Volume 39,Issue 5,2011 Table of Contents
2011, 39(5):529-536.
Abstract:
In recent years， several Bogus schemes have been put forward to improve the initial thermodynamic and circumfluent structures of typhoons， which performed well in typhoon numerical forecasting. It has great significance for typhoon numerical simulation and forecasting to understand， compare， and improve various Bogus techniques. An introduction is made to four initialization schemes of typhoons， which include the Bogus data assimilation scheme （BDA）based on four dimensional variational data assimilation (4DVAR)， the incidental Bogus scheme of MM5， the Bogus scheme advanced by Wang Guomin， and one used by the Institute of Tropical and Marine Meteorology in Guangzhou， and then the effects of these models in typhoon numerical forecasting are compared. The results show that the BDA scheme is obviously better for improving both typhoon track and intensity simulations.
In recent years， several Bogus schemes have been put forward to improve the initial thermodynamic and circumfluent structures of typhoons， which performed well in typhoon numerical forecasting. It has great significance for typhoon numerical simulation and forecasting to understand， compare， and improve various Bogus techniques. An introduction is made to four initialization schemes of typhoons， which include the Bogus data assimilation scheme （BDA）based on four dimensional variational data assimilation (4DVAR)， the incidental Bogus scheme of MM5， the Bogus scheme advanced by Wang Guomin， and one used by the Institute of Tropical and Marine Meteorology in Guangzhou， and then the effects of these models in typhoon numerical forecasting are compared. The results show that the BDA scheme is obviously better for improving both typhoon track and intensity simulations.
2 Numerical Simulation of a High Temperature Weather Process Based on Different Land Surface Schemes
2011, 39(5):537-544.
Abstract:
The high temperature weather process occurred in the region along the ShanghaiNanjing Expressway in July of 2009 is simulated by the WRF model with three different land surface parameterization schemes (SLAB, NOAH, and RUC). The results show that: (1) The simulation results integrated the land surface parameterization schemes in the WRF model is closer to the reality, and the sensitivity of high temperature weather simulation to land surface physical processes is significant. (2) The simulated temperature values of Meicun Station based on the three different land surface schemes are close to the observed values, and when the NOAH scheme is coupled into the WRF model, the prediction accuracy of air temperature simulation is the highest. (3) The simulations coupling the three different land surface schemes show that the sensible heat flux is high and the latent heat flux is low along the ShanghaiNanjing expressway. The integrated simulation coupling the NOAH scheme is more satisfactory. (4) The vertical movement simulated by the WRF model is sensitive to the selection of different land surface schemes and the NOAH scheme gives more reasonable results than the others. (5) In the simulations on the relative humidity, there are some differences between the three schemes, and the SLAB scheme performs better than NOAH or RUC. (6) All the horizontal wind speeds at the ground simulated by the three land surface schemes are small, which is conducive to the emergence of high temperature at the surface. The simulation of wind speeds by WRF model is sensitive to the selection of different land surface processes. Results simulated by the NOAH scheme are better in effectiveness than that by the others.
The high temperature weather process occurred in the region along the ShanghaiNanjing Expressway in July of 2009 is simulated by the WRF model with three different land surface parameterization schemes (SLAB, NOAH, and RUC). The results show that: (1) The simulation results integrated the land surface parameterization schemes in the WRF model is closer to the reality, and the sensitivity of high temperature weather simulation to land surface physical processes is significant. (2) The simulated temperature values of Meicun Station based on the three different land surface schemes are close to the observed values, and when the NOAH scheme is coupled into the WRF model, the prediction accuracy of air temperature simulation is the highest. (3) The simulations coupling the three different land surface schemes show that the sensible heat flux is high and the latent heat flux is low along the ShanghaiNanjing expressway. The integrated simulation coupling the NOAH scheme is more satisfactory. (4) The vertical movement simulated by the WRF model is sensitive to the selection of different land surface schemes and the NOAH scheme gives more reasonable results than the others. (5) In the simulations on the relative humidity, there are some differences between the three schemes, and the SLAB scheme performs better than NOAH or RUC. (6) All the horizontal wind speeds at the ground simulated by the three land surface schemes are small, which is conducive to the emergence of high temperature at the surface. The simulation of wind speeds by WRF model is sensitive to the selection of different land surface processes. Results simulated by the NOAH scheme are better in effectiveness than that by the others.
2011, 39(5):545-551.
