Volume 43,Issue 3,2015 Table of Contents
2015, 43(3):349-354.
Abstract:
The factors that affect observation height of wind profiler radars are analyzed according to weather radar equation. In addition, the mathematical model for the effect of array unflatness on antenna radiation pattern of wind profiler radars is established. The variations of antenna gain and side lobe level with array unflatness for vertical pointing beam and 15° offzenith beam are simulated. Simulation results show that antenna gain of wind profiler radar reduces approximately in exponential as array unflatness increases, and the overall antenna sidelobe level goes up with increased array unflatness. Therefore, it is suggested that in the acceptable degradation for observation height of wind profiler radar, considering domestic antenna structure design, manufacturing level and mounting accuracy, engineers can put forward reasonable technical specifications on array unflatness.
The factors that affect observation height of wind profiler radars are analyzed according to weather radar equation. In addition, the mathematical model for the effect of array unflatness on antenna radiation pattern of wind profiler radars is established. The variations of antenna gain and side lobe level with array unflatness for vertical pointing beam and 15° offzenith beam are simulated. Simulation results show that antenna gain of wind profiler radar reduces approximately in exponential as array unflatness increases, and the overall antenna sidelobe level goes up with increased array unflatness. Therefore, it is suggested that in the acceptable degradation for observation height of wind profiler radar, considering domestic antenna structure design, manufacturing level and mounting accuracy, engineers can put forward reasonable technical specifications on array unflatness.
2015, 43(3):355-360.
Abstract:
On the basis of brief introduction of Shanghai TWP3 wind profiler radar system, the radar detection performance is assessed from the three aspects of operation situation, wind data acquisition rate, and product data analysis. Through the statistical analysis of the average height wind data acquisition rate in different layers throughout the year and monthly data, it is concluded that TWP3 wind profiler radar can get a higher data acquisition rate under 3 km; the detection capability in the boundary layer was much higher than that in the top layer; and summer data acquisition rate was significantly higher than in winter. A weak precipitation detection process is analyzed by using the signal to noise ratio (SNR), vertical velocity, and refractive index structure constant (C2n) and other data. The secondary products can clearly reflect the start and end time of the precipitation process, and the significantly increased detection height of about 2 km during precipitation. Assessment results indicate that TWP3 boundary layer wind profiler radar has a lower failure rate and better detection performance, reliable and applicable product data.
On the basis of brief introduction of Shanghai TWP3 wind profiler radar system, the radar detection performance is assessed from the three aspects of operation situation, wind data acquisition rate, and product data analysis. Through the statistical analysis of the average height wind data acquisition rate in different layers throughout the year and monthly data, it is concluded that TWP3 wind profiler radar can get a higher data acquisition rate under 3 km; the detection capability in the boundary layer was much higher than that in the top layer; and summer data acquisition rate was significantly higher than in winter. A weak precipitation detection process is analyzed by using the signal to noise ratio (SNR), vertical velocity, and refractive index structure constant (C2n) and other data. The secondary products can clearly reflect the start and end time of the precipitation process, and the significantly increased detection height of about 2 km during precipitation. Assessment results indicate that TWP3 boundary layer wind profiler radar has a lower failure rate and better detection performance, reliable and applicable product data.
2015, 43(3):361-367.
Abstract:
Frequency source stability is an important indicator of Doppler radar. If there is frequency amplitude and phase fluctuations in the radar frequency itself, it is impossible to obtain accurately strength and velocity field information. An introduction is made to the composite methods and main signal process of CINRAD/CC frequency sources, as well as the characterization methods of frequency source stability and its relationship. The impacts of the short and longterm stability on frequency source formation are studied, and the radar repair platform is used to simulate the fault. The measures how to improve the frequency stability are discussed, aiming at the rapid judgment and repair. It is summarized by means of time domain and frequency domain, combining with practical illustrations, that the phase noise (stability) of frequency sources is the main factor influencing radar echo intensity and speed measurements in modern radar. These techniques have certain reference significance for repair and maintenance of CINRAD/CC frequency sources.
Frequency source stability is an important indicator of Doppler radar. If there is frequency amplitude and phase fluctuations in the radar frequency itself, it is impossible to obtain accurately strength and velocity field information. An introduction is made to the composite methods and main signal process of CINRAD/CC frequency sources, as well as the characterization methods of frequency source stability and its relationship. The impacts of the short and longterm stability on frequency source formation are studied, and the radar repair platform is used to simulate the fault. The measures how to improve the frequency stability are discussed, aiming at the rapid judgment and repair. It is summarized by means of time domain and frequency domain, combining with practical illustrations, that the phase noise (stability) of frequency sources is the main factor influencing radar echo intensity and speed measurements in modern radar. These techniques have certain reference significance for repair and maintenance of CINRAD/CC frequency sources.
2015, 43(3):368-372.
Abstract:
According to the significant lowlevel divergence characteristics in the flow field of a downburst and the identification technology of the connected area in pattern recognition, an identification algorithm of downbursts using Doppler radar data is developed. The binary processing of radial velocity is carried out by setting the threshold of speed. The 8neighborhood method is applied for searching big speed value zones, and the big positive and negative speed zones are matched by using constraints such as distance, angle, difference of positive and negative speeds, and so on. The secondary matching for the adjacent areas is conducted on big speed zones where matching failed, thus to identify the alert area of downbursts. Some real radar detection data are used to verify the algorithm. The results show that this algorithm can detect the small scale downburst with the clear lowlevel divergence characteristic, especially for the downburst with asymmetric divergence characteristics that affected by the environment wind field.
According to the significant lowlevel divergence characteristics in the flow field of a downburst and the identification technology of the connected area in pattern recognition, an identification algorithm of downbursts using Doppler radar data is developed. The binary processing of radial velocity is carried out by setting the threshold of speed. The 8neighborhood method is applied for searching big speed value zones, and the big positive and negative speed zones are matched by using constraints such as distance, angle, difference of positive and negative speeds, and so on. The secondary matching for the adjacent areas is conducted on big speed zones where matching failed, thus to identify the alert area of downbursts. Some real radar detection data are used to verify the algorithm. The results show that this algorithm can detect the small scale downburst with the clear lowlevel divergence characteristic, especially for the downburst with asymmetric divergence characteristics that affected by the environment wind field.
2015, 43(3):373-379.
Abstract:
Based on the concept and methods of standardized maintenance and the requirements of universality, a universal offline test & maintenance platform for largescale electronic equipment is developed. The I/O interface parameters of the tested components in the electronic equipment were configured on site, on the humancomputer interaction interface of the test program. The working conditions, for which the tested components were simulated, and the realization of the offline test & maintenance meet the requirements of universality. The test & maintenance database was tightly combined with repairing processes and the concept and methods of standardized maintenance were always implemented, which is helpful to different level technicians in the technical support of electronic equipment. The combined loads under high voltage, large current, and irregular pulse waves are designed and its working conditions are fully simulated. The disadvantages of typical offline test & maintenance for electronic equipment are remedied by the platform.
