Volume 41,Issue 2,2013 Table of Contents
2013, 41(2):207-211.
Abstract:
Geostationary meteorological satellites are an important means for monitoring the land surface, atmosphere, ocean, and space environment, widely used in meteorological, agricultural, space, and environmental fields，providing a large amount of scientific data for researchers The design and implementation of the FY2 receiver are described，mainly including the secondary frequency conversion method, digital demodulation based on HSP50110/HSP50210, differential decoding, signal indicating, key parameter settings, and so on Taking the bit error rate as direct indicator for evaluating the performance of the receiver， in combination with the images, a performance evaluation of the receiver is conducted, and the results show that the designed receiver has a low error rate, and provides satisfactory images.
Geostationary meteorological satellites are an important means for monitoring the land surface, atmosphere, ocean, and space environment, widely used in meteorological, agricultural, space, and environmental fields，providing a large amount of scientific data for researchers The design and implementation of the FY2 receiver are described，mainly including the secondary frequency conversion method, digital demodulation based on HSP50110/HSP50210, differential decoding, signal indicating, key parameter settings, and so on Taking the bit error rate as direct indicator for evaluating the performance of the receiver， in combination with the images, a performance evaluation of the receiver is conducted, and the results show that the designed receiver has a low error rate, and provides satisfactory images.
2013, 41(2):212-216.
Abstract:
To reveal the influence of artificial buildings on observed data effectively, it is of importance to identify the ratio of the building area around a meteorological station. The software was developed in order to identify the building area based on the obtained satellite remote sensing images. The proposed software is developed in the Windows system and can provide reliable data analysis for meteorological researches. Hundreds of satellite remote sensing images are experimented using the proposed software. The results indicate that the proposed software achieves higher precision, reliability and efficiency compared with the manual statistical methods.
To reveal the influence of artificial buildings on observed data effectively, it is of importance to identify the ratio of the building area around a meteorological station. The software was developed in order to identify the building area based on the obtained satellite remote sensing images. The proposed software is developed in the Windows system and can provide reliable data analysis for meteorological researches. Hundreds of satellite remote sensing images are experimented using the proposed software. The results indicate that the proposed software achieves higher precision, reliability and efficiency compared with the manual statistical methods.
2013, 41(2):217-223.
Abstract:
The Local Standard Deviation (LSD) images play an important role in the spatial coherence test with satellite imagery. The traditional sliding window approach, however, is very slow in computing LSD owing to its longer iteration times during operation. Especially, in the case of large imagery and small size of the sliding window, the operation is remarkably time consuming. A fast algorithm for calculating LSD is presented based on the idea of matrix operation. The first step of the algorithm is to shift the raw image matrix in different directions to generate a series of new image matrices. Then, LSD is calculated by using mathematic operation on the shifted image matrices generated in firs step. Finally, the NOAA 16/AVHRR images measured on January 1, 2005 are used as an example to calculate the LSD of Channel 4 brightness temperature by using the fast algorithm presented and the sliding window approach, respectively. The results show that the compute efficiency of the fast algorithm is evidently higher than that of the sliding window approach.
The Local Standard Deviation (LSD) images play an important role in the spatial coherence test with satellite imagery. The traditional sliding window approach, however, is very slow in computing LSD owing to its longer iteration times during operation. Especially, in the case of large imagery and small size of the sliding window, the operation is remarkably time consuming. A fast algorithm for calculating LSD is presented based on the idea of matrix operation. The first step of the algorithm is to shift the raw image matrix in different directions to generate a series of new image matrices. Then, LSD is calculated by using mathematic operation on the shifted image matrices generated in firs step. Finally, the NOAA 16/AVHRR images measured on January 1, 2005 are used as an example to calculate the LSD of Channel 4 brightness temperature by using the fast algorithm presented and the sliding window approach, respectively. The results show that the compute efficiency of the fast algorithm is evidently higher than that of the sliding window approach.
2013, 41(2):224-230.
Abstract:
In the summers of 2009 and 2010, observation experiments of lightning flashes striking on tall buildings to the southeast of Guangdong Provincial Meteorological Service were conducted. The video recording data obtained by ordinary cameras were processed and analyzed. Based on the characteristic analysis of pixels number distribution with different brightness variation values, a video data processing program was devised to extract lightning pictures from video recording data. The characteristics of natural lightning on tall buildings in the viewing range were statistically analyzed. The results show that the mean duration of 87 natural cloud to ground lightning striking on tall buildings in Guangzhou is 348 ms. By comparing the lightning flashes striking on buildings higher than 500 m with those with heights from 100 m to 500 m, the average number for the former is significantly larger than that of the latter, and the mean duration of the former is longer. Some video images of “spider” flash and long discharge are also presented.
In the summers of 2009 and 2010, observation experiments of lightning flashes striking on tall buildings to the southeast of Guangdong Provincial Meteorological Service were conducted. The video recording data obtained by ordinary cameras were processed and analyzed. Based on the characteristic analysis of pixels number distribution with different brightness variation values, a video data processing program was devised to extract lightning pictures from video recording data. The characteristics of natural lightning on tall buildings in the viewing range were statistically analyzed. The results show that the mean duration of 87 natural cloud to ground lightning striking on tall buildings in Guangzhou is 348 ms. By comparing the lightning flashes striking on buildings higher than 500 m with those with heights from 100 m to 500 m, the average number for the former is significantly larger than that of the latter, and the mean duration of the former is longer. Some video images of “spider” flash and long discharge are also presented.
2013, 41(2):231-235.
Abstract:
The operation monitoring system of mesoscale automatic weather stations is a real time operational system for guaranteeing the stable and reliable operation of the observation network The system is based on the multi thread distributed data processing technology, adopting a mode of two level deployment, multi level application, and multi sharing, taking fully the advantages of the Internet and CMA LAN to realize the real time monitoring of the operation status, observation data quality, and equipment maintenance, as well as the technical support of the observation network The logic structure, technique structure, main technology roadmap, main functions and the key techniques of the system are described comprehensively in detail
The operation monitoring system of mesoscale automatic weather stations is a real time operational system for guaranteeing the stable and reliable operation of the observation network The system is based on the multi thread distributed data processing technology, adopting a mode of two level deployment, multi level application, and multi sharing, taking fully the advantages of the Internet and CMA LAN to realize the real time monitoring of the operation status, observation data quality, and equipment maintenance, as well as the technical support of the observation network The logic structure, technique structure, main technology roadmap, main functions and the key techniques of the system are described comprehensively in detail
2013, 41(2):236-241.
Abstract:
Concerning various kinds of low visibility weather phenomena and based on the existing dichromatic atmospheric scattering model, a modified calculating method of dichromatic model is proposed, to range weather phenomenon via revising the atmospheric scattering direction, improving the calculating method of vector angles and adding humidity parameter information The improved algorithm model has higher stability, considering that the scatter light direction is not all consistent and pixels have three dimensional character in the RGB space Embedding the algorithm into the model and computing the corresponding eigenvalues, these weather phenomena can be recognized through the empirical thresholds By improving the calculating method and processing the seasonal data of Columbia University and two month data of Zhangye Observatory, it is shown that the improved method is excellent in identifying various kinds of low visibility weather phenomena, such as fog, haze, dust blowing, dust floating, and sand storm, whose total identification rates for the above two regions are 732% , 905%, respectively.
