. The correlation coefficient varies with rainfall thresholds, higher than 097 for all 20 stations, peaking at a threshold of 240 mm/d. The rain rate and fractional rain day were nonlinearly related at low rain rate thresholds. The threshold method can be applied widely, for examples, to achieve a better understanding of the forming mechanics of precipitation, to seek better algorithms for the estimation of precipitation, to develop better parameterization schemes for numerical forecasting models, and to validate the outputs of various numerical weather models, and so on.
Based on the principle of threshold method with daily precipitation data from 1980 to 2009, observed by 20 rain gauges over the Yangtze Huaihe region, a investigation is conducted on the characteristics of precipitation over the Yangtze Huaihe region, with emphasis on the highly correlative relation between the monthly mean daily rainfall and the ratio of the number of rainy days with rainfall exceeding a certain threshold to the number of days of the month when the rainfall thresholds being 01, 10, 50, 100, 240, and 480 mm/d, respectively. A high correlation is found between the monthly mean daily rainfall and the ratio of the number of rainy days with rainfall exceeding a certain threshold to the number of days of the month. The correlation coefficient varies with rainfall thresholds, higher than 097 for all 20 stations, peaking at a threshold of 240 mm/d. The rain rate and fractional rain day were nonlinearly related at low rain rate thresholds. The threshold method can be applied widely, for examples, to achieve a better understanding of the forming mechanics of precipitation, to seek better algorithms for the estimation of precipitation, to develop better parameterization schemes for numerical forecasting models, and to validate the outputs of various numerical weather models, and so on.
2014, 42(2):294-301.
Abstract:
Based on the CloudSat 2B CLDCLASS LIDAR data from January 2007 to December 2008, the occurrence frequency, mean height, and thickness of different types of clouds in the single layer and multi layer cloud systems over North China are analyzed. The results show that the occurrence frequencies of single layer and multi layer clouds have a distinct seasonal variation, with maximum in summer and minimum in winter. The frequency of single layer clouds is far greater than that of multi layer clouds, 443％, 461％, 378％, and 328％ for spring, summer, autumn, and winter, respectively. Two layer clouds account for the largest proportion in the multi layer cloud system. The analysis of average cloud height and thickness of different layers shows that the height of upper level three layer clouds is the greatest, and the height of lower level three layer clouds is the least; the thickness of single layer clouds is significantly greater than those of multi layer clouds; furthermore, the mean thickness of cloud layers decreases with increasing total number of layers of clouds. The analysis of the occurrence frequencies of different types of clouds shows that cirrus appears mostly in single layer clouds, as well as in middle and upper level multi layer clouds; altostratus and altocumulus account for a certain proportion of single layer clouds and multi layer clouds at various levels; stratus appears mostly in lower level multi layer clouds; and stratocumulus, cumulus, and deep convective clouds mainly appear in single layer clouds and lower level multi layer clouds; nimbostratus mainly appears in single layer clouds in summer. For cirrus, altostratus, and altocumulus, the mean height and thickness have significant differences in different cloud systems.
Based on the CloudSat 2B CLDCLASS LIDAR data from January 2007 to December 2008, the occurrence frequency, mean height, and thickness of different types of clouds in the single layer and multi layer cloud systems over North China are analyzed. The results show that the occurrence frequencies of single layer and multi layer clouds have a distinct seasonal variation, with maximum in summer and minimum in winter. The frequency of single layer clouds is far greater than that of multi layer clouds, 443％, 461％, 378％, and 328％ for spring, summer, autumn, and winter, respectively. Two layer clouds account for the largest proportion in the multi layer cloud system. The analysis of average cloud height and thickness of different layers shows that the height of upper level three layer clouds is the greatest, and the height of lower level three layer clouds is the least; the thickness of single layer clouds is significantly greater than those of multi layer clouds; furthermore, the mean thickness of cloud layers decreases with increasing total number of layers of clouds. The analysis of the occurrence frequencies of different types of clouds shows that cirrus appears mostly in single layer clouds, as well as in middle and upper level multi layer clouds; altostratus and altocumulus account for a certain proportion of single layer clouds and multi layer clouds at various levels; stratus appears mostly in lower level multi layer clouds; and stratocumulus, cumulus, and deep convective clouds mainly appear in single layer clouds and lower level multi layer clouds; nimbostratus mainly appears in single layer clouds in summer. For cirrus, altostratus, and altocumulus, the mean height and thickness have significant differences in different cloud systems.