Based on the concept and methods of standardized maintenance and the requirements of universality, a universal offline test & maintenance platform for largescale electronic equipment is developed. The I/O interface parameters of the tested components in the electronic equipment were configured on site, on the humancomputer interaction interface of the test program. The working conditions, for which the tested components were simulated, and the realization of the offline test & maintenance meet the requirements of universality. The test & maintenance database was tightly combined with repairing processes and the concept and methods of standardized maintenance were always implemented, which is helpful to different level technicians in the technical support of electronic equipment. The combined loads under high voltage, large current, and irregular pulse waves are designed and its working conditions are fully simulated. The disadvantages of typical offline test & maintenance for electronic equipment are remedied by the platform.
2015, 43(3):380-386.
Abstract:
The Severe Weather Automatically Nowcast System (SWAN) has been widely used in weather nowcasting operation. The technology and features of radar quantitative precipitation estimation (QPE) are introduced. The practicability of QPE is evaluated, and the causation of QPE error is preliminarily analyzed, selecting the data during rainstorm weather from 6 Sband Doppler weather radar sets in 2012 in Hubei Province. The results show that the mean absolute error rate (MAER) is below 30% overall; the increasing range of radar has little influence on QPE precision; the MAER is keeping small in above 30 mm cases, while QPE is underestimated comparing with rain gauge records; moreover, the proportion of the underestimated is increasing in heavier rainfall. Concerning a single radar set, the worst is in Yichang due to the radar beam blocking of mountains, and worse in Wuhan due to the radar beam blocking of buildings, and the best is in Enshi.
The Severe Weather Automatically Nowcast System (SWAN) has been widely used in weather nowcasting operation. The technology and features of radar quantitative precipitation estimation (QPE) are introduced. The practicability of QPE is evaluated, and the causation of QPE error is preliminarily analyzed, selecting the data during rainstorm weather from 6 Sband Doppler weather radar sets in 2012 in Hubei Province. The results show that the mean absolute error rate (MAER) is below 30% overall; the increasing range of radar has little influence on QPE precision; the MAER is keeping small in above 30 mm cases, while QPE is underestimated comparing with rain gauge records; moreover, the proportion of the underestimated is increasing in heavier rainfall. Concerning a single radar set, the worst is in Yichang due to the radar beam blocking of mountains, and worse in Wuhan due to the radar beam blocking of buildings, and the best is in Enshi.
2015, 43(3):387-392.
Abstract:
Selecting three calculation methods of atmospheric precipitable water: groundbased GPS remote sensing water vapor, radiosonde data inversion, and empirical formula methods, taking Weining as an example, the similarities and differences of three methods in the Wumeng Mountain area are analyzed. It is concluded that selecting the radiosonde inversion value as the baseline, the results of GPS remote sensing and empirical formulas are bigger than the baseline; there is a good correlation among three values, especially between GPS remote sensing and radiosonde inversion; the minimum average absolute error value is 3.5 mm and the root mean square error is 4.14 mm. The empirical formulas of the weighted mean tropospheric temperature for the Wumeng mountain area is established, with the average error between empirical formulas and baseline is 1.1 K. The empirical formulas of weighted average〖WTBX〗 〖WTBZ〗air temperature have little influence on the atmospheric precipitable water. The GPS inversion accuracy of water vapor is higher when there is precipitation and the quasistationary front over Kunming between November and April, with the average absolute error being only 1 mm. The average absolute error between radiosonde inversion and experience calculation is 0.74 mm from May to October.
Selecting three calculation methods of atmospheric precipitable water: groundbased GPS remote sensing water vapor, radiosonde data inversion, and empirical formula methods, taking Weining as an example, the similarities and differences of three methods in the Wumeng Mountain area are analyzed. It is concluded that selecting the radiosonde inversion value as the baseline, the results of GPS remote sensing and empirical formulas are bigger than the baseline; there is a good correlation among three values, especially between GPS remote sensing and radiosonde inversion; the minimum average absolute error value is 3.5 mm and the root mean square error is 4.14 mm. The empirical formulas of the weighted mean tropospheric temperature for the Wumeng mountain area is established, with the average error between empirical formulas and baseline is 1.1 K. The empirical formulas of weighted average〖WTBX〗 〖WTBZ〗air temperature have little influence on the atmospheric precipitable water. The GPS inversion accuracy of water vapor is higher when there is precipitation and the quasistationary front over Kunming between November and April, with the average absolute error being only 1 mm. The average absolute error between radiosonde inversion and experience calculation is 0.74 mm from May to October.
2015, 43(3):393-398.
Abstract:
In order to realize the integration of observation data from municipal meteorological departments, water management and hydrological departments, as well as to make data of the Automatic Weather Station (AWS) available to meteorological units of the other provinces, the premode sharing network is built, based on network protocols and data exchange methods such as FTP and Web Service. This sharing network makes use of the objectoriented programming to integrate data from different information sources. It realizes the multisource data integration under the Sql Server database environment. The establishment of the multisource data integration mechanism and the operating system realizes information sharing among different departments, and the sharing of data from AWS’s among different provinces, which provides more comprehensive basic observation data for the monitoring and warning of local meteorological departments.
In order to realize the integration of observation data from municipal meteorological departments, water management and hydrological departments, as well as to make data of the Automatic Weather Station (AWS) available to meteorological units of the other provinces, the premode sharing network is built, based on network protocols and data exchange methods such as FTP and Web Service. This sharing network makes use of the objectoriented programming to integrate data from different information sources. It realizes the multisource data integration under the Sql Server database environment. The establishment of the multisource data integration mechanism and the operating system realizes information sharing among different departments, and the sharing of data from AWS’s among different provinces, which provides more comprehensive basic observation data for the monitoring and warning of local meteorological departments.
2015, 43(3):399-404.
Abstract:
An overview of the current status of soil moisture observation stations and an analysis of data quality are conducted in detail, including absolute error and linear correlation between manual and automatic data, the main reason leading to the data errors, and data quality control methods. The results indicate that there are obvious errors between manual and automatic data in some stations during the period of comparative observation, far beyond the acceptance standard of the China Meteorological Administration, and data errors are even above 20% in some stations; however, in nearly 60 percent of stations, the linear correlation coefficient between manual and automatic data exceeds 0.7, which provides an important basis for instrument correction. Also the stability of data in case of drought and precipitation is analyzed, so to present higher quality data on the status of special soil moisture conditions. Considering the actual situation comprehensively， two relatively reasonable data quality control methods of automatic soil moisture measurements are established, which provide support for data quality control and supervision of equipment running status.
An overview of the current status of soil moisture observation stations and an analysis of data quality are conducted in detail, including absolute error and linear correlation between manual and automatic data, the main reason leading to the data errors, and data quality control methods. The results indicate that there are obvious errors between manual and automatic data in some stations during the period of comparative observation, far beyond the acceptance standard of the China Meteorological Administration, and data errors are even above 20% in some stations; however, in nearly 60 percent of stations, the linear correlation coefficient between manual and automatic data exceeds 0.7, which provides an important basis for instrument correction. Also the stability of data in case of drought and precipitation is analyzed, so to present higher quality data on the status of special soil moisture conditions. Considering the actual situation comprehensively， two relatively reasonable data quality control methods of automatic soil moisture measurements are established, which provide support for data quality control and supervision of equipment running status.