Abstract:
The severe convective predictive equation is set up with the method of stepwise discrimination analysis by using the TBB data from 2005 to 2008，to decide if a cloud cluster in the monitoring area will produce regional severe weather with the indicator superposition method. Based on the statistics of radar parameters during hail and gust events with thunderstorms for many years in Fujian， the radar parameter thresholds for severe convective weather， such as big hail， hail， and gust with thunderstorm， are decided.According to the height difference between the height of the 0 ℃ level and the storm top and that between the height of the -20 ℃ level and the storm top， the storms captured by CINRAD are chosen one by one，so to identify the area that will be influenced in the next one hour by storms that may bring about big hail， hail or gust weather.
The severe convective predictive equation is set up with the method of stepwise discrimination analysis by using the TBB data from 2005 to 2008，to decide if a cloud cluster in the monitoring area will produce regional severe weather with the indicator superposition method. Based on the statistics of radar parameters during hail and gust events with thunderstorms for many years in Fujian， the radar parameter thresholds for severe convective weather， such as big hail， hail， and gust with thunderstorm， are decided.According to the height difference between the height of the 0 ℃ level and the storm top and that between the height of the -20 ℃ level and the storm top， the storms captured by CINRAD are chosen one by one，so to identify the area that will be influenced in the next one hour by storms that may bring about big hail， hail or gust weather.
4 Refined Estimating Method of Meteorological Elements over Complex Terrain on Low Latitude Plateau
2011, 39(5):552-557.
Abstract:
The variations of meteorological elements on the lowlatitude plateau are influenced by not only variation in atmospheric circulation but also the effects of topographic factors as elevation， slope， aspect， etc. Taking Yunnan as an example， a relation model is built by means of the precipitation data， temperature and dewpoint temperature data at 125 stations in Yunnan and topographic factor data of 125 stations， such as longitude， latitude， elevation， slope and aspect. The regression coefficients calculated by the multiple regression analysis are used in the regression model of random stations for testing. The fitting and observational results indicate that the regression model considering topographic factors is better in estimating meteorological elements. The fitting and observational data have high coherence， and the errors are in the tolerance range. The smaller the area calculated in the model and the more similar the topographic factors of the stations in the regression analysis， the better the simulated results of testing stations. The model allows to estimate the meteorological elements in the areas without observation. The results will contribute to the refined meteorological element forecasting for the lowlatitude plateau areas.
The variations of meteorological elements on the lowlatitude plateau are influenced by not only variation in atmospheric circulation but also the effects of topographic factors as elevation， slope， aspect， etc. Taking Yunnan as an example， a relation model is built by means of the precipitation data， temperature and dewpoint temperature data at 125 stations in Yunnan and topographic factor data of 125 stations， such as longitude， latitude， elevation， slope and aspect. The regression coefficients calculated by the multiple regression analysis are used in the regression model of random stations for testing. The fitting and observational results indicate that the regression model considering topographic factors is better in estimating meteorological elements. The fitting and observational data have high coherence， and the errors are in the tolerance range. The smaller the area calculated in the model and the more similar the topographic factors of the stations in the regression analysis， the better the simulated results of testing stations. The model allows to estimate the meteorological elements in the areas without observation. The results will contribute to the refined meteorological element forecasting for the lowlatitude plateau areas.
5 Heavy Rain Forecasting Models Based on Numerical Forecast Products during Flood Season for Sanming
2011, 39(5):558-561.
Abstract:
Heavy rainfall occurs frequently in Sanming of Fujian Province. Numerical models have played an active role in the improvement of the forecast accuracy of disastrous weather, such as heavy rainfall. An analysis is made of several physical quantities and daily rainfall in May and June from 2004 to 2008. The results indicate that 13 physical parameters, such as vertical velocity, vapor flux, relative humidity etc., have clear correlations with heavy rainfall during the flooding season in Sanming. Through combining these physical parameters together, the heavy rainfall numerical forecasting models for counties of Sanming are built and the verification indicates that the models performed well during the flooding season. The coverage of heavy rainfall forecasting is between 60% to 83% from 2004 to 2008, and that the 24hour forecasting accuracy of is 37.5% in 2009.
Heavy rainfall occurs frequently in Sanming of Fujian Province. Numerical models have played an active role in the improvement of the forecast accuracy of disastrous weather, such as heavy rainfall. An analysis is made of several physical quantities and daily rainfall in May and June from 2004 to 2008. The results indicate that 13 physical parameters, such as vertical velocity, vapor flux, relative humidity etc., have clear correlations with heavy rainfall during the flooding season in Sanming. Through combining these physical parameters together, the heavy rainfall numerical forecasting models for counties of Sanming are built and the verification indicates that the models performed well during the flooding season. The coverage of heavy rainfall forecasting is between 60% to 83% from 2004 to 2008, and that the 24hour forecasting accuracy of is 37.5% in 2009.
2011, 39(5):562-568.
