Volume 49,Issue 2,2021 Table of Contents
2021, 49(2):149-156.
Abstract:
Fengyun3D（FY3D）, the Chinese nextgeneration polar orbiting meteorological satellite，launched in 2017， offers several advances over the FY3C. To support the major objective of developing data application of FY3D， it contains rich surface information such as vegetation and mountain areas, and plays an important role in remote sensing application monitoring. However, as a polar orbit satellite, FY3D orbits cover the corresponding area every 102 minutes. Because of the difference of zenith angle, solar altitude angle and calibration of each orbit, the brightness of different orbit data varies significantly in the global mosaic, and there are obvious gaps, as well as the movement and change of clouds, so there are obvious differences in cloud data between different orbits, which affects the application of MERSIII global data, especially in vegetation monitoring and urban heat island monitoring. Based on the global saw browsing system of the Fengyun3D satellite service system, this paper innovatively proposes a technology of data fusion between orbits by using the satellite zenith angle based on a certain optimization algorithm, designs and develops the corresponding engineering modules to eliminate the data difference between orbits. The practice proves that this technology has obvious effect and can significantly improve the telemetry of subsequent MERSIII loads to improve product application.
Fengyun3D（FY3D）, the Chinese nextgeneration polar orbiting meteorological satellite，launched in 2017， offers several advances over the FY3C. To support the major objective of developing data application of FY3D， it contains rich surface information such as vegetation and mountain areas, and plays an important role in remote sensing application monitoring. However, as a polar orbit satellite, FY3D orbits cover the corresponding area every 102 minutes. Because of the difference of zenith angle, solar altitude angle and calibration of each orbit, the brightness of different orbit data varies significantly in the global mosaic, and there are obvious gaps, as well as the movement and change of clouds, so there are obvious differences in cloud data between different orbits, which affects the application of MERSIII global data, especially in vegetation monitoring and urban heat island monitoring. Based on the global saw browsing system of the Fengyun3D satellite service system, this paper innovatively proposes a technology of data fusion between orbits by using the satellite zenith angle based on a certain optimization algorithm, designs and develops the corresponding engineering modules to eliminate the data difference between orbits. The practice proves that this technology has obvious effect and can significantly improve the telemetry of subsequent MERSIII loads to improve product application.
2021, 49(2):157-165.
Abstract:
In order to detect and analyze the threedimensional fine structure and evolution law of severe convective weather such as tornado with a small scale, short life cycle and heavy disaster, Jiangsu is building a highresolution dual polarization weather radar network in the North Jiangsu Plain, where tornadoes occur freguently. This paper focuses on the networking strategy of the tornado radar network in the northern Jiangsu to support the construction of the tornado radar network. The study shows: (1) The tornado radar network in the northern Jiangsu adopts the Xband weather radar (dual polarization) network with large antenna, all solid state and high performance, and high performance indexes, which can not only realize longdistance detection, but also obtain data products with a great deal of high spatial consistency and high spatialtemporal resolution data, to a large extent meeting the requirements of fast and fine detection 〖JP2〗for tornadoes and other severe convection weather. In addition, in order to overcome the problem of velocity ambiguity for Xband weather radar, a higher pulse repetition frequency can be used to 〖JP2〗expand the speed measurement range. (2) In the North Jiangsu tornado radar network, a triangle (〖WTBX〗N〖WTBZ〗 = 3,〖JP〗〖WTBX〗 L〖WTBZ〗 = 60 km) network topology is used for theoretical calculation. When the cumulative spatial density value is 90%, the performance indicators are: beam size 〖WTBX〗b〖WTBZ〗s is 282.0 m, the minimum beam height 〖WTBX〗b〖WTBZ〗h is 52.6 m, and the detection sensitivity 〖WTBX〗Z〖WTBZ〗min is 2.7 dB. Compared with the single Sband operational radar, the beam size of Xband network radar in the northern Jiangsu has reduced by about 2 times, the minimum beam height by about 1.5 times, and the detection sensitivity by about 2.4 dB. That is to say, the azimuth resolution, detection blind area, weak echo detection ability, and data spatial consistency have been greatly improved, which can provide more radar data with a high spatial resolution, less than 1 km or even 100 m, high weak echo detection capability, and high spatial consistency. All that is convenient for monitoring, forecasting, and early warning of severe convective weather such as tornadoes. (3) Five Xband allsolidstate dual polarization Doppler weather radar sets are respectively equipped in Yandu, Funing, Dafeng, Baoying, and Xinghua (tornadoprone areas), which forms the tornado radar network in the northern Jiangsu. Considering the various factors of radar location selection in the North Jiangsu Plain, the basic unit of the final network adopts the topology structure of approximate triangle (〖WTBX〗N〖WTBZ〗=3, 〖WTBX〗L〖WTBZ〗=45-65 km). The high spatialtemporal resolution tornado detection radar network is composed of three basic networking units, which is similar to a trapezoid structure, embedded in the Sband radar service network (equipped in Yancheng, Huai’an, Taizhou, respectively). In the future, the number of radar sets can further increase and the observation area can be widened. Xband weather radar or Cband phased array weather radar can be added in the tornado prone areas such as Gaoyou.