2015, 43(3):405-409.
Abstract:
With the improvement of numerical prediction model resolution, more attention is paid to the balloon drifting deviation caused by radiosonde sounding and the precise algorithm of balloon latitude and longitude deviation. In view of the fact that the influence of earth curvature is ignored in the existing algorithm, a more precise algorithm is deduced based on the geocentric coordinate system, starting from the analysis of principles of the sounding system, compared with the original algorithm through radiosonde data files.
With the improvement of numerical prediction model resolution, more attention is paid to the balloon drifting deviation caused by radiosonde sounding and the precise algorithm of balloon latitude and longitude deviation. In view of the fact that the influence of earth curvature is ignored in the existing algorithm, a more precise algorithm is deduced based on the geocentric coordinate system, starting from the analysis of principles of the sounding system, compared with the original algorithm through radiosonde data files.
2015, 43(3):410-416.
Abstract:
A thorough analysis is made of the upperair sounding records after balloon explosion from the Sheyang station, and it is found that temperature differences between ascending and descending periods in the same air layer were a combined effects of frictional heating，hysteresis error，instrument failures，spatially and temporally varying temperatures， etc. Based on practical records， the approaches to evaluate frictional heating and hysteresis errors caused by the rapid descending of radiosondes are investigated, and the usage and potentials of applying this type of data to obtain more accurate meteorological information about the surrounding environment are discussed. Some suggestions are given about the radiosonde data after balloon explosion, such as using a parachute to decrease the descending speed so that more meteorological information can be acquired.
A thorough analysis is made of the upperair sounding records after balloon explosion from the Sheyang station, and it is found that temperature differences between ascending and descending periods in the same air layer were a combined effects of frictional heating，hysteresis error，instrument failures，spatially and temporally varying temperatures， etc. Based on practical records， the approaches to evaluate frictional heating and hysteresis errors caused by the rapid descending of radiosondes are investigated, and the usage and potentials of applying this type of data to obtain more accurate meteorological information about the surrounding environment are discussed. Some suggestions are given about the radiosonde data after balloon explosion, such as using a parachute to decrease the descending speed so that more meteorological information can be acquired.
2015, 43(3):417-421.
Abstract:
The actinometer of the new type DZZ5 automatic weather station at Nyingch of Tibet is equipped with the fullautomatic precise dualaxis tracker, which is of the function of automatic sunshine observation. By comparing the differences of the sunshine measurements from newtype instrument and the formerly used, the conversion factor is given, and the reasons and regularity of the difference formation are analyzed further, which provides basis and reference for scientific researches. According to the related requirements of radiation observation, some suggestions about the problems in the equipment configuration and application software of newtype DZZ5 automatic meteorological stations are put forward for improvement, so to facilitate automatic sunshine observation to replace artificial observation safely and reliably.
The actinometer of the new type DZZ5 automatic weather station at Nyingch of Tibet is equipped with the fullautomatic precise dualaxis tracker, which is of the function of automatic sunshine observation. By comparing the differences of the sunshine measurements from newtype instrument and the formerly used, the conversion factor is given, and the reasons and regularity of the difference formation are analyzed further, which provides basis and reference for scientific researches. According to the related requirements of radiation observation, some suggestions about the problems in the equipment configuration and application software of newtype DZZ5 automatic meteorological stations are put forward for improvement, so to facilitate automatic sunshine observation to replace artificial observation safely and reliably.
2015, 43(3):422-425.
Abstract:
To improve the accuracy of precipitation observations, a statistical analysis of precipitation data obtained by 38 weighing gauges in Beijing is made. The abnormal precipitation records are divided into four categories: power interference, temperaturesensitive, lag, and thawing. According to the causes and features of the four kinds of records, the corresponding suggestions are proposed, such as installing a DC manostat into the power supply, strengthening the verification of temperature coefficient, improving the structure or processing craft of weighing gauges, standardizing the maintenance operations, etc.
To improve the accuracy of precipitation observations, a statistical analysis of precipitation data obtained by 38 weighing gauges in Beijing is made. The abnormal precipitation records are divided into four categories: power interference, temperaturesensitive, lag, and thawing. According to the causes and features of the four kinds of records, the corresponding suggestions are proposed, such as installing a DC manostat into the power supply, strengthening the verification of temperature coefficient, improving the structure or processing craft of weighing gauges, standardizing the maintenance operations, etc.
2015, 43(3):426-429.
Abstract:
The characteristics of two types of temperature and humidity sensor HMP45D and HMP155A at low and high temperature are analyzed. Using the automatic metrological verification system, three sensors of each type, and three temperatures, and six humidity points are selected to measure the accuracy and stability at different temperature points. The results show that the measurement deviation between the two types of sensors is large and the stability is poor at 0 ℃, and both are better at 20 ℃; the accuracy and stability of measurements from the two types of sensors decrease at low temperature and high temperature. The HMP155A sensor is better and can meet the requirements of operation application.
The characteristics of two types of temperature and humidity sensor HMP45D and HMP155A at low and high temperature are analyzed. Using the automatic metrological verification system, three sensors of each type, and three temperatures, and six humidity points are selected to measure the accuracy and stability at different temperature points. The results show that the measurement deviation between the two types of sensors is large and the stability is poor at 0 ℃, and both are better at 20 ℃; the accuracy and stability of measurements from the two types of sensors decrease at low temperature and high temperature. The HMP155A sensor is better and can meet the requirements of operation application.
15 Repeatability Index and Calibration Method of Evaporation Indications of Automatic Weather Stations
2015, 43(3):430-433.
Abstract:
The over fluctuation of indication often occurs when calibrating evaporating sensors of automatic weather stations in Sichuan Province. The measured errors can meet the requirement of the calibration specification at one time and cannot the other time, which result in poor repeatability of calibration data. Regarding such situation, it is hard to judge the quantification index of the measuring system on the basis of the field trial use calibration method of automatic weather stations published by the Department of Observation and Telecommunication, CMA. In accordance with JJF 10012011 General Measuring Terminology and Definition and JJF 11262004 Specifications for Calibration of Ultrasonic Thickness Gauge, etc., this technical problem can be solved by specifying the indication repeatability of the measuring system. Based on a great number of experiments and work experiences, the repeatability index and calibration method of the evaporation indications are developed, which provides theoretical reference for making specifications for the onsite calibration for the evaporating measuring system of automatic weather stations.
The over fluctuation of indication often occurs when calibrating evaporating sensors of automatic weather stations in Sichuan Province. The measured errors can meet the requirement of the calibration specification at one time and cannot the other time, which result in poor repeatability of calibration data. Regarding such situation, it is hard to judge the quantification index of the measuring system on the basis of the field trial use calibration method of automatic weather stations published by the Department of Observation and Telecommunication, CMA. In accordance with JJF 10012011 General Measuring Terminology and Definition and JJF 11262004 Specifications for Calibration of Ultrasonic Thickness Gauge, etc., this technical problem can be solved by specifying the indication repeatability of the measuring system. Based on a great number of experiments and work experiences, the repeatability index and calibration method of the evaporation indications are developed, which provides theoretical reference for making specifications for the onsite calibration for the evaporating measuring system of automatic weather stations.
