Volume 45,Issue 3,2017 Table of Contents
2017, 45(3):409-414.
Abstract:
In order to obtain the eigenvalues of rain particles. In this paper, the threshold processing method is adopted to segment raindrops and the background image. The complex raindrop figure is converted to a binary image of the real boundary. The raindrops centroid is marked by using the mean algorithm, and the raindrop shape model is established by using the long axis information of raindrops. Combined with the global thresholds of Otsu and the local threshold method, a method for detecting the characteristic values of raindrops by Ostu is proposed. Through the experiment, it is shown that the method can effectively extract the characteristic values of raindrops from the image data. The number of particles and the shape of raindrops are indispensable parameters to measure the intensity of rainfall.
In order to obtain the eigenvalues of rain particles. In this paper, the threshold processing method is adopted to segment raindrops and the background image. The complex raindrop figure is converted to a binary image of the real boundary. The raindrops centroid is marked by using the mean algorithm, and the raindrop shape model is established by using the long axis information of raindrops. Combined with the global thresholds of Otsu and the local threshold method, a method for detecting the characteristic values of raindrops by Ostu is proposed. Through the experiment, it is shown that the method can effectively extract the characteristic values of raindrops from the image data. The number of particles and the shape of raindrops are indispensable parameters to measure the intensity of rainfall.
2017, 45(3):415-419.
Abstract:
The receiving system, which is called the parallel filter system with the integrated multireceiver, as the most critical component of the groundbased microwave radiometer, it is necessary to examine its structure and technical characteristics. The advantage, compared with the single receiver， i.e., frequency conversion technology, is described and the actual application effectiveness of the receiving system is analyzed by means of radiation data and products. It is concluded that this receiving system can improve the detecting capability of the groundbased microwave radiometer. The findings can be used to provide reference for relevant technicians in the application and analysis of groundbased microwave radiometers.
The receiving system, which is called the parallel filter system with the integrated multireceiver, as the most critical component of the groundbased microwave radiometer, it is necessary to examine its structure and technical characteristics. The advantage, compared with the single receiver， i.e., frequency conversion technology, is described and the actual application effectiveness of the receiving system is analyzed by means of radiation data and products. It is concluded that this receiving system can improve the detecting capability of the groundbased microwave radiometer. The findings can be used to provide reference for relevant technicians in the application and analysis of groundbased microwave radiometers.
2017, 45(3):420-424.
Abstract:
The measurement of EIRP (Effective Isotropic Radiated Power) is an important test in satellite onorbit tests，which represents the quality of the communication link and receiving satellite data. The previous methods generally use the manual test, which is not only inefficient, but also has sometimes the low accuracy of test results. This paper provides an automated test method of EIRP, in which through a host computer to automatically collect the data and calculate EIRP. It avoids the artificial error of the traditional test method, which has the advantages of high efficiency and realtime. Taking the FY3C’s EIRP test as an example, the test procedures of the method are briefly described.
The measurement of EIRP (Effective Isotropic Radiated Power) is an important test in satellite onorbit tests，which represents the quality of the communication link and receiving satellite data. The previous methods generally use the manual test, which is not only inefficient, but also has sometimes the low accuracy of test results. This paper provides an automated test method of EIRP, in which through a host computer to automatically collect the data and calculate EIRP. It avoids the artificial error of the traditional test method, which has the advantages of high efficiency and realtime. Taking the FY3C’s EIRP test as an example, the test procedures of the method are briefly described.
2017, 45(3):425-429.
Abstract:
In order to study the diurnal variation and seasonal characteristics of the atmospheric boundary layer structure in Suzhou, this study conducted continuous observation of aerosols detected by lidar from January to July 2014 The measurements of diurnal variation about extinction coefficient on 15 January, 16 March, 7 May, and 22 July 2014 are selected and the daily ABL heights by the optimized gradient method in this area are calculated. The correlation between ABL height and ground temperature & humidity is relatively high. The results show that the changes of the ABL height have a significant positive correlation with surface temperature and a negative relationship with the relative humidity, except for 15 January. Meanwhile, a joint study is conducted between the profiles of temperature and humidity data from the microwave radiometer and the profiles of extinction coefficient, and gained a good consistency between this two data.
In order to study the diurnal variation and seasonal characteristics of the atmospheric boundary layer structure in Suzhou, this study conducted continuous observation of aerosols detected by lidar from January to July 2014 The measurements of diurnal variation about extinction coefficient on 15 January, 16 March, 7 May, and 22 July 2014 are selected and the daily ABL heights by the optimized gradient method in this area are calculated. The correlation between ABL height and ground temperature & humidity is relatively high. The results show that the changes of the ABL height have a significant positive correlation with surface temperature and a negative relationship with the relative humidity, except for 15 January. Meanwhile, a joint study is conducted between the profiles of temperature and humidity data from the microwave radiometer and the profiles of extinction coefficient, and gained a good consistency between this two data.
2017, 45(3):430-434.
Abstract:
A NoSQL storage design for meteorological grid data products is introduced. An analysis is made of the meteorological structure of grid data products and their application scenarios, and the column storage database in NoSQL is designed to increase the efficiency of storage and access through optimizing the way of table store. According to the type, time and forecast effectiveness of data products, we work out the primary key column, attribute column, and data column, then, split the big grids of data column, use the grid sequence number to record data column names, and design data compression strategies to improve the overall efficiency of data access. Taking numerical prediction products as an example, we make use of Aliyun OTS to simulate tests. The results show that the column storage database based on NoSQL technology can meet with the requirements of the underlying data support of product service platform, which has a certain reference significance for the extension and application of key technologies, such as distributed data environment, cloud computing, and so on.