Abstract:
Based on daily thunderstorm data， topography data， temperature data in Hainan for the period of 1966 to 2005 and radiosonde data from 2004 to 2006， the possible causes of the spatial and temporal distribution patterns of summer thunderstorm in Hainan are analyzed. The results show that: (1) In most parts of Hainan， thunderstorms mostly occur around afternoon time， while in Sanya thunderstorms happen mainly in night time. (2) The landsea breeze convection shear induces thunderstorms frequently in summer in north and west coast areas， and thunderstorm mainly occurs at afternoon， whose main reason is the convection of the local northerly from sea and largescale southerly. In Sanya， thunderstorms mainly happen at night because of the convection of the local northerly from landsea breeze and the southerly of the largescale environment in nighttime, but not in the daytime. (3) Thunderstorms are closely in associated with the local heat convection in the northern inner land and the western Hainan. Topography also shapes the spatial distribution of thunderstorms. The activities of thunderstorms in the Wuzhishan mountain area are more frequenlt than those in other areas around. Topography also affects the daily distribution of thunderstorms， mainly in north of the Wuzhishan mountain. (4) The seasonal distribution of thunderstorms in Hainan is mainly influenced by radiation in the Haikou area. (5) The heat fluxes can well account for the seasonal variation of thunderstorm activities in the Haikou area; and the anticorrelation between thunderstorm days and Bowen ratio (ratio of sensible to latent heat flux) of the wholeday heat flux is much higher than that at noon.
Based on daily thunderstorm data， topography data， temperature data in Hainan for the period of 1966 to 2005 and radiosonde data from 2004 to 2006， the possible causes of the spatial and temporal distribution patterns of summer thunderstorm in Hainan are analyzed. The results show that: (1) In most parts of Hainan， thunderstorms mostly occur around afternoon time， while in Sanya thunderstorms happen mainly in night time. (2) The landsea breeze convection shear induces thunderstorms frequently in summer in north and west coast areas， and thunderstorm mainly occurs at afternoon， whose main reason is the convection of the local northerly from sea and largescale southerly. In Sanya， thunderstorms mainly happen at night because of the convection of the local northerly from landsea breeze and the southerly of the largescale environment in nighttime, but not in the daytime. (3) Thunderstorms are closely in associated with the local heat convection in the northern inner land and the western Hainan. Topography also shapes the spatial distribution of thunderstorms. The activities of thunderstorms in the Wuzhishan mountain area are more frequenlt than those in other areas around. Topography also affects the daily distribution of thunderstorms， mainly in north of the Wuzhishan mountain. (4) The seasonal distribution of thunderstorms in Hainan is mainly influenced by radiation in the Haikou area. (5) The heat fluxes can well account for the seasonal variation of thunderstorm activities in the Haikou area; and the anticorrelation between thunderstorm days and Bowen ratio (ratio of sensible to latent heat flux) of the wholeday heat flux is much higher than that at noon.
2011, 39(5):569-574.
Abstract:
Using the International Satellite Cloud Climatology Project (ISCCP) monthly climate dataset, the climatological features of the total cloud amount over the South China Sea (SCS) are studied by applying the methods of EOF， wavelet， MannKendall mutation analysis, etc. The results show that: (1) The spatial characteristic field of the total cloud amount over SCS is the northtosouth type. The partition line is near 16°N. The distribution in the north part is along latitudes, most obviously affected by the diversity of thermodynamics, and the distribution in the south part is along the coastline, most obviously affected by the diversity between ocean and lands. (2) There is the remarkable seasonal feature in the distribution of total cloud amount. It is the northsouth type in winner and spring, but the westeast type in summer and autumn. The seasonal transition occurs at April and October. (3) The abnormal total cloud amounts correspond to the climate abnormal years. In the year of abnormally increased total cloud amount, there often occur drought disasters in South China, while in the abnormally reducing year, there occur flood disasters. (4) There exists strong periodic oscillation in total cloud amount with the period being five years and weak period oscillation with the period being two years. (5) The abrupt change of the total cloud amount happened in 2006, and afterwards the total cloud amount has been increasing.
Using the International Satellite Cloud Climatology Project (ISCCP) monthly climate dataset, the climatological features of the total cloud amount over the South China Sea (SCS) are studied by applying the methods of EOF， wavelet， MannKendall mutation analysis, etc. The results show that: (1) The spatial characteristic field of the total cloud amount over SCS is the northtosouth type. The partition line is near 16°N. The distribution in the north part is along latitudes, most obviously affected by the diversity of thermodynamics, and the distribution in the south part is along the coastline, most obviously affected by the diversity between ocean and lands. (2) There is the remarkable seasonal feature in the distribution of total cloud amount. It is the northsouth type in winner and spring, but the westeast type in summer and autumn. The seasonal transition occurs at April and October. (3) The abnormal total cloud amounts correspond to the climate abnormal years. In the year of abnormally increased total cloud amount, there often occur drought disasters in South China, while in the abnormally reducing year, there occur flood disasters. (4) There exists strong periodic oscillation in total cloud amount with the period being five years and weak period oscillation with the period being two years. (5) The abrupt change of the total cloud amount happened in 2006, and afterwards the total cloud amount has been increasing.
