Volume 43,Issue 4,2015 Table of Contents
2015, 43(4):561-568.
Abstract:
Based on the working principles and performances under each working models of phased array radar, combined with the basic demands of weather radar, taking account of continual technology development, fast cost reduction, and increasing financial investment in phased array radar in China, the application potentials of active digital phased array Doppler weather radar are expected. The current development status of active digital phased array Doppler radar and challenges facing weather radar are introduced, such as the reduction of the total costs of the radar〖KG-*3〗’〖KG-*2〗s digital T/R components, the transplantation and improvement of each kinds of digital beam forming models and selfadaptation technologies, the development of the digital signal process (software and hardware) technologies and weather products, power consume, the technical support of equipment during the total life cycle of radar, and so on. The preliminary ideas to solve some problems are put forward.
Based on the working principles and performances under each working models of phased array radar, combined with the basic demands of weather radar, taking account of continual technology development, fast cost reduction, and increasing financial investment in phased array radar in China, the application potentials of active digital phased array Doppler weather radar are expected. The current development status of active digital phased array Doppler radar and challenges facing weather radar are introduced, such as the reduction of the total costs of the radar〖KG-*3〗’〖KG-*2〗s digital T/R components, the transplantation and improvement of each kinds of digital beam forming models and selfadaptation technologies, the development of the digital signal process (software and hardware) technologies and weather products, power consume, the technical support of equipment during the total life cycle of radar, and so on. The preliminary ideas to solve some problems are put forward.
2015, 43(4):569-575.
Abstract:
Detection and processing of ground clutter have an important influence on the quality of radar data. The early detection of ground clutter depends on clutter maps under the clear air condition or artificial discrimination. With the improvement of processing capacity, the frequency domain filter in the whole process is adapted for adaptive filtering, especially after the realization of the GAMP filter. However, in actual operation, it is found that the algorithm weakens high elevation weather signals with velocity being zero. The scheme of realtime identification of ground clutter and dealing it with a filter becomes a trend. It can restrain ground clutter while reducing the loss of weather signals. The described algorithm is based on IQ data. Four parameters obtained from the SCI algorithm, which has been tested on Cband weather radar, are employed as the inputs of fuzzy logic theory. After redesigned the algorithm flaw, the SCI algorithm is introduced into Sband weather radar. Through example analysis and comparison with the CMD algorithm, it is found that the SCI algorithm has lower misjudgment rate than the CMD algorithm, and the recognition rate is nearly the same as that of CMD algorithm.
Detection and processing of ground clutter have an important influence on the quality of radar data. The early detection of ground clutter depends on clutter maps under the clear air condition or artificial discrimination. With the improvement of processing capacity, the frequency domain filter in the whole process is adapted for adaptive filtering, especially after the realization of the GAMP filter. However, in actual operation, it is found that the algorithm weakens high elevation weather signals with velocity being zero. The scheme of realtime identification of ground clutter and dealing it with a filter becomes a trend. It can restrain ground clutter while reducing the loss of weather signals. The described algorithm is based on IQ data. Four parameters obtained from the SCI algorithm, which has been tested on Cband weather radar, are employed as the inputs of fuzzy logic theory. After redesigned the algorithm flaw, the SCI algorithm is introduced into Sband weather radar. Through example analysis and comparison with the CMD algorithm, it is found that the SCI algorithm has lower misjudgment rate than the CMD algorithm, and the recognition rate is nearly the same as that of CMD algorithm.
2015, 43(4):576-581.
Abstract:
Taking FY2E satellite as an example, the operation data accumulated by NSMC from January 2010 to December 2013 are studied to analyze the number, proportion and time distribution of the cloud images affected by the special events. The mechanism, occurrence regularity and impact of the special events on cloud images are analyzed, and suggestions for improvement are put forward accordingly to reduce the impact of special events. The results show that the number of cloud images affected by special events accounts for 282 percent of the planned number of received images, and the sequence of the impact of special events on cloud images is: earth shadow, station keeping and attitude determination, sun transit outage, lunar, solar image and stray radiation interference, losing lock of antenna, and lunar shadow. The respective percentages of cloud images affected by these special events are: 9400%, 282%, 141%, 067%, 059%, and 052% approximately. About 97% of the affected cloud images are distributed between February to April and August to October, because earth shadow, sun transit outage, and solar image interference occurs before or after the vernal equinox and autumnal equinox each year, and the other special events have no relation with seasons and solar terms. In order to reduce the impact of special events, ground systems should make more accurate cloud image observation plans based on the prediction time of earth shadow and choose reasonably orbital station keeping and attitude determination time. FY2 satellites should improve the design and technology of optical system and electronic devices.
Taking FY2E satellite as an example, the operation data accumulated by NSMC from January 2010 to December 2013 are studied to analyze the number, proportion and time distribution of the cloud images affected by the special events. The mechanism, occurrence regularity and impact of the special events on cloud images are analyzed, and suggestions for improvement are put forward accordingly to reduce the impact of special events. The results show that the number of cloud images affected by special events accounts for 282 percent of the planned number of received images, and the sequence of the impact of special events on cloud images is: earth shadow, station keeping and attitude determination, sun transit outage, lunar, solar image and stray radiation interference, losing lock of antenna, and lunar shadow. The respective percentages of cloud images affected by these special events are: 9400%, 282%, 141%, 067%, 059%, and 052% approximately. About 97% of the affected cloud images are distributed between February to April and August to October, because earth shadow, sun transit outage, and solar image interference occurs before or after the vernal equinox and autumnal equinox each year, and the other special events have no relation with seasons and solar terms. In order to reduce the impact of special events, ground systems should make more accurate cloud image observation plans based on the prediction time of earth shadow and choose reasonably orbital station keeping and attitude determination time. FY2 satellites should improve the design and technology of optical system and electronic devices.
2015, 43(4):582-586.
Abstract:
The number of negative air ions is one of important indexes of air quality. Most of the current observing instruments for negative air ions are designed and manufactured for indoor use or short time outdoor use. When applying these devices outdoors, some factors as wind will influence the observing results, leading to measurement accuracy decreasing. The principles of negative airion observing instruments are introduced, and its deviations when used outdoors are analyzed. The different structures of the sensor package are designed, and their different impacts on sensors are compared through the computational hydro mechanical methods. The results indicate that the Ttype package has a more even wind field, and better for the packaging of outdoor instruments.
The number of negative air ions is one of important indexes of air quality. Most of the current observing instruments for negative air ions are designed and manufactured for indoor use or short time outdoor use. When applying these devices outdoors, some factors as wind will influence the observing results, leading to measurement accuracy decreasing. The principles of negative airion observing instruments are introduced, and its deviations when used outdoors are analyzed. The different structures of the sensor package are designed, and their different impacts on sensors are compared through the computational hydro mechanical methods. The results indicate that the Ttype package has a more even wind field, and better for the packaging of outdoor instruments.
2015, 43(4):587-594.