A NoSQL storage design for meteorological grid data products is introduced. An analysis is made of the meteorological structure of grid data products and their application scenarios, and the column storage database in NoSQL is designed to increase the efficiency of storage and access through optimizing the way of table store. According to the type, time and forecast effectiveness of data products, we work out the primary key column, attribute column, and data column, then, split the big grids of data column, use the grid sequence number to record data column names, and design data compression strategies to improve the overall efficiency of data access. Taking numerical prediction products as an example, we make use of Aliyun OTS to simulate tests. The results show that the column storage database based on NoSQL technology can meet with the requirements of the underlying data support of product service platform, which has a certain reference significance for the extension and application of key technologies, such as distributed data environment, cloud computing, and so on.
2017, 45(3):435-439.
Abstract:
Radar performance parameter test is the important means for testing CINRAD performance indicators, the pulse power of signals and the pulse envelope in the transmitter will affects the normal work of the radar directly. To resolve the problem of complex operation, low efficiency, and high error rate of manual testing, a special CINRAD transmitter auto testing system based on LabVIEW is devised. Based on the analysis of mathematical models of S band CINRAD transmitter and the existed test methods, this paper tries to design a system to test radar transmitters by LabVIEW and remote controlling hardware test circuit. This system, in the premise of guarantee the accuracy, is a system with the characteristics of friendly interface, easy operation, and good expansibility, can provide reference and help for CINRADs parameter test and signal analysis.
Radar performance parameter test is the important means for testing CINRAD performance indicators, the pulse power of signals and the pulse envelope in the transmitter will affects the normal work of the radar directly. To resolve the problem of complex operation, low efficiency, and high error rate of manual testing, a special CINRAD transmitter auto testing system based on LabVIEW is devised. Based on the analysis of mathematical models of S band CINRAD transmitter and the existed test methods, this paper tries to design a system to test radar transmitters by LabVIEW and remote controlling hardware test circuit. This system, in the premise of guarantee the accuracy, is a system with the characteristics of friendly interface, easy operation, and good expansibility, can provide reference and help for CINRADs parameter test and signal analysis.
2017, 45(3):440-445.
Abstract:
Considering the current situation and demands of meteorological data sharing and exchange, the application of meteorological data sharing and exchange technology based on SkyDrive cloud virtualization aims to improve the efficiency and availability of existing resources, efficiently implement the dynamic utilization of municipal meteorological resources, and centrally store and use the meteorological sharing and exchange data and disaster recovery. The application provides multiplatform, multimeans data exchange and sharing support. Under the premise of the security control of access to users, the application opens up a new way for meteorological service and meteorological data sharing and exchange. This application is an effective attempt to improve the efficiency of data exchange and sharing among city, county, and municipallevel meteorological service, as well as the city disaster prevention and mitigation departments, and meteorological users. This article puts forward a new idea for the sharing and exchange of municipal meteorological data, which well fits the requirements of the related government departments.
Considering the current situation and demands of meteorological data sharing and exchange, the application of meteorological data sharing and exchange technology based on SkyDrive cloud virtualization aims to improve the efficiency and availability of existing resources, efficiently implement the dynamic utilization of municipal meteorological resources, and centrally store and use the meteorological sharing and exchange data and disaster recovery. The application provides multiplatform, multimeans data exchange and sharing support. Under the premise of the security control of access to users, the application opens up a new way for meteorological service and meteorological data sharing and exchange. This application is an effective attempt to improve the efficiency of data exchange and sharing among city, county, and municipallevel meteorological service, as well as the city disaster prevention and mitigation departments, and meteorological users. This article puts forward a new idea for the sharing and exchange of municipal meteorological data, which well fits the requirements of the related government departments.
2017, 45(3):446-452.
Abstract:
Because of the low automation level and manual operation of the current typhoon report production system in the Zhejiang Meteorological Observatory, a new production and release system for typhoon reports is devised, combined with the Word document processing modular and the database system, which is based on the gridding and fine forecast data, and can generate meaningful text according to the objective transformation rules. All functional modules are integrated into the system, and various kinds of necessary pictures can be automatically inserted. Therefore，the work efficiency is greatly improved and the error rate is obviously reduced by using this new system.
Because of the low automation level and manual operation of the current typhoon report production system in the Zhejiang Meteorological Observatory, a new production and release system for typhoon reports is devised, combined with the Word document processing modular and the database system, which is based on the gridding and fine forecast data, and can generate meaningful text according to the objective transformation rules. All functional modules are integrated into the system, and various kinds of necessary pictures can be automatically inserted. Therefore，the work efficiency is greatly improved and the error rate is obviously reduced by using this new system.
2017, 45(3):453-459.
Abstract:
The integrated automatic monitoring and alarming system based on CIMISS is designed according to the demand for meteorological disaster prevention and mitigation services. It can provide the customized disastrous weather alarm information services to various kinds of users, and enable users get more information about the realtime disastrous weather through mobile devices or PCs anytime and anywhere. The content and implementation ways are introduced from the aspects of system structure, information collection and processing, algorithm for judging the timing of disaster weather warning, and realtime information generating.