Concerning various kinds of low visibility weather phenomena and based on the existing dichromatic atmospheric scattering model, a modified calculating method of dichromatic model is proposed, to range weather phenomenon via revising the atmospheric scattering direction, improving the calculating method of vector angles and adding humidity parameter information The improved algorithm model has higher stability, considering that the scatter light direction is not all consistent and pixels have three dimensional character in the RGB space Embedding the algorithm into the model and computing the corresponding eigenvalues, these weather phenomena can be recognized through the empirical thresholds By improving the calculating method and processing the seasonal data of Columbia University and two month data of Zhangye Observatory, it is shown that the improved method is excellent in identifying various kinds of low visibility weather phenomena, such as fog, haze, dust blowing, dust floating, and sand storm, whose total identification rates for the above two regions are 732% , 905%, respectively.
2013, 41(2):242-249.
Abstract:
A severe hail event occurred in the south of Shenyang in 21 August 20011 is studied by using automatic weather station data, weather map, T lgp map, mosaic and ROSE products, and the evolvement and structure of the severe hail are analyzed in detail. The results demonstrate that the severe hail occurred under the background of an upper level trough and wind convergence. The characteristics of CAPE, vertical wind shear, and radar echoes all indicate that there were favorable conditions for the occurrence of severe hail. Some indexes are put forward for severe hail nowcasting by means of derived radar products before and after the hail.
A severe hail event occurred in the south of Shenyang in 21 August 20011 is studied by using automatic weather station data, weather map, T lgp map, mosaic and ROSE products, and the evolvement and structure of the severe hail are analyzed in detail. The results demonstrate that the severe hail occurred under the background of an upper level trough and wind convergence. The characteristics of CAPE, vertical wind shear, and radar echoes all indicate that there were favorable conditions for the occurrence of severe hail. Some indexes are put forward for severe hail nowcasting by means of derived radar products before and after the hail.
2013, 41(2):250-253.
Abstract:
By using the back scanning charging technique, the charging switch 3A10 and charging transformer 3A7T2 can provide modulator pulse charging energy to the PFN in CINRAD/S. Although the technique has many advantages, it is hard to use in the maintenance of radar stations, because of its complexity in hardware and relatively high failure rate in routine operation. The operating principles of Switch 3A10 is discussed, and hardware analyses and the functional block diagram of Switch 3A10A1 are given in details. A number of key point waveforms are introduced. According to the practical experiences from radar system maintenance, in combination with the relevant alarm massages, some suggestions about troubleshooting and maintenance methods are discussed and summarized.
By using the back scanning charging technique, the charging switch 3A10 and charging transformer 3A7T2 can provide modulator pulse charging energy to the PFN in CINRAD/S. Although the technique has many advantages, it is hard to use in the maintenance of radar stations, because of its complexity in hardware and relatively high failure rate in routine operation. The operating principles of Switch 3A10 is discussed, and hardware analyses and the functional block diagram of Switch 3A10A1 are given in details. A number of key point waveforms are introduced. According to the practical experiences from radar system maintenance, in combination with the relevant alarm massages, some suggestions about troubleshooting and maintenance methods are discussed and summarized.
2013, 41(2):254-258.
Abstract:
The GTS1 type radiosonde has been used in the radiosonede sounding network of the China Meteorological Administration for 10 years, and its technology has become lagged, so technical improvements are urgently needed. On the basis of the original technical structure, in September 2010, the test of the improved radiosonde was carried out at Yangjiang Station, and in December 2011, the test of temperature radiation correction algorithm to improve was conducted at the same place. The results show that the temperature from the improved radiosonde at night has a deviation of about 01 ℃, and no more than 03 ℃ in daytime. The measured pressure is smaller than that from the RS92 radiosonde, whose accuracy is better than the GTS1 radiosonde. The humidity sensor is responsive, and the measured results have good consistency with those from RS92 The bias between them is basically less than 5%.
The GTS1 type radiosonde has been used in the radiosonede sounding network of the China Meteorological Administration for 10 years, and its technology has become lagged, so technical improvements are urgently needed. On the basis of the original technical structure, in September 2010, the test of the improved radiosonde was carried out at Yangjiang Station, and in December 2011, the test of temperature radiation correction algorithm to improve was conducted at the same place. The results show that the temperature from the improved radiosonde at night has a deviation of about 01 ℃, and no more than 03 ℃ in daytime. The measured pressure is smaller than that from the RS92 radiosonde, whose accuracy is better than the GTS1 radiosonde. The humidity sensor is responsive, and the measured results have good consistency with those from RS92 The bias between them is basically less than 5%.
2013, 41(2):259-263.
Abstract:
The principles, design schemes, and usages of architectural sunshine measurement instrument are described. Through observing the occluders on the diurnal circle of the sun in the daytime by the instrument display, the time duration obscured by each occluder is measured by the encoder. As the mechanical devices in the instrument are used to simulate the dynamic relationship between changes in sun earth azimuth, the monitor camera is ensured always scanning along the diurnal circle of the sun (instrument patent No: 2011200073019). Comparison test shows that when using the 1000 pulse encoder, with 4 fold frequency and a resolution of 216 s, the measurement error is less than 15 min. The instrument is compact, portable, and easy to use, and the measurement cost is greatly reduced. This instrument can be used in various sunshine measurements, such as the sunshine duration measuring related to sunshine dispute arbitration, architectural sunshine, and ambient occlusion angle for meteorological and radar stations.
The principles, design schemes, and usages of architectural sunshine measurement instrument are described. Through observing the occluders on the diurnal circle of the sun in the daytime by the instrument display, the time duration obscured by each occluder is measured by the encoder. As the mechanical devices in the instrument are used to simulate the dynamic relationship between changes in sun earth azimuth, the monitor camera is ensured always scanning along the diurnal circle of the sun (instrument patent No: 2011200073019). Comparison test shows that when using the 1000 pulse encoder, with 4 fold frequency and a resolution of 216 s, the measurement error is less than 15 min. The instrument is compact, portable, and easy to use, and the measurement cost is greatly reduced. This instrument can be used in various sunshine measurements, such as the sunshine duration measuring related to sunshine dispute arbitration, architectural sunshine, and ambient occlusion angle for meteorological and radar stations.
2013, 41(2):264-269.
Abstract:
The structural principles of the sensor in “Digital Network Hail Rain Tester” (DNHRT) are introduced. Based on the principles of buoyancy, tipping bucket rain gauge measurement, computer recording, and network transmission, the measurement errors between the theoretical and experimental values are simulated, and such technical issues as the causes of the errors, field observation regulations, and evaporation compensation revision are discussed. The tests reveal that DNHRT has a reasonable and reliable structure and good performance; the experimental results are stable and have negligible measurement errors. The field data indicate that the measured rainfall difference between DNHRT and automatic weather station observations is in an acceptable range. DNHRT has the advantage of real time monitoring of extreme hail events, for it can measure hail and rain separately at the same time, so can play an vital role in the assessment of hail disasters on wild fruits and crops. It can be widely used in the field monitoring network of disasters in agriculture and forestry with the same modernization level as telemetry rain gauges and other remote sensing devices of meteorological elements.
The structural principles of the sensor in “Digital Network Hail Rain Tester” (DNHRT) are introduced. Based on the principles of buoyancy, tipping bucket rain gauge measurement, computer recording, and network transmission, the measurement errors between the theoretical and experimental values are simulated, and such technical issues as the causes of the errors, field observation regulations, and evaporation compensation revision are discussed. The tests reveal that DNHRT has a reasonable and reliable structure and good performance; the experimental results are stable and have negligible measurement errors. The field data indicate that the measured rainfall difference between DNHRT and automatic weather station observations is in an acceptable range. DNHRT has the advantage of real time monitoring of extreme hail events, for it can measure hail and rain separately at the same time, so can play an vital role in the assessment of hail disasters on wild fruits and crops. It can be widely used in the field monitoring network of disasters in agriculture and forestry with the same modernization level as telemetry rain gauges and other remote sensing devices of meteorological elements.
2013, 41(2):270-273.