2011, 39(5):575-581.
Abstract:
With the methods of moving average and moving variance, an analysis is made of the temperature and precipitation over Jilin from 1951 to 2008. The results show that temperature over Jilin tends to ascend, with the average temperature ascending speed being 0.10 ℃/10a greater than that over the whole China, but 0.03 ℃/10a lower than that over Northeast China. Annual precipitation tends to decrease overall. Precipitation in spring shows a tendency of ascending, while precipitation in summer shows a decreasing tendency at present. There is no obvious change in precipitation in autumn, and there is a gradual increase tendency in snowy in winter. The variability of precipitations was obviously greater than that of temperature, and the variability of snow in winter was obviously greater than that of rainfall in summer. 〖JP2〗The analysis of NCEP data shows that the trough of East Asia lasted for a longer time in cold winters, while the trough of East Asia was weaker and a little eastward in warm winters. In wet years, the subtropical high over West Pacific was stronger and more northward, and there was a significant abnormal low in the areas around Lake Baikal, with the strong farther southern flow over Northeast China.
With the methods of moving average and moving variance, an analysis is made of the temperature and precipitation over Jilin from 1951 to 2008. The results show that temperature over Jilin tends to ascend, with the average temperature ascending speed being 0.10 ℃/10a greater than that over the whole China, but 0.03 ℃/10a lower than that over Northeast China. Annual precipitation tends to decrease overall. Precipitation in spring shows a tendency of ascending, while precipitation in summer shows a decreasing tendency at present. There is no obvious change in precipitation in autumn, and there is a gradual increase tendency in snowy in winter. The variability of precipitations was obviously greater than that of temperature, and the variability of snow in winter was obviously greater than that of rainfall in summer. 〖JP2〗The analysis of NCEP data shows that the trough of East Asia lasted for a longer time in cold winters, while the trough of East Asia was weaker and a little eastward in warm winters. In wet years, the subtropical high over West Pacific was stronger and more northward, and there was a significant abnormal low in the areas around Lake Baikal, with the strong farther southern flow over Northeast China.
2011, 39(5):582-586.
Abstract:
A soft (fuzzy) clustering algorithm is used to divide the precipitation region of China into n clusters according to the precipitation amount, based on the data from 160 meteorological stations of China in the last 50 years, with each station having a degree of belonging to clusters, as in the fuzzy logic, rather than belonging completely to just one cluster. The effect of clustering parameters on regionalization is examined. The further study of the conventional 5category precipitation regionalization shows that some regions allocated into a specific category do not exactly belong to one certain cluster, but has some similarity with the other regions, such as Tongliao and Dalian, etc. The soft (fuzzy) clustering algorithm can provide more information on the study of the factors affecting the precipitation to better describe the similarity, and be able to obtain the agreement with the results from other classification approaches after degradation.
A soft (fuzzy) clustering algorithm is used to divide the precipitation region of China into n clusters according to the precipitation amount, based on the data from 160 meteorological stations of China in the last 50 years, with each station having a degree of belonging to clusters, as in the fuzzy logic, rather than belonging completely to just one cluster. The effect of clustering parameters on regionalization is examined. The further study of the conventional 5category precipitation regionalization shows that some regions allocated into a specific category do not exactly belong to one certain cluster, but has some similarity with the other regions, such as Tongliao and Dalian, etc. The soft (fuzzy) clustering algorithm can provide more information on the study of the factors affecting the precipitation to better describe the similarity, and be able to obtain the agreement with the results from other classification approaches after degradation.
2011, 39(5):587-595.
Abstract:
According to the symmetrical characteristic of reflectivity factor, a simple methodcorrelation method is developed based on the reflectivity data from the radar network, which can locate the typhoon eye in the landing period with a high temporal resolution. Two cases, HAGUPIT and GONI, are chosen to examine the proposed algorithm. The results show that the method is better with the absolute error within 15 km compared with that of the Central Meteorological Office of CMA. Another method using radial velocity to locate the center of a typhoon is compared with this method. The advantages and disadvantages between the radial velocity method and the methodcorrelation method are analyzed: the former is restricted by the observing range and the processing of velocity aliasing; the later was restricted by the integrity of echo structure around the eye of a typhoon, but it can avoid dealing with the velocity aliasing. Considering various problems, it is better to use the way of humanmachine interaction to locate the center of a typhoon.