2015, 43(3):434-439.
Abstract:
By means of the Flex and AnyMap technology, an emergency response system of meteorological disasters based on the Flex and AnyMap framework is established. Using the secondary development interface of the AnyMap map control of AnyChart Flash chart family, the real time publishing system of Meteorological Disaster Emergency Response for Guangdong Province is developed. The main characteristics can be listed as follows: (1) using the binary data transmission based on the AMF protocol to realize the highefficient exchange of information between service and client ends; (2) using FluorineFx to implement the AMF protocol to raise the development efficiency, and reduce the difficulty in development; (3) using Action Script 3 development language with the platform of the second development interface of the map objects from the AnyChart Flash chat family to get the gorgeous Flex interface. This framework is used in the development of the realtime publishing system of the Meteorological Disaster Emergency Response for Guangdong Province. The system not only has a simple interface and is easy to operate, but also realizes the realtime publishing and timely update of meteorological disaster emergency response information, and improves the level of meteorological disaster emergency response information releasing.
By means of the Flex and AnyMap technology, an emergency response system of meteorological disasters based on the Flex and AnyMap framework is established. Using the secondary development interface of the AnyMap map control of AnyChart Flash chart family, the real time publishing system of Meteorological Disaster Emergency Response for Guangdong Province is developed. The main characteristics can be listed as follows: (1) using the binary data transmission based on the AMF protocol to realize the highefficient exchange of information between service and client ends; (2) using FluorineFx to implement the AMF protocol to raise the development efficiency, and reduce the difficulty in development; (3) using Action Script 3 development language with the platform of the second development interface of the map objects from the AnyChart Flash chat family to get the gorgeous Flex interface. This framework is used in the development of the realtime publishing system of the Meteorological Disaster Emergency Response for Guangdong Province. The system not only has a simple interface and is easy to operate, but also realizes the realtime publishing and timely update of meteorological disaster emergency response information, and improves the level of meteorological disaster emergency response information releasing.
2015, 43(3):440-443.
Abstract:
The lowpower consumption MCU MSP430F149 is used as the core processor and the PT100 platinum resistance as the sensor, a temperature acquisition system is designed according to the highprecision requirement. To improve the reusability of the system, the precise resistance method is used. It can eliminate the effect on temperature measurement of the drift of constantcurrent source and the precision of reference voltage of A/D circuits. The system design scheme, the standards of constant current source choosing and the current way of deviation elimination, and the operation steps of AD7792 are described in detail. The experiment results show that the measuring accuracy can be up to 0.1 ℃, and comparative tests proved the good stability of the system. The system has been applied to operational service products.
The lowpower consumption MCU MSP430F149 is used as the core processor and the PT100 platinum resistance as the sensor, a temperature acquisition system is designed according to the highprecision requirement. To improve the reusability of the system, the precise resistance method is used. It can eliminate the effect on temperature measurement of the drift of constantcurrent source and the precision of reference voltage of A/D circuits. The system design scheme, the standards of constant current source choosing and the current way of deviation elimination, and the operation steps of AD7792 are described in detail. The experiment results show that the measuring accuracy can be up to 0.1 ℃, and comparative tests proved the good stability of the system. The system has been applied to operational service products.
2015, 43(3):444-450.
Abstract:
The Content Management System (CMS) is an operational system used by the members of the Sichuan Rural Economic Information Center and its city, county and township branches. It is the key technology for the Sichuan Rural Economic Information Center. In the process of operational application of opensource Java CMS, the transformation of Windows to Linux, C# to Java, database to CMS is accomplished. Metadata technology is applied in content classification and content type definition. Based on the concept of role in CMS, the organizational structure of system administrator, development team and branch portal management is formed. Under the concept of content control, virtual file system, editing, and publishing workflow, the multisite content management is realized. With the portal technology, template management and page content are achieved. The Sichuan Meteorological Network, Sichuan Rural Information Network, and 21 subcenter websites are accomplished. Under the impact of workflow mechanism, Apache and Tomcat are integrated, and static Web page output is realized.
The Content Management System (CMS) is an operational system used by the members of the Sichuan Rural Economic Information Center and its city, county and township branches. It is the key technology for the Sichuan Rural Economic Information Center. In the process of operational application of opensource Java CMS, the transformation of Windows to Linux, C# to Java, database to CMS is accomplished. Metadata technology is applied in content classification and content type definition. Based on the concept of role in CMS, the organizational structure of system administrator, development team and branch portal management is formed. Under the concept of content control, virtual file system, editing, and publishing workflow, the multisite content management is realized. With the portal technology, template management and page content are achieved. The Sichuan Meteorological Network, Sichuan Rural Information Network, and 21 subcenter websites are accomplished. Under the impact of workflow mechanism, Apache and Tomcat are integrated, and static Web page output is realized.
2015, 43(3):451-457.
Abstract:
With the rapid development of meteorological modernization, the demands for meteorological operation and public service have increased sharply; therefore, it is necessary to achieve unified management and monitoring of meteorological data, a meteorological data acquisition and monitoring system is designed and realized based on MQ. Since the meteorological data sources of different kinds of meteorological equipments are distributed dispersely in various locations, the unified data management is difficult to conduct. In order to improve the flexibility and timeliness of data acquisition and processing, a consistent meteorological data acquisition procedure is realized through abstracting data type, organizing diversified data format and data inputing by configuration. In addition, for the sake of system monitoring, different kinds of monitoring information coding are defined in each joint of data processing to achieve program and data monitoring. The system realizes the monitoring of client programs, meterological data updating status, data queue server, and so on. The monitoring system can help find equipment faults and fault locations in practical application.
With the rapid development of meteorological modernization, the demands for meteorological operation and public service have increased sharply; therefore, it is necessary to achieve unified management and monitoring of meteorological data, a meteorological data acquisition and monitoring system is designed and realized based on MQ. Since the meteorological data sources of different kinds of meteorological equipments are distributed dispersely in various locations, the unified data management is difficult to conduct. In order to improve the flexibility and timeliness of data acquisition and processing, a consistent meteorological data acquisition procedure is realized through abstracting data type, organizing diversified data format and data inputing by configuration. In addition, for the sake of system monitoring, different kinds of monitoring information coding are defined in each joint of data processing to achieve program and data monitoring. The system realizes the monitoring of client programs, meterological data updating status, data queue server, and so on. The monitoring system can help find equipment faults and fault locations in practical application.
2015, 43(3):458-463.
Abstract:
Channel performance parameters of Beidou shortmessage communication (BDSMC) are urgently needed. There are few analysis results of civilian channel performance, especially lack of test data for huge data. The impact of sample size on statistical results is analyzed, and the calculation methods of minimum sample size for transmission success rate and transmission delay in BDSMC are presented. A long time channel test is conducted and a great deal of test data that meets statistical requirements is obtained. The statistics results show that the transmission success rate of single packet is 95.5% and the average transmission delay is 3.8 s. Test samples obtained make up for the lack of civilian Beidou channel test data. The results can be used as a reference in the BDSMCbased system design.