Abstract:
An analysis is made of the application of the observation data provided by Lband radar system, in order to solve the existing problems and improve the accuracy of upperair meteorological observation. The main technical methods are discussed, including the data smoothing algorithm, outlier value judgment, eliminating and fitting compensation algorithm, sequence calculation method of the measured wind layer data per second, and so on. The results show that the value of wind second observation is to optimize and adjust the calculation steps (time interval) of the measured wind layer thickness, which can improve Lband system observation accuracy to reach the same level with the RS92 GPS sounding system and meet the basic requirements of the weather forecast service department. It is pointed out that the balloon sinking records can be properly kept by adjusting the operating procedures. Those comprehensive identification and interpolation methods for outliers can be used to improve the utilization rate of the second observation data provided by the Lband radar system, further enhance the level of intellectualization and automation of the operational service system. Such suggestions and improvements are expected to take effect on the revision of UpperAir Meteorological Service Specification.
An analysis is made of the application of the observation data provided by Lband radar system, in order to solve the existing problems and improve the accuracy of upperair meteorological observation. The main technical methods are discussed, including the data smoothing algorithm, outlier value judgment, eliminating and fitting compensation algorithm, sequence calculation method of the measured wind layer data per second, and so on. The results show that the value of wind second observation is to optimize and adjust the calculation steps (time interval) of the measured wind layer thickness, which can improve Lband system observation accuracy to reach the same level with the RS92 GPS sounding system and meet the basic requirements of the weather forecast service department. It is pointed out that the balloon sinking records can be properly kept by adjusting the operating procedures. Those comprehensive identification and interpolation methods for outliers can be used to improve the utilization rate of the second observation data provided by the Lband radar system, further enhance the level of intellectualization and automation of the operational service system. Such suggestions and improvements are expected to take effect on the revision of UpperAir Meteorological Service Specification.
2015, 43(4):595-600.
Abstract:
By means of the visibility measurements from July 2013 to March 2014 at Yangjiang, the difference characteristics in visibility between M6000 visibility sensor and manual observation and the causes are explored in order to improve the visibility observation quality. The results show that the difference is mostly between -20 and 30 km, and the absolute value of the difference increases with visibility; generally, the difference is normal in 90% of cases, but in bad weather, the automatic observation visibility is smaller, and the mean difference is negative and the error rate reaches the maximum when the visibility is less than 5 km. It is found that the causes of the difference, in addition to the habits and subjectivity of observers, include also the improper maintenance of the instrument and the differences between the concepts and measuring principles of the observation instruments. By strengthening the routine visibility sensor maintenance, the quality of automatic visibility observation can be improved. The automatic visibility observation can be well used to determine haze days, and in fog weather, the automatic observations can be used to make appropriate amendments to improve the consistency, so to basically meet the requirements of automatic visibility observation.
By means of the visibility measurements from July 2013 to March 2014 at Yangjiang, the difference characteristics in visibility between M6000 visibility sensor and manual observation and the causes are explored in order to improve the visibility observation quality. The results show that the difference is mostly between -20 and 30 km, and the absolute value of the difference increases with visibility; generally, the difference is normal in 90% of cases, but in bad weather, the automatic observation visibility is smaller, and the mean difference is negative and the error rate reaches the maximum when the visibility is less than 5 km. It is found that the causes of the difference, in addition to the habits and subjectivity of observers, include also the improper maintenance of the instrument and the differences between the concepts and measuring principles of the observation instruments. By strengthening the routine visibility sensor maintenance, the quality of automatic visibility observation can be improved. The automatic visibility observation can be well used to determine haze days, and in fog weather, the automatic observations can be used to make appropriate amendments to improve the consistency, so to basically meet the requirements of automatic visibility observation.
2015, 43(4):601-606.
Abstract:
The veracity of the sounding data and weather forecasts would be influenced if the sounding instrument was degenerated. The sounding data, such as the height and meteorological elements of the isobaric surface, the ascending velocity of the balloon, and altitude difference profiles, are analyzed. The characteristics of different sounding instrument degeneration and discrimination methods are summarized. Using the method of absolute error calculation and intensive meteorological element calculation, combined with graphics, data comparison, the time to change for induction curves can be determined. Thus the sounding data can be treated timely and effectively, and the quality of the sounding data can be improved.
The veracity of the sounding data and weather forecasts would be influenced if the sounding instrument was degenerated. The sounding data, such as the height and meteorological elements of the isobaric surface, the ascending velocity of the balloon, and altitude difference profiles, are analyzed. The characteristics of different sounding instrument degeneration and discrimination methods are summarized. Using the method of absolute error calculation and intensive meteorological element calculation, combined with graphics, data comparison, the time to change for induction curves can be determined. Thus the sounding data can be treated timely and effectively, and the quality of the sounding data can be improved.
2015, 43(4):607-611.
Abstract:
With the increasing of meteorological elements in observation, the number of cables in the automatic meteorological observation field is increasing, and the failure rate is also arising. The cables of observation fields are mostly buried under the ground, so it is difficult to repair or replace. A wireless meteorological data acquisition system based on ZigBee technology is designed, and the overall scheme of the system and the hardware circuit of the ZigBee module are introduced. The software design of network establishing, data acceptances and transmitting to the server by coordinator is conducted. The system can transmits data stably, accurately, and in realtime to the server from the sensor and realize the acquisition of meteorological data in the ZigBee wireless network.
With the increasing of meteorological elements in observation, the number of cables in the automatic meteorological observation field is increasing, and the failure rate is also arising. The cables of observation fields are mostly buried under the ground, so it is difficult to repair or replace. A wireless meteorological data acquisition system based on ZigBee technology is designed, and the overall scheme of the system and the hardware circuit of the ZigBee module are introduced. The software design of network establishing, data acceptances and transmitting to the server by coordinator is conducted. The system can transmits data stably, accurately, and in realtime to the server from the sensor and realize the acquisition of meteorological data in the ZigBee wireless network.
2015, 43(4):612-616.
Abstract:
The raw data management and case reorganization system for new generation weather radar is developed to meet the requirement of current shortterm forecasting and nowcasting, as well as other scientific research services. The VC++ 60 programming language and MSSQL Server 2008 database development technology are used to set up the corresponding database for different historical case data in this system. This system uses the method of direct warehousing after compression for raw data files. The realtime and high efficient query and downloading of CINRAD data are realized for the provinciallevel, municipal, and countylevel weather forecasters and researchers, meteorological service, and weather modification projects. The system has the realtime query function of different retrieval conditions, case materials, and real and history raw data downloading. It is convenient for all level weather forecasters in shortterm weather forecasting and nowcasting, as well as the other researchers and technical personnel for providing detailed and fullscale observation data. This system performed well since put into operation one year ago, and has great application potentials.
The raw data management and case reorganization system for new generation weather radar is developed to meet the requirement of current shortterm forecasting and nowcasting, as well as other scientific research services. The VC++ 60 programming language and MSSQL Server 2008 database development technology are used to set up the corresponding database for different historical case data in this system. This system uses the method of direct warehousing after compression for raw data files. The realtime and high efficient query and downloading of CINRAD data are realized for the provinciallevel, municipal, and countylevel weather forecasters and researchers, meteorological service, and weather modification projects. The system has the realtime query function of different retrieval conditions, case materials, and real and history raw data downloading. It is convenient for all level weather forecasters in shortterm weather forecasting and nowcasting, as well as the other researchers and technical personnel for providing detailed and fullscale observation data. This system performed well since put into operation one year ago, and has great application potentials.
2015, 43(4):617-621.