In order to detect and analyze the threedimensional fine structure and evolution law of severe convective weather such as tornado with a small scale, short life cycle and heavy disaster, Jiangsu is building a highresolution dual polarization weather radar network in the North Jiangsu Plain, where tornadoes occur freguently. This paper focuses on the networking strategy of the tornado radar network in the northern Jiangsu to support the construction of the tornado radar network. The study shows: (1) The tornado radar network in the northern Jiangsu adopts the Xband weather radar (dual polarization) network with large antenna, all solid state and high performance, and high performance indexes, which can not only realize longdistance detection, but also obtain data products with a great deal of high spatial consistency and high spatialtemporal resolution data, to a large extent meeting the requirements of fast and fine detection 〖JP2〗for tornadoes and other severe convection weather. In addition, in order to overcome the problem of velocity ambiguity for Xband weather radar, a higher pulse repetition frequency can be used to 〖JP2〗expand the speed measurement range. (2) In the North Jiangsu tornado radar network, a triangle (〖WTBX〗N〖WTBZ〗 = 3,〖JP〗〖WTBX〗 L〖WTBZ〗 = 60 km) network topology is used for theoretical calculation. When the cumulative spatial density value is 90%, the performance indicators are: beam size 〖WTBX〗b〖WTBZ〗s is 282.0 m, the minimum beam height 〖WTBX〗b〖WTBZ〗h is 52.6 m, and the detection sensitivity 〖WTBX〗Z〖WTBZ〗min is 2.7 dB. Compared with the single Sband operational radar, the beam size of Xband network radar in the northern Jiangsu has reduced by about 2 times, the minimum beam height by about 1.5 times, and the detection sensitivity by about 2.4 dB. That is to say, the azimuth resolution, detection blind area, weak echo detection ability, and data spatial consistency have been greatly improved, which can provide more radar data with a high spatial resolution, less than 1 km or even 100 m, high weak echo detection capability, and high spatial consistency. All that is convenient for monitoring, forecasting, and early warning of severe convective weather such as tornadoes. (3) Five Xband allsolidstate dual polarization Doppler weather radar sets are respectively equipped in Yandu, Funing, Dafeng, Baoying, and Xinghua (tornadoprone areas), which forms the tornado radar network in the northern Jiangsu. Considering the various factors of radar location selection in the North Jiangsu Plain, the basic unit of the final network adopts the topology structure of approximate triangle (〖WTBX〗N〖WTBZ〗=3, 〖WTBX〗L〖WTBZ〗=45-65 km). The high spatialtemporal resolution tornado detection radar network is composed of three basic networking units, which is similar to a trapezoid structure, embedded in the Sband radar service network (equipped in Yancheng, Huai’an, Taizhou, respectively). In the future, the number of radar sets can further increase and the observation area can be widened. Xband weather radar or Cband phased array weather radar can be added in the tornado prone areas such as Gaoyou.
2021, 49(2):166-173.
Abstract:
In order to make up for the lack of evaporation data after the stop of evaporation pan manual observations at the National Meteorological Observatory, three regional datasets of the northern Shaanxi, Guanzhong and southern Shaanxi and three single station datasets of Yulin, Jinghe and Hanzhong are established. By establishing and optimizing the KNN (KNearest Neighbor method) and MLP (MultiLayer Perceptron) models and its parameters, the regional estimation model of evaporation and the single station estimation model are constructed and verified respectively. The results show that: (1) While estimating the regional evaporation, the KNN model shows good generalization performance, and the average Mean Square Error, Total Relative Error and Correct Rate values are 0.42 and 2.1%, 57.0%, respectively; the generalization performance of the MLP model in the northern Shaanxi is poor. (2) While estimating the evaporation of a single station, the performance of the single station estimation model based on the Knearest neighbor method is superior to the regional estimation model, and the average Mean Square Error and Correct Rate index values are 0.48 and 55.0%, the absolute average value of Total Relative Error at Yulin and Jinghe 1.6%, and that at Hanzhong is relatively high, reaching 10.3%. This research provides a tool based on the Machine Learning for the estimation of daily, monthly, seasonal and annual evaporation in different climate regions and single stations and the quality control of daily evaporation data.
In order to make up for the lack of evaporation data after the stop of evaporation pan manual observations at the National Meteorological Observatory, three regional datasets of the northern Shaanxi, Guanzhong and southern Shaanxi and three single station datasets of Yulin, Jinghe and Hanzhong are established. By establishing and optimizing the KNN (KNearest Neighbor method) and MLP (MultiLayer Perceptron) models and its parameters, the regional estimation model of evaporation and the single station estimation model are constructed and verified respectively. The results show that: (1) While estimating the regional evaporation, the KNN model shows good generalization performance, and the average Mean Square Error, Total Relative Error and Correct Rate values are 0.42 and 2.1%, 57.0%, respectively; the generalization performance of the MLP model in the northern Shaanxi is poor. (2) While estimating the evaporation of a single station, the performance of the single station estimation model based on the Knearest neighbor method is superior to the regional estimation model, and the average Mean Square Error and Correct Rate index values are 0.48 and 55.0%, the absolute average value of Total Relative Error at Yulin and Jinghe 1.6%, and that at Hanzhong is relatively high, reaching 10.3%. This research provides a tool based on the Machine Learning for the estimation of daily, monthly, seasonal and annual evaporation in different climate regions and single stations and the quality control of daily evaporation data.
2021, 49(2):174-183.
Abstract:
Based on the inversion model of wind measurement for meteorological rockets, the method for evaluating the uncertainty of wind inversion results is studied by the error theory and curve fitting least square principle. According to the motion law of the rocket sonde in the air, a mathematical model is established and the inversion function of wind speed and wind direction is derived. According to the error theory, the general expressions of the uncertainty of wind speed and wind direction are given. Based on the principle of polynomial least square fitting, the formulas of the systematic error and random error of wind speed and direction are derived, and the coefficients in the formulas are obtained. Taking the measured data as an example, the above formulas are used to analyze and calculate the atmospheric wind and the uncertainty. The results show that the uncertainty of wind speed decreases with the decrease of height. The uncertainty is 3.5 to 2.8 m/s in the 60 to 50 km, and less than 1 m/s below 50 km. When the wind direction is around the north (0°), the inversion uncertainty of wind direction will increase abnormally, and the inversion uncertainty is basically within 10° in the other cases.
Based on the inversion model of wind measurement for meteorological rockets, the method for evaluating the uncertainty of wind inversion results is studied by the error theory and curve fitting least square principle. According to the motion law of the rocket sonde in the air, a mathematical model is established and the inversion function of wind speed and wind direction is derived. According to the error theory, the general expressions of the uncertainty of wind speed and wind direction are given. Based on the principle of polynomial least square fitting, the formulas of the systematic error and random error of wind speed and direction are derived, and the coefficients in the formulas are obtained. Taking the measured data as an example, the above formulas are used to analyze and calculate the atmospheric wind and the uncertainty. The results show that the uncertainty of wind speed decreases with the decrease of height. The uncertainty is 3.5 to 2.8 m/s in the 60 to 50 km, and less than 1 m/s below 50 km. When the wind direction is around the north (0°), the inversion uncertainty of wind direction will increase abnormally, and the inversion uncertainty is basically within 10° in the other cases.