The integrated automatic monitoring and alarming system based on CIMISS is designed according to the demand for meteorological disaster prevention and mitigation services. It can provide the customized disastrous weather alarm information services to various kinds of users, and enable users get more information about the realtime disastrous weather through mobile devices or PCs anytime and anywhere. The content and implementation ways are introduced from the aspects of system structure, information collection and processing, algorithm for judging the timing of disaster weather warning, and realtime information generating.
2017, 45(3):460-468.
Abstract:
Strong convection mechanisms of the Pearl River Delta vary in different weather conditions, and there are some differences in strong convection indexes accordingly. This paper divides the strong convection triggering mechanisms of weather patterns into four sorts: cold air influence, southwest warm moisture flow, impact on the edge of the subtropical anticyclone, and typhoon influence. Outputs of the mesoscale numerical weather prediction (NWP) model of the Guangzhou Institute of Tropic and Marine Meteorology of CMA were used to calculate the thunderstorm environment characteristics, such as water vapor, unstable energy, and dynamic conditions one hour before strong convection, which were selected to verify the convective index thresholds for Pearl River Delta under different synoptic patterns and to establish the corresponding potential forecast system. Through the verification of a typical thunderstorm process and a shorttime strong rainfall case, it is proved that the strong convection potential forecast products provided by the system can indicate the occurrence time and position of strong convection and convective type, which provides a reference for forecasters.
Strong convection mechanisms of the Pearl River Delta vary in different weather conditions, and there are some differences in strong convection indexes accordingly. This paper divides the strong convection triggering mechanisms of weather patterns into four sorts: cold air influence, southwest warm moisture flow, impact on the edge of the subtropical anticyclone, and typhoon influence. Outputs of the mesoscale numerical weather prediction (NWP) model of the Guangzhou Institute of Tropic and Marine Meteorology of CMA were used to calculate the thunderstorm environment characteristics, such as water vapor, unstable energy, and dynamic conditions one hour before strong convection, which were selected to verify the convective index thresholds for Pearl River Delta under different synoptic patterns and to establish the corresponding potential forecast system. Through the verification of a typical thunderstorm process and a shorttime strong rainfall case, it is proved that the strong convection potential forecast products provided by the system can indicate the occurrence time and position of strong convection and convective type, which provides a reference for forecasters.
2017, 45(3):469-476.
Abstract:
Based on the daily temperature data from 1961 to 2005 of Three Gorges Reservoir, the capability of the RegCM4 driven by the BCC_CSM11 and CCLM driven by the MPIESMLR to simulate the annual mean temperature and extreme high temperature is examined. According to the regional climate model, in which simulations are closer to observations, projected are the temperature changes in Three Gorges Reservoir from 2016 to 2035 under the RCP45 scenario. The results show that the temporal and spatial changes of simulated annual mean temperature, high temperature days, and high temperature intensity are broadly comparable with the observations. But both RegCM4 and CCLM underestimate the annual mean temperature, high temperature days, and high temperature intensity in the northeast part of the Three Gorges Reservoir region. Meanwhile, RegCM4 and CCLM can simulate the annual variations of mean temperature and high temperature days quite well, except for high temperature intensity. On the whole, the temperature simulated by CCLM is better than that by RegCM4 The annual mean temperature and high temperature days over the whole basin will increase 06 ℃ and 5 days in 2016-2035 under the RCP45 scenario, respectively, relative to the observations of 1986-2005 The variation of high temperature intensity is not obvious.
Based on the daily temperature data from 1961 to 2005 of Three Gorges Reservoir, the capability of the RegCM4 driven by the BCC_CSM11 and CCLM driven by the MPIESMLR to simulate the annual mean temperature and extreme high temperature is examined. According to the regional climate model, in which simulations are closer to observations, projected are the temperature changes in Three Gorges Reservoir from 2016 to 2035 under the RCP45 scenario. The results show that the temporal and spatial changes of simulated annual mean temperature, high temperature days, and high temperature intensity are broadly comparable with the observations. But both RegCM4 and CCLM underestimate the annual mean temperature, high temperature days, and high temperature intensity in the northeast part of the Three Gorges Reservoir region. Meanwhile, RegCM4 and CCLM can simulate the annual variations of mean temperature and high temperature days quite well, except for high temperature intensity. On the whole, the temperature simulated by CCLM is better than that by RegCM4 The annual mean temperature and high temperature days over the whole basin will increase 06 ℃ and 5 days in 2016-2035 under the RCP45 scenario, respectively, relative to the observations of 1986-2005 The variation of high temperature intensity is not obvious.
2017, 45(3):477-484.
Abstract:
The characteristics of clearsky precipitation echoes are analyzed by using Doppler radar data from May to September, 2008 to 2013 to study the application potential of clearsky echoes to the warning of stratiform precipitation. The results show that the days with clearsky echoes account for about 87% from May to September in Linyi, with more than 90% of cases within the range of 100 km from the radar station. The reflectivity factors are mostly among 10 to 25 dBz and there is obvious diurnal variation. Clear sky echo velocity products can effectively reflect the wind of lowerlayers before stratiform precipitation and lower turbulence dissipation rate in a certain extent, and can also have indication of the precipitation process. These results are meaningful to reduce the missing alarm rates and earlier warning of convective weather.
The characteristics of clearsky precipitation echoes are analyzed by using Doppler radar data from May to September, 2008 to 2013 to study the application potential of clearsky echoes to the warning of stratiform precipitation. The results show that the days with clearsky echoes account for about 87% from May to September in Linyi, with more than 90% of cases within the range of 100 km from the radar station. The reflectivity factors are mostly among 10 to 25 dBz and there is obvious diurnal variation. Clear sky echo velocity products can effectively reflect the wind of lowerlayers before stratiform precipitation and lower turbulence dissipation rate in a certain extent, and can also have indication of the precipitation process. These results are meaningful to reduce the missing alarm rates and earlier warning of convective weather.