Abstract:
The construction of Atmospheric Observing System Operations and Monitoring (ASOM) improved the capacity of operational supporting on the meteorological detection equipment. As a mobile extension of the monitoring system, the mobile application development platform of the integrated meteorological observation system is constructed, which uses the Sencha Touch framework as the core technology and Hybrid App as the application type. The Cinrad Operations and Monitoring Mobile Application System is developed based on this platform. The system framework and function design is explained, and the key technologies of system implementation are discussed. The method of rapid transformation on the mobiles from the integrated meteorological observation system is explored. The results provide a reference for the construction and development of the integrated meteorological observation system in our nation.
The construction of Atmospheric Observing System Operations and Monitoring (ASOM) improved the capacity of operational supporting on the meteorological detection equipment. As a mobile extension of the monitoring system, the mobile application development platform of the integrated meteorological observation system is constructed, which uses the Sencha Touch framework as the core technology and Hybrid App as the application type. The Cinrad Operations and Monitoring Mobile Application System is developed based on this platform. The system framework and function design is explained, and the key technologies of system implementation are discussed. The method of rapid transformation on the mobiles from the integrated meteorological observation system is explored. The results provide a reference for the construction and development of the integrated meteorological observation system in our nation.
2015, 43(4):622-626.
Abstract:
In order to resolve the problem of mass TIGGE data archiving and improve the service efficiency of historical longtime series data, a data automatic archive model is designed, and the organization and structure of TIGGE data and the service requirement of historical data are studied by adopting the function of batch automatic archiving technology. The TIGGE data batch archive function is realized automatically, which improves the organization method of historical the data, the organization structure of tape volume, and the service efficiency of archive data significantly. The realization of TIGGE mass data archiving technology can be used a reference for increasing other data archiving and service efficiency.
In order to resolve the problem of mass TIGGE data archiving and improve the service efficiency of historical longtime series data, a data automatic archive model is designed, and the organization and structure of TIGGE data and the service requirement of historical data are studied by adopting the function of batch automatic archiving technology. The TIGGE data batch archive function is realized automatically, which improves the organization method of historical the data, the organization structure of tape volume, and the service efficiency of archive data significantly. The realization of TIGGE mass data archiving technology can be used a reference for increasing other data archiving and service efficiency.
2015, 43(4):627-633.
Abstract:
The METeorological Pictures Autocreating System (MEPAS) is an operational automatic plotting system of meteorological charts being close to the operational data environment, which supports several data formats, such as GRIB1/GRIB2, includes many algorithms on calculating meteorological variables and convection indexes, and supports mesoscale analysis. MEPAS runs on command lines by writing Analogue scripts in XML files, being easy to learn, convenient to use, running steadily and effectively. It is designed for the meteorological operational system and the relative research programs, and can be used in the nextgeneration MICAPS, filling the gap of MICAPS script technique.
The METeorological Pictures Autocreating System (MEPAS) is an operational automatic plotting system of meteorological charts being close to the operational data environment, which supports several data formats, such as GRIB1/GRIB2, includes many algorithms on calculating meteorological variables and convection indexes, and supports mesoscale analysis. MEPAS runs on command lines by writing Analogue scripts in XML files, being easy to learn, convenient to use, running steadily and effectively. It is designed for the meteorological operational system and the relative research programs, and can be used in the nextgeneration MICAPS, filling the gap of MICAPS script technique.
2015, 43(4):634-639.
Abstract:
With the quick developing of mobile Internet technologies, the clientbased APP is an important way to meet the needs of convenience, high efficiency, movability, and location for meteorological information service. Through research and practice on the fast GISbased visualization technology of meteorological information, which has the features of high update frequency, high spatial resolution, and data quantity, such as radar echoes, gridded weather charts, and MWP outputs, the visualization software SURFER is deployed on the application layer of the server. The preprocessed tiled Raster Map, which was rendered by Google, is deployed on the data layer of the client. The OpenLayers WebGIS is deployed on the application layer of the client. The techniques of data buffering and distributed storage both on server and client application and logic layers are also applied, which ensures the fast visualization for GISbased meteorological information, especially for gridded data, radar echoes, specific pictures, and so on.
With the quick developing of mobile Internet technologies, the clientbased APP is an important way to meet the needs of convenience, high efficiency, movability, and location for meteorological information service. Through research and practice on the fast GISbased visualization technology of meteorological information, which has the features of high update frequency, high spatial resolution, and data quantity, such as radar echoes, gridded weather charts, and MWP outputs, the visualization software SURFER is deployed on the application layer of the server. The preprocessed tiled Raster Map, which was rendered by Google, is deployed on the data layer of the client. The OpenLayers WebGIS is deployed on the application layer of the client. The techniques of data buffering and distributed storage both on server and client application and logic layers are also applied, which ensures the fast visualization for GISbased meteorological information, especially for gridded data, radar echoes, specific pictures, and so on.
2015, 43(4):640-642.
Abstract:
In order to exclude a dynamic antenna fault of Guangzhou Doppler radar, the servo system is divided into four parts: machinery, amplifiers, communication link, and signal control to conduct failure analysis one by one. By using BDAVC5 to analyze the antenna running trajectory, it is found that the problem appeared on the control of antenna elevation, and the failure was excluded by replacing the analog board of the digital control unit. Through elaborating the process of failure analysis, the occasions that antenna dynamic faults may occur and preliminary identification methods are discussed. The ideas and methods that were used during the fault location process can provide a reference for the technical support of new generation weather radar.
In order to exclude a dynamic antenna fault of Guangzhou Doppler radar, the servo system is divided into four parts: machinery, amplifiers, communication link, and signal control to conduct failure analysis one by one. By using BDAVC5 to analyze the antenna running trajectory, it is found that the problem appeared on the control of antenna elevation, and the failure was excluded by replacing the analog board of the digital control unit. Through elaborating the process of failure analysis, the occasions that antenna dynamic faults may occur and preliminary identification methods are discussed. The ideas and methods that were used during the fault location process can provide a reference for the technical support of new generation weather radar.
2015, 43(4):643-646.
Abstract:
The Google Maps JavaScript API technology is described briefly, with the emphasis on the monitoring webpage design for ship automatic weather stations by using the mainstream WebGIS technology. The AJAX technology is used to solve the key problem that large amounts of meteorological data are requested by the webpage from remote data server, and the returned data, which are JOSN data format, are loaded into the Google Maps. The custommade ship icons and track icons are rendered into the monitoring webpage visually by using the Google Maps JavaScript. This technique has been applied to the devices monitoring system of the Guangdong Provincial Meteorological Service successfully.
The Google Maps JavaScript API technology is described briefly, with the emphasis on the monitoring webpage design for ship automatic weather stations by using the mainstream WebGIS technology. The AJAX technology is used to solve the key problem that large amounts of meteorological data are requested by the webpage from remote data server, and the returned data, which are JOSN data format, are loaded into the Google Maps. The custommade ship icons and track icons are rendered into the monitoring webpage visually by using the Google Maps JavaScript. This technique has been applied to the devices monitoring system of the Guangdong Provincial Meteorological Service successfully.
2015, 43(4):647-658.