2014, 42(2):302-308.
Abstract:
During the transition season between winter and spring in Guangdong Province, many objects such as indoor floors, walls and glasses easily become damp and are often covered by a thin clay of condensed water. An analysis is made of such five cases of the special high humidity weather during February and March in 2012 in the aspects of physical processes and circulation patterns, air temperature and humidity characteristics, etc. The results indicates: after the termination of the influence of cold air, warm and wet air affects Guangdong when the dew point of outdoor air is higher than the indoor object temperature, and a high humidity weather event appears on the background of cold air making a sudden turn into warm air. During the transition season between winter and spring, when the high pressure ridge weakens rapidly, meanwhile there is obvious southerly air flow on 925 hPa, it is necessary to consider whether there appears a high humidity phenomenon during daily weather forecasting; the rapid rise of air temperature is the necessary condition for the high humidity phenomenon; the trend of future dew point should be selectively analyzed. The high humidity phenomenon normally disappears in two ways: cold ending and warm ending. Namely, Guangdong is affected by new cold air and the air temperature and dew point decrease dramatically, and the dew point is lower than the indoor object temperature; or air temperature rises up and lasts for a certain time period and the indoor object temperature is higher than the outdoor air dew point.
During the transition season between winter and spring in Guangdong Province, many objects such as indoor floors, walls and glasses easily become damp and are often covered by a thin clay of condensed water. An analysis is made of such five cases of the special high humidity weather during February and March in 2012 in the aspects of physical processes and circulation patterns, air temperature and humidity characteristics, etc. The results indicates: after the termination of the influence of cold air, warm and wet air affects Guangdong when the dew point of outdoor air is higher than the indoor object temperature, and a high humidity weather event appears on the background of cold air making a sudden turn into warm air. During the transition season between winter and spring, when the high pressure ridge weakens rapidly, meanwhile there is obvious southerly air flow on 925 hPa, it is necessary to consider whether there appears a high humidity phenomenon during daily weather forecasting; the rapid rise of air temperature is the necessary condition for the high humidity phenomenon; the trend of future dew point should be selectively analyzed. The high humidity phenomenon normally disappears in two ways: cold ending and warm ending. Namely, Guangdong is affected by new cold air and the air temperature and dew point decrease dramatically, and the dew point is lower than the indoor object temperature; or air temperature rises up and lasts for a certain time period and the indoor object temperature is higher than the outdoor air dew point.
2014, 42(2):309-313.
Abstract:
The statistical analysis of drought disasters over Sichuan Basin in recent 30 years is conducted by using the local drought standards of the Sichuan Meteorological Service (DB51/T581 2007) with the daily precipitation data of 17 cities and 103 counties from 1980 to 2009. The main results indicate that summer droughts in May and June occur most frequently in Sichuan Basin, mainly in the Chengdu plain, including Chengdu, Deyang, and Mianyang. Summer droughts in July and August occur the least frequently. The areas frequently attacked by spring droughts in March and April, summer droughts in May and June, and summer droughts in July and August are mainly distributed from northwest to southeast in the basin, and the occurrence frequency of drought disasters in the Sichuan Basin has a growing trend on the whole; especially, the occurrence frequency of severe droughts increases rapidly. The frequency in the 1990s increased 110.3% comparing with that in the 1980s, and that in the 2000s increased 20% comparing with that in the 1990s, which is 2.5 times of that in the 1980s.
The statistical analysis of drought disasters over Sichuan Basin in recent 30 years is conducted by using the local drought standards of the Sichuan Meteorological Service (DB51/T581 2007) with the daily precipitation data of 17 cities and 103 counties from 1980 to 2009. The main results indicate that summer droughts in May and June occur most frequently in Sichuan Basin, mainly in the Chengdu plain, including Chengdu, Deyang, and Mianyang. Summer droughts in July and August occur the least frequently. The areas frequently attacked by spring droughts in March and April, summer droughts in May and June, and summer droughts in July and August are mainly distributed from northwest to southeast in the basin, and the occurrence frequency of drought disasters in the Sichuan Basin has a growing trend on the whole; especially, the occurrence frequency of severe droughts increases rapidly. The frequency in the 1990s increased 110.3% comparing with that in the 1980s, and that in the 2000s increased 20% comparing with that in the 1990s, which is 2.5 times of that in the 1980s.