According to the symmetrical characteristic of reflectivity factor, a simple methodcorrelation method is developed based on the reflectivity data from the radar network, which can locate the typhoon eye in the landing period with a high temporal resolution. Two cases, HAGUPIT and GONI, are chosen to examine the proposed algorithm. The results show that the method is better with the absolute error within 15 km compared with that of the Central Meteorological Office of CMA. Another method using radial velocity to locate the center of a typhoon is compared with this method. The advantages and disadvantages between the radial velocity method and the methodcorrelation method are analyzed: the former is restricted by the observing range and the processing of velocity aliasing; the later was restricted by the integrity of echo structure around the eye of a typhoon, but it can avoid dealing with the velocity aliasing. Considering various problems, it is better to use the way of humanmachine interaction to locate the center of a typhoon.
2011, 39(5):596-602.
Abstract:
With the development of scientific technology, more and more methods are being used in automatic weather observation. However, presently weather phenomenon observation is mainly conducted manually. The researches are carried out on the present situation of automatic weather observation of weather phenomenon at home and abroad, trying to find the ways to realize the automatic observation of 34 weather phenomena based on their characteristics. The results show that the automatic recording of most weather phenomena can be realized. Besides, the approach to establish the WMO weather codes automatically is presented. In all of the 100 codes, 63 codes may be automatically established.
With the development of scientific technology, more and more methods are being used in automatic weather observation. However, presently weather phenomenon observation is mainly conducted manually. The researches are carried out on the present situation of automatic weather observation of weather phenomenon at home and abroad, trying to find the ways to realize the automatic observation of 34 weather phenomena based on their characteristics. The results show that the automatic recording of most weather phenomena can be realized. Besides, the approach to establish the WMO weather codes automatically is presented. In all of the 100 codes, 63 codes may be automatically established.
2011, 39(5):603-607.
Abstract:
Several instruments on the newgeneration greenhouse gases observing satellites are discussed and reviewed， especially GOSAT (Greenhouse Gases Observing Satellite) and OCO (Orbiting Carbon Observatory)， which were launched by NASA and JAXA， in order to follow the advances in the field of greenhouse gases observation in the world Taking GOSAT and OCO as examples， the configuration setting of the sensors onboarded is analyzed By contrasting and analyzing the sensors onboarded in new generation satellites and traditional ones， some suggestions are given on the condition of lacking greenhouse gases observing data
Several instruments on the newgeneration greenhouse gases observing satellites are discussed and reviewed， especially GOSAT (Greenhouse Gases Observing Satellite) and OCO (Orbiting Carbon Observatory)， which were launched by NASA and JAXA， in order to follow the advances in the field of greenhouse gases observation in the world Taking GOSAT and OCO as examples， the configuration setting of the sensors onboarded is analyzed By contrasting and analyzing the sensors onboarded in new generation satellites and traditional ones， some suggestions are given on the condition of lacking greenhouse gases observing data
2011, 39(5):608-614.
Abstract:
The correctness and accuracy of observation data of Xband dual polarization Doppler weather radar are important prerequisites for subsequent application researches. The theoretical meaning of differential reflectivity, correlation coefficient, and differential phase shift are analyzed, and in combination with the experiences from several observation activities, the values of various polarimetric products in pure precipitation are studied and verified. Meanwhile, the polarimetric parameters for indicating the presence of hardware attenuation and faults are studied. The verification procedures of each parameter before observation are described. The TSG (Test Signal Generator) is used to ensure the consistency between horizontal and vertical channels.
The correctness and accuracy of observation data of Xband dual polarization Doppler weather radar are important prerequisites for subsequent application researches. The theoretical meaning of differential reflectivity, correlation coefficient, and differential phase shift are analyzed, and in combination with the experiences from several observation activities, the values of various polarimetric products in pure precipitation are studied and verified. Meanwhile, the polarimetric parameters for indicating the presence of hardware attenuation and faults are studied. The verification procedures of each parameter before observation are described. The TSG (Test Signal Generator) is used to ensure the consistency between horizontal and vertical channels.
2011, 39(5):615-619.
Abstract:
While processing the data obtained by three dimensional sonic anemometers, it is skillful to calculate the wind direction. Based on the difference between the coordinate system of an instrument and the geographic coordinate system, a method for calculating wind direction is presented. The data collected from the Xinlinhot flux tower is used to validate the method. Comparing the wind direction calculated by the method with that from observed, the distributions of the two data sets match well and there is a high correlation between them with the correlation coefficient being 0.97. It is suggested that the method can be used for reference in processing and applying the data measured by sonic anemometers.