2021, 49(2):184-191.
Abstract:
Along with the increasing flights at the Beijing Capital International Airport in recent years, the probability of encountering wind shear has greatly increased. Until now, there is no effective method for wind shear early warning. Wind LIDAR can quickly scan a wind field in three dimensions, and its measurement range is 45 to 4000 m. The LIDAR of the Beijing Capital International Airport is installed next to the west runway, and it adopts the glide path scanning mode which can capture the wind field of the aircraft’s takeoff and landing areas in three dimensions. In this paper, the realtime detection data is interpolated, and the data in the area passed by the aircrafts during the descent are selected to form the glide path headwind profile, and the wind shear detection algorithm is used to detect the wind shear from the headwind profile. Then the location and the time when wind shear happens are obtained and identified.In this paper, the wind shear reports provided by the flight crew are used to verify the research results. The verified results show that the method can detect wind shear on the path of the aircraft glide path, and the warning rate reaches 73.33%. The research proves that Lidar can detect and identify wind shear effectively.
Along with the increasing flights at the Beijing Capital International Airport in recent years, the probability of encountering wind shear has greatly increased. Until now, there is no effective method for wind shear early warning. Wind LIDAR can quickly scan a wind field in three dimensions, and its measurement range is 45 to 4000 m. The LIDAR of the Beijing Capital International Airport is installed next to the west runway, and it adopts the glide path scanning mode which can capture the wind field of the aircraft’s takeoff and landing areas in three dimensions. In this paper, the realtime detection data is interpolated, and the data in the area passed by the aircrafts during the descent are selected to form the glide path headwind profile, and the wind shear detection algorithm is used to detect the wind shear from the headwind profile. Then the location and the time when wind shear happens are obtained and identified.In this paper, the wind shear reports provided by the flight crew are used to verify the research results. The verified results show that the method can detect wind shear on the path of the aircraft glide path, and the warning rate reaches 73.33%. The research proves that Lidar can detect and identify wind shear effectively.
2021, 49(2):192-199.
Abstract:
Combining the weather situation and the data of the upper level wind field, 370 m tower monitoring, ground elements, laser cloud height meter, and millimeter wave radar monitoring, the sea fog process on 15 February 2018 in the waterway of Ningbo Beilun Port is analyzed. The results show that this was a sea fog process dominated by the prefrontal fog. Under the background of the upper warm and lower cold front, the surface water vapor was abundant, the wind force was mild, and the structure of nearinverse temperature provided favorable conditions for the formation and maintenance of the sea fog. The upper and lower atmospheric wind directions were inconsistent, which was not conducive to the vertical air exchange, but conducive to the generation of fogs or hazes. The optical properties and process evolution trend of fog droplet particles can be clearly obtained by the backscattering coefficient, extinction coefficient and depolarization ratio monitored by the laser cloud altimeter. With the formation, development and dissipation of the sea fog, the intensity of the backscattering coefficient also became increased, intensified and gradually weakened. The droplet particles were small and light in fog weather, and the fluctuation amplitude was large. The Fourier transform frequency spectrum of particles at a certain height had a higher corresponding frequency, the proportion of which was more than 50%.
Combining the weather situation and the data of the upper level wind field, 370 m tower monitoring, ground elements, laser cloud height meter, and millimeter wave radar monitoring, the sea fog process on 15 February 2018 in the waterway of Ningbo Beilun Port is analyzed. The results show that this was a sea fog process dominated by the prefrontal fog. Under the background of the upper warm and lower cold front, the surface water vapor was abundant, the wind force was mild, and the structure of nearinverse temperature provided favorable conditions for the formation and maintenance of the sea fog. The upper and lower atmospheric wind directions were inconsistent, which was not conducive to the vertical air exchange, but conducive to the generation of fogs or hazes. The optical properties and process evolution trend of fog droplet particles can be clearly obtained by the backscattering coefficient, extinction coefficient and depolarization ratio monitored by the laser cloud altimeter. With the formation, development and dissipation of the sea fog, the intensity of the backscattering coefficient also became increased, intensified and gradually weakened. The droplet particles were small and light in fog weather, and the fluctuation amplitude was large. The Fourier transform frequency spectrum of particles at a certain height had a higher corresponding frequency, the proportion of which was more than 50%.
7 Influencing Factors and Physical Statistical Prediction Methods of Summer Rainfall Anomaly in Yunnan
2021, 49(2):200-210.
Abstract:
Because of the obvious interannual variation of summer precipitation in Yunnan and various influencing factors, it is difficult to predict summer precipitation. The daily precipitation observation data from 122 meteorological stations in Yunnan Province from 1965 to 2017 and NCEP atmospheric circulation data and the yeartoyear increment method are used to predict summer precipitation in Yunnan. In order to provide a theoretical basis for the prediction of summer precipitation in Yunnan, it is indispensable to analyze the varying regularities and physical processes affecting the yeartoyear increments of summer rainfall and atmospheric circulation. The prediction model is established based on the method of multiple linear regression analysis. Six predictors that have explicitly physical meaning are selected: the anomaly of the SST (Sea Surface Temperature) in the South Pacific in February, SLP (Sea Level Pressure) in Northeast Asia in February, 500 hPa geopotential height in May over the North America in April, SLP in the northern Pacific in May, 500 hPa geopotential height in the northern India in January, and 200 hPa geopotential height in South Australia in February. Using the above six predictors, the prediction model of summer rainfall is established. In addition, not only the crossingtest verification is conducted on the prediction model is with the independent samples from 1965 to 2017, but also the prediction test verification is conducted from 1998 to 2017. In the crossingtest verification, the correlation coefficients between predicted and observed interannual increments of summer rainfall is 0.85, and the root mean square relative error is 8.0%. In the prediction test verification, the root mean square relative error of is 9.1%. The prediction model makes good predictions, about 63.0% of the summer rainfall anomaly. The prediction model shows satisfactory forecasting ability.