2017, 45(3):485-491.
Abstract:
The identification and tracking of convective clouds and the 3hours rainfall forecasting are discussed by using the multithreshold, area overlapping, and statistical method, based on various weather data, including the data from FY meteorological satellite, weather radar and automatic meteorological stations. On the basis of this analysis, we established the operational software system of monitoring and forecasting convective clouds based on satellite data. In order to test the reliability of the software system, we choose 4 typical convective weather processes for trial operation. The results show that the software system can track the occurring and development of convective clouds accurately, and the precipitation regions of convective clouds were consistent with the ground precipitation observation. The forecasting index of maximum precipitation for convective clouds performed well with an accuracy of 61 %, a vacancy rate of 33 %, and a miss rate of 6%, which indicates that the findings can be used for monitoring and forecasting convective clouds in Fujian Province.
The identification and tracking of convective clouds and the 3hours rainfall forecasting are discussed by using the multithreshold, area overlapping, and statistical method, based on various weather data, including the data from FY meteorological satellite, weather radar and automatic meteorological stations. On the basis of this analysis, we established the operational software system of monitoring and forecasting convective clouds based on satellite data. In order to test the reliability of the software system, we choose 4 typical convective weather processes for trial operation. The results show that the software system can track the occurring and development of convective clouds accurately, and the precipitation regions of convective clouds were consistent with the ground precipitation observation. The forecasting index of maximum precipitation for convective clouds performed well with an accuracy of 61 %, a vacancy rate of 33 %, and a miss rate of 6%, which indicates that the findings can be used for monitoring and forecasting convective clouds in Fujian Province.
2017, 45(3):492-498.
Abstract:
The relationship between autumn rainfall in West China and autumn Eurasian teleconnection pattern (EUa) is examined by using the EOF, correlation and composite analysis and so on. The results show that significant negative correlation is found between autumn rainfall in West China and autumn EUa index, both with the phasic and jumping characteristics. The correlation coefficient of both oscillated significantly before 1986, and the significantly related areas mainly concentrated in the southwest Sichuan basin and Guizhou. The correlation coefficient increased significantly after 1986; the significantly related regions moved northward; the obviously correlated areas mainly concentrated in the northeastern Sichuan basin, Chongqing, and southern Shanxi. In the positive anomaly phase of EUa, the insufficient water vapor supply gave rise to the recession of the rainfall. In the negative anomaly phase of EUa, the rainfall amount of the eastern part of the autumn rainfall area increased, while the western shows the opposite reaction.
The relationship between autumn rainfall in West China and autumn Eurasian teleconnection pattern (EUa) is examined by using the EOF, correlation and composite analysis and so on. The results show that significant negative correlation is found between autumn rainfall in West China and autumn EUa index, both with the phasic and jumping characteristics. The correlation coefficient of both oscillated significantly before 1986, and the significantly related areas mainly concentrated in the southwest Sichuan basin and Guizhou. The correlation coefficient increased significantly after 1986; the significantly related regions moved northward; the obviously correlated areas mainly concentrated in the northeastern Sichuan basin, Chongqing, and southern Shanxi. In the positive anomaly phase of EUa, the insufficient water vapor supply gave rise to the recession of the rainfall. In the negative anomaly phase of EUa, the rainfall amount of the eastern part of the autumn rainfall area increased, while the western shows the opposite reaction.
15 Cause Analysis of Three Wind Speed Fluctuation Events during a Cold Air Gale Process over Bohai Sea
2017, 45(3):499-507.
Abstract:
There was occurred a strong wind process from 31 December 2014 to 1 January 2015 over the Bohai Sea, which has the characteristics of strong burst, long duration, strong winds with three wave peak of wind Speed. The reanalysis data of NCEP/NCAR are used in the diagnosis and analysis of the offshore wind induced by strong cold air. The analysis shows that when the cold air affected the Bohai Sea, the warm and cold air contrast enlarged the lowlevel front zone, and wind force increased obviously. Three fluctuations of the Bohai Sea wind correspond to the low layer cold advection strengthening, and temperature advection and vertical structural variation indicate that above the deep cold advection from top to bottom formed a retroverted cold advection transport channel, which transmitted the cold air to the lower levels for three times, corresponding to the three peaks of wind fluctuation. The highlevel downward momentum transformation played an important role in the rapid growth and maintenance of the strong winds. The three wind speed fluctuations over the Bohai Sea are related to the highlevel downward momentum transformation and the higher the radial degree of the air flows, the stronger the momentum transformation at the upper levels, the greater the wind speeds on the ground were.
There was occurred a strong wind process from 31 December 2014 to 1 January 2015 over the Bohai Sea, which has the characteristics of strong burst, long duration, strong winds with three wave peak of wind Speed. The reanalysis data of NCEP/NCAR are used in the diagnosis and analysis of the offshore wind induced by strong cold air. The analysis shows that when the cold air affected the Bohai Sea, the warm and cold air contrast enlarged the lowlevel front zone, and wind force increased obviously. Three fluctuations of the Bohai Sea wind correspond to the low layer cold advection strengthening, and temperature advection and vertical structural variation indicate that above the deep cold advection from top to bottom formed a retroverted cold advection transport channel, which transmitted the cold air to the lower levels for three times, corresponding to the three peaks of wind fluctuation. The highlevel downward momentum transformation played an important role in the rapid growth and maintenance of the strong winds. The three wind speed fluctuations over the Bohai Sea are related to the highlevel downward momentum transformation and the higher the radial degree of the air flows, the stronger the momentum transformation at the upper levels, the greater the wind speeds on the ground were.