Abstract:
By analyzing the observed temperature from a small and a large louvered screen from March 2009 to February 2010, it is found that the mean monthly temperature and mean annual temperature from a small louvered screen are generally lower than those from a large louvered screen, but this difference is less, mostly less than 02 ℃. 〖JP2〗The mean maximum temperature has large differences in winter, with the maximum being 04 ℃. The difference of monthly extreme temperature is large and unstable, within ± 1 ℃. The differences of daily extreme temperature are more centralized, with the maximum temperature mainly distributed within -065 to 014 ℃, the minimum temperature within -04 to 002 ℃. The daily variation trends of temperature are about the same. The large louvered screen has faster heating speed and rapider reducing temperature at the stage of dramatic change. The difference is positive at cooling phase, and negative at heating stage; the maximum difference appears at 09:00 and 12:00 No matter under what cloud cover or wind velocity, the mean difference of air temperature in the two kinds of screens is almost within 02 ℃.
By analyzing the observed temperature from a small and a large louvered screen from March 2009 to February 2010, it is found that the mean monthly temperature and mean annual temperature from a small louvered screen are generally lower than those from a large louvered screen, but this difference is less, mostly less than 02 ℃. 〖JP2〗The mean maximum temperature has large differences in winter, with the maximum being 04 ℃. The difference of monthly extreme temperature is large and unstable, within ± 1 ℃. The differences of daily extreme temperature are more centralized, with the maximum temperature mainly distributed within -065 to 014 ℃, the minimum temperature within -04 to 002 ℃. The daily variation trends of temperature are about the same. The large louvered screen has faster heating speed and rapider reducing temperature at the stage of dramatic change. The difference is positive at cooling phase, and negative at heating stage; the maximum difference appears at 09:00 and 12:00 No matter under what cloud cover or wind velocity, the mean difference of air temperature in the two kinds of screens is almost within 02 ℃.
2013, 41(2):274-277.
Abstract:
The “Global Eyes” video monitoring system is based on the remote transmission and processing system of networking digital images and has been applied in many fields. The “Global Eyes” video monitoring system for meteorological service is designed and realized based on the Google Maps. It achieves the “Global Eyes” video monitoring for meteorological services based on the B/S mode flexibly, combines video control technology and Google Maps, and provides rich specific visualized images for meteorological services, which has been applied in meteorological services, 〖JP2〗such as meteorological websites, meteorological films and videos, and multimedia meteorological electronic display screens. The application of “Global Eyes” video monitoring system to meteorological services has great significance for disaster prevention and mitigation, for it provides real time video images and the stable, reliable and effective meteorological data for meteorological services and increases weather service capability in flood control.
The “Global Eyes” video monitoring system is based on the remote transmission and processing system of networking digital images and has been applied in many fields. The “Global Eyes” video monitoring system for meteorological service is designed and realized based on the Google Maps. It achieves the “Global Eyes” video monitoring for meteorological services based on the B/S mode flexibly, combines video control technology and Google Maps, and provides rich specific visualized images for meteorological services, which has been applied in meteorological services, 〖JP2〗such as meteorological websites, meteorological films and videos, and multimedia meteorological electronic display screens. The application of “Global Eyes” video monitoring system to meteorological services has great significance for disaster prevention and mitigation, for it provides real time video images and the stable, reliable and effective meteorological data for meteorological services and increases weather service capability in flood control.
2013, 41(2):278-281.
Abstract:
An automatic microclimate observation system set up in a rice field is introduced. Its performance is evaluated in respect of the practicality, data arrival rate, and equipment reliability. The result shows that this system can provide timely and accurate microclimate information without delay. The data arrival rate is over 95% and the equipment reliability beyond 85% with a low proportion of format errors and abnormal records. Lightning disasters is the main factor influencing the stability and reliability of the system. Therefore, the practical advantage of this system is obvious in the field of agro meteorological research and services.
An automatic microclimate observation system set up in a rice field is introduced. Its performance is evaluated in respect of the practicality, data arrival rate, and equipment reliability. The result shows that this system can provide timely and accurate microclimate information without delay. The data arrival rate is over 95% and the equipment reliability beyond 85% with a low proportion of format errors and abnormal records. Lightning disasters is the main factor influencing the stability and reliability of the system. Therefore, the practical advantage of this system is obvious in the field of agro meteorological research and services.
2013, 41(2):282-285.
Abstract:
To satisfy the needs of meteorological modernization construction and to ensure the safety of meteorological record files for surface automatic meteorological stations, the characteristics and types of electronic documents are discussed. The adequate formats of the electronic documents are important for the safety of electronic files. There are two types of the document formats: plain text files and database files, of which the characteristics are analyzed repectively. It is suggested that pure text documents are safer than dafabase files, while database files are more convenient to use than pure text files. Thus, if both types are copied, the data from automatic meteorological stations will be safe and convenient to use.
To satisfy the needs of meteorological modernization construction and to ensure the safety of meteorological record files for surface automatic meteorological stations, the characteristics and types of electronic documents are discussed. The adequate formats of the electronic documents are important for the safety of electronic files. There are two types of the document formats: plain text files and database files, of which the characteristics are analyzed repectively. It is suggested that pure text documents are safer than dafabase files, while database files are more convenient to use than pure text files. Thus, if both types are copied, the data from automatic meteorological stations will be safe and convenient to use.
2013, 41(2):286-293.
Abstract:
Particle swarm optimization (PSO) develops rapidly for its simple code and easy operationThe performance of PSO rests with two critical factors: inertia weight and acceleration coefficients A proper PSO configured inertia weight and acceleration coefficients are presented and applied to the variational data assimilation (VDA) In order to verify its effectiveness, a simplified partial differential equation containing discontinuous “on off” switch is used as the governing equation and three kind of comparative assimilation numerical experiments (VDA based on the conventional adjoint method, genetic algorithm and PSO) are conducted, respectivelyThe numerical results show that the quality of VDA with “on off” switches based on PSO is much better than the one based on the other two algorithms, and the performance of PSO during the optimization is most stable Moreover, the sensitivity experiment for observational noise and model errors shows that PSO possesses more strong robust characteristics comparing to the conventional adjoint method and genetic algorithm In addition, it is shown that the effectiveness of VDA based on PSO is related to the configuration of algorithm parameters, more proper parameters resulting in higher quality of assimilation results.
Particle swarm optimization (PSO) develops rapidly for its simple code and easy operationThe performance of PSO rests with two critical factors: inertia weight and acceleration coefficients A proper PSO configured inertia weight and acceleration coefficients are presented and applied to the variational data assimilation (VDA) In order to verify its effectiveness, a simplified partial differential equation containing discontinuous “on off” switch is used as the governing equation and three kind of comparative assimilation numerical experiments (VDA based on the conventional adjoint method, genetic algorithm and PSO) are conducted, respectivelyThe numerical results show that the quality of VDA with “on off” switches based on PSO is much better than the one based on the other two algorithms, and the performance of PSO during the optimization is most stable Moreover, the sensitivity experiment for observational noise and model errors shows that PSO possesses more strong robust characteristics comparing to the conventional adjoint method and genetic algorithm In addition, it is shown that the effectiveness of VDA based on PSO is related to the configuration of algorithm parameters, more proper parameters resulting in higher quality of assimilation results.
2013, 41(2):294-299.
Abstract:
Researches and operational application of numerical weather prediction (NWP) are crucial to high quality weather forecasting. The accuracy of NWP lies on the errors of atmosphere models and initial conditions directly. Given evolutionary computation has effective performance for solving numerical optimization problems, the cost function of 3D Var is used as the object function that would be optimized, to balance the background and observation conditions to get optimal analysis conditions. Data Assimilation is the effective method to solve the initial condition problems. Two ideal numerical experiments are implemented with Lorenz 96 and Lorenz 63 The results show that after optimization, errors can be controlled in a minor range.