Because of the obvious interannual variation of summer precipitation in Yunnan and various influencing factors, it is difficult to predict summer precipitation. The daily precipitation observation data from 122 meteorological stations in Yunnan Province from 1965 to 2017 and NCEP atmospheric circulation data and the yeartoyear increment method are used to predict summer precipitation in Yunnan. In order to provide a theoretical basis for the prediction of summer precipitation in Yunnan, it is indispensable to analyze the varying regularities and physical processes affecting the yeartoyear increments of summer rainfall and atmospheric circulation. The prediction model is established based on the method of multiple linear regression analysis. Six predictors that have explicitly physical meaning are selected: the anomaly of the SST (Sea Surface Temperature) in the South Pacific in February, SLP (Sea Level Pressure) in Northeast Asia in February, 500 hPa geopotential height in May over the North America in April, SLP in the northern Pacific in May, 500 hPa geopotential height in the northern India in January, and 200 hPa geopotential height in South Australia in February. Using the above six predictors, the prediction model of summer rainfall is established. In addition, not only the crossingtest verification is conducted on the prediction model is with the independent samples from 1965 to 2017, but also the prediction test verification is conducted from 1998 to 2017. In the crossingtest verification, the correlation coefficients between predicted and observed interannual increments of summer rainfall is 0.85, and the root mean square relative error is 8.0%. In the prediction test verification, the root mean square relative error of is 9.1%. The prediction model makes good predictions, about 63.0% of the summer rainfall anomaly. The prediction model shows satisfactory forecasting ability.
2021, 49(2):211-217.
Abstract:
This paper adopts the precipitation data of 74 meteorological stations in Tibet from 2012 to 2018, as well as the hourly, daily, monthly, seasonal, and annual precipitation data of Modog Station to analyze the spatial distribution of precipitation days, cumulative precipitation, and intense rainfall in Tibet. The results show that Medog is the precipitation center of Tibet, with the most precipitation days and the largest accumulated precipitation, and it is also the area with the highest probability of extreme intense precipitation. The precipitation in Medog is mainly concentrated from March to October, and the precipitation presents a dualpeak pattern, with peaks appearing in June and September, respectively. The precipitation in September has a high correlation with the annual precipitation. The rainstorms occur most frequently in Medog in May, August, and September. The number of rainstorm days increases sharply in May, which was equivalent to the number of rainstorm days in August and September. The dry and wet seasons of Medog are distinct, and there occur night rains frequently. The probability of rainfall from 03:00 to 07:00 presents 50% or above. Medog is located at the southernmost tip of Tibet, with the altitude rising from the lowest 115 meters to 1200 meters. The humid air currents from the Indian Ocean drive along the Yarlung Zangbo Valley. The uplift of the terrain makes the precipitation in Medog comparable to that of coastal cities at the same latitude in China.
This paper adopts the precipitation data of 74 meteorological stations in Tibet from 2012 to 2018, as well as the hourly, daily, monthly, seasonal, and annual precipitation data of Modog Station to analyze the spatial distribution of precipitation days, cumulative precipitation, and intense rainfall in Tibet. The results show that Medog is the precipitation center of Tibet, with the most precipitation days and the largest accumulated precipitation, and it is also the area with the highest probability of extreme intense precipitation. The precipitation in Medog is mainly concentrated from March to October, and the precipitation presents a dualpeak pattern, with peaks appearing in June and September, respectively. The precipitation in September has a high correlation with the annual precipitation. The rainstorms occur most frequently in Medog in May, August, and September. The number of rainstorm days increases sharply in May, which was equivalent to the number of rainstorm days in August and September. The dry and wet seasons of Medog are distinct, and there occur night rains frequently. The probability of rainfall from 03:00 to 07:00 presents 50% or above. Medog is located at the southernmost tip of Tibet, with the altitude rising from the lowest 115 meters to 1200 meters. The humid air currents from the Indian Ocean drive along the Yarlung Zangbo Valley. The uplift of the terrain makes the precipitation in Medog comparable to that of coastal cities at the same latitude in China.
2021, 49(2):218-226.
Abstract:
Based on the automatic meteorological station data, Doppler radar data and NECP /FNL reanalysis data, the circulation background, trigger and maintenance mechanisms, supercell structure, and cloud microphysical characters of a supercell hailstorm occurred on 13 June 2018 in the central Shandong Province are studied with the WRF model. The study shows that the hailstorm was a supercell hailstorm triggered by the mesoscale convergence line under the background of cold vortex in North China. The suction of the strong divergent flow at the top of the hail cloud was the dynamic instability maintenance mechanism. In the mature stage of the simulated hail cloud, the height of the 0 ℃ level was 4 km, and the echo height of more than 40 dBz reached 12 km; in the flow field, ascending motion was dominated, and there was a motion conversion of ascendingdescendingascending on both sides of the ascending motion, which was conducive to the collision and growth of the hail. The snow crystals were formed by the collision of supercooled cloud water and cloud ice at first, and then transformed into graupel particles by the collision of supercooled water and cloud ice, which provided enough hail embryos for hail formation. Graupel and hail particles, driven by the ascending motion, passed through the supercooled water accumulation zone of the hail cloud repeatedly, which was conducive to their continuous growth and transformation into large hailstones.