2017, 45(3):508-515.
Abstract:
The features and formation causes of a shortterm heavy rainstorm process is studied by the conventional observation data, automatic weather station data, GFS analysis field data with the special resolution of 05° and the temporal resolution of 6 hours, Doppler radar and FY2E satellite data in the northern part of Zhejiang Province on 24 June 2013 The results suggests that due to the influences by the southwest warm moist air flow near the edge of subtropical high and the shear line at 850 hPa, the severe convection was triggered. It has good predictability for severe convection that the 925 hPa mesoscale convergence line overlaid the vertical upward region in the middle troposphere at 700 hPa. That is to say, severe convection could happen near the mesoscale convergence line under the situation. The mesoscale convergence line, which occurred earlier than the rainfall and induced by the confluence of easterly flow and northeasterly flow, triggered the shortterm heavy rainstorm in the northern part of Zhejiang Province.
The features and formation causes of a shortterm heavy rainstorm process is studied by the conventional observation data, automatic weather station data, GFS analysis field data with the special resolution of 05° and the temporal resolution of 6 hours, Doppler radar and FY2E satellite data in the northern part of Zhejiang Province on 24 June 2013 The results suggests that due to the influences by the southwest warm moist air flow near the edge of subtropical high and the shear line at 850 hPa, the severe convection was triggered. It has good predictability for severe convection that the 925 hPa mesoscale convergence line overlaid the vertical upward region in the middle troposphere at 700 hPa. That is to say, severe convection could happen near the mesoscale convergence line under the situation. The mesoscale convergence line, which occurred earlier than the rainfall and induced by the confluence of easterly flow and northeasterly flow, triggered the shortterm heavy rainstorm in the northern part of Zhejiang Province.
2017, 45(3):516-525.
Abstract:
Based on the meteorological observations from December 2010 to May 2014 of the 370 m observation tower on the Liangmaoshan Island of Ningbo and the automatic weather stations along the northern coastal Zhejiang province, an analysis is made of the wind profile characteristics in the nearsurface boundary layer in different prevailing winds and different wind forces. Results show that wind speed at the tower base was stronger than that of the next upper layer in north or south wind because of topography. The wind profiles were different under different weather patterns, which basically meets the logarithm law at layers below 320 m when wind is from south, but when the tower was affected by TCs or the winds from north, the profile could be separated into 3 layers: within the constant flux layer, the winds meets basically the logarithm law; at the next layer above, there exists usually a layer with hardly changing velocity because of TCs, and there is slight decreasing in north winds; at the upper layers, winds increase. The threelayer structure is more obviously while north winds prevailing than TCs affecting, with the maximum velocity at about 80 to 109 m and the minimum at 200 to 250 m. Within the layers with the wind profile following the logarithm law, the fitting goodness of weak wind profiles is better than that of strong winds. Investigation on the profile of AWS observations indicates a consistent performance.
Based on the meteorological observations from December 2010 to May 2014 of the 370 m observation tower on the Liangmaoshan Island of Ningbo and the automatic weather stations along the northern coastal Zhejiang province, an analysis is made of the wind profile characteristics in the nearsurface boundary layer in different prevailing winds and different wind forces. Results show that wind speed at the tower base was stronger than that of the next upper layer in north or south wind because of topography. The wind profiles were different under different weather patterns, which basically meets the logarithm law at layers below 320 m when wind is from south, but when the tower was affected by TCs or the winds from north, the profile could be separated into 3 layers: within the constant flux layer, the winds meets basically the logarithm law; at the next layer above, there exists usually a layer with hardly changing velocity because of TCs, and there is slight decreasing in north winds; at the upper layers, winds increase. The threelayer structure is more obviously while north winds prevailing than TCs affecting, with the maximum velocity at about 80 to 109 m and the minimum at 200 to 250 m. Within the layers with the wind profile following the logarithm law, the fitting goodness of weak wind profiles is better than that of strong winds. Investigation on the profile of AWS observations indicates a consistent performance.
2017, 45(3):526-534.
Abstract:
By using the high temporal resolution temperature profile data observed from multichannel microwave radiometer over the ricewheat rotation cropping field observation site at Shouxian from July 2015 through May 2016, the atmospheric boundary layer heights are calculated with the potential temperature gradient method, and the diurnal, monthly, and seasonal variation characteristics of the atmospheric boundary layer heights are studied in this paper. It is found that the atmospheric boundary layer heights have a typical diurnal variation in fine weather, which is almost in the same phase of the diurnal temperature variation. During a day, the average largest height usually appears in afternoon, with the largest value in August (greater than 1520 meters) and smallest value in January (520 meters). The atmospheric boundary layer heights also show a seasonal cycle: the smallest in winter (322 meters), and the second smallest in autumn (377 meters), the second largest in spring (436 meters), and the largest in summer (499 meters). The atmospheric boundary layer height calculated from the temperature observations is 258 meters (346 meters) greater than the value from the FNL (ERAInterim) data during the daytime (i.e., 08:00-19:00 local time), while it is 144 meters (102 meters) smaller than the value from the FNL (ERAInterim data) during the nighttime (i.e., 19:00-8:00 local time).