2014, 42(2):314-318.
Abstract:
By using the conventional observation and NCEP reanalysis data, two soaking rain processes in Heilongjiang Province from 21 to 23 and 25 to 26 April 2012 are compared. The contrast analysis of their meteorological characteristics is made from the aspects of the synoptic circulation pattern and physical mechanisms. The results show that two soaking rain processes was influenced by a low vortex. The rainfall area of the first soaking rain process was near the low vortex center; there was a uniform rainfall distribution and 3 ℃ to 5 ℃ temperature fall at 850 hPa. The rainfall of the second soaking rain process was near the shear line from the low vortex; there was a uneven rainfall distribution and 9 ℃ to 15 ℃ temperature fall at 850 hPa. The low level south west airflow provided sufficient moisture from the Yellow Sea and the Sea of Japan. Water vapor, dynamic, and thermal conditions of the second soaking rain were more favorable than those of the first soaking rain, but there was little difference in rainfall between the two processes in the western Sanjiang Plain.
By using the conventional observation and NCEP reanalysis data, two soaking rain processes in Heilongjiang Province from 21 to 23 and 25 to 26 April 2012 are compared. The contrast analysis of their meteorological characteristics is made from the aspects of the synoptic circulation pattern and physical mechanisms. The results show that two soaking rain processes was influenced by a low vortex. The rainfall area of the first soaking rain process was near the low vortex center; there was a uniform rainfall distribution and 3 ℃ to 5 ℃ temperature fall at 850 hPa. The rainfall of the second soaking rain process was near the shear line from the low vortex; there was a uneven rainfall distribution and 9 ℃ to 15 ℃ temperature fall at 850 hPa. The low level south west airflow provided sufficient moisture from the Yellow Sea and the Sea of Japan. Water vapor, dynamic, and thermal conditions of the second soaking rain were more favorable than those of the first soaking rain, but there was little difference in rainfall between the two processes in the western Sanjiang Plain.
2014, 42(2):319-323.
Abstract:
The icing on electric wires is a complicated physical process affected by all kinds of meteorological factors. The theoretical frame of the model for icing and the main influencing meteorological factors on the increase of icing accretion on electric wires are analyzed, and the moisture transportation index related to ice growth is built. The meteorological forecasting model of icing accretion on electric wires is proposed. Using the icing and common meteorological data from 1951 to 2010 from meteorological observation stations of Guizhou Province, the empirical function of the efficiency factor in the model is fitted, and compared with the existing icing model. The results indicate that this model has better maneuverability, and the fitting results of the model for historical data are satisfactory.
The icing on electric wires is a complicated physical process affected by all kinds of meteorological factors. The theoretical frame of the model for icing and the main influencing meteorological factors on the increase of icing accretion on electric wires are analyzed, and the moisture transportation index related to ice growth is built. The meteorological forecasting model of icing accretion on electric wires is proposed. Using the icing and common meteorological data from 1951 to 2010 from meteorological observation stations of Guizhou Province, the empirical function of the efficiency factor in the model is fitted, and compared with the existing icing model. The results indicate that this model has better maneuverability, and the fitting results of the model for historical data are satisfactory.
2014, 42(2):324-329.
Abstract:
RVR (Runway Visual Range) calculation and estimate methods of illumination threshold and light intensity are summarized, and the estimate methods in the Vaisala AviMet system are discussed in combination with the ICAO (International Civil Aviation Organization) convention Annex 3 (Meteorological Services for International Air Navigation). A method for estimationg illumination thresholds and light intensities in the Vaisala AviMet system is devised by means of historical data. The analysis indicates that the estimate methods of illumination threshold in the Vaisala AviMet system are not in accordance with the formula recommended by ICAO; the light intensity is always set to be 1000 cd instead of the actual value in the Vaisala AviMet system .
RVR (Runway Visual Range) calculation and estimate methods of illumination threshold and light intensity are summarized, and the estimate methods in the Vaisala AviMet system are discussed in combination with the ICAO (International Civil Aviation Organization) convention Annex 3 (Meteorological Services for International Air Navigation). A method for estimationg illumination thresholds and light intensities in the Vaisala AviMet system is devised by means of historical data. The analysis indicates that the estimate methods of illumination threshold in the Vaisala AviMet system are not in accordance with the formula recommended by ICAO; the light intensity is always set to be 1000 cd instead of the actual value in the Vaisala AviMet system .