Based on the automatic meteorological station data, Doppler radar data and NECP /FNL reanalysis data, the circulation background, trigger and maintenance mechanisms, supercell structure, and cloud microphysical characters of a supercell hailstorm occurred on 13 June 2018 in the central Shandong Province are studied with the WRF model. The study shows that the hailstorm was a supercell hailstorm triggered by the mesoscale convergence line under the background of cold vortex in North China. The suction of the strong divergent flow at the top of the hail cloud was the dynamic instability maintenance mechanism. In the mature stage of the simulated hail cloud, the height of the 0 ℃ level was 4 km, and the echo height of more than 40 dBz reached 12 km; in the flow field, ascending motion was dominated, and there was a motion conversion of ascendingdescendingascending on both sides of the ascending motion, which was conducive to the collision and growth of the hail. The snow crystals were formed by the collision of supercooled cloud water and cloud ice at first, and then transformed into graupel particles by the collision of supercooled water and cloud ice, which provided enough hail embryos for hail formation. Graupel and hail particles, driven by the ascending motion, passed through the supercooled water accumulation zone of the hail cloud repeatedly, which was conducive to their continuous growth and transformation into large hailstones.
2021, 49(2):227-234.
Abstract:
Based on the data from meteorological satellites, the macrophysical and microphysical characteristics of the stratocumulus cloud system on 20 May 2019 are analyzed by using the cloud physical data from DMT (Droplet Measurement Technologies) and SPEC (Stratton Park Engineering Compang). The results show that the maximum particle number concentrations of CDP (Cloud Droplet Probe) and CIP(Cloud Imaging Probe) were 362.10 cm-3 and 191.08 L-1, respectively. The content of liquid water ranged from 0 to 0.88 g/m3. The spectral distribution shows that the particle spectra of CDP and CIP exhibited exponentialtype decline. The spectral width of the CDP particle spectrum is narrow. The spectral width of the CIP particle spectrum is narrow on the top of clouds while the lower layer is wide. The observed results of CPI show that the upper stratocumulus was mainly composed of ice and snow particles, which were dominated by nucleation and coagulation growth of ice crystals. The upper and middle particles were mainly composed of small ice crystals, some ice crystal polymers and dendritic ice crystals. The middle and lower parts were composed of supercooled water and ice crystal particles, with rich supercooled water.
Based on the data from meteorological satellites, the macrophysical and microphysical characteristics of the stratocumulus cloud system on 20 May 2019 are analyzed by using the cloud physical data from DMT (Droplet Measurement Technologies) and SPEC (Stratton Park Engineering Compang). The results show that the maximum particle number concentrations of CDP (Cloud Droplet Probe) and CIP(Cloud Imaging Probe) were 362.10 cm-3 and 191.08 L-1, respectively. The content of liquid water ranged from 0 to 0.88 g/m3. The spectral distribution shows that the particle spectra of CDP and CIP exhibited exponentialtype decline. The spectral width of the CDP particle spectrum is narrow. The spectral width of the CIP particle spectrum is narrow on the top of clouds while the lower layer is wide. The observed results of CPI show that the upper stratocumulus was mainly composed of ice and snow particles, which were dominated by nucleation and coagulation growth of ice crystals. The upper and middle particles were mainly composed of small ice crystals, some ice crystal polymers and dendritic ice crystals. The middle and lower parts were composed of supercooled water and ice crystal particles, with rich supercooled water.
2021, 49(2):235-243.
Abstract:
In the outer rain band of Typhoon Haitang, an EF1 tornado struck the Huaian District of Huaian, Jiangsu Province from 18:10 to 18:30 on 1 August 2017. Using the data of conventional observation, NCEP 1°×1° reanalysis data, and Doppler weather radar observation, this paper analyzes a tornado process. The results show that the tornado occurred in the southeast warm and wet jet between the residual low pressure of the typhoon and the edge of the subtropical high. One hour before the occurrence, the smallscale vortex appeared on the ground and moved along the ground convergence line. The adjacent ground automatic station observed an increase in air pressure, a decrease in temperature and dew point, and a significant increase in wind force when the tornado passed by. Increasing convective available potential energy, small convection inhibition energy, large vertical wind shear between 0 and 1 km, low lifting condensation level, and dry intrusion were all conducive to the formation of this tornado storm. Huaian Doppler radar detected the inflow gap, TVS characteristic, and cyclonic wind field structure. Based on the vertical helicity analysis and double Doppler radar wind field inversion methods, the structures and evolutions of tornado are studied. It is found that the smallscale vortices had generated in the vertical wind shear of the lower environment before the tornado occurred. The horizontal wind field was dominated by convergence. When the tornado occurred, the descending of cyclonic convergence center was favorable for the vortex to touch the ground. The tornado appeared on the left front of the vortex in the lower level and formed in the horizontal wind shear below 1.5 km.
In the outer rain band of Typhoon Haitang, an EF1 tornado struck the Huaian District of Huaian, Jiangsu Province from 18:10 to 18:30 on 1 August 2017. Using the data of conventional observation, NCEP 1°×1° reanalysis data, and Doppler weather radar observation, this paper analyzes a tornado process. The results show that the tornado occurred in the southeast warm and wet jet between the residual low pressure of the typhoon and the edge of the subtropical high. One hour before the occurrence, the smallscale vortex appeared on the ground and moved along the ground convergence line. The adjacent ground automatic station observed an increase in air pressure, a decrease in temperature and dew point, and a significant increase in wind force when the tornado passed by. Increasing convective available potential energy, small convection inhibition energy, large vertical wind shear between 0 and 1 km, low lifting condensation level, and dry intrusion were all conducive to the formation of this tornado storm. Huaian Doppler radar detected the inflow gap, TVS characteristic, and cyclonic wind field structure. Based on the vertical helicity analysis and double Doppler radar wind field inversion methods, the structures and evolutions of tornado are studied. It is found that the smallscale vortices had generated in the vertical wind shear of the lower environment before the tornado occurred. The horizontal wind field was dominated by convergence. When the tornado occurred, the descending of cyclonic convergence center was favorable for the vortex to touch the ground. The tornado appeared on the left front of the vortex in the lower level and formed in the horizontal wind shear below 1.5 km.
2021, 49(2):244-252.