Researches and operational application of numerical weather prediction (NWP) are crucial to high quality weather forecasting. The accuracy of NWP lies on the errors of atmosphere models and initial conditions directly. Given evolutionary computation has effective performance for solving numerical optimization problems, the cost function of 3D Var is used as the object function that would be optimized, to balance the background and observation conditions to get optimal analysis conditions. Data Assimilation is the effective method to solve the initial condition problems. Two ideal numerical experiments are implemented with Lorenz 96 and Lorenz 63 The results show that after optimization, errors can be controlled in a minor range.
2013, 41(2):300-306.
Abstract:
An enhanced WSR 88D hail detection algorithm (HDA) is used for its performance evaluation in 110 sever convective weather processes. From 2006 to 2011, this method was used to detect the extreme weather with CINRAD/CD radar data in the northeastern Tibetan Plateau, including the calculation of Sever Hail Index (SHI) and the Maximum Evaluation Hail Size (MEHS). The localization of the default hail parameters is conducted. The result shows that the detection performance is evidently improved; POD (Probability Of Detection) increases from 85% to 89%; FAR (False Alarm Ratio) reduces from 41% to 21%; CSI (Critical Success Index) raises from 53% to 75%; MEHS (Expected Maximum Hail Size) drops from 74%to 33%, which is bigger than the actual maximum hail size. The results are useful to the hail detection with CINRAD/CD radar in nowcasting service.
An enhanced WSR 88D hail detection algorithm (HDA) is used for its performance evaluation in 110 sever convective weather processes. From 2006 to 2011, this method was used to detect the extreme weather with CINRAD/CD radar data in the northeastern Tibetan Plateau, including the calculation of Sever Hail Index (SHI) and the Maximum Evaluation Hail Size (MEHS). The localization of the default hail parameters is conducted. The result shows that the detection performance is evidently improved; POD (Probability Of Detection) increases from 85% to 89%; FAR (False Alarm Ratio) reduces from 41% to 21%; CSI (Critical Success Index) raises from 53% to 75%; MEHS (Expected Maximum Hail Size) drops from 74%to 33%, which is bigger than the actual maximum hail size. The results are useful to the hail detection with CINRAD/CD radar in nowcasting service.
2013, 41(2):307-313.
Abstract:
Based on the sounding data of Qingyuan Station from May to October from 2004 to 2009,11 kinds of vertical temperature differences are studied. The correlations between temperature differences and severe convective events are calculated and three kinds with higher correlations are further studied. The occurrence frequencies of severe convective events with different temperature differences are analyzed. The results show that temperature differences in severe convection days at lower altitudes in different months are small, compared with distinct amplitude at high altitudes. The frequencies of severe convective events increased with the increasing of temperature differences at both low and high altitudes. Severe convective events mainly occurred when the temperature difference between 850 hPa and 500 hPa was no less than 20 ℃, and that between 850 hPa and 700 hPa was no less than 6 ℃. When temperature difference between 400 hPa and 100 hPa was between 64 ℃ and 66 ℃ and that between 850 hPa and 500 hPa was between 23 and 26 ℃ or temperature difference between 850 hPa and 700 hPa was between 8 ℃ and 11 ℃, the frequeny would be the highest. As for large scale convective events when temperature difference between 850 hPa and 500 hPa was equal or greater than 24 ℃ or temperature difference between 850 hPa and 700 hPa reached 10 ℃，usually there was gale accompanied with heavy precipitation. When temperature difference between 400 hPa and 100 hPa was less than 60 ℃, the probability of large scale heavy precipitation would be very little.
Based on the sounding data of Qingyuan Station from May to October from 2004 to 2009,11 kinds of vertical temperature differences are studied. The correlations between temperature differences and severe convective events are calculated and three kinds with higher correlations are further studied. The occurrence frequencies of severe convective events with different temperature differences are analyzed. The results show that temperature differences in severe convection days at lower altitudes in different months are small, compared with distinct amplitude at high altitudes. The frequencies of severe convective events increased with the increasing of temperature differences at both low and high altitudes. Severe convective events mainly occurred when the temperature difference between 850 hPa and 500 hPa was no less than 20 ℃, and that between 850 hPa and 700 hPa was no less than 6 ℃. When temperature difference between 400 hPa and 100 hPa was between 64 ℃ and 66 ℃ and that between 850 hPa and 500 hPa was between 23 and 26 ℃ or temperature difference between 850 hPa and 700 hPa was between 8 ℃ and 11 ℃, the frequeny would be the highest. As for large scale convective events when temperature difference between 850 hPa and 500 hPa was equal or greater than 24 ℃ or temperature difference between 850 hPa and 700 hPa reached 10 ℃，usually there was gale accompanied with heavy precipitation. When temperature difference between 400 hPa and 100 hPa was less than 60 ℃, the probability of large scale heavy precipitation would be very little.
2013, 41(2):314-319.
Abstract:
Based on the conventional radiosonde rainfall data from 2004 to 2011 of the northern Zhejiang and 2011 NCEP/NCAR reanalysis data, analyzed are the statistic Characteristics of low level jets and their relationship with heavy rain events. The results show that the south west low level jet at 700 hPa appeared most frequently; the frequency decreased with altitude, and there was significant diurnal variation, strengthening in the morning and weakening in the evening; in different types of low level jets, SJ DJU, and TJ occurred relatively frequently. There were nearly 90% rainstorms over the northern Zhejiang in Meiyu season accompanied with low level jets, most of which were the DJU type. The night rainstorms were more closely related to low level jets, compared with daytime rainstorms, and low level jets occur usually 12 h before the happening of the night storms. The heavy rain process in mid June 2011 corresponded to two enhancing processes of the south west low level jet, with the maximum wind speed at 600 hPa and stretching down to the lower levels.
Based on the conventional radiosonde rainfall data from 2004 to 2011 of the northern Zhejiang and 2011 NCEP/NCAR reanalysis data, analyzed are the statistic Characteristics of low level jets and their relationship with heavy rain events. The results show that the south west low level jet at 700 hPa appeared most frequently; the frequency decreased with altitude, and there was significant diurnal variation, strengthening in the morning and weakening in the evening; in different types of low level jets, SJ DJU, and TJ occurred relatively frequently. There were nearly 90% rainstorms over the northern Zhejiang in Meiyu season accompanied with low level jets, most of which were the DJU type. The night rainstorms were more closely related to low level jets, compared with daytime rainstorms, and low level jets occur usually 12 h before the happening of the night storms. The heavy rain process in mid June 2011 corresponded to two enhancing processes of the south west low level jet, with the maximum wind speed at 600 hPa and stretching down to the lower levels.
2013, 41(2):320-325.
Abstract:
On the basis of the analysis of Doppler radar data, combined with conventional weather data，satellite data, AWOS data, and automatic meteorological station data, the gust front event occurred in the Urumqi International Airport is analyzed. The results show that: (1) Meteorological elements changed obviously during the gust front, such as pressure rising, temperature dropping, and wind speed increasing, and the real time AWOS data show that wind direction and speed at both ends of the runway appeared discontinuous at the same time, and a strong horizontal wind shear occurred on the runway. (2) There was unstable energy accumulated because the moist air was capped by a dry and warm “lid”, and the atmosphere became potentially unstable. The sandstorm occurred near the surface convergence and dry line. (3) The convective clouds destroyed the inversion layer over Urumqi, and released unstable energy during moving eastward to the airport, strong wind and sandstorm from Hutubi to Urumqi occurred where TBB isoline converged with high gradient. (4) The gust front occurred on a narrow band of weak reflectivity and convergence area.