While processing the data obtained by three dimensional sonic anemometers, it is skillful to calculate the wind direction. Based on the difference between the coordinate system of an instrument and the geographic coordinate system, a method for calculating wind direction is presented. The data collected from the Xinlinhot flux tower is used to validate the method. Comparing the wind direction calculated by the method with that from observed, the distributions of the two data sets match well and there is a high correlation between them with the correlation coefficient being 0.97. It is suggested that the method can be used for reference in processing and applying the data measured by sonic anemometers.
2011, 39(5):620-624.
Abstract:
On the basis of the idea that averaged wind direction calculation must reflect the correlation between former and latter wind directions. It is suggested that the trapezoidal mean method is better in calculating the averaged wind direction than the arithmetical average method. The analysis indicates that the trapezoidal mean method is equivalent with the arithmetical average method in dealing with observation errors， but better in dealing with fitting errors. The statistics show that the trapezoidal mean method and arithmetical average method both pass the WatsonWilliams test， but the trapezoidal mean method is more accurate in terms of average deviation and reliability.
On the basis of the idea that averaged wind direction calculation must reflect the correlation between former and latter wind directions. It is suggested that the trapezoidal mean method is better in calculating the averaged wind direction than the arithmetical average method. The analysis indicates that the trapezoidal mean method is equivalent with the arithmetical average method in dealing with observation errors， but better in dealing with fitting errors. The statistics show that the trapezoidal mean method and arithmetical average method both pass the WatsonWilliams test， but the trapezoidal mean method is more accurate in terms of average deviation and reliability.
2011, 39(5):625-628.
Abstract:
The data acquisition software of FY3 meteorological satellite is an import part of the FY3 computer and network system, and there are occasionally abnormal data in data acquisition in operation. The abnormal data affect not only the accuracy of level 0 data but the stability of the software in operation. The data acquisition software adopts a simple and practical faulttolerant design on the basis of data recognition, classification, and processing. The implementation of the faulttolerance approach has been realized in the operational systems. The application practice shows that it can effectively detect and discriminate a variety of abnormal data, deal with the classification, and thereby significantly improve the software’s capability of fault tolerance.
The data acquisition software of FY3 meteorological satellite is an import part of the FY3 computer and network system, and there are occasionally abnormal data in data acquisition in operation. The abnormal data affect not only the accuracy of level 0 data but the stability of the software in operation. The data acquisition software adopts a simple and practical faulttolerant design on the basis of data recognition, classification, and processing. The implementation of the faulttolerance approach has been realized in the operational systems. The application practice shows that it can effectively detect and discriminate a variety of abnormal data, deal with the classification, and thereby significantly improve the software’s capability of fault tolerance.
2011, 39(5):629-634.
Abstract:
Network security is one important factor that affecting the performance and functions of a communications network. The construction of the network security system for Qingdao Meteorological Service is introduced from the following aspects: the redundancy of the communication line， the central unit of heat backup, the application of network security devices, safety control strategy, and the regulations of user and administrator security management. The implementation of key technologies, such as firewall configuration, the hot standby of the core switch, and the access control of the key server, is described in detail. Some suggestions are presented for the construction of the network security systems for the citylevel meteorological services.
Network security is one important factor that affecting the performance and functions of a communications network. The construction of the network security system for Qingdao Meteorological Service is introduced from the following aspects: the redundancy of the communication line， the central unit of heat backup, the application of network security devices, safety control strategy, and the regulations of user and administrator security management. The implementation of key technologies, such as firewall configuration, the hot standby of the core switch, and the access control of the key server, is described in detail. Some suggestions are presented for the construction of the network security systems for the citylevel meteorological services.
2011, 39(5):635-640.
Abstract:
The System of Ningxia Drought Monitoring and Early Warning considers three inflenecing fators:disasterinducing environment， disasterinducing factor， and hazardbearing body. The input data of the system include GIS data， remote sensing data， and data on the characteristics of crops and the properties of soil， and early warning is performed by means of the integrated model. The system is discussed from the five aspects of system framework model， system architecture， data processing， data access， and system functionality. Based on the current advancement in this field， the system developed drought monitoring and prediction models and established the integrated operational system of data collection， processing， and output. The application proved that the system is applicable and efficient.
The System of Ningxia Drought Monitoring and Early Warning considers three inflenecing fators:disasterinducing environment， disasterinducing factor， and hazardbearing body. The input data of the system include GIS data， remote sensing data， and data on the characteristics of crops and the properties of soil， and early warning is performed by means of the integrated model. The system is discussed from the five aspects of system framework model， system architecture， data processing， data access， and system functionality. Based on the current advancement in this field， the system developed drought monitoring and prediction models and established the integrated operational system of data collection， processing， and output. The application proved that the system is applicable and efficient.
2011, 39(5):641-645.