By using the high temporal resolution temperature profile data observed from multichannel microwave radiometer over the ricewheat rotation cropping field observation site at Shouxian from July 2015 through May 2016, the atmospheric boundary layer heights are calculated with the potential temperature gradient method, and the diurnal, monthly, and seasonal variation characteristics of the atmospheric boundary layer heights are studied in this paper. It is found that the atmospheric boundary layer heights have a typical diurnal variation in fine weather, which is almost in the same phase of the diurnal temperature variation. During a day, the average largest height usually appears in afternoon, with the largest value in August (greater than 1520 meters) and smallest value in January (520 meters). The atmospheric boundary layer heights also show a seasonal cycle: the smallest in winter (322 meters), and the second smallest in autumn (377 meters), the second largest in spring (436 meters), and the largest in summer (499 meters). The atmospheric boundary layer height calculated from the temperature observations is 258 meters (346 meters) greater than the value from the FNL (ERAInterim) data during the daytime (i.e., 08:00-19:00 local time), while it is 144 meters (102 meters) smaller than the value from the FNL (ERAInterim data) during the nighttime (i.e., 19:00-8:00 local time).
2017, 45(3):535-541.
Abstract:
Selecting the 17 cities in Shandong Province as research objects, the index system is determined by three factors of affecting agricultural droughts in Shandong Province: natural environment, economic environment, and social environment. The model of agricultural drought frangibility zoning is constructed, and the judgment matrix for Shandong Province is established. Agricultural drought frangibility assessment studies in Shandong Province are conducted, and the frangibility zoning chart of agriculture drought for 17 cities/prefectures in Shandong Province. The results show that from 2000 to 2013, there were 5 nonfrangible cities, 4 slight frangible ones, 4 frangible ones, 3 seriously frangible ones, 1 extremely serious frangible one in fragile rating in Shandong Province. Overall, the spatial distribution pattern of agricultural drought frangibility in Shandong Province is roughly lower in southeast and northwest, higher in central and southwest. The frangibility zoning results reflect the regional differences of agricultural drought risk degree in Shandong Province, and the higher frangibility cities should be as the key area of agricultural drought disaster prevention.
Selecting the 17 cities in Shandong Province as research objects, the index system is determined by three factors of affecting agricultural droughts in Shandong Province: natural environment, economic environment, and social environment. The model of agricultural drought frangibility zoning is constructed, and the judgment matrix for Shandong Province is established. Agricultural drought frangibility assessment studies in Shandong Province are conducted, and the frangibility zoning chart of agriculture drought for 17 cities/prefectures in Shandong Province. The results show that from 2000 to 2013, there were 5 nonfrangible cities, 4 slight frangible ones, 4 frangible ones, 3 seriously frangible ones, 1 extremely serious frangible one in fragile rating in Shandong Province. Overall, the spatial distribution pattern of agricultural drought frangibility in Shandong Province is roughly lower in southeast and northwest, higher in central and southwest. The frangibility zoning results reflect the regional differences of agricultural drought risk degree in Shandong Province, and the higher frangibility cities should be as the key area of agricultural drought disaster prevention.
Yang Yuanjian
,
Kong Junsong
,
Wu Biwen
,
Shi Chune
,
Sun Yi
,
Song Youzhi
,
Sheng Shaoxue
,
Wang Xiang
,
He Binfang
,
Song Weiheng
,
Wang Deshan
2017, 45(3):542-547.
Abstract:
Based on the regional meteorological ecoenvironmental observations and satellite remote sensing data, the visibility, haze frequency, temperaturehumidity adaptive frequency, and vegetation cover are selected as four key factors and analyzed to build the regional Meteorological Ecoenvironmental Index (MEI) for rural regions. The applicability and reliability of MEI are tested and validated from August to December 2015 MEI can reasonably reflect differences in spatial and seasonal variations of regional ecoenvironmental quality, which are according with the fact, which is applicable in the haze monitoring and assessment in rural regions, as well as the impact assessment of local socioeconomic development on ecoenvironment. The findings provide a scientific reference for the health development of regional ecoenvironment in rural regions.
Based on the regional meteorological ecoenvironmental observations and satellite remote sensing data, the visibility, haze frequency, temperaturehumidity adaptive frequency, and vegetation cover are selected as four key factors and analyzed to build the regional Meteorological Ecoenvironmental Index (MEI) for rural regions. The applicability and reliability of MEI are tested and validated from August to December 2015 MEI can reasonably reflect differences in spatial and seasonal variations of regional ecoenvironmental quality, which are according with the fact, which is applicable in the haze monitoring and assessment in rural regions, as well as the impact assessment of local socioeconomic development on ecoenvironment. The findings provide a scientific reference for the health development of regional ecoenvironment in rural regions.
2017, 45(3):548-554.
Abstract:
Safety and reliability for lightning protection design of a new generation weather radar is an important prerequisite to guarantee the normal operation of radar equipment, particularly in the design of the direct lightning protection scheme. This paper presents a back stepping method for calculating the height of a lightning rod for a new generation weather radar station by using the rolling ball method, and calculate the minimum height of the lightning rod under certain conditions in three schemes respectively: two lightning rods, three lightning rods, and four lightning rods. By using threedimensional graphics method to verify, the results show that the calculation results of the rolling the ball method is the same as that of threedimensional graphics method. By comparison and analysis of calculation results, it is found that the best lightning protection solution for new generation weather radar stations is the three lightning rod scheme, and the horizontal distance between the roof edge and the radome of the radar must be greater than 334 m when the three lightning rod scheme is adopted.