Abstract:
Based on a typical stratiform cloud precipitation weather process in the Northwest Sichuan Basin from 16 to 17 March 2018, the conditions and physical responses of artificial precipitation enhancement operations are analyzed by using the cloud model results, satellite images, radar echoes, and sounding data. Meanwhile, based on the observation data of raindrop spectra, the microphysical characteristic response analysis of artificial precipitation enhancement operations is carried out, and the distribution characteristics of particle size velocity spectra are mainly studied. The results show that: after the rainfall enhancement operations, the number of particles with different particle diameters and different particle speeds changed significantly; large particles increased obviously; the raindrop spectra widened; and the 0.437-1.625 mm diameter spectrum and 1.5-5.2 m/s speed spectrum became significantly wider. Meanwhile, there was no obvious jump in particle size and particle velocity. The interval value distribution relatively concentrated in the particle size of 0.312 to 2.125 mm with the particle velocity of 1.1 to 6.8 m/s. The artificial precipitation has a limited influence on the size and velocity of precipitation particles. During the influence period of artificial rain enhancement operations, the intensity of precipitation, rain water content, total number concentration and effective particle size remained consistent with their respective peaks, valleys, and oscillations, as that of the natural precipitation period. Artificial precipitation does not change the correlation between the physical quantities.
Based on a typical stratiform cloud precipitation weather process in the Northwest Sichuan Basin from 16 to 17 March 2018, the conditions and physical responses of artificial precipitation enhancement operations are analyzed by using the cloud model results, satellite images, radar echoes, and sounding data. Meanwhile, based on the observation data of raindrop spectra, the microphysical characteristic response analysis of artificial precipitation enhancement operations is carried out, and the distribution characteristics of particle size velocity spectra are mainly studied. The results show that: after the rainfall enhancement operations, the number of particles with different particle diameters and different particle speeds changed significantly; large particles increased obviously; the raindrop spectra widened; and the 0.437-1.625 mm diameter spectrum and 1.5-5.2 m/s speed spectrum became significantly wider. Meanwhile, there was no obvious jump in particle size and particle velocity. The interval value distribution relatively concentrated in the particle size of 0.312 to 2.125 mm with the particle velocity of 1.1 to 6.8 m/s. The artificial precipitation has a limited influence on the size and velocity of precipitation particles. During the influence period of artificial rain enhancement operations, the intensity of precipitation, rain water content, total number concentration and effective particle size remained consistent with their respective peaks, valleys, and oscillations, as that of the natural precipitation period. Artificial precipitation does not change the correlation between the physical quantities.
2021, 49(2):253-259.
Abstract:
In order to analyze the characteristics of waterlogging disaster of summer maize in Anhui Province, and quantitatively evaluate the risk level of waterlogging disaster, in this paper we use the 48year meteorological data of Anhui Province (1971-2018), based on the waterlogging index model of summer maize, to calculate the temporal and spatial characteristics of waterlogging disaster and establish the grade index of waterlogging. Finally, through the disaster damage risk index model, we gain the risk distribution of waterlogginginduced yield loss of summer maize. The results show that the waterlogging index in the whole growth period of summer maize increased significantly at a rate of 0.027 per 10 years, and the upward trend was most obvious in early June and early August. The value of waterlogging index is between 0.08 and 0.38, and the high value area of summer maize waterlogging index include the Dabie mountain area, the central and eastern Jiangnan regions and some areas of the Huaibei region. The grade index of waterlogging disaster is relatively unanimous with the actual waterlogginginduced yield reduction, and the proportion of waterlogging grade being consistent with the actual yield reduction rate was 82.2%; The risk distributions of waterlogginginduced yield loss shows that the Dabie mountain and eastern Jianghuai and Jiangnan are high risk areas. The results have a good reference significance for regional agrometeorological disaster prevention and mitigation.
In order to analyze the characteristics of waterlogging disaster of summer maize in Anhui Province, and quantitatively evaluate the risk level of waterlogging disaster, in this paper we use the 48year meteorological data of Anhui Province (1971-2018), based on the waterlogging index model of summer maize, to calculate the temporal and spatial characteristics of waterlogging disaster and establish the grade index of waterlogging. Finally, through the disaster damage risk index model, we gain the risk distribution of waterlogginginduced yield loss of summer maize. The results show that the waterlogging index in the whole growth period of summer maize increased significantly at a rate of 0.027 per 10 years, and the upward trend was most obvious in early June and early August. The value of waterlogging index is between 0.08 and 0.38, and the high value area of summer maize waterlogging index include the Dabie mountain area, the central and eastern Jiangnan regions and some areas of the Huaibei region. The grade index of waterlogging disaster is relatively unanimous with the actual waterlogginginduced yield reduction, and the proportion of waterlogging grade being consistent with the actual yield reduction rate was 82.2%; The risk distributions of waterlogginginduced yield loss shows that the Dabie mountain and eastern Jianghuai and Jiangnan are high risk areas. The results have a good reference significance for regional agrometeorological disaster prevention and mitigation.
2021, 49(2):260-268.
Abstract:
Based on the meteorological data of Sichuan Province from 1961 to 2019 and the drought data of the counties from 1991 to 2019, this paper adopts the information diffusion method to analyze the spatial distribution of drought duration， economic loss rate, crop drought rate and the rate of population exposed to drought for the 10year and 50year return periods. The extreme model based on the generalized Pareto distribution is used to analyze the Possible Maximum economic Loss rate (PML) under different confidence levels in seven arid climate zones of Sichuan Province. The results show that: (1) For the 10year return period, the drought durations are relatively short, about 60 to 80 days in the northeastern, central and western parts of the Sichuan basin, but longer, about 100 days in the Panxi region, southern Sichuan basin and Longquan mountains. For the 50year return period, the drought durations are relatively short, about 90 to 120 days in the Jialing River basin, Fujiang River basin, Dujiangyan irrigation area, central Ganzi prefecture and northwestern Sichuan Plateau, but longer, about 150 days in the Panxi region, southwestern and central Ganzi prefecture and southern Sichuan basin. (2) For 10year and 50year return periods, the drought rates of crops are higher than 60% and 90% respectively, in the northern part of the western Sichuan Plateau, the northeastern and central parts of the Sichuan basin. In the Panxi region and Chengdu Plain, the drought rates of crops are less than 60%. (3) For the 10year and 50year return periods, the rates of population exposed to drought in the western Sichuan Plateau and the northeastern, central and southern parts of the Sichuan basin are over 60% and 80%, respectively. (4) For the 10year and 50year return periods, in the Panxi region, the western and southern Sichuan basin, the economic loss rates are less than 3% and 5%, respectively. In the western Sichuan Plateau and the northeastern and central part of the Sichuan basin, the economic loss rates are higher. Especially for some areas in the northeast Sichuan basin and northwestern Ganzi prefecture, the loss rates are larger than 10% and 20%, respectively. (5) At different confidence levels, the PMLs of Zone IV (the northeastern Sichuan basin) and Zone V (the northern Ganzi prefecture, the central and western Aba prefecture) are quite different and obviously higher than those of other five zones, with the maximum values of 28.5% and 38.6%, respectively; The PMLs of Zone VII (the southern Ganzi prefecture and the northern Panxi prefecture) have the minimum difference under different confidence levels, and the minimum difference is 3.1%. The PMLs of Zone I (Chengdu Plain) are small under different confidence levels and the overall difference is not significant.