On the basis of the analysis of Doppler radar data, combined with conventional weather data，satellite data, AWOS data, and automatic meteorological station data, the gust front event occurred in the Urumqi International Airport is analyzed. The results show that: (1) Meteorological elements changed obviously during the gust front, such as pressure rising, temperature dropping, and wind speed increasing, and the real time AWOS data show that wind direction and speed at both ends of the runway appeared discontinuous at the same time, and a strong horizontal wind shear occurred on the runway. (2) There was unstable energy accumulated because the moist air was capped by a dry and warm “lid”, and the atmosphere became potentially unstable. The sandstorm occurred near the surface convergence and dry line. (3) The convective clouds destroyed the inversion layer over Urumqi, and released unstable energy during moving eastward to the airport, strong wind and sandstorm from Hutubi to Urumqi occurred where TBB isoline converged with high gradient. (4) The gust front occurred on a narrow band of weak reflectivity and convergence area.
2013, 41(2):326-333.
Abstract:
The synoptic background, stability index, and vertical shear of horizontal winds in a heavy rain happened on 25 and 26 July 2011 in Zhenjiang are analyzed. By using the SWAN system, the evolution characteristics of CAPPI radar echo images and VIL are studied. The TITAN storm identification and tracing techniques in SWAN are tested. The results show that the adequate dynamic condition, vapor condition, unsteady stratified atmosphere, and strong vertical shear of horizontal winds provided a favorable environment for the heavy rain process and resulted in the strong wind weather in Zhenjiang on 25 and 26 July. The characteristics of heavy rainfall in the two time periods were different: there was a squall weather process in the first period, and a group of rainstorms in the second period; both squall line and rainstorms contain common cells and high precipitation super cells, both of which have the characteristics of strong centers and high echo tops. A good corresponding relation between the evolution of VIL and the strength of storm is obtained. For the position and outline of a storm, the one hour forecast is less accurate than 30 minute forecast. For a developing or a well developed storm, the 30 minute tracking and forecasting are close to the real case, and for a weakening storm, there is a lag.
The synoptic background, stability index, and vertical shear of horizontal winds in a heavy rain happened on 25 and 26 July 2011 in Zhenjiang are analyzed. By using the SWAN system, the evolution characteristics of CAPPI radar echo images and VIL are studied. The TITAN storm identification and tracing techniques in SWAN are tested. The results show that the adequate dynamic condition, vapor condition, unsteady stratified atmosphere, and strong vertical shear of horizontal winds provided a favorable environment for the heavy rain process and resulted in the strong wind weather in Zhenjiang on 25 and 26 July. The characteristics of heavy rainfall in the two time periods were different: there was a squall weather process in the first period, and a group of rainstorms in the second period; both squall line and rainstorms contain common cells and high precipitation super cells, both of which have the characteristics of strong centers and high echo tops. A good corresponding relation between the evolution of VIL and the strength of storm is obtained. For the position and outline of a storm, the one hour forecast is less accurate than 30 minute forecast. For a developing or a well developed storm, the 30 minute tracking and forecasting are close to the real case, and for a weakening storm, there is a lag.
23 Responses of Maximum and Minimum Temperature to Climate Changes in Xishuangbanna in Past 50 Years
2013, 41(2):334-338.
Abstract:
Based on the data of monthly mean maximum and minimum air temperature, mean temperature at 14:00 and 02:00 in Xishuangbanna from 1961 to 2010, and using climatic statistic methods, the trends of the mean maximum and minimum air temperature, abrupt climate change, and anomalous years are studied. The results show that except spring mean maximum temperature and mean temperature at 14:00, annual and seasonal mean maximum and minimum temperature, mean temperature at 14:00 and 02:00, etc., all increased, with the increasing rate being 0208 to 0544 ℃ per 10 years, the largest increase in winter. Mean maximum and minimum temperature showed an abrupt change in 1978, and in the period before the abrupt change, it was colder and in the period after it was warmer. Before the abrupt change, the mean minimum temperature decreased obviously, but after the abrupt change, the mean minimum temperature was significantly higher. The abnormal low maximum and minimum temperature were normally appeared in the 1960s and 1970s, and abnormally high temperature mainly occurred after the 1980s of the 20th Century, especially since 2000.
Based on the data of monthly mean maximum and minimum air temperature, mean temperature at 14:00 and 02:00 in Xishuangbanna from 1961 to 2010, and using climatic statistic methods, the trends of the mean maximum and minimum air temperature, abrupt climate change, and anomalous years are studied. The results show that except spring mean maximum temperature and mean temperature at 14:00, annual and seasonal mean maximum and minimum temperature, mean temperature at 14:00 and 02:00, etc., all increased, with the increasing rate being 0208 to 0544 ℃ per 10 years, the largest increase in winter. Mean maximum and minimum temperature showed an abrupt change in 1978, and in the period before the abrupt change, it was colder and in the period after it was warmer. Before the abrupt change, the mean minimum temperature decreased obviously, but after the abrupt change, the mean minimum temperature was significantly higher. The abnormal low maximum and minimum temperature were normally appeared in the 1960s and 1970s, and abnormally high temperature mainly occurred after the 1980s of the 20th Century, especially since 2000.
2013, 41(2):339-342.
Abstract:
An analysis is made of the hail data from 2001 to 2010 of Longyan, the western Fujian Province, and the spatial and temporal distribution of characteristics of hails, and the new generation weather radar data on hailing process are collected. The characteristics of the radar data were compared qualitatively, and then some data were put into the quantitative analysis. Through the analysis, some initial results, which exhibit the spatial and temporal distribution of hails in the past 10 years in Longyan, and some important features and indexes of new generation weather radar data of hails are obtained. The results can provide effective reference and instruction for local users in weather forecasting and early warning of hails.
An analysis is made of the hail data from 2001 to 2010 of Longyan, the western Fujian Province, and the spatial and temporal distribution of characteristics of hails, and the new generation weather radar data on hailing process are collected. The characteristics of the radar data were compared qualitatively, and then some data were put into the quantitative analysis. Through the analysis, some initial results, which exhibit the spatial and temporal distribution of hails in the past 10 years in Longyan, and some important features and indexes of new generation weather radar data of hails are obtained. The results can provide effective reference and instruction for local users in weather forecasting and early warning of hails.
2013, 41(2):343-346.
Abstract:
A severe haze event happened from 25 to 28 December 2005 in the downtown area of Chongqing is analyzed based on NCEP reanalysis L band radar, conventional observation, and radiosonde data, as well as the air quality data. The results show that the severe haze event was related to the certain synoptic background. The southwesterly airflow before the wide southern branch trough at the south side of the Tibetan Plateau was strong at 500 hPa, and Chongqing was controlled by the uniform pressure field at 850 hPa, resulting in the small pressure gradient force and horizontal velocity. The cold air activities affecting Chongqing were few and weak, which were beneficial to the formation and maintenance of the severe haze event. The small wind speed at the low level and the sustained existence of inversion layer at mid low level, as well as the low temperature, were the important conditions of the haze. Under the unsaturation circumstances, the appropriate increase of humidity was conductive to the strengthening of the haze. During the haze, the coagulation of moisture particles would aggravate the visibility.
A severe haze event happened from 25 to 28 December 2005 in the downtown area of Chongqing is analyzed based on NCEP reanalysis L band radar, conventional observation, and radiosonde data, as well as the air quality data. The results show that the severe haze event was related to the certain synoptic background. The southwesterly airflow before the wide southern branch trough at the south side of the Tibetan Plateau was strong at 500 hPa, and Chongqing was controlled by the uniform pressure field at 850 hPa, resulting in the small pressure gradient force and horizontal velocity. The cold air activities affecting Chongqing were few and weak, which were beneficial to the formation and maintenance of the severe haze event. The small wind speed at the low level and the sustained existence of inversion layer at mid low level, as well as the low temperature, were the important conditions of the haze. Under the unsaturation circumstances, the appropriate increase of humidity was conductive to the strengthening of the haze. During the haze, the coagulation of moisture particles would aggravate the visibility.