Safety and reliability for lightning protection design of a new generation weather radar is an important prerequisite to guarantee the normal operation of radar equipment, particularly in the design of the direct lightning protection scheme. This paper presents a back stepping method for calculating the height of a lightning rod for a new generation weather radar station by using the rolling ball method, and calculate the minimum height of the lightning rod under certain conditions in three schemes respectively: two lightning rods, three lightning rods, and four lightning rods. By using threedimensional graphics method to verify, the results show that the calculation results of the rolling the ball method is the same as that of threedimensional graphics method. By comparison and analysis of calculation results, it is found that the best lightning protection solution for new generation weather radar stations is the three lightning rod scheme, and the horizontal distance between the roof edge and the radome of the radar must be greater than 334 m when the three lightning rod scheme is adopted.
2017, 45(3):555-560.
Abstract:
In order to avoid the errors of the site observation data during the spatial interpolation and improve the accuracy of the spatialization on corn temperature suitability index, the CMA Land Data Assimilation System is used, which applies hourly temperature data. The daily temperature suitability index calculation model is set up in the space, which is based on the corn dynamic suitability calculation method of Inner Mongolia by using of GIS spatial analysis and Model Builder. The temperature suitability dynamic model requires inputting date that is used to calculate the spatial distribution of temperature indicators, such as optimum temperature, maximum temperature, and minimum temperature. Combining with the spatial distribution of the average daily temperature of CLDAS, the temperature suitability index is calculated on the space by using condition functions. Regular site suitability and model calculation results are compared from May to August 2015 as an example. The results show that the maximum absolute error is 0156, and the absolute error of about 90% results is less than 01 The maximum relative error is 369%, and the relative error of about 70% results is less than 8%. CLDAS data can reflect the influence of high temperature in May and low temperature in August, in which suitability index is 0 By using the Model Builder, the constructed calculation model of suitability index has higher practicability. Based on CLDAS temperature data, the temperature suitability index error is relatively small, and the precision of the spatialization can be used for further researches.
In order to avoid the errors of the site observation data during the spatial interpolation and improve the accuracy of the spatialization on corn temperature suitability index, the CMA Land Data Assimilation System is used, which applies hourly temperature data. The daily temperature suitability index calculation model is set up in the space, which is based on the corn dynamic suitability calculation method of Inner Mongolia by using of GIS spatial analysis and Model Builder. The temperature suitability dynamic model requires inputting date that is used to calculate the spatial distribution of temperature indicators, such as optimum temperature, maximum temperature, and minimum temperature. Combining with the spatial distribution of the average daily temperature of CLDAS, the temperature suitability index is calculated on the space by using condition functions. Regular site suitability and model calculation results are compared from May to August 2015 as an example. The results show that the maximum absolute error is 0156, and the absolute error of about 90% results is less than 01 The maximum relative error is 369%, and the relative error of about 70% results is less than 8%. CLDAS data can reflect the influence of high temperature in May and low temperature in August, in which suitability index is 0 By using the Model Builder, the constructed calculation model of suitability index has higher practicability. Based on CLDAS temperature data, the temperature suitability index error is relatively small, and the precision of the spatialization can be used for further researches.
2017, 45(3):561-565.
Abstract:
Human comfort index evaluates the comfortability of human bodies in different climatic conditions from a meteorological point of view, according to the heat exchange between human body and the atmosphere to develop biometeorological indicators. Comfort index is universal in the application for various seasons. The human comfort index algorithm is studied, and the data is used to revise the standards of comfort classification. The human comfort index collection software is designed for data collection, processing, display and application. After two years of trial operation, it is proved that the software is stable and can meet the operational requirements.
Human comfort index evaluates the comfortability of human bodies in different climatic conditions from a meteorological point of view, according to the heat exchange between human body and the atmosphere to develop biometeorological indicators. Comfort index is universal in the application for various seasons. The human comfort index algorithm is studied, and the data is used to revise the standards of comfort classification. The human comfort index collection software is designed for data collection, processing, display and application. After two years of trial operation, it is proved that the software is stable and can meet the operational requirements.
2017, 45(3):566-570.
Abstract:
The temperature variation and seasonal difference around Beijing Fifth Ring Road are analyzed based on the observed air temperature of 1998-2009 of the Beijing Meteorological Observatory, Daxing Station and Fengtai Station, using the average of the data from Daxing and Fengtai stations as reference. Using the observed daily air temperature at 2 m in 2008 and 2009 from Beijing Meteorological Observatory and the stations within 20 km, the the representativeness of temperature data is studied through calculating correlation coefficient, the average of the absolute values of temperature differences, and the average of the absolute values of the differences between minimum and maximum temperature from Beijing Meteorological Observatory and those from other stations in Beijing. The results show that the average temperature in five years after the completion of the Beijing Fifth Ring Road increased by 098 ℃. The impact of the Fifth Ring Road on temperature data of the Beijing Meteorological Observatory varies from season to season. The increase is the biggest in spring and the smallest in autumn. The ratio of good representativeness of temperature is 521%. and the temperature from the Beijing Meteorological Observatory is well representative of average temperature of 0 to 5 km，5 km to 10 km，10 km to 15 km，and 15 km to 20 km zones.