Based on the meteorological data of Sichuan Province from 1961 to 2019 and the drought data of the counties from 1991 to 2019, this paper adopts the information diffusion method to analyze the spatial distribution of drought duration， economic loss rate, crop drought rate and the rate of population exposed to drought for the 10year and 50year return periods. The extreme model based on the generalized Pareto distribution is used to analyze the Possible Maximum economic Loss rate (PML) under different confidence levels in seven arid climate zones of Sichuan Province. The results show that: (1) For the 10year return period, the drought durations are relatively short, about 60 to 80 days in the northeastern, central and western parts of the Sichuan basin, but longer, about 100 days in the Panxi region, southern Sichuan basin and Longquan mountains. For the 50year return period, the drought durations are relatively short, about 90 to 120 days in the Jialing River basin, Fujiang River basin, Dujiangyan irrigation area, central Ganzi prefecture and northwestern Sichuan Plateau, but longer, about 150 days in the Panxi region, southwestern and central Ganzi prefecture and southern Sichuan basin. (2) For 10year and 50year return periods, the drought rates of crops are higher than 60% and 90% respectively, in the northern part of the western Sichuan Plateau, the northeastern and central parts of the Sichuan basin. In the Panxi region and Chengdu Plain, the drought rates of crops are less than 60%. (3) For the 10year and 50year return periods, the rates of population exposed to drought in the western Sichuan Plateau and the northeastern, central and southern parts of the Sichuan basin are over 60% and 80%, respectively. (4) For the 10year and 50year return periods, in the Panxi region, the western and southern Sichuan basin, the economic loss rates are less than 3% and 5%, respectively. In the western Sichuan Plateau and the northeastern and central part of the Sichuan basin, the economic loss rates are higher. Especially for some areas in the northeast Sichuan basin and northwestern Ganzi prefecture, the loss rates are larger than 10% and 20%, respectively. (5) At different confidence levels, the PMLs of Zone IV (the northeastern Sichuan basin) and Zone V (the northern Ganzi prefecture, the central and western Aba prefecture) are quite different and obviously higher than those of other five zones, with the maximum values of 28.5% and 38.6%, respectively; The PMLs of Zone VII (the southern Ganzi prefecture and the northern Panxi prefecture) have the minimum difference under different confidence levels, and the minimum difference is 3.1%. The PMLs of Zone I (Chengdu Plain) are small under different confidence levels and the overall difference is not significant.
2021, 49(2):269-277.
Abstract:
According to the theory of natural disaster risk, combined with the meteorological observation data, geographic information, population, and economic data, the comprehensive evaluation of lightning disaster risks is carried out. This paper studies the quantitative relationship between the risk and the disastercausing factor, disasterbreeding environment, and disaster bearing body, establishes the evaluation index and the AHP model, calculates the comprehensive evaluation index, divides the regional risk levels by the fuzzy comprehensive judgment and cluster analysis, and draws the lightning disaster risk zoning map. The results show that: the highrisk areas of lightning disasters are mainly concentrated in the central and southwestern Yunnan, and the southeastern Lijiang in Northwest Yunnan; the secondary highrisk areas are distributed in Xishuangbanna, Puer, Kunming, Chuxiong, the western Qujing, northern Yuxi and central Dali; medium risk areas are mainly concentrated in Lincang, Dehong, Qujing, Honghe, Lijiang, and the northern Wenshan; the lowrisk areas are mainly located in Diqing, Nujiang, and Zhaotong. The results of risk zoning are compared with the distribution of historical lightning disasters, which correspond well. To carry out the risk analysis based on predisaster defense, judge and evaluate the possibility of regional lightning risk, and analyze the influence scope and risk level of disaster causing factors, are helpful to control and dispose risks in advance, and provide references for defense decisionmaking, risk management, and emergency disposal. With the improvement of information and technical methods, the confidence and reliability of risk assessment will also be improved.
According to the theory of natural disaster risk, combined with the meteorological observation data, geographic information, population, and economic data, the comprehensive evaluation of lightning disaster risks is carried out. This paper studies the quantitative relationship between the risk and the disastercausing factor, disasterbreeding environment, and disaster bearing body, establishes the evaluation index and the AHP model, calculates the comprehensive evaluation index, divides the regional risk levels by the fuzzy comprehensive judgment and cluster analysis, and draws the lightning disaster risk zoning map. The results show that: the highrisk areas of lightning disasters are mainly concentrated in the central and southwestern Yunnan, and the southeastern Lijiang in Northwest Yunnan; the secondary highrisk areas are distributed in Xishuangbanna, Puer, Kunming, Chuxiong, the western Qujing, northern Yuxi and central Dali; medium risk areas are mainly concentrated in Lincang, Dehong, Qujing, Honghe, Lijiang, and the northern Wenshan; the lowrisk areas are mainly located in Diqing, Nujiang, and Zhaotong. The results of risk zoning are compared with the distribution of historical lightning disasters, which correspond well. To carry out the risk analysis based on predisaster defense, judge and evaluate the possibility of regional lightning risk, and analyze the influence scope and risk level of disaster causing factors, are helpful to control and dispose risks in advance, and provide references for defense decisionmaking, risk management, and emergency disposal. With the improvement of information and technical methods, the confidence and reliability of risk assessment will also be improved.