2013, 41(2):347-351.
Abstract:
The daily maximum temperature from 1951 to 2005 for the main capital cities of China is used to analyze the characteristics of temporal and spatial distribution of the number of hot days and heat waves. The results show that the Yangtze River basin is the area attacked by heat waves frequently with long duration (more than 5 days); the temperature increase in main capital cites in China exhibited a “increase-decrease-increase” pattern from southeast to northwest, but most cities experienced increasing temperature in the recent years; the appearance dates and density of high temperature weather are different in different regions.
The daily maximum temperature from 1951 to 2005 for the main capital cities of China is used to analyze the characteristics of temporal and spatial distribution of the number of hot days and heat waves. The results show that the Yangtze River basin is the area attacked by heat waves frequently with long duration (more than 5 days); the temperature increase in main capital cites in China exhibited a “increase-decrease-increase” pattern from southeast to northwest, but most cities experienced increasing temperature in the recent years; the appearance dates and density of high temperature weather are different in different regions.
27 Variations of Visibility, Aerosol Optical Depth and Solar Radiation in Three Cities over East China
2013, 41(2):352-359.
Abstract:
Using the data of visibility and vapor pressure measured in Nanjing, Hangzhou, and Hefei from 1961 to 2001, the 055 μm aerosol optical depths (AOD) of these areas are inverted, and the variation characteristics of visibility and AOD are analyzed. In addition, the variation characteristics of solar radiation from routine radiation measurements are analyzed and compared with the variation characteristics of AOD. The results shows that the visibility over these three cities had significant decreasing trends from 1961 to 2001; the fastest decrease of visibility appeared in Nanjing and Hangzhou, while the slowest in Hefei. Visibility had also seasonal variation, maximum in summer and minimum in winter. AOD not only showed increasing trends, fastest in Nanjing and slowest in Hefei, but also had seasonality, higher in spring and summer, lower in autumn and winter. The global radiation and direct radiation had a significant decline in all the three cities before 1990, while the diffuse radiation did not change obviously. However, a slight increasing trend of global radiation was found in Nanjing and Hefei after 1990 Seasonal total of radiation is in the following descending order: summer, spring, autumn, and winter. A negative correlation between AOD and direct radiation has been found.
Using the data of visibility and vapor pressure measured in Nanjing, Hangzhou, and Hefei from 1961 to 2001, the 055 μm aerosol optical depths (AOD) of these areas are inverted, and the variation characteristics of visibility and AOD are analyzed. In addition, the variation characteristics of solar radiation from routine radiation measurements are analyzed and compared with the variation characteristics of AOD. The results shows that the visibility over these three cities had significant decreasing trends from 1961 to 2001; the fastest decrease of visibility appeared in Nanjing and Hangzhou, while the slowest in Hefei. Visibility had also seasonal variation, maximum in summer and minimum in winter. AOD not only showed increasing trends, fastest in Nanjing and slowest in Hefei, but also had seasonality, higher in spring and summer, lower in autumn and winter. The global radiation and direct radiation had a significant decline in all the three cities before 1990, while the diffuse radiation did not change obviously. However, a slight increasing trend of global radiation was found in Nanjing and Hefei after 1990 Seasonal total of radiation is in the following descending order: summer, spring, autumn, and winter. A negative correlation between AOD and direct radiation has been found.
2013, 41(2):360-364.
Abstract:
Using several indexes of urbanization, the relationship between urbanization and Urban Heat Island effect (UHI) from 1980 to 2009 in Taiyuan is studied. It is discovered that urbanization was the main reason for the formation and reinforcement of UHI. The conclusions are as following: (1) In recent 30 years, the tendency of temperature in Taiyuan was 090 ℃ per 10 years, 051 ℃ per 10 years in the suburbs; UHI also increased, and the tendency of UHI intensity was 039 ℃ per 10 years. (2) There was a significantly positive correlation between urbanization and UHI for all types of indexes. (3) There is a linear correlation between the urban rural temperature difference and the logarithm of total population logarithm, and the long term correlative coefficient reached to 081 (4) The natural logarithm of housing construction area and the difference were linearly correlated, and the long term correlative coefficient reached to 085
Using several indexes of urbanization, the relationship between urbanization and Urban Heat Island effect (UHI) from 1980 to 2009 in Taiyuan is studied. It is discovered that urbanization was the main reason for the formation and reinforcement of UHI. The conclusions are as following: (1) In recent 30 years, the tendency of temperature in Taiyuan was 090 ℃ per 10 years, 051 ℃ per 10 years in the suburbs; UHI also increased, and the tendency of UHI intensity was 039 ℃ per 10 years. (2) There was a significantly positive correlation between urbanization and UHI for all types of indexes. (3) There is a linear correlation between the urban rural temperature difference and the logarithm of total population logarithm, and the long term correlative coefficient reached to 081 (4) The natural logarithm of housing construction area and the difference were linearly correlated, and the long term correlative coefficient reached to 085
2013, 41(2):365-371.
Abstract:
The layout and application of a meteorological experts system designed for road meteorological service is introduced. The layout frame of the meteorological experts system, the technical procedures, and products related to road weather conditions, such as the puddle index and slipperiness index of the road surface, visibility index, high temperature tyre breaking index, and heavy wind index, are discussed. The application tests are conducted on the system during high risk weather processes, and the results indicate that the meteorological expert system performed satisfactorily in road weather service.
The layout and application of a meteorological experts system designed for road meteorological service is introduced. The layout frame of the meteorological experts system, the technical procedures, and products related to road weather conditions, such as the puddle index and slipperiness index of the road surface, visibility index, high temperature tyre breaking index, and heavy wind index, are discussed. The application tests are conducted on the system during high risk weather processes, and the results indicate that the meteorological expert system performed satisfactorily in road weather service.
2013, 41(2):372-377.
Abstract:
Based on the investigation and data analysis, the objective index system of applicability analysis is established, and the applicability of meteorological monitoring stations on expressway is studied. The main conclusions are as follows: (1) The distribution of traffic meteorological monitoring equipment on expressway among different cities is greatly uneven. There almost is no any special traffic meteorological station in most cities, except in Jiangsu, Beijing and Hainan provinces. (2) The stations with the capability of monitoring specific factors match relatively well with local meteorological disasters; however, they call for refined layout. (3) At present, the domestic traffic weather station layout guides do not consider the characteristics of traffic weather and are lack of feasible standards. (4) Because China has wide territory, high mileage highways, and high cost traffic meteorological monitor equipment, depending on traffic meteorological stations solely is not the optimum way to solve the problems in traffic meteorological service. (5) The observation data of meteorological stations have certain accuracy; however, the monitoring of surface conditions and rain strength and visibility based on optical sensing and remote sensing can be easily affected by the environment. The monitoring data have not been shared fully between traffic and meteorological departments. (6) The main application of data includes real time monitoring, primary product developing, and relevant scientific research projects. At present, the data have not been shared fully and used practically; there are no specific guide products for traffic users. Some practical suggestions about traffic weather monitoring are presented, such as data assimilation and inversion technology, improvement of forecast and warning skills, etc.