Channel performance parameters of Beidou shortmessage communication (BDSMC) are urgently needed. There are few analysis results of civilian channel performance, especially lack of test data for huge data. The impact of sample size on statistical results is analyzed, and the calculation methods of minimum sample size for transmission success rate and transmission delay in BDSMC are presented. A long time channel test is conducted and a great deal of test data that meets statistical requirements is obtained. The statistics results show that the transmission success rate of single packet is 95.5% and the average transmission delay is 3.8 s. Test samples obtained make up for the lack of civilian Beidou channel test data. The results can be used as a reference in the BDSMCbased system design.
2015, 43(3):464-468.
Abstract:
The JJQ1 signal simulator, which has relative perfect functions in the provincial level laboratories, has been used for three years, but there is no reporting about using the signal simulator to calibrate collectors of automatic meteorological stations. There are complicated factors for this phenomenon; for example, the calibration software is not reasonable, and signal interference among channels (especially the analog channel) results in too long calibration time and low efficiency; as well as the analog signal drift with the environmental temperature; it is not compatible with all common data collectors. These problems are analyzed by the theoretical and empirical methods, and some suggestions and opinions are put forward for signal simulator users, as well as research and development personnel.
The JJQ1 signal simulator, which has relative perfect functions in the provincial level laboratories, has been used for three years, but there is no reporting about using the signal simulator to calibrate collectors of automatic meteorological stations. There are complicated factors for this phenomenon; for example, the calibration software is not reasonable, and signal interference among channels (especially the analog channel) results in too long calibration time and low efficiency; as well as the analog signal drift with the environmental temperature; it is not compatible with all common data collectors. These problems are analyzed by the theoretical and empirical methods, and some suggestions and opinions are put forward for signal simulator users, as well as research and development personnel.
2015, 43(3):469-473.
Abstract:
The coverage and quality of AMVWV (Atmospheric Motion VectorsWater Vapor) are discussed. To verify the AMVWV impaction, the quasioperational edition GRAPES_GFS_1423 is used to carry out a onemonth test. The AMVWV observations come from the database of the National Meteorological Information Center (NMIC). The results indicate that AMVWV data distribute above 700 hPa, and the observation errors of the AMVWV with QI above 80% can compare with that of AMVIR. The assimilation of AMVWV can improve the analysis of the wind from 500 hPa to 100 hPa. The RMS of the wind analysis is reduced slightly. The anomaly correlation coefficient of the 500 hPa height for 144hour forecast is enhanced by 0.02. The data quality of AMVWV in the clear sky above 700 hPa is relatively poor. The third experiment does not have much improvement in analysis and forecast.
The coverage and quality of AMVWV (Atmospheric Motion VectorsWater Vapor) are discussed. To verify the AMVWV impaction, the quasioperational edition GRAPES_GFS_1423 is used to carry out a onemonth test. The AMVWV observations come from the database of the National Meteorological Information Center (NMIC). The results indicate that AMVWV data distribute above 700 hPa, and the observation errors of the AMVWV with QI above 80% can compare with that of AMVIR. The assimilation of AMVWV can improve the analysis of the wind from 500 hPa to 100 hPa. The RMS of the wind analysis is reduced slightly. The anomaly correlation coefficient of the 500 hPa height for 144hour forecast is enhanced by 0.02. The data quality of AMVWV in the clear sky above 700 hPa is relatively poor. The third experiment does not have much improvement in analysis and forecast.
2015, 43(3):474-481.
Abstract:
Climatology characteristics of several hazardous aviation weather phenomena including low visibility and sea fog, low cloud and cumulonimbus, high wind and thunderstorm in China offing seas are analyzed using the ICOADS individual observations，monthly summaries and gridded LISOTD climatological data. Low visibility and sea fogs occur most frequently on the Yellow Sea and the northern East China Sea from May to July. The occurrence frequency of sea fogs in the Bohai Sea Bay is lower except in July. Sea fogs occur less frequently in the southern East China Sea and South China Sea, except for in the coastal regions from January to May. Low cloud occurs most frequently in the East China Sea from November to next April. Especially in January the frequency of sea fogs is so high, and the extent is so extensive as to extend to the southern Yellow Sea and the northeastern South China Sea. The frequent appearance region of cumulonimbus locates in the western Pacific warm pool. The occurrence frequency of cumulonimbus in China costal region is lower. High wind occurs frequently in the East China Sea and northeastern South China Sea, especially in the Taiwan Strait and Bashi Channel, during October to next March. Thunderstorms occur frequently in the coastal regions including the northwestern coastal region of the Bohai Sea, the coastal regions of the Yellow Sea, south of Shandong, and north of Jiangsu Provinces, and the northern coastal region of the South China Sea.
Climatology characteristics of several hazardous aviation weather phenomena including low visibility and sea fog, low cloud and cumulonimbus, high wind and thunderstorm in China offing seas are analyzed using the ICOADS individual observations，monthly summaries and gridded LISOTD climatological data. Low visibility and sea fogs occur most frequently on the Yellow Sea and the northern East China Sea from May to July. The occurrence frequency of sea fogs in the Bohai Sea Bay is lower except in July. Sea fogs occur less frequently in the southern East China Sea and South China Sea, except for in the coastal regions from January to May. Low cloud occurs most frequently in the East China Sea from November to next April. Especially in January the frequency of sea fogs is so high, and the extent is so extensive as to extend to the southern Yellow Sea and the northeastern South China Sea. The frequent appearance region of cumulonimbus locates in the western Pacific warm pool. The occurrence frequency of cumulonimbus in China costal region is lower. High wind occurs frequently in the East China Sea and northeastern South China Sea, especially in the Taiwan Strait and Bashi Channel, during October to next March. Thunderstorms occur frequently in the coastal regions including the northwestern coastal region of the Bohai Sea, the coastal regions of the Yellow Sea, south of Shandong, and north of Jiangsu Provinces, and the northern coastal region of the South China Sea.
2015, 43(3):482-487.
Abstract:
The NCEP/NCAR reanalysis Ⅱ datasets are used to investigate the spatial and temporal variations of the Latent Heat Flux (LHF) over the Pacific from 1979 to 2010, as well as its relationship with summer precipitation in the Huanghuai region. Results show that both of the climatological and variance fields of LHF have clear seasonal changes. The extreme value centers in the climatological fields are also the regions with larg variability. In addition, the seasonal LHF fields are analyzed through EOF analysis, and it is conclued that there existed an abrupt climate change in the spring LHF field around 1997, as well as in summer. In autumn and winter, the abrupt change happened before 1995. Summer precipitation index of the Huanghuai region was defined to investigate the key areas of LHF, and it is found that prespring LHF fields were closely related to precipitation. Key areas of the spring LHF field were over the middleeastern Pacific between 10°N and 20°N and the eastern tropical Pacific, and their relationships with atmospheric circulation show that when the LHF over the two regions mentioned above increases in spring, geopotential height anomaly both at 500 hPa and 850 hPa in summer over the western coast of Pacific displays a distribution pattern of “positivenegativepositive,” and there will be more precipitation in the Huanghuai region.