Abstract:
According to the workflow model of meteorological service products for decisionmaking purposes in Sichuan province, by the toolboxt in ArcGIS92 Desktop, combined with the MSPGS component developed by CMA, the second development was conducted to meet the demands of meteorological services for decision making over the Sichuan province. The workflow model of meteorological service products for spatial analysis was established, which is applied in batch processing and produces successfully such meteorological service products as temperature, precipitation, visibility, etc. The developed software can effectively reduce time and monetary costs, and enhance the effectiveness and pertinence of meteorological service products for decision making.
According to the workflow model of meteorological service products for decisionmaking purposes in Sichuan province, by the toolboxt in ArcGIS92 Desktop, combined with the MSPGS component developed by CMA, the second development was conducted to meet the demands of meteorological services for decision making over the Sichuan province. The workflow model of meteorological service products for spatial analysis was established, which is applied in batch processing and produces successfully such meteorological service products as temperature, precipitation, visibility, etc. The developed software can effectively reduce time and monetary costs, and enhance the effectiveness and pertinence of meteorological service products for decision making.
2011, 39(5):646-649.
Abstract:
An introduction is made to the information exchange mode of receiving and sending information in cell broadcast and the principles of Web Service. Through analyzing the working flow of sending information in cell broadcast towards some given areas or cell grids and the methods of receiving the current population distribution data within the grids, it is proved that the method of receiving and sending information in cell broadcast with Web Service is feasible and efficient. The application and prospects of receiving and sending meteorological service information in cell broadcast with the Web Service technology in the meteorological field are also discussed.
An introduction is made to the information exchange mode of receiving and sending information in cell broadcast and the principles of Web Service. Through analyzing the working flow of sending information in cell broadcast towards some given areas or cell grids and the methods of receiving the current population distribution data within the grids, it is proved that the method of receiving and sending information in cell broadcast with Web Service is feasible and efficient. The application and prospects of receiving and sending meteorological service information in cell broadcast with the Web Service technology in the meteorological field are also discussed.
2011, 39(5):650-655.
Abstract:
In order to determine the protection level and security spacing of lightning electromagnetic pulses around gas stations， based on the characteristics of lightning current and the explosive nature of oil combustion， the effects of the lightning electromagnetic field and the damage range of fire and explosion resulted from a nearby lightning stroke or a direct lightning stroke around the gas station are analyzed with the lightning monitoring data of the ADTD system， through assessing the lightning safety of the Chongqing Huaxing gas station. The results indicate that， if the distance between devices and station is 33.54 m to 41 m， the impact of the electromagnetic field generated by a lightning stroke can be neglected when the station is stroked by lightning; the using of the shielding grids less than 5 m×5 m is a condition of safety for the electromagnetic field of LPZ1 when the station is stroked by lightning; the distances of damaging range are 5.22 m and 138.95 m， respectively， when the station is on fire or explosive because of lightning. These provide a theoretical basis for the lightning protection and construction planning of a gas station and the surrounding area.
In order to determine the protection level and security spacing of lightning electromagnetic pulses around gas stations， based on the characteristics of lightning current and the explosive nature of oil combustion， the effects of the lightning electromagnetic field and the damage range of fire and explosion resulted from a nearby lightning stroke or a direct lightning stroke around the gas station are analyzed with the lightning monitoring data of the ADTD system， through assessing the lightning safety of the Chongqing Huaxing gas station. The results indicate that， if the distance between devices and station is 33.54 m to 41 m， the impact of the electromagnetic field generated by a lightning stroke can be neglected when the station is stroked by lightning; the using of the shielding grids less than 5 m×5 m is a condition of safety for the electromagnetic field of LPZ1 when the station is stroked by lightning; the distances of damaging range are 5.22 m and 138.95 m， respectively， when the station is on fire or explosive because of lightning. These provide a theoretical basis for the lightning protection and construction planning of a gas station and the surrounding area.
2011, 39(5):656-660.
Abstract:
Based on the airborne observation data obtained by the Particle Measuring System (PMS) in Sichuan Province on 24 October 2008, the characteristics of the autumn lowlevel warm clouds without ground precipitation are discussed. The results show that: (1) The lowlevel warm clouds were composed mainly of small cloud droplets, and the number concentration of large cloud droplets was relatively low, and the precipitation particles in the clouds were very few.(2) The liquid water content, number concentration and diameter of small cloud droplets were inhomogeneous in horizontal direction.(3) There was a positive correlation between the liquid water content and the mean diameter of small cloud droplets.(4) Compared with the upper layer of the clouds, there were less small cloud droplets and large cloud droplets (small raindrops) and fewer large raindrops in the cloud base.(5) Because of the small cloud liquid water content, thin cloud thickness, difficult condensation growth of cloud droplets, inactive coalescence growth, and short path and time of collision growth, there was no precipitation reaching the ground.