Based on the investigation and data analysis, the objective index system of applicability analysis is established, and the applicability of meteorological monitoring stations on expressway is studied. The main conclusions are as follows: (1) The distribution of traffic meteorological monitoring equipment on expressway among different cities is greatly uneven. There almost is no any special traffic meteorological station in most cities, except in Jiangsu, Beijing and Hainan provinces. (2) The stations with the capability of monitoring specific factors match relatively well with local meteorological disasters; however, they call for refined layout. (3) At present, the domestic traffic weather station layout guides do not consider the characteristics of traffic weather and are lack of feasible standards. (4) Because China has wide territory, high mileage highways, and high cost traffic meteorological monitor equipment, depending on traffic meteorological stations solely is not the optimum way to solve the problems in traffic meteorological service. (5) The observation data of meteorological stations have certain accuracy; however, the monitoring of surface conditions and rain strength and visibility based on optical sensing and remote sensing can be easily affected by the environment. The monitoring data have not been shared fully between traffic and meteorological departments. (6) The main application of data includes real time monitoring, primary product developing, and relevant scientific research projects. At present, the data have not been shared fully and used practically; there are no specific guide products for traffic users. Some practical suggestions about traffic weather monitoring are presented, such as data assimilation and inversion technology, improvement of forecast and warning skills, etc.
2013, 41(2):378-383.
Abstract:
Based on the needs of the urban waterlogging monitoring and early warning in Shenzhen, an introduction is made to the design method of a water logging system, which consists of the high accuracy pressure and water level gauges and automatic weather stations at key points of the urban river, in the aspects of the system architecture, measurement principles, parameter setting, design error compensation, etc. The system adopts a set of data collected every minute, and the water level measurements have an accuracy of 01%. Through comparison with the measurements from national standard hydrological stations, it is found out that the water level measurements from the station are consistent with the astronomical tide water level fluctuation, with the phase being 1 hour lagged and the measurement error being less than 006 m. Through a case analysis, it is concluded that when the average area rainfall in the Maozhou River basin is greater than 40 mm and the measured water level reaches 15 m, and maintains more than four hours, the urban area is prone to waterlogging. The combination of water level measurements and the observed area rainfall help improve the capabilities of waterlogging early warning and forecasting for a city.
Based on the needs of the urban waterlogging monitoring and early warning in Shenzhen, an introduction is made to the design method of a water logging system, which consists of the high accuracy pressure and water level gauges and automatic weather stations at key points of the urban river, in the aspects of the system architecture, measurement principles, parameter setting, design error compensation, etc. The system adopts a set of data collected every minute, and the water level measurements have an accuracy of 01%. Through comparison with the measurements from national standard hydrological stations, it is found out that the water level measurements from the station are consistent with the astronomical tide water level fluctuation, with the phase being 1 hour lagged and the measurement error being less than 006 m. Through a case analysis, it is concluded that when the average area rainfall in the Maozhou River basin is greater than 40 mm and the measured water level reaches 15 m, and maintains more than four hours, the urban area is prone to waterlogging. The combination of water level measurements and the observed area rainfall help improve the capabilities of waterlogging early warning and forecasting for a city.
2013, 41(2):384-388.
Abstract:
In order to reduce the number of non occupational carbon monoxide poisoning events during winter in Beijing, the data of the daily number of CO poisoned patients from 16 emergency centers of the Beijing urban area from 2002 to 2005 was collected. The correlation between daily number of CO poisoned patients in the Beijing urban area in the winter half year (October to next April) and meteorological elements from the Beijing observatory, as well as the sea level pressure field data of areas around Beijing (8 weather stations in Hebei Province), are studied. Using the method of quasi multiple regression index probability classification, the CO poisoning index (4 classes) forecast model and the corresponding CO poisoning risk level assessment model are established. The results show that the number of CO poisoned patients varied obviously and seasonally, higher from January to March and relatively low from October to April of the next year. The historical fitting rate of completely correct and less than 1 class forecast of CO poisoning meteorological index for 24, 48 and 72 hours reached 502% to 605% and 852% to 552%, respectively. From January 2008 to April 2009, the research findings had been used in TV, newspaper, broadcast and mobile weather service.
In order to reduce the number of non occupational carbon monoxide poisoning events during winter in Beijing, the data of the daily number of CO poisoned patients from 16 emergency centers of the Beijing urban area from 2002 to 2005 was collected. The correlation between daily number of CO poisoned patients in the Beijing urban area in the winter half year (October to next April) and meteorological elements from the Beijing observatory, as well as the sea level pressure field data of areas around Beijing (8 weather stations in Hebei Province), are studied. Using the method of quasi multiple regression index probability classification, the CO poisoning index (4 classes) forecast model and the corresponding CO poisoning risk level assessment model are established. The results show that the number of CO poisoned patients varied obviously and seasonally, higher from January to March and relatively low from October to April of the next year. The historical fitting rate of completely correct and less than 1 class forecast of CO poisoning meteorological index for 24, 48 and 72 hours reached 502% to 605% and 852% to 552%, respectively. From January 2008 to April 2009, the research findings had been used in TV, newspaper, broadcast and mobile weather service.
2013, 41(2):389-393.
Abstract:
A new interpretation method for making 10 day average temperature and precipitation prediction during different wheat growth stages is developed based on the predictions of a climate model, the NCEP/NCAP reanalysis data, and in site observations of temperature and precipitation. Meanwhile, a new drought prediction model is devised, which has been put into operation. The operational use shows that this model is practicable.
A new interpretation method for making 10 day average temperature and precipitation prediction during different wheat growth stages is developed based on the predictions of a climate model, the NCEP/NCAP reanalysis data, and in site observations of temperature and precipitation. Meanwhile, a new drought prediction model is devised, which has been put into operation. The operational use shows that this model is practicable.
2013, 41(2):394-400.
Abstract:
Based on the artificial environmental control experiments designed with different low temperatures (5, 7, 9, 11, 25 ℃) as a control experiment (CK), the photosynthesis characteristics, fluorescence parameters, and antioxidant enzyme activity of cucumbers （Cucumis sativus 〖WTBZ〗L. cv. 〖WTBZ〗Jingyou 35） leaves were investigated in 2011 It aimed at determining the low temperature meteorological disaster index of greenhouse cucumbers. Results show that: the maximum photosynthesis rate of cucumber leaves reduced with the increasing low temperature stress；with the prolonging and aggravation of low temperature stress, the light compensation point of cucumbers rose and the light saturation point reduced；under the low temperature treatment of 5, 7, 9 ℃, with the prolonging of the stress,the maximal efficiency of PSⅡ photochemistry of cucumbers and photochemical quenching decreased, while the tendency of non photochemical quenching was opposite to photochemical quenching; with the decreasing treatment temperature, the hyperoxide mutase activity in cucumber leaves increased first and then decreased; the peroxidase activity reached the highest after the 24 h treatment at 9 ℃; as a result of reducing temperature, the catalase activity increased; affected by low temperature stress, malondialdehyde content was greater than that of the control, and with the increasing stress level, it rose first, then descended slightly. The low temperature meteorological disaster index is established, which can be divided into 4 levels: mild, moderate, severe, and very severe, can provide a scientific basis for agro meteorological services.
Based on the artificial environmental control experiments designed with different low temperatures (5, 7, 9, 11, 25 ℃) as a control experiment (CK), the photosynthesis characteristics, fluorescence parameters, and antioxidant enzyme activity of cucumbers （Cucumis sativus 〖WTBZ〗L. cv. 〖WTBZ〗Jingyou 35） leaves were investigated in 2011 It aimed at determining the low temperature meteorological disaster index of greenhouse cucumbers. Results show that: the maximum photosynthesis rate of cucumber leaves reduced with the increasing low temperature stress；with the prolonging and aggravation of low temperature stress, the light compensation point of cucumbers rose and the light saturation point reduced；under the low temperature treatment of 5, 7, 9 ℃, with the prolonging of the stress,the maximal efficiency of PSⅡ photochemistry of cucumbers and photochemical quenching decreased, while the tendency of non photochemical quenching was opposite to photochemical quenching; with the decreasing treatment temperature, the hyperoxide mutase activity in cucumber leaves increased first and then decreased; the peroxidase activity reached the highest after the 24 h treatment at 9 ℃; as a result of reducing temperature, the catalase activity increased; affected by low temperature stress, malondialdehyde content was greater than that of the control, and with the increasing stress level, it rose first, then descended slightly. The low temperature meteorological disaster index is established, which can be divided into 4 levels: mild, moderate, severe, and very severe, can provide a scientific basis for agro meteorological services.