The NCEP/NCAR reanalysis Ⅱ datasets are used to investigate the spatial and temporal variations of the Latent Heat Flux (LHF) over the Pacific from 1979 to 2010, as well as its relationship with summer precipitation in the Huanghuai region. Results show that both of the climatological and variance fields of LHF have clear seasonal changes. The extreme value centers in the climatological fields are also the regions with larg variability. In addition, the seasonal LHF fields are analyzed through EOF analysis, and it is conclued that there existed an abrupt climate change in the spring LHF field around 1997, as well as in summer. In autumn and winter, the abrupt change happened before 1995. Summer precipitation index of the Huanghuai region was defined to investigate the key areas of LHF, and it is found that prespring LHF fields were closely related to precipitation. Key areas of the spring LHF field were over the middleeastern Pacific between 10°N and 20°N and the eastern tropical Pacific, and their relationships with atmospheric circulation show that when the LHF over the two regions mentioned above increases in spring, geopotential height anomaly both at 500 hPa and 850 hPa in summer over the western coast of Pacific displays a distribution pattern of “positivenegativepositive,” and there will be more precipitation in the Huanghuai region.
2015, 43(3):488-496.
Abstract:
Based on the Northern polar vortex index of the National Climate Center and the precipitation in Yunnan Province from 1961 to 2012, using the statistical analysis methods such as linear trend, composite analysis, and correlation analysis, the relationship between them is studied. The results show: (1) The polar vortex area (PVA), intensity (PVI) and position (St) index decreased during the period from 1961 to 2012； PVA and PVI in four seasons all had significant downward trends，while the trend of S(t) declined significantly only in summer. (2) A significant downward trend of precipitation at 124 stations in Yunnan Province was found; precipitation exhibited an increasing trend in spring and decreasing trends in the other seasons. (3) The correlation of the precipitation with PVA and in Yunnan Province was mainly characterized by negative value, and that with PVI was the opposite; in the early summer, PVA and PVI had significant effects on the later rainfall in Yunnan Province.
Based on the Northern polar vortex index of the National Climate Center and the precipitation in Yunnan Province from 1961 to 2012, using the statistical analysis methods such as linear trend, composite analysis, and correlation analysis, the relationship between them is studied. The results show: (1) The polar vortex area (PVA), intensity (PVI) and position (St) index decreased during the period from 1961 to 2012； PVA and PVI in four seasons all had significant downward trends，while the trend of S(t) declined significantly only in summer. (2) A significant downward trend of precipitation at 124 stations in Yunnan Province was found; precipitation exhibited an increasing trend in spring and decreasing trends in the other seasons. (3) The correlation of the precipitation with PVA and in Yunnan Province was mainly characterized by negative value, and that with PVI was the opposite; in the early summer, PVA and PVI had significant effects on the later rainfall in Yunnan Province.
2015, 43(3):497-502.
Abstract:
Based on the daily precipitation data of 76 weather stations in the BeijingTianjinHebei region from 1961 to 2012, the spatial and temporal evolution of torrential rainy days is analyzed by the methods of trend and correlation analysis, Morlet and Mexicanhat wavelet, Cramer, and 〖WTBX〗t〖WTBZ〗test. The results show that the number of average annual torrential rainy days was 1.3 days, and there were three centers of high values for the torrential rainy days: the west of Shijiazhuang, Luanping, and Daming and Quzhou, respectively. There was a decreasing trend in torrential rainy days from 1961 to 2012， but the change trend was not significant. The average annual rainfall and the changing trend were not only related to the intensity of the precipitation, but also associated with its frequency closely. The greater the intensity and the frequency of rainfall, the higher the average annual precipitation was, and vice versa. The number of torrential rainy days changed abruptly in 1978 and 1996.
Based on the daily precipitation data of 76 weather stations in the BeijingTianjinHebei region from 1961 to 2012, the spatial and temporal evolution of torrential rainy days is analyzed by the methods of trend and correlation analysis, Morlet and Mexicanhat wavelet, Cramer, and 〖WTBX〗t〖WTBZ〗test. The results show that the number of average annual torrential rainy days was 1.3 days, and there were three centers of high values for the torrential rainy days: the west of Shijiazhuang, Luanping, and Daming and Quzhou, respectively. There was a decreasing trend in torrential rainy days from 1961 to 2012， but the change trend was not significant. The average annual rainfall and the changing trend were not only related to the intensity of the precipitation, but also associated with its frequency closely. The greater the intensity and the frequency of rainfall, the higher the average annual precipitation was, and vice versa. The number of torrential rainy days changed abruptly in 1978 and 1996.
2015, 43(3):503-505.
Abstract:
The statistical analysis of hails in recent 30 years is conducted by use of the hail records of Chengdu Meteorological Service from 1984 to 2012, and the temporal variation, spatial distribution, and topographic characteristics of the hails are studied. The results show that the time of hail occurrence mainly concentrated around 13:00 to 20:00; the hail occurred most frequently in May and August; the annual number of hail days increased with a maximum of 8 before in 2004 and declined afterwards. The areas with most hails were Guancang, Baihe, and Shufang of the eastern Chengdu, influenced by the Tuojiang River basin, while the areas with least hails were Longfeng, Ande, and Xilai of the north and southwest Chengdu, influenced by the Baima River.
The statistical analysis of hails in recent 30 years is conducted by use of the hail records of Chengdu Meteorological Service from 1984 to 2012, and the temporal variation, spatial distribution, and topographic characteristics of the hails are studied. The results show that the time of hail occurrence mainly concentrated around 13:00 to 20:00; the hail occurred most frequently in May and August; the annual number of hail days increased with a maximum of 8 before in 2004 and declined afterwards. The areas with most hails were Guancang, Baihe, and Shufang of the eastern Chengdu, influenced by the Tuojiang River basin, while the areas with least hails were Longfeng, Ande, and Xilai of the north and southwest Chengdu, influenced by the Baima River.
2015, 43(3):506-511.
Abstract:
Using the conventional observation data and FNL data, the interaction between binary typhoons Tembin and Bolaven is analyzed. The results show that the path of Tembin was complicated, while that of Bolaven was relatively stable. For the cyclotron period of Tembin, through the introduction of Rankin vortex theory model, the mutual rotation angular velocity between binary typhoons caused by Fujiwara effect is quantitatively analyzed. It can be seen that the Fujiwara effect between binary typhoons Tembin and Bolaven played a decisive role to the steering of Tembin, while the guidance of the environment field had less effect. Through force analysis, find that the total pressure had less effect on the steering of Tembin, but obvious effect on the moving path of Bolaven. Bolaven had stronger strength and larger volume, which is the main cause of Fujiwara effect between binary typhoons Tembin and Bolaven.