Based on the airborne observation data obtained by the Particle Measuring System (PMS) in Sichuan Province on 24 October 2008, the characteristics of the autumn lowlevel warm clouds without ground precipitation are discussed. The results show that: (1) The lowlevel warm clouds were composed mainly of small cloud droplets, and the number concentration of large cloud droplets was relatively low, and the precipitation particles in the clouds were very few.(2) The liquid water content, number concentration and diameter of small cloud droplets were inhomogeneous in horizontal direction.(3) There was a positive correlation between the liquid water content and the mean diameter of small cloud droplets.(4) Compared with the upper layer of the clouds, there were less small cloud droplets and large cloud droplets (small raindrops) and fewer large raindrops in the cloud base.(5) Because of the small cloud liquid water content, thin cloud thickness, difficult condensation growth of cloud droplets, inactive coalescence growth, and short path and time of collision growth, there was no precipitation reaching the ground.
2011, 39(5):661-665.
Abstract:
Based on the Rayleigh scattering theory， the model of specific inductive capacity of liquid water， and fogdrop size distribution， the transmission characteristics of individual cloud and fogdrop particles and fogdrop cluster are analyzed. The results show that the electrical length is the main factor that affects the electromagnetic transmission characteristics of clouds and fogdrops. The transmission characteristics of advection fog size distribution are stronger than those of radiation fog size distribution. The effect of incidence wave frequency on the transmission of fogdrop clusters is the strongest， water content the second， and temperature relatively the weakest. The results have great significance in improving precipitation precision and decreasing satellite communication errors.
Based on the Rayleigh scattering theory， the model of specific inductive capacity of liquid water， and fogdrop size distribution， the transmission characteristics of individual cloud and fogdrop particles and fogdrop cluster are analyzed. The results show that the electrical length is the main factor that affects the electromagnetic transmission characteristics of clouds and fogdrops. The transmission characteristics of advection fog size distribution are stronger than those of radiation fog size distribution. The effect of incidence wave frequency on the transmission of fogdrop clusters is the strongest， water content the second， and temperature relatively the weakest. The results have great significance in improving precipitation precision and decreasing satellite communication errors.
2011, 39(5):666-669.
Abstract:
A detailed description is conducted on the maintenance and quality control of File A and File J (contains surface meteorological information), by means of the intelligent checking approaches, such as the format check, file maintenance in the operational software of ground meteorological observation and reporting, taking the computerized data processing of the National Meteorological Observation Skill Competition as an example. In combination with the experiences from manual checking, a comprehensive analysis is made of the rational coordination among manual observation items, such as clouds, visibility, weather phenomena, etc., as well as problems appearing in the ground information files, such as suspicious data, missing data, and data format error. Some technical hints and solutions for data checking are presented.
A detailed description is conducted on the maintenance and quality control of File A and File J (contains surface meteorological information), by means of the intelligent checking approaches, such as the format check, file maintenance in the operational software of ground meteorological observation and reporting, taking the computerized data processing of the National Meteorological Observation Skill Competition as an example. In combination with the experiences from manual checking, a comprehensive analysis is made of the rational coordination among manual observation items, such as clouds, visibility, weather phenomena, etc., as well as problems appearing in the ground information files, such as suspicious data, missing data, and data format error. Some technical hints and solutions for data checking are presented.
2011, 39(5):670-672.
Abstract:
The widely used rain gauges at present include basically telemetering rainfall sensors for automatic weather stations， doubleskip telemetering raingauges， siphonage raingauges， common raingauges and so on. By means of the rainfall data in recent years from Chaoyang Station of Beijing， the causes of errors in the measurements of various raingauges under different rainfall conditions are analyzed. It is found out that although the working principles of the instruments are about the same， the performance may be different obviously because of their capability differences and unpredictable breakdowns. As the rainfall intensity may vary suddenly， it is inevitable for raingauges to produce measuring errors. Some suggestions are proposed， which can provide reference for precipitation metrical data analysis.
The widely used rain gauges at present include basically telemetering rainfall sensors for automatic weather stations， doubleskip telemetering raingauges， siphonage raingauges， common raingauges and so on. By means of the rainfall data in recent years from Chaoyang Station of Beijing， the causes of errors in the measurements of various raingauges under different rainfall conditions are analyzed. It is found out that although the working principles of the instruments are about the same， the performance may be different obviously because of their capability differences and unpredictable breakdowns. As the rainfall intensity may vary suddenly， it is inevitable for raingauges to produce measuring errors. Some suggestions are proposed， which can provide reference for precipitation metrical data analysis.
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.