The temperature variation and seasonal difference around Beijing Fifth Ring Road are analyzed based on the observed air temperature of 1998-2009 of the Beijing Meteorological Observatory, Daxing Station and Fengtai Station, using the average of the data from Daxing and Fengtai stations as reference. Using the observed daily air temperature at 2 m in 2008 and 2009 from Beijing Meteorological Observatory and the stations within 20 km, the the representativeness of temperature data is studied through calculating correlation coefficient, the average of the absolute values of temperature differences, and the average of the absolute values of the differences between minimum and maximum temperature from Beijing Meteorological Observatory and those from other stations in Beijing. The results show that the average temperature in five years after the completion of the Beijing Fifth Ring Road increased by 098 ℃. The impact of the Fifth Ring Road on temperature data of the Beijing Meteorological Observatory varies from season to season. The increase is the biggest in spring and the smallest in autumn. The ratio of good representativeness of temperature is 521%. and the temperature from the Beijing Meteorological Observatory is well representative of average temperature of 0 to 5 km，5 km to 10 km，10 km to 15 km，and 15 km to 20 km zones.
2017, 45(3):571-574.
Abstract:
Climatic regionalization of high acid apple is studied, which can provide scientific and technological support for the rational distribution of the planting base of high acid apple in Ningxia. Based on the previous research results, the climatic zoning index and zoning principles of the high acid apple in Ningxia are established. Meteorological observation data of 30 year (1981 to 2010) of 23 meteorological stations in Ningxia are collected. According to the ≥10 ℃ active accumulated temperature, annual mean temperature, sunshine duration from July to September, daily temperature range from July to September，the refined climate zoning map of the high acid apple is given. The results show that in the Yellow River irrigation area and the Qingshui River basin of the middle arid belt are more suitable for latematuring high acid apple，and most areas in central and southern mountainous areas are not suitable for planting latematuring high acid apple.
Climatic regionalization of high acid apple is studied, which can provide scientific and technological support for the rational distribution of the planting base of high acid apple in Ningxia. Based on the previous research results, the climatic zoning index and zoning principles of the high acid apple in Ningxia are established. Meteorological observation data of 30 year (1981 to 2010) of 23 meteorological stations in Ningxia are collected. According to the ≥10 ℃ active accumulated temperature, annual mean temperature, sunshine duration from July to September, daily temperature range from July to September，the refined climate zoning map of the high acid apple is given. The results show that in the Yellow River irrigation area and the Qingshui River basin of the middle arid belt are more suitable for latematuring high acid apple，and most areas in central and southern mountainous areas are not suitable for planting latematuring high acid apple.
2017, 45(3):575-578.
Abstract:
Through the analysis of a lightning protection scheme, the correct understanding of the nominal parameters such as discharge current and voltage protection level (〖WTBX〗U〖WTBZ〗p) in the lightning protection design scheme of the Surge Protective Device (SPD). Based on two types of products of SPDⅡlevel tests, comparing and analyzing the data in the test reports, it is found out that 〖WTBX〗U〖WTBZ〗p should be judged not only according to the marked value on the name plate of a SPD, but also determined by considering comprehensively the data in the test report of the SPD. So it is suggested that the manufacturers provide several 〖WTBX〗U〖WTBZ〗p values corresponding to the characteristic current values under the nominal discharge current values, according to the test reports, or provide a figure of the inrush current residual voltage curve in the product description to help users in understanding of the characteristics of SPD pressure limits.
Through the analysis of a lightning protection scheme, the correct understanding of the nominal parameters such as discharge current and voltage protection level (〖WTBX〗U〖WTBZ〗p) in the lightning protection design scheme of the Surge Protective Device (SPD). Based on two types of products of SPDⅡlevel tests, comparing and analyzing the data in the test reports, it is found out that 〖WTBX〗U〖WTBZ〗p should be judged not only according to the marked value on the name plate of a SPD, but also determined by considering comprehensively the data in the test report of the SPD. So it is suggested that the manufacturers provide several 〖WTBX〗U〖WTBZ〗p values corresponding to the characteristic current values under the nominal discharge current values, according to the test reports, or provide a figure of the inrush current residual voltage curve in the product description to help users in understanding of the characteristics of SPD pressure limits.
2017, 45(3):579-582.
Abstract:
By analyzing the hardware structure and working principles of CTL713C Doppler weather radar digital receiving and processing system, this paper introduces the normal working conditions of the digital receiving and processing system based on the hardware status. The diagnosis of the CTL713C Doppler weather radar digital signal processing system is divided into signal processor and digital receiver, connected with three kinds of faults. The corresponding faults are identified according to terminal display and system hardware status indicator comprehensively. The diagnosis results are verified by a fault case of the Jiaozuo CTL713C Doppler weather radar digital signal processing system. The fault diagnosis methods and principles of the radar digital receiving and processing system are summarized, and the importance of the daily maintenance of the system hardware is discussed
By analyzing the hardware structure and working principles of CTL713C Doppler weather radar digital receiving and processing system, this paper introduces the normal working conditions of the digital receiving and processing system based on the hardware status. The diagnosis of the CTL713C Doppler weather radar digital signal processing system is divided into signal processor and digital receiver, connected with three kinds of faults. The corresponding faults are identified according to terminal display and system hardware status indicator comprehensively. The diagnosis results are verified by a fault case of the Jiaozuo CTL713C Doppler weather radar digital signal processing system. The fault diagnosis methods and principles of the radar digital receiving and processing system are summarized, and the importance of the daily maintenance of the system hardware is discussed
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.