Using the conventional observation data and FNL data, the interaction between binary typhoons Tembin and Bolaven is analyzed. The results show that the path of Tembin was complicated, while that of Bolaven was relatively stable. For the cyclotron period of Tembin, through the introduction of Rankin vortex theory model, the mutual rotation angular velocity between binary typhoons caused by Fujiwara effect is quantitatively analyzed. It can be seen that the Fujiwara effect between binary typhoons Tembin and Bolaven played a decisive role to the steering of Tembin, while the guidance of the environment field had less effect. Through force analysis, find that the total pressure had less effect on the steering of Tembin, but obvious effect on the moving path of Bolaven. Bolaven had stronger strength and larger volume, which is the main cause of Fujiwara effect between binary typhoons Tembin and Bolaven.
2015, 43(3):512-521.
Abstract:
By using the data of conventional observation, NCEP/NCAR 1°×1° reanalysis, and radar echo, a persistent heavy rain occurred on the southern coast of the Shandong Peninsula on 21 September 2012 is diagnosed and analyzed. The results show: (1) The heavy rainfall was affected by the westerly trough at 500 hPa when the first westerly trough passed and the second westerly trough was moving toward the area. Beneath 850 hPa was the southern winds toward the shore, and the wind speed increased with time so that south wind jet was formed below 925 hPa, which transported water vapor and energy and caused water vapor convergence, increased humidity and convective instability energy. The moisture and instability condition of producing heavy rainfall were smaller than those in inland. (2) The mesoscale vortex and convergence ascending motion were formed on the left side of the shoreward wind ultralowlevel jet. The effect of seaboard topographic lifting impelled ascending movement to increase, which triggered the instability energy releasing, leading to strong rainfall. (3) In radar echoes, small scale convective cells grew along the coastline toward southwest, and bowshaped echoes formed along the coast near Rizhao in the later period, and moved toward the southeast sea area.
By using the data of conventional observation, NCEP/NCAR 1°×1° reanalysis, and radar echo, a persistent heavy rain occurred on the southern coast of the Shandong Peninsula on 21 September 2012 is diagnosed and analyzed. The results show: (1) The heavy rainfall was affected by the westerly trough at 500 hPa when the first westerly trough passed and the second westerly trough was moving toward the area. Beneath 850 hPa was the southern winds toward the shore, and the wind speed increased with time so that south wind jet was formed below 925 hPa, which transported water vapor and energy and caused water vapor convergence, increased humidity and convective instability energy. The moisture and instability condition of producing heavy rainfall were smaller than those in inland. (2) The mesoscale vortex and convergence ascending motion were formed on the left side of the shoreward wind ultralowlevel jet. The effect of seaboard topographic lifting impelled ascending movement to increase, which triggered the instability energy releasing, leading to strong rainfall. (3) In radar echoes, small scale convective cells grew along the coastline toward southwest, and bowshaped echoes formed along the coast near Rizhao in the later period, and moved toward the southeast sea area.
2015, 43(3):522-529.
Abstract:
The realtime altitude fields, ECMWF nest grid data at 12UTC and NCEP reanalysis data are used to analyze the extreme heat process from August 6 to 10 in 2013 along the north shore of the Hangzhou Bay. The results show that the largescale circulation background of the persistent extreme high temperature (40 ℃) weather include the subtropical ridge steadily at 30°N, divergence at upper levels, 26 ℃ warm air mass at lower levels under the strong subtropical high center. The subtropical high extended westwards and the South Asia high moved eastwards, which produced a profound secondary circulation loop in the vertical direction, which was an important reason for the extreme high temperature lasted longer and wider. The emergence of extreme heat was closely related with the exceptionally dry air. The reasons for more extreme temperature records have been broken along the north shore of the Hangzhou Bay are: those highlevel dry air superimposed on the southward lowerlevel subtropical dry warm mass, the adiabatic heating effect of sinking airflow from top to ground, and the warm advection at lower levels. The prediction verification of four major numerical models for high temperature service indicates: the error of EC model prediction is small and stable, about 1 ℃, and the errors of GFS, JMA, and T639 are 3, 4, and 5 ℃, respectively, which need to correct in service. These results can be used as references in the summer high temperature forecast.
The realtime altitude fields, ECMWF nest grid data at 12UTC and NCEP reanalysis data are used to analyze the extreme heat process from August 6 to 10 in 2013 along the north shore of the Hangzhou Bay. The results show that the largescale circulation background of the persistent extreme high temperature (40 ℃) weather include the subtropical ridge steadily at 30°N, divergence at upper levels, 26 ℃ warm air mass at lower levels under the strong subtropical high center. The subtropical high extended westwards and the South Asia high moved eastwards, which produced a profound secondary circulation loop in the vertical direction, which was an important reason for the extreme high temperature lasted longer and wider. The emergence of extreme heat was closely related with the exceptionally dry air. The reasons for more extreme temperature records have been broken along the north shore of the Hangzhou Bay are: those highlevel dry air superimposed on the southward lowerlevel subtropical dry warm mass, the adiabatic heating effect of sinking airflow from top to ground, and the warm advection at lower levels. The prediction verification of four major numerical models for high temperature service indicates: the error of EC model prediction is small and stable, about 1 ℃, and the errors of GFS, JMA, and T639 are 3, 4, and 5 ℃, respectively, which need to correct in service. These results can be used as references in the summer high temperature forecast.
2015, 43(3):530-536.
Abstract:
Based on the site error optimization model, the lightning flash data in Shenzhen are analyzed and corrected. The lightning location system of Shenzhen is introduced, and the site errors of the lightning location system are analyzed, the lightningradiated electromagnetic field are calculated and analyzed with the improved transmission line model under real surface environment. Based on the site errors and site error model, the lightning flash data in Shenzhen are corrected. The results show that the irregular terrains with different azimuths have different effects on the electromagnetic waves of subsequent strokes. With the increasing root mean square of the height of irregular terrain, the peak value of electric field reduces and the waveform risetime increases. Meanwhile, the risetime of electric field waveform varies with the changes in azimuth, which may bring some errors in using the TOA (time of arrival) location method. To verify the reasonableness of the site error model, the optimization accuracy in the covered area of the lightning location system is also calculated and analyzed. It is found that this optimization method is feasible and reliable, and the location accuracy of the optimized lightning scheme is significantly improved.
Based on the site error optimization model, the lightning flash data in Shenzhen are analyzed and corrected. The lightning location system of Shenzhen is introduced, and the site errors of the lightning location system are analyzed, the lightningradiated electromagnetic field are calculated and analyzed with the improved transmission line model under real surface environment. Based on the site errors and site error model, the lightning flash data in Shenzhen are corrected. The results show that the irregular terrains with different azimuths have different effects on the electromagnetic waves of subsequent strokes. With the increasing root mean square of the height of irregular terrain, the peak value of electric field reduces and the waveform risetime increases. Meanwhile, the risetime of electric field waveform varies with the changes in azimuth, which may bring some errors in using the TOA (time of arrival) location method. To verify the reasonableness of the site error model, the optimization accuracy in the covered area of the lightning location system is also calculated and analyzed. It is found that this optimization method is feasible and reliable, and the location accuracy of the optimized lightning scheme is significantly improved.