2014, 42(2):330-335.
Abstract:
By means of the observation data from the Aletai station of the northern Xinjiang from 1954 to 2010, the probabilistic risk analysis for snow disasters is conducted for five major climate factors, and based on the fuzzy information diffusion theory, a comprehensive analysis experiment is carried out. The results show that in the case of unknown theoretical distribution, for the probability risk analysis of snow climate factors, the fuzzy information diffusion method is simple and reliable, but rough. The theoretical analysis of distribution indicates that the theoretical models of the number of heavy snow days in winter (≥6 mm), maximum snow depth, maximum daily snowfall, snowfall in winter, and the number of snow days with snowfall greater than or equal to 10 cm have the distribution characteristics of Gamma, with a confidence degree of 0001, passing through the test of significant correlation coefficient. The probability density distributions of climate factors are analyzed for the numbers of the days with different boundary snow depths. The results exhibit the two peak characteristic, which does not belong to the conventional canonical distribution, and the theoretical distribution needs further study. The proposed snow climate factors with gamma distribution are of significance for understanding the climate risk of snow disasters in theory.
By means of the observation data from the Aletai station of the northern Xinjiang from 1954 to 2010, the probabilistic risk analysis for snow disasters is conducted for five major climate factors, and based on the fuzzy information diffusion theory, a comprehensive analysis experiment is carried out. The results show that in the case of unknown theoretical distribution, for the probability risk analysis of snow climate factors, the fuzzy information diffusion method is simple and reliable, but rough. The theoretical analysis of distribution indicates that the theoretical models of the number of heavy snow days in winter (≥6 mm), maximum snow depth, maximum daily snowfall, snowfall in winter, and the number of snow days with snowfall greater than or equal to 10 cm have the distribution characteristics of Gamma, with a confidence degree of 0001, passing through the test of significant correlation coefficient. The probability density distributions of climate factors are analyzed for the numbers of the days with different boundary snow depths. The results exhibit the two peak characteristic, which does not belong to the conventional canonical distribution, and the theoretical distribution needs further study. The proposed snow climate factors with gamma distribution are of significance for understanding the climate risk of snow disasters in theory.
2014, 42(2):336-340.
Abstract:
The snow disaster risk zoning is conducted based on the climatic characteristics of less rainfall in spring and winter, great annual change rate of precipitation in Bayannur, and frequent snowstorm disasters, targeting at the days with snowfall greater than 3 mm, along with snow cover and freeze weather from November to next March of 1971 to 2010 The inter decadal variations of the numbers of snow days with snowfall greater than 3 mm, and snow depth greater than 5 cm are analyzed in combination with the historical records, field surveys, agricultural and animal husbandry production, and a variety of basic information and data, as well as GIS technology. From the aspects of hazard, vulnerability assessment and analysis, by using the methods of comprehensive weighting and Analytic Hierarchy Process, the snowstorm discriminating model is build, and the snow risk zoning of Bayannur is given on the NOAA satellite snow cover monitoring image. The risk zoning of snow disasters is useful to disaster prevention and loss reduction
The snow disaster risk zoning is conducted based on the climatic characteristics of less rainfall in spring and winter, great annual change rate of precipitation in Bayannur, and frequent snowstorm disasters, targeting at the days with snowfall greater than 3 mm, along with snow cover and freeze weather from November to next March of 1971 to 2010 The inter decadal variations of the numbers of snow days with snowfall greater than 3 mm, and snow depth greater than 5 cm are analyzed in combination with the historical records, field surveys, agricultural and animal husbandry production, and a variety of basic information and data, as well as GIS technology. From the aspects of hazard, vulnerability assessment and analysis, by using the methods of comprehensive weighting and Analytic Hierarchy Process, the snowstorm discriminating model is build, and the snow risk zoning of Bayannur is given on the NOAA satellite snow cover monitoring image. The risk zoning of snow disasters is useful to disaster prevention and loss reduction
2014, 42(2):341-247.