Abstract:
By evaluating of the ability to predict the 2m temperature and relative humidity, 10m wind direction, and wind speed, as well as T639 model products of two precipitation processes in Inner Mongolia, it is concluded: the forecast accuracy of temperature and relative humidity is better than those of the wind direction and wind speed; the errors of temperature and relative humidity forecast are smaller systematically; the probability of larger wind speed forecast error is high relatively; the precipitation forecast accuracy decreases with the rainfall intensity; in terms of the light rain, the missing alarm rate is lower than the false alarm rate, and the deviations of both overestimated and underestimated rainfall intensity are about the same; the deviations of wind direction are along the clockwise with the angle less than 45°; the temperature deviation is smaller in general, and the distribution of the relative humidity forecast deviation is “＋ － ＋ －” from west to East. The rain falling area is larger for light and moderate rains, and smaller for others. The predicted Lake Baikal cold vortex strength is stronger; the West Pacific subtropical high is weaker; and its influence range is farther north and west.
By evaluating of the ability to predict the 2m temperature and relative humidity, 10m wind direction, and wind speed, as well as T639 model products of two precipitation processes in Inner Mongolia, it is concluded: the forecast accuracy of temperature and relative humidity is better than those of the wind direction and wind speed; the errors of temperature and relative humidity forecast are smaller systematically; the probability of larger wind speed forecast error is high relatively; the precipitation forecast accuracy decreases with the rainfall intensity; in terms of the light rain, the missing alarm rate is lower than the false alarm rate, and the deviations of both overestimated and underestimated rainfall intensity are about the same; the deviations of wind direction are along the clockwise with the angle less than 45°; the temperature deviation is smaller in general, and the distribution of the relative humidity forecast deviation is “＋ － ＋ －” from west to East. The rain falling area is larger for light and moderate rains, and smaller for others. The predicted Lake Baikal cold vortex strength is stronger; the West Pacific subtropical high is weaker; and its influence range is farther north and west.
2015, 43(4):659-665.
Abstract:
Combining statistic analysis with typical case analysis method, by use of the NCEP/NCAR grid reanalysis data (25°×25°), and routine observation data such as temperature, dewpoint temperature, visibility, pressure in Nanning, and radiosonde data in Hechi and Beihai, the circulation pattern and meteorological element features of several typical “HighHumidity weather” in Guangxi from 2005 to 2013 are analyzed. The results show that: (1) “HighHumidity weather” events of different degree are influenced by the stronger cold air before it; (2) “HighHumidity weather” occurs when the dewpoint temperature at 14:00 is higher than the lowest temperature of that day and the temperature, and humidity increase suddenly, with the development of warm low or inverted trough and no obvious southward cold air in midhigh latitude，as well as the strong south wind prevails at 850 hPa and 925 hPa, and the front inversion layer is on the ground; (3) “HighHumidity weather” usually disappears in two ways: cold ending and warm ending; (4) if Guangxi is affected by longer cold air in the winter and spring, and the temperature and humidity suddenly increases at 850 hPa and 925 hPa, and the dewpoint temperature at 14:00 is higher than the lowest temperature of that day in the further one or two days, “HighHumidity weather” can be forecasted.
Combining statistic analysis with typical case analysis method, by use of the NCEP/NCAR grid reanalysis data (25°×25°), and routine observation data such as temperature, dewpoint temperature, visibility, pressure in Nanning, and radiosonde data in Hechi and Beihai, the circulation pattern and meteorological element features of several typical “HighHumidity weather” in Guangxi from 2005 to 2013 are analyzed. The results show that: (1) “HighHumidity weather” events of different degree are influenced by the stronger cold air before it; (2) “HighHumidity weather” occurs when the dewpoint temperature at 14:00 is higher than the lowest temperature of that day and the temperature, and humidity increase suddenly, with the development of warm low or inverted trough and no obvious southward cold air in midhigh latitude，as well as the strong south wind prevails at 850 hPa and 925 hPa, and the front inversion layer is on the ground; (3) “HighHumidity weather” usually disappears in two ways: cold ending and warm ending; (4) if Guangxi is affected by longer cold air in the winter and spring, and the temperature and humidity suddenly increases at 850 hPa and 925 hPa, and the dewpoint temperature at 14:00 is higher than the lowest temperature of that day in the further one or two days, “HighHumidity weather” can be forecasted.
2015, 43(4):666-674.
Abstract:
The PWV data of GPS/MET from May to September 2012, the automatic rain gauge data and the radiosonde data are analyzed. The results are as follows: (1) There existed high correlation and small errors between GPSPWV and radiosondePWV measurements observed at the same station, but less obvious correlation when there was rainfall. (2) GPSPWV values were about 10 mm lower on plains than in hilly areas when rainfall. (3) 69% of GPSPWV values rose before a storm appearing, and in the cases of not rising, the GPSPWV reached a higher value. When the GPSPWV values of 6 hours and 12 hours were positive, it is indicated that rainstorm will start. (4) GPSPWV characteristics were different under different types of rainstorms: the storm centers of local rainstorms caused by the westerly system and subtropicalhigh in Hubei Province correspond with GPSPWV high values, with the GPSPWV threshold values being less than 40 mm and 55 mm, respectively, in west of Hubei Province and the GPSPWV threshold values being less than 52 mm and 60 mm, respectively, in mideast of Hubei Province. The local rainstorms affected by Typhoon usually lie around the dense zones of GPSPWV nearby the high values area, with the threshold values less than 45 mm. During heavy rain processes, GPSPWV high value centers appear 1 hour earlier comparing with the heavy rainfall centers under favorable weather conditions. (5) There were three kinds of situations in which storm centers locate in GPSPWV dense zones: rainstorms caused by a fastmoving storm systems, local rainstorms affected by a Typhoon, rainstorms in mountains areas. (6) It can be indicative of rainstorms very well in the mideastern Hubei Province, but poor in the mountainous area of the western Hubei, while comprehensively considering GPSPWV high values and ground convergence zone 1 hour before.
The PWV data of GPS/MET from May to September 2012, the automatic rain gauge data and the radiosonde data are analyzed. The results are as follows: (1) There existed high correlation and small errors between GPSPWV and radiosondePWV measurements observed at the same station, but less obvious correlation when there was rainfall. (2) GPSPWV values were about 10 mm lower on plains than in hilly areas when rainfall. (3) 69% of GPSPWV values rose before a storm appearing, and in the cases of not rising, the GPSPWV reached a higher value. When the GPSPWV values of 6 hours and 12 hours were positive, it is indicated that rainstorm will start. (4) GPSPWV characteristics were different under different types of rainstorms: the storm centers of local rainstorms caused by the westerly system and subtropicalhigh in Hubei Province correspond with GPSPWV high values, with the GPSPWV threshold values being less than 40 mm and 55 mm, respectively, in west of Hubei Province and the GPSPWV threshold values being less than 52 mm and 60 mm, respectively, in mideast of Hubei Province. The local rainstorms affected by Typhoon usually lie around the dense zones of GPSPWV nearby the high values area, with the threshold values less than 45 mm. During heavy rain processes, GPSPWV high value centers appear 1 hour earlier comparing with the heavy rainfall centers under favorable weather conditions. (5) There were three kinds of situations in which storm centers locate in GPSPWV dense zones: rainstorms caused by a fastmoving storm systems, local rainstorms affected by a Typhoon, rainstorms in mountains areas. (6) It can be indicative of rainstorms very well in the mideastern Hubei Province, but poor in the mountainous area of the western Hubei, while comprehensively considering GPSPWV high values and ground convergence zone 1 hour before.