2015, 43(3):537-542.
Abstract:
The propagation and attenuation of lightning electromagnetic field through stratified soil are studied with the Wait and Cooray approximate methods, considering different conductivities in the upper and lower soil layers. The simulation results are examined by the FDTD method. Under the condition of larger soil conductivity in the upper layer than the lower layer, both approximate methods can acquire good simulation accuracy. While under the condition of a smaller soil conductivity in the upper layer than the lower layer, some errors are involved in the Cooray approximation, and the result of Wait approximation with good accuracy reasonably represent the interference effect which leads to elective enhancement of lightning electromagnetic field in high frequency, and consequently, with the attenuation factor being larger than 1 and oscillation occurred.
The propagation and attenuation of lightning electromagnetic field through stratified soil are studied with the Wait and Cooray approximate methods, considering different conductivities in the upper and lower soil layers. The simulation results are examined by the FDTD method. Under the condition of larger soil conductivity in the upper layer than the lower layer, both approximate methods can acquire good simulation accuracy. While under the condition of a smaller soil conductivity in the upper layer than the lower layer, some errors are involved in the Cooray approximation, and the result of Wait approximation with good accuracy reasonably represent the interference effect which leads to elective enhancement of lightning electromagnetic field in high frequency, and consequently, with the attenuation factor being larger than 1 and oscillation occurred.
2015, 43(3):543-550.
Abstract:
Focused on the demands of highway weather forecasting and early warning along the highway, an automatic observing system, the Road Weather Information System (RWIS), is designed, which adopts the technical specifications according with routine meteorological observation and the requirements of highway weather observation for timeliness and reliability are also taken into account. Compared with the routine meteorological observation, the design of RWIS has the following characteristics: the adaptation to field unmanned detection environment, observation elements selected on needs, modularization design for flexible configuration, sensor layout with special requirements, and the compatibility and parallel of data flow, status flow, and control flow. The hardware structure of RWIS uses the modularized design of integrating all kinds of sensors. The communication transmission uses the data object dictionary approach to organize meteorological observation data and equipment status information, and uploads in realtime by data flow, which are analyzed and managed by acquisition software and central software. The system has been applied presently nationwide and the collected data have been uploaded to CMA to be used in the operational system platform. The observation products distributed by the CMACast system have been shared and applied nationwide.
Focused on the demands of highway weather forecasting and early warning along the highway, an automatic observing system, the Road Weather Information System (RWIS), is designed, which adopts the technical specifications according with routine meteorological observation and the requirements of highway weather observation for timeliness and reliability are also taken into account. Compared with the routine meteorological observation, the design of RWIS has the following characteristics: the adaptation to field unmanned detection environment, observation elements selected on needs, modularization design for flexible configuration, sensor layout with special requirements, and the compatibility and parallel of data flow, status flow, and control flow. The hardware structure of RWIS uses the modularized design of integrating all kinds of sensors. The communication transmission uses the data object dictionary approach to organize meteorological observation data and equipment status information, and uploads in realtime by data flow, which are analyzed and managed by acquisition software and central software. The system has been applied presently nationwide and the collected data have been uploaded to CMA to be used in the operational system platform. The observation products distributed by the CMACast system have been shared and applied nationwide.
2015, 43(3):551-556.
Abstract:
The correlation between minimum temperature, maximum temperature, and other meteorological elements on that day and the previous day are analyzed by using the meteorological observation data inside solar greenhouse in winter of 2012 and 2013. The forecast model is established by using the principal component regression based on the significantly related elements. The results show: (1) There was significant correlation between minimum temperature and 8 meteorological elements inside and outside the greenhouse on that day and previous day, while maximum temperature and 9 meteorological elements had significant correlation, and similar correlation also existed between these elements.（2）The principal component regression extracted 3 principal component factors influencing minimum and maximum temperature inside solar greenhouse, and the forecast model of temperature passed significant testing. （3）The results of fitting test show that the average absolute errors of forecast minimum temperature in different conditions are 1 ℃ or so, while the average absolute errors of forecast maximum temperature in different conditions are 1.5 ℃ or so. The results of application test show that the average absolute errors are 1.1 ℃ and 1.5 ℃, respectively, and especially the test results of minimum temperature are better in sunny conditions, with the absolute error being 0.9 ℃; the test result of maximum temperature is better in sunless day, with the absolute errors being 1.4 ℃.
The correlation between minimum temperature, maximum temperature, and other meteorological elements on that day and the previous day are analyzed by using the meteorological observation data inside solar greenhouse in winter of 2012 and 2013. The forecast model is established by using the principal component regression based on the significantly related elements. The results show: (1) There was significant correlation between minimum temperature and 8 meteorological elements inside and outside the greenhouse on that day and previous day, while maximum temperature and 9 meteorological elements had significant correlation, and similar correlation also existed between these elements.（2）The principal component regression extracted 3 principal component factors influencing minimum and maximum temperature inside solar greenhouse, and the forecast model of temperature passed significant testing. （3）The results of fitting test show that the average absolute errors of forecast minimum temperature in different conditions are 1 ℃ or so, while the average absolute errors of forecast maximum temperature in different conditions are 1.5 ℃ or so. The results of application test show that the average absolute errors are 1.1 ℃ and 1.5 ℃, respectively, and especially the test results of minimum temperature are better in sunny conditions, with the absolute error being 0.9 ℃; the test result of maximum temperature is better in sunless day, with the absolute errors being 1.4 ℃.
2015, 43(3):557-560.
Abstract:
By using the daily electricity data and meteorological data from 2009 to 2010 in Wuhan, an algorithm is presented based on the load decompositon, in which the daily maximum load is divided into the fundamental load and the weathersensitive load related to the weathersensitive load index that integrates the synthetically influence of temperature, relative humidity, and wind speed.By using the method of correlation ratio, the nonlinear relation between weathersensitive load and sensitive load index is analyzed， and the changing ratio between weathersensitive load index and load is analyzed. Based on the least meansquared deviation and nonlinear generalized least square, the polynomial forecasting model for weathersensitive load in Wuhan power grid in summer is established. Application tests show that the mean predicting errors are about 6 percent in summer from 2011 to 2012. Thus, the model can be used in the meteorological service in power grid dispatching in summer.
By using the daily electricity data and meteorological data from 2009 to 2010 in Wuhan, an algorithm is presented based on the load decompositon, in which the daily maximum load is divided into the fundamental load and the weathersensitive load related to the weathersensitive load index that integrates the synthetically influence of temperature, relative humidity, and wind speed.By using the method of correlation ratio, the nonlinear relation between weathersensitive load and sensitive load index is analyzed， and the changing ratio between weathersensitive load index and load is analyzed. Based on the least meansquared deviation and nonlinear generalized least square, the polynomial forecasting model for weathersensitive load in Wuhan power grid in summer is established. Application tests show that the mean predicting errors are about 6 percent in summer from 2011 to 2012. Thus, the model can be used in the meteorological service in power grid dispatching in summer.
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.