Abstract:
Based on the theoretical analysis of the characteristics of the comprehensive monitoring index of meteorological drought (IMCI), together with drought characteristics in Hubei Province, the IMCI proposed by the National Climate Center (NCC) is modified for use in Hubei Province, and then tested in the aspects of the statistic characteristics of droughts and the diagnosis capability of typical drought processes through comparing with the commonly used compound meteorological drought index (ICI). Results show that there is no significant difference between IMCI and ICI in the general conclusion of drought monitoring, but IMCI shows a slower rate than ICI in drought development, and IMCI performs better at characterizing long term severe droughts. In addition, the modified IMCI has effectively corrected the insensitivity of the NCC IMCI in detecting of the occurrence, development and relief of droughts as well as its overestimate of drought severity, and the modified IMCI is no more too sensitive to precipitation compared to ICI. However, both indexes still tend to too sensitive to small precipitation in winter season and there are unreasonable phenomena: sudden enhancement of droughts in both. The results suggest that it is advisable to perform a proper evaluation and modification if necessary before applying IMCI to a new specific region.
Based on the theoretical analysis of the characteristics of the comprehensive monitoring index of meteorological drought (IMCI), together with drought characteristics in Hubei Province, the IMCI proposed by the National Climate Center (NCC) is modified for use in Hubei Province, and then tested in the aspects of the statistic characteristics of droughts and the diagnosis capability of typical drought processes through comparing with the commonly used compound meteorological drought index (ICI). Results show that there is no significant difference between IMCI and ICI in the general conclusion of drought monitoring, but IMCI shows a slower rate than ICI in drought development, and IMCI performs better at characterizing long term severe droughts. In addition, the modified IMCI has effectively corrected the insensitivity of the NCC IMCI in detecting of the occurrence, development and relief of droughts as well as its overestimate of drought severity, and the modified IMCI is no more too sensitive to precipitation compared to ICI. However, both indexes still tend to too sensitive to small precipitation in winter season and there are unreasonable phenomena: sudden enhancement of droughts in both. The results suggest that it is advisable to perform a proper evaluation and modification if necessary before applying IMCI to a new specific region.
2014, 42(2):352-358.
Abstract:
Taking a Cangzhou chemical project as an example, based on the site investigation and drawing analysis, a lightning hazard assessment is conducted on the current situation of lightning protection for chemical processing devices. The statistical analysis of lightning disaster features, possible influences, lightning hazard analysis, etc. are made by using the lightning data in this project. Referring to the evaluation methods in IEC62305 2, targeting at the project for lightning risk assessment, the risk management measures and suggestions are put forward. The results show that the lightning density is large relatively, and the lightning current amplitude is mainly from 20 to 60 kA. The personal injury risk caused by lightning is mainly due to physical damage caused by flashes to structure, making up about 7050%. The second is the risk caused by flashes happened in the related pipes and lines, making up about 2937%, but mainly in the power system. According to the formal estimation, each structure can meet the basic lightning protection requirements. As for the buildings in this region, the personal injury risk caused by lightning is less than the universally tolerable risk home and abroad. But the original design is short of voltage protection level design. For automation equipment interruption caused by lightning strike to buildings, facilities, pipes and lines, as well as misoperations, may lead to the leakage of toxic substances and flammable accidents, it is still necessary to take further risk control measures. It is important to point out that flammable areas are considered as the third type of lightning protection in the designs of design institutes, as well as the automation control system, is the main sources of lightning risk.
Taking a Cangzhou chemical project as an example, based on the site investigation and drawing analysis, a lightning hazard assessment is conducted on the current situation of lightning protection for chemical processing devices. The statistical analysis of lightning disaster features, possible influences, lightning hazard analysis, etc. are made by using the lightning data in this project. Referring to the evaluation methods in IEC62305 2, targeting at the project for lightning risk assessment, the risk management measures and suggestions are put forward. The results show that the lightning density is large relatively, and the lightning current amplitude is mainly from 20 to 60 kA. The personal injury risk caused by lightning is mainly due to physical damage caused by flashes to structure, making up about 7050%. The second is the risk caused by flashes happened in the related pipes and lines, making up about 2937%, but mainly in the power system. According to the formal estimation, each structure can meet the basic lightning protection requirements. As for the buildings in this region, the personal injury risk caused by lightning is less than the universally tolerable risk home and abroad. But the original design is short of voltage protection level design. For automation equipment interruption caused by lightning strike to buildings, facilities, pipes and lines, as well as misoperations, may lead to the leakage of toxic substances and flammable accidents, it is still necessary to take further risk control measures. It is important to point out that flammable areas are considered as the third type of lightning protection in the designs of design institutes, as well as the automation control system, is the main sources of lightning risk.
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.