Wang Hongbo
,
Feng Rui
,
Zhang Yushu
,
Ji Ruipeng
,
Wu Jinwen
,
Yu Wenying
,
Dai Ping
,
Liu Xiaomei
,
Wan Zhihong
2013, 41(2):401-406.
Abstract:
The chilling damage can be easily initiated by climate change. Under the development environment of Visual Studio 2005 and Microsoft SQL Server 2005, based on ground observation data, weather forecast data, and remote sensing data, the normal chilling index and monitoring and evaluation methods are summarized. By means of the ArcGIS Engine development toolbox, the chilling damage monitoring and evaluation system (CDMES) for North China, where maize and rice are main crops, is established, which can be used to monitor the growth delaying type chill damage for maize and the disturbance type chill damage for rice, as well as the monitoring of annual chill damage and delayed chill damage and the impact assessment and prediction of chill damage for maize and rice.
The chilling damage can be easily initiated by climate change. Under the development environment of Visual Studio 2005 and Microsoft SQL Server 2005, based on ground observation data, weather forecast data, and remote sensing data, the normal chilling index and monitoring and evaluation methods are summarized. By means of the ArcGIS Engine development toolbox, the chilling damage monitoring and evaluation system (CDMES) for North China, where maize and rice are main crops, is established, which can be used to monitor the growth delaying type chill damage for maize and the disturbance type chill damage for rice, as well as the monitoring of annual chill damage and delayed chill damage and the impact assessment and prediction of chill damage for maize and rice.
2013, 41(2):407-411.
Abstract:
Using the data from 16 counties (cities) of Shijiazhuang from 1959 to 2007 (including county annals), an analysis is made of the spatial and temporal distribution of hails in Shijiazhuang and their paths. The results indicate: (1) There were cyclical changes with the periods being 1, 11, 12, and 25 years in the number of hail days in Shijiazhuang; mutations appeared in 1971 and 2003 (2) Hails in Shijiazhuang occurred most frequently from late May to July, 14:00 to 20:00 (3) Hails occurred more frequently in the western mountain areas than in the eastern plain; more in the areas near the rivers. (4) Through analysis, three hail suppression operation lines are set up, and hail suppression points increased，so to rationalize the arrangement of hail suppression points and carry out the stepwise hail suppression operations.
Using the data from 16 counties (cities) of Shijiazhuang from 1959 to 2007 (including county annals), an analysis is made of the spatial and temporal distribution of hails in Shijiazhuang and their paths. The results indicate: (1) There were cyclical changes with the periods being 1, 11, 12, and 25 years in the number of hail days in Shijiazhuang; mutations appeared in 1971 and 2003 (2) Hails in Shijiazhuang occurred most frequently from late May to July, 14:00 to 20:00 (3) Hails occurred more frequently in the western mountain areas than in the eastern plain; more in the areas near the rivers. (4) Through analysis, three hail suppression operation lines are set up, and hail suppression points increased，so to rationalize the arrangement of hail suppression points and carry out the stepwise hail suppression operations.
2013, 41(2):412-416.
Abstract:
A comparative analysis is made of the shielding failure rates obtained with IEEE and DL/T620’s formulas, and a regionalization is conducted on the shielding failure rate over Chongqing with the data of LLS (Lightning Location System) from 1999 to 2008 The results show that the shielding failure rate increased with the increasing rolling sphere radius. When the rolling sphere radius was the same, the shielding failure rate provided by IEEE was higher than the reality and lower than that by DL/T620’s. When the rolling sphere radius was lower than 120 m, the shielding failure rate provided by IEEE was lower than that by DL/T620; on the contrary, the shielding failure rate provided by IEEE was higher than that by DL/T620’s. The shielding failure rate provided by IEEE was close to the reality. Based on that, a satisfactory shielding failure rate expression is given, with which the shielding failure rates of various types of buildings are regionalized. The results can be used as theoretical bases for lightning disaster risk assessment and lightning protection design.
A comparative analysis is made of the shielding failure rates obtained with IEEE and DL/T620’s formulas, and a regionalization is conducted on the shielding failure rate over Chongqing with the data of LLS (Lightning Location System) from 1999 to 2008 The results show that the shielding failure rate increased with the increasing rolling sphere radius. When the rolling sphere radius was the same, the shielding failure rate provided by IEEE was higher than the reality and lower than that by DL/T620’s. When the rolling sphere radius was lower than 120 m, the shielding failure rate provided by IEEE was lower than that by DL/T620; on the contrary, the shielding failure rate provided by IEEE was higher than that by DL/T620’s. The shielding failure rate provided by IEEE was close to the reality. Based on that, a satisfactory shielding failure rate expression is given, with which the shielding failure rates of various types of buildings are regionalized. The results can be used as theoretical bases for lightning disaster risk assessment and lightning protection design.
2013, 41(2):417-421.
Abstract:
Lightning weather often induces hazards to electrical systems. A lightning induced electrical system accident is studied in detail, which happened at the electronic pile examination spot for car drivers in Weihai. The structure of the electronic piles, the layout of lines, and the measures of lightning protection are investigated. Based on the assessment of lightning risk, combined with the safety standards and the features of the examination spot, the design of lightning protection scheme for the electronic pile examination spot is given. The direct lightning protection and induction lightning protection design are discussed emphatically. The examination spot signal lines within the system, the office building monitoring system, the control room grounding system are reasonably designed. The lightning protection design of electrical systems is also discussed, and the results can be used as references for electrical system lightning protection design.
Lightning weather often induces hazards to electrical systems. A lightning induced electrical system accident is studied in detail, which happened at the electronic pile examination spot for car drivers in Weihai. The structure of the electronic piles, the layout of lines, and the measures of lightning protection are investigated. Based on the assessment of lightning risk, combined with the safety standards and the features of the examination spot, the design of lightning protection scheme for the electronic pile examination spot is given. The direct lightning protection and induction lightning protection design are discussed emphatically. The examination spot signal lines within the system, the office building monitoring system, the control room grounding system are reasonably designed. The lightning protection design of electrical systems is also discussed, and the results can be used as references for electrical system lightning protection design.
2013, 41(2):422-424.
Abstract:
An analysis is made of the lightning electromagnetic pulses in the elevator on a high building top, combined with its geographical location, lightning environment, and lightning protection status. For the various types of shielding conditions of the elevator room, the induced voltages of the equipment are calculated, respectively. The shielding measures and other protection measures needed for the elevator are discussed. It is concluded that without shielding measures, the operation of the elevator will be affected, whether the lightning strikes on the elevator machine room or nearby buildings. With basic lightning protection measures, the elevator at the top of the building should install also a metal grid shielding (steel), with a radius of 0002 m, a grid width of 001 m.
An analysis is made of the lightning electromagnetic pulses in the elevator on a high building top, combined with its geographical location, lightning environment, and lightning protection status. For the various types of shielding conditions of the elevator room, the induced voltages of the equipment are calculated, respectively. The shielding measures and other protection measures needed for the elevator are discussed. It is concluded that without shielding measures, the operation of the elevator will be affected, whether the lightning strikes on the elevator machine room or nearby buildings. With basic lightning protection measures, the elevator at the top of the building should install also a metal grid shielding (steel), with a radius of 0002 m, a grid width of 001 m.
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.