2015, 43(4):675-680.
Abstract:
By means of the historical landslide hazards data and the corresponding hourly precipitation, taking Huaping Station of Yunnan Province as an example, the effective rainfall days and the corresponding antecedent precipitation are calculated. The method of principal components analysis is applied to study the impact of the rainfall factors on the occurrence of landslides in order to understand the contribution of antecedent precipitation. The results show that the antecedent precipitation, occurrence precipitation, and excitation precipitation are important for the occurrence of landslides. The weighted relation between antecedent precipitation and occurrence precipitation is discussed. The landslideinduced rainfall includes shortterm heavy rainfall and prolonged lowintensity rainfall. The relation of rainfall intensity to duration thresholds, which contains two types of rainfall characteristics, is obtained for the initiation of landslides at Huaping. A method for defining the end point of rainfall duration and issues needing further study are discussed. The findings about warning rainfall thresholds for Huaping Station can be used as a reference for determining warning rainfall thresholds for landslide disasters.
By means of the historical landslide hazards data and the corresponding hourly precipitation, taking Huaping Station of Yunnan Province as an example, the effective rainfall days and the corresponding antecedent precipitation are calculated. The method of principal components analysis is applied to study the impact of the rainfall factors on the occurrence of landslides in order to understand the contribution of antecedent precipitation. The results show that the antecedent precipitation, occurrence precipitation, and excitation precipitation are important for the occurrence of landslides. The weighted relation between antecedent precipitation and occurrence precipitation is discussed. The landslideinduced rainfall includes shortterm heavy rainfall and prolonged lowintensity rainfall. The relation of rainfall intensity to duration thresholds, which contains two types of rainfall characteristics, is obtained for the initiation of landslides at Huaping. A method for defining the end point of rainfall duration and issues needing further study are discussed. The findings about warning rainfall thresholds for Huaping Station can be used as a reference for determining warning rainfall thresholds for landslide disasters.
2015, 43(4):681-687.
Abstract:
By using the hourtohour rainfall data from automatic weather stations and the inflow of Zhouning Reservoir in Fujian from 2008 to 2012， 30 precipitation cases are selected, and the average area rainfall over the Zhouning Reservoir drainage basin is calculated with 12 differential estimation methods based on the secondary development of Surfer 8.0. The numerical estimates and the spatial distribution characteristics of the regional rainfall are analyzed to find a relatively convenient, effective and accurate computational method. The results show that in various interpolation algorithm methods, the mean relative errors of Modified Quadratic, Kriging, and Radial Basis Function are obviously lower. Further research illustrates that the first selected interpolation algorithm for the area rainfall of <20 m is the Radial Basis Function method, while for the area rainfall of >60mm, Kriging is the best.
By using the hourtohour rainfall data from automatic weather stations and the inflow of Zhouning Reservoir in Fujian from 2008 to 2012， 30 precipitation cases are selected, and the average area rainfall over the Zhouning Reservoir drainage basin is calculated with 12 differential estimation methods based on the secondary development of Surfer 8.0. The numerical estimates and the spatial distribution characteristics of the regional rainfall are analyzed to find a relatively convenient, effective and accurate computational method. The results show that in various interpolation algorithm methods, the mean relative errors of Modified Quadratic, Kriging, and Radial Basis Function are obviously lower. Further research illustrates that the first selected interpolation algorithm for the area rainfall of <20 m is the Radial Basis Function method, while for the area rainfall of >60mm, Kriging is the best.
2015, 43(4):688-696.
Abstract:
Using the conventional observations, satellite images and, Doppler radar and NCEP, 1°×1° reanalysis data, a comparative analysis is made of the MCS (Mesoscale Convective System) developing characteristics, environmental conditions, and triggering mechanisms between the two regional rainstorms on 30 July 2012 and 9 July 2013 in Shandong. The results show that the two processes were caused by the shear lines at 850 hPa; the lineshaped MCS was the direct cause, and the ground convergence line triggered the rainstorms. They have different synoptic systems at 500 hPa. The rainstorm on 30 July 2012 occurred under the domination of highlevel stepped slot, but the rainstorm on 9 July 2013 occurred in a typical context of “high in the east and low in the west.” The water vapor supply of the rainstorm on 30 July 2012 was from the East Sea and Western Pacific Ocean, and dynamic conditions were more favorable, with the water vapor flux divergence and specific humidity at 925 hPa being 10 g〖DK〗·hPa-1〖DK〗·cm-2〖DK〗·s-1and -0.2 Pa〖DK〗·s-1larger than those on 9 July 2013; while the storm on 9 July 2013 carried water vapor to the raining area from the South Sea, whose moisture conditions were more favorable. For two processes, the occurrence and development processes of MCSs and the ways to form and the structure at the mature stage were significantly different. In the rainstorm process on 30 July 2012, convective cells gradually merged into βmesoscale and finally into αmesoscale convective systems. In the storm on 9 July 2013, multiple convective cells merged into βmesoscale. Analyzing their trigger mechanisms, it is found that key points of shearline rainstorm trigger mechanisms are the formation and strengthening of the ground convergence line,as well as the frontogenesis caused by cold air intrusion.
Using the conventional observations, satellite images and, Doppler radar and NCEP, 1°×1° reanalysis data, a comparative analysis is made of the MCS (Mesoscale Convective System) developing characteristics, environmental conditions, and triggering mechanisms between the two regional rainstorms on 30 July 2012 and 9 July 2013 in Shandong. The results show that the two processes were caused by the shear lines at 850 hPa; the lineshaped MCS was the direct cause, and the ground convergence line triggered the rainstorms. They have different synoptic systems at 500 hPa. The rainstorm on 30 July 2012 occurred under the domination of highlevel stepped slot, but the rainstorm on 9 July 2013 occurred in a typical context of “high in the east and low in the west.” The water vapor supply of the rainstorm on 30 July 2012 was from the East Sea and Western Pacific Ocean, and dynamic conditions were more favorable, with the water vapor flux divergence and specific humidity at 925 hPa being 10 g〖DK〗·hPa-1〖DK〗·cm-2〖DK〗·s-1and -0.2 Pa〖DK〗·s-1larger than those on 9 July 2013; while the storm on 9 July 2013 carried water vapor to the raining area from the South Sea, whose moisture conditions were more favorable. For two processes, the occurrence and development processes of MCSs and the ways to form and the structure at the mature stage were significantly different. In the rainstorm process on 30 July 2012, convective cells gradually merged into βmesoscale and finally into αmesoscale convective systems. In the storm on 9 July 2013, multiple convective cells merged into βmesoscale. Analyzing their trigger mechanisms, it is found that key points of shearline rainstorm trigger mechanisms are the formation and strengthening of the ground convergence line,as well as the frontogenesis caused by cold air intrusion.
2015, 43(4):697-703.
Abstract:
There are 22 reference stations and 31 correction stations determined in 76 meteorological stations in Hubei Province. Based on onedimensional regression method, the monthly mean winter temperature correction series in correction stations from 1961 to 2013 are built. The correction series are compared and analyzed in the statistical method and in correction errors, and the results are applied to winter climate impact assessment. The results indicate that the impact of the revised results of stations is significantly greater than those of the divisional and provincial adjustments; the results of divisional and provincial adjustments are basically consistent before and after adjusting, and there is an increasing trend in the number of inconsistency in winter types in provincial adjustment; the changes in winter for typical stations are significant, and there is a transition from cold winter to warm winter, and the reducing of cold winter becomes weakened, and the increasing of warm winter becomes strong.
There are 22 reference stations and 31 correction stations determined in 76 meteorological stations in Hubei Province. Based on onedimensional regression method, the monthly mean winter temperature correction series in correction stations from 1961 to 2013 are built. The correction series are compared and analyzed in the statistical method and in correction errors, and the results are applied to winter climate impact assessment. The results indicate that the impact of the revised results of stations is significantly greater than those of the divisional and provincial adjustments; the results of divisional and provincial adjustments are basically consistent before and after adjusting, and there is an increasing trend in the number of inconsistency in winter types in provincial adjustment; the changes in winter for typical stations are significant, and there is a transition from cold winter to warm winter, and the reducing of cold winter becomes weakened, and the increasing of warm winter becomes strong.
2015, 43(4):704-708.
Abstract:
Using the data from 157 manual observation stations and AWS’s, the spatial and temporal characteristics of the shortlasting heavy rainfall in Beijing are analyzed. The results show that: (1) The number of shortlasting heavy rainfall events increased generally from 2007 to 2012 There are large differences among years. (2) From the spatial and temporal characteristics, it is found that the shortlasting heavy rainfall occurred more frequently in July, evening and early morning, in the plain area in front of the Xishan mountain, including the central and east parts of Changping, the western Shunyi, Shijingsha, western Fengtai, and southeastern Fangshan districts. (3) The relationship between shortlasting heavy rainfall and annual total rainfall is examined, and it is found that the annual total rainfall was larger in the year with more shortlasting heavy rainfall events, and the shortlasting heavy rainfall made an important contribution to annual total rainfall.
Using the data from 157 manual observation stations and AWS’s, the spatial and temporal characteristics of the shortlasting heavy rainfall in Beijing are analyzed. The results show that: (1) The number of shortlasting heavy rainfall events increased generally from 2007 to 2012 There are large differences among years. (2) From the spatial and temporal characteristics, it is found that the shortlasting heavy rainfall occurred more frequently in July, evening and early morning, in the plain area in front of the Xishan mountain, including the central and east parts of Changping, the western Shunyi, Shijingsha, western Fengtai, and southeastern Fangshan districts. (3) The relationship between shortlasting heavy rainfall and annual total rainfall is examined, and it is found that the annual total rainfall was larger in the year with more shortlasting heavy rainfall events, and the shortlasting heavy rainfall made an important contribution to annual total rainfall.
2015, 43(4):709-714.
Abstract:
Based on the data of ground, radiosonde, and numerical forecast data, an analysis is conducted on the foggy weather in the southern Shandong from 2001 to 2012, with the emphases on the climatic features, humidity, and physical quantity index in the nearground layer. It is found that: fogs in the southern Shandong were mainly concentrated in the period of October to December after 2010, and fog days increased significantly in the southern Shandong. The wet layer top of 90% relative humidity was lower than 925 hPa on average. The average height of the inversion layer during fogs in the southern Shandong was at 950 hPa, and there is an obvious weaktostrong warm advection center between 850 and 925 hPa, and the builtup time of the warm advection is 0 to 24 hours ahead of the fog. The formation of high humidity area at 925 hPa was 6 to 24 hours earlier than the apearing of the fog. The appearing of extreme descending motion values at 500 hPa was 6 to 24 hours earlier than the apearing of the fog, and the establishment of the obvious convergence center at 850-925 hPa was 0 to 24 hours earlier than the apearing of the fog.
Based on the data of ground, radiosonde, and numerical forecast data, an analysis is conducted on the foggy weather in the southern Shandong from 2001 to 2012, with the emphases on the climatic features, humidity, and physical quantity index in the nearground layer. It is found that: fogs in the southern Shandong were mainly concentrated in the period of October to December after 2010, and fog days increased significantly in the southern Shandong. The wet layer top of 90% relative humidity was lower than 925 hPa on average. The average height of the inversion layer during fogs in the southern Shandong was at 950 hPa, and there is an obvious weaktostrong warm advection center between 850 and 925 hPa, and the builtup time of the warm advection is 0 to 24 hours ahead of the fog. The formation of high humidity area at 925 hPa was 6 to 24 hours earlier than the apearing of the fog. The appearing of extreme descending motion values at 500 hPa was 6 to 24 hours earlier than the apearing of the fog, and the establishment of the obvious convergence center at 850-925 hPa was 0 to 24 hours earlier than the apearing of the fog.
2015, 43(4):715-721.
Abstract:
Water vapor condition is an essential meteorological element for lightning activity. Using the monitored cloudground lightning data from lightning detection system in Hebei Province and relative humidity data in NCEP/NCAR data in 2013, the lightning characteristics and response relationship between lightning activity and vertical structural characteristics of atmospheric relative humidity are analyzed. The results show that (1) The time distribution of lightning at Zhangjiakou was basically consistent with that of Hebei Province, and lightning activity was the strongest in summer and uneven in monthly change;there was a daily summit appearing from 17:00 to 18:00 and a valley from 01:00 to 09:00. (2) There was obvious response relationship between lightning activity and relative humidity vertical structure: the relative humidity was not high at about 850 hPa, but more humid at about 700 hPa, then became dry at upper layers; the relative humidity increased with height below 700 hPa and deceased above 600 to 700 hPa. (3) When lightning occurred, the local characteristics of atmospheric environmental conditions of relative humidity in Zhangjiakou include: relative humidity was about 40%～60% at about 850 hPa; 60%～80% between 600 and 700 hPa, and decreased to about 20%～40% between 200 to 400 hPa.
Water vapor condition is an essential meteorological element for lightning activity. Using the monitored cloudground lightning data from lightning detection system in Hebei Province and relative humidity data in NCEP/NCAR data in 2013, the lightning characteristics and response relationship between lightning activity and vertical structural characteristics of atmospheric relative humidity are analyzed. The results show that (1) The time distribution of lightning at Zhangjiakou was basically consistent with that of Hebei Province, and lightning activity was the strongest in summer and uneven in monthly change;there was a daily summit appearing from 17:00 to 18:00 and a valley from 01:00 to 09:00. (2) There was obvious response relationship between lightning activity and relative humidity vertical structure: the relative humidity was not high at about 850 hPa, but more humid at about 700 hPa, then became dry at upper layers; the relative humidity increased with height below 700 hPa and deceased above 600 to 700 hPa. (3) When lightning occurred, the local characteristics of atmospheric environmental conditions of relative humidity in Zhangjiakou include: relative humidity was about 40%～60% at about 850 hPa; 60%～80% between 600 and 700 hPa, and decreased to about 20%～40% between 200 to 400 hPa.
2015, 43(4):722-727.
Abstract:
Using the meteorological observation records of frozen soil from eight stations during the period of 1962 to 2008 in Datong, by means of linear trend estimation and accumulated anomaly methods, an analysis is made of the variation characteristics and influencing factors of frozen soil, such as the dates of beginning to freeze and completely defrosting, freezing duration, and the maximum depth of frozen soil. The results show that the largest permafrost depth reduced; the date of freezing beginning delayed; the date of defrosting advanced, the freezing duration shortened in general. Frozen soil is not only affected by the temperature, and local factors have great influence on the maximum depth of frozen soil.
Using the meteorological observation records of frozen soil from eight stations during the period of 1962 to 2008 in Datong, by means of linear trend estimation and accumulated anomaly methods, an analysis is made of the variation characteristics and influencing factors of frozen soil, such as the dates of beginning to freeze and completely defrosting, freezing duration, and the maximum depth of frozen soil. The results show that the largest permafrost depth reduced; the date of freezing beginning delayed; the date of defrosting advanced, the freezing duration shortened in general. Frozen soil is not only affected by the temperature, and local factors have great influence on the maximum depth of frozen soil.
2015, 43(4):728-733.
Abstract:
Negative oxygen concentration has become an important indicator to measure air quality. Choosing 17 national meteorological stations in Hubei on behalf of the observation stations with the same environment and using the equipment in line with national and industry standards, the spatialtemporal characteristics of the air negative oxygen ion from March to May in 2014 and its relationship with environmental and meteorological factors are analyzed following the definition of negative oxygen ion. The results show that negative oxygen concentration in the western Hubei is higher than that in middleeast, and the average concentration of the Shennongjia forest district is the highest, but it is low in Wuhan, the central of the middleeast. Over the span of a whole day, it is high early in the morning, but low during the day, and then it has a trend of rising in the evening. It is also reveals that the concentration correlates positively with altitude and vegetation coverage, and negatively with small particles in the air. However, the concentration has poor correlates with temperature, air pressure, relative humidity, speed, sunshine duration, and other meteorological factors. Besides, the precipitation and thunderstorm is favorable to the increase of negative oxygen ions.
Negative oxygen concentration has become an important indicator to measure air quality. Choosing 17 national meteorological stations in Hubei on behalf of the observation stations with the same environment and using the equipment in line with national and industry standards, the spatialtemporal characteristics of the air negative oxygen ion from March to May in 2014 and its relationship with environmental and meteorological factors are analyzed following the definition of negative oxygen ion. The results show that negative oxygen concentration in the western Hubei is higher than that in middleeast, and the average concentration of the Shennongjia forest district is the highest, but it is low in Wuhan, the central of the middleeast. Over the span of a whole day, it is high early in the morning, but low during the day, and then it has a trend of rising in the evening. It is also reveals that the concentration correlates positively with altitude and vegetation coverage, and negatively with small particles in the air. However, the concentration has poor correlates with temperature, air pressure, relative humidity, speed, sunshine duration, and other meteorological factors. Besides, the precipitation and thunderstorm is favorable to the increase of negative oxygen ions.
2015, 43(4):734-739.
Abstract:
In recent years, more and more attention is focused on the characteristic changes of weather in Beijing, the frequency of fog and haze, and the changes of visibility. In virtue of regression analysis and MannKendall rank statistics, the trends and the abrupt variations of visibility are analyzed by using the data of manual air horizontal visibility at surface meteorological stations from 1980 to 2014 in the southwestern Beijing. The annual mean values of visibility show decreasing trends at the stations of plain and mountain areas. The visibility is better in spring and winter, and the diurnal variation of visibility is significantly. The analysis results show that abrupt variations of the annual mean visibility in the plain areas appeared in 1997 There existed significant correlation between visibility and surface meteorological conditions and air pollutants, with the correlation between the humidity and visibility being the best. Using air pollution data published by the local authorities in 2013, the analysis of visibility and air pollutant concentration illustrates that the correlation between PM25 and visibility is the best, while that between SO2 and visibility is the poorest.
In recent years, more and more attention is focused on the characteristic changes of weather in Beijing, the frequency of fog and haze, and the changes of visibility. In virtue of regression analysis and MannKendall rank statistics, the trends and the abrupt variations of visibility are analyzed by using the data of manual air horizontal visibility at surface meteorological stations from 1980 to 2014 in the southwestern Beijing. The annual mean values of visibility show decreasing trends at the stations of plain and mountain areas. The visibility is better in spring and winter, and the diurnal variation of visibility is significantly. The analysis results show that abrupt variations of the annual mean visibility in the plain areas appeared in 1997 There existed significant correlation between visibility and surface meteorological conditions and air pollutants, with the correlation between the humidity and visibility being the best. Using air pollution data published by the local authorities in 2013, the analysis of visibility and air pollutant concentration illustrates that the correlation between PM25 and visibility is the best, while that between SO2 and visibility is the poorest.
2015, 43(4):740-743.
Abstract:
The meteorological index of fireworks burning is one of meteorological service products for government emergency response to safety management and air pollution controlling. By considering the meteorological factors affecting the safety of firework burning, the spread of pollutants, cleaning after burning, and air quality, such as wind speed, relative humidity, precipitation, air pollution, etc., the meteorological index of fireworks burning is devised by means of the methods of membership degree and function's maximum. The burning index is divided into four levels from low to high: suitable, fairly suitable, unsuitable, and very unsuitable. The background of burning index, scientific connotation, forecast methods, and service strategy are discussed.
The meteorological index of fireworks burning is one of meteorological service products for government emergency response to safety management and air pollution controlling. By considering the meteorological factors affecting the safety of firework burning, the spread of pollutants, cleaning after burning, and air quality, such as wind speed, relative humidity, precipitation, air pollution, etc., the meteorological index of fireworks burning is devised by means of the methods of membership degree and function's maximum. The burning index is divided into four levels from low to high: suitable, fairly suitable, unsuitable, and very unsuitable. The background of burning index, scientific connotation, forecast methods, and service strategy are discussed.
2015, 43(4):744-749.
Abstract:
Using the daily temperature data of 153 stations from 1961 to 2010, the characteristics of cold disasters and their response to regional warming in Northeast China in recent 50 years are analyzed. The results show that the rice steriletype cold disasters declined, but the regional feature is obvious in Northeast China. There is a significant negative correlation between temperature and cold disasters. When temperature rises 1 ℃, the cold disasters reduce 35 stations. The whole Northeast China temperature increased, but the chilling injury increased in the western Jilin Province. In order to probe into the causes, the key developmental stages of temperature variability and climate variability are analyzed. The explanation for the effect of local chilling injury increasing is mainly the increase of climate variability, and the daily temperature variation rate has little effect.
Using the daily temperature data of 153 stations from 1961 to 2010, the characteristics of cold disasters and their response to regional warming in Northeast China in recent 50 years are analyzed. The results show that the rice steriletype cold disasters declined, but the regional feature is obvious in Northeast China. There is a significant negative correlation between temperature and cold disasters. When temperature rises 1 ℃, the cold disasters reduce 35 stations. The whole Northeast China temperature increased, but the chilling injury increased in the western Jilin Province. In order to probe into the causes, the key developmental stages of temperature variability and climate variability are analyzed. The explanation for the effect of local chilling injury increasing is mainly the increase of climate variability, and the daily temperature variation rate has little effect.
2015, 43(4):750-753.
Abstract:
According to the actual situation in rice observation of the national agricultural meteorological observation station of Jiangxia, Hubei and the survey in recent years, it is found that direct seeding rice has become the trend of rapid development, and it is inevitable for agricultural meteorological observation to encounter the problem of directseeding rice observation in growing process. Due to the change in the way of planting, the field plant distribution form has undergone a fundamental change, making the currently used “agricultural meteorological observation standards,” which was devised specially for transplanting rice, unable to deal with the direct seeding rice. Therefore, based on the observation standards, combined with the actual observation and experiences, the difference between directseeding rice and transplanting rice and the new problems that brings about are analyzed. A new processing method of observation is discussed.
According to the actual situation in rice observation of the national agricultural meteorological observation station of Jiangxia, Hubei and the survey in recent years, it is found that direct seeding rice has become the trend of rapid development, and it is inevitable for agricultural meteorological observation to encounter the problem of directseeding rice observation in growing process. Due to the change in the way of planting, the field plant distribution form has undergone a fundamental change, making the currently used “agricultural meteorological observation standards,” which was devised specially for transplanting rice, unable to deal with the direct seeding rice. Therefore, based on the observation standards, combined with the actual observation and experiences, the difference between directseeding rice and transplanting rice and the new problems that brings about are analyzed. A new processing method of observation is discussed.
2015, 43(4):754-758.
Abstract:
While installing airtermination System in the Great Wall watchtowers in sections open to tourists, it is necessary to take into account fully not only the type and scope of protection, but also the lightning disturbance on the watchtowers and the influence on the overall outlook of the Great Wall. The installation method of lightning rods for direct lightning protection on the watchtowers is described. According to the lightning protection categories of the Great Wall and the principle of the rolling ball method, the lightning rod heights in four outer corners of different watchtowers are calculated, which should be controlled below 45 m to protect visitors. Simultaneously, the lightning rod heights in the watchtowers prohibiting climbing should not exceed 1 m. According to the cultural relics principle of the minimal intervention on the Great Wall when installing lightning arrester, the possibilities of reducing the number of lightning rods are discussed. It is found that when the number of lightning rods is less than four, the lightning rod height will increase significantly and obvious negative effects will be brought on the appearance, so this way should not be used. In addition, the protective measures should be taken to prevent the contact voltage where visitors may come into contact with the lightning rod parts.
While installing airtermination System in the Great Wall watchtowers in sections open to tourists, it is necessary to take into account fully not only the type and scope of protection, but also the lightning disturbance on the watchtowers and the influence on the overall outlook of the Great Wall. The installation method of lightning rods for direct lightning protection on the watchtowers is described. According to the lightning protection categories of the Great Wall and the principle of the rolling ball method, the lightning rod heights in four outer corners of different watchtowers are calculated, which should be controlled below 45 m to protect visitors. Simultaneously, the lightning rod heights in the watchtowers prohibiting climbing should not exceed 1 m. According to the cultural relics principle of the minimal intervention on the Great Wall when installing lightning arrester, the possibilities of reducing the number of lightning rods are discussed. It is found that when the number of lightning rods is less than four, the lightning rod height will increase significantly and obvious negative effects will be brought on the appearance, so this way should not be used. In addition, the protective measures should be taken to prevent the contact voltage where visitors may come into contact with the lightning rod parts.
2015, 43(4):759-763.
Abstract:
〖WTBX〗P〖WTBZ〗B is given as a function value of lightning protection level (LPL) in the national standard GB/T217142-2008, without considering the sizes of buildings, which is not precise. The model of the struck is established by using electricalgeometry theory. The relationship between risk and building characters is provided. The method related to the heights of buildings and lightning arresters for calculating 〖WTBX〗P〖WTBZ〗B is given. Compared with the old method, this method is used to calculate the 〖WTBX〗P〖WTBZ〗B value of physical buildings. The result shows that 〖WTBX〗P〖WTBZ〗B calculated with the new methods is generally larger than that with the old one; the practical significance of this method is demonstrated as well.
〖WTBX〗P〖WTBZ〗B is given as a function value of lightning protection level (LPL) in the national standard GB/T217142-2008, without considering the sizes of buildings, which is not precise. The model of the struck is established by using electricalgeometry theory. The relationship between risk and building characters is provided. The method related to the heights of buildings and lightning arresters for calculating 〖WTBX〗P〖WTBZ〗B is given. Compared with the old method, this method is used to calculate the 〖WTBX〗P〖WTBZ〗B value of physical buildings. The result shows that 〖WTBX〗P〖WTBZ〗B calculated with the new methods is generally larger than that with the old one; the practical significance of this method is demonstrated as well.
2015, 43(4):764-768.
Abstract:
Using the manmachine interactive definition of meteorological indexes, a universal service system of common weather indexes in Tibet is devised. The input meteorological data, including numerical weather prediction, weather reality data, forecast products, station number, longitude, latitude, and time information, can be defined and read in a unified user interface. The corresponding data put into the formula in the form of the number of floating points to complete the calculation of meteorological indices. The data are stored interactively with universal MICPAS format, and weather indexes and service production are administrated under a uniform platform. Weather forecasting and service staff can provide new weather index service without programming.
Using the manmachine interactive definition of meteorological indexes, a universal service system of common weather indexes in Tibet is devised. The input meteorological data, including numerical weather prediction, weather reality data, forecast products, station number, longitude, latitude, and time information, can be defined and read in a unified user interface. The corresponding data put into the formula in the form of the number of floating points to complete the calculation of meteorological indices. The data are stored interactively with universal MICPAS format, and weather indexes and service production are administrated under a uniform platform. Weather forecasting and service staff can provide new weather index service without programming.
2015, 43(4):769-774.
Abstract:
The climate comfortability for travel in Lishui is evaluated by using four comprehensive climate indexes: human body comfort meteorological index (BCMI), coldness index (CI), temperature humidity index (THI), and holiday climate index (HCI). The characterization capability of BCMI and HCI are compared and discussed. The results show that Lishui belongs to the firstlevel region of climate comfortability, because there are 8 months with its BCMI grade between 4 and 6 in one whole year. The CI is lower in winter, which means that there is no cold winter. The THI shows that about 60% of regions with its altitude over 600 m have a cool summer, but the other regions with rather high THI. HCI is more comprehensive and objective than BCMI, because HCI considers not only the thermal comfort of climate but also the effects of precipitation and cloud cover on traveling, which is more suitable for daily travel comfort prediction in time scale.
The climate comfortability for travel in Lishui is evaluated by using four comprehensive climate indexes: human body comfort meteorological index (BCMI), coldness index (CI), temperature humidity index (THI), and holiday climate index (HCI). The characterization capability of BCMI and HCI are compared and discussed. The results show that Lishui belongs to the firstlevel region of climate comfortability, because there are 8 months with its BCMI grade between 4 and 6 in one whole year. The CI is lower in winter, which means that there is no cold winter. The THI shows that about 60% of regions with its altitude over 600 m have a cool summer, but the other regions with rather high THI. HCI is more comprehensive and objective than BCMI, because HCI considers not only the thermal comfort of climate but also the effects of precipitation and cloud cover on traveling, which is more suitable for daily travel comfort prediction in time scale.
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.