2021, 49(2):278-283.
Abstract:
In order to reveal the characteristics of lightning activities along the Fujian expressway and to make a proper lightning protection of expressway, this paper uses the lightning monitoring data of 2015 to 2018 from the expressway network of Fujian to make statistical analysis. An analysis is made of the monthly and daily changing characteristics of ground lightning, and results show that ground lightning occurs more frequently from May to September, from 14:00 to 18:00. The lightning activity distribution diagram is drawn along the Fujian expressway based on the ground lightning density, and it is concluded that the proportion of less thunder area, middle thunder area, more thunder and strong thunder area are 519%, 12.65%, 63.03% and 19.13%, respectively. The lightning intensity level distribution diagram is drawn based on the lightning current magnitude and lightning steepness, and it is concluded that 89.87% of the expressway are classified as Grade 3. Finally this paper makes statistics of cumulative probability distribution of lightning current magnitude and calculates its fitting function, and the results show that the cumulative probability distribution of lightning current magnitude along the Fujian expressway accords with that recommended by IEEE, and the fitting function is 〖WTBX〗P〖WTBZ〗=1/［1+(〖WTBX〗I〖WTBZ〗/20.05)2.642］.
In order to reveal the characteristics of lightning activities along the Fujian expressway and to make a proper lightning protection of expressway, this paper uses the lightning monitoring data of 2015 to 2018 from the expressway network of Fujian to make statistical analysis. An analysis is made of the monthly and daily changing characteristics of ground lightning, and results show that ground lightning occurs more frequently from May to September, from 14:00 to 18:00. The lightning activity distribution diagram is drawn along the Fujian expressway based on the ground lightning density, and it is concluded that the proportion of less thunder area, middle thunder area, more thunder and strong thunder area are 519%, 12.65%, 63.03% and 19.13%, respectively. The lightning intensity level distribution diagram is drawn based on the lightning current magnitude and lightning steepness, and it is concluded that 89.87% of the expressway are classified as Grade 3. Finally this paper makes statistics of cumulative probability distribution of lightning current magnitude and calculates its fitting function, and the results show that the cumulative probability distribution of lightning current magnitude along the Fujian expressway accords with that recommended by IEEE, and the fitting function is 〖WTBX〗P〖WTBZ〗=1/［1+(〖WTBX〗I〖WTBZ〗/20.05)2.642］.
2021, 49(2):284-290.
Abstract:
The content of negative oxygen ions in air has become one of the main evaluation indexes for health and tourist areas. The value of negative oxygen ions in the coastal area is high, and it is significantly influenced by thunderstorms and other weather factors. In this paper, the daily monitoring data of air negative oxygen ions, the data of lightning, rainfall and rainfall intensity from the automatic weather station in the Rizhao Dashawa National Forest Park are used to analyze and verify the relationship between the variation rate of the negative oxygen ion concentration and the meteorological factors related to thunderstorm weather. The results shows: （1） The variation rate of the negative oxygen ion concentration is closely related to thunderstorm weather. The variation rate of negative oxygen ion concentration in thunderstorm weather is higher than that in nothunderstorm weather. (2） In the initial stage of the thunderstorm, the influence of thunderstorm factors on the change rate of air negative oxygen ion concentration is obvious. With the increasing duration of the thunderstorm, the influence of the thunderstorm factors on the concentration of negative oxygen ions tends to be gentle, with a state of fluctuation. (3) During thunderstorms, there is a significant positive correlation between rainfall intensity and variation rate of the negative oxygen ion concentration. The stronger the rainfall, the more obvious the increase of the negative oxygen ion concentration in the air. There is also a significant positive correlation between lightning intensity and variation rate of the negative oxygen ion concentration. The higher the lightning intensity, the higher the variation rate of the negative oxygen ion concentration becomes.（4） According to the regression model established by the numerical change rate of negative oxygen ion concentration and the intensity of rainfall and lightning, for thunderstorms with a rainfall intensity of greater than 1.0 mm per 5 minutes and a negative lightning intensity of greater than 50 kA, the model has a high accuracy in predicting the change rate of negative oxygen ions. For thunderstorms with a rainfall intensity of less than 1.0 mm per 5 minutes and a negative lightning intensity of less than 45 kA, the ability of the model to predict the change rate of negative oxygen ions is slightly inadequate.
The content of negative oxygen ions in air has become one of the main evaluation indexes for health and tourist areas. The value of negative oxygen ions in the coastal area is high, and it is significantly influenced by thunderstorms and other weather factors. In this paper, the daily monitoring data of air negative oxygen ions, the data of lightning, rainfall and rainfall intensity from the automatic weather station in the Rizhao Dashawa National Forest Park are used to analyze and verify the relationship between the variation rate of the negative oxygen ion concentration and the meteorological factors related to thunderstorm weather. The results shows: （1） The variation rate of the negative oxygen ion concentration is closely related to thunderstorm weather. The variation rate of negative oxygen ion concentration in thunderstorm weather is higher than that in nothunderstorm weather. (2） In the initial stage of the thunderstorm, the influence of thunderstorm factors on the change rate of air negative oxygen ion concentration is obvious. With the increasing duration of the thunderstorm, the influence of the thunderstorm factors on the concentration of negative oxygen ions tends to be gentle, with a state of fluctuation. (3) During thunderstorms, there is a significant positive correlation between rainfall intensity and variation rate of the negative oxygen ion concentration. The stronger the rainfall, the more obvious the increase of the negative oxygen ion concentration in the air. There is also a significant positive correlation between lightning intensity and variation rate of the negative oxygen ion concentration. The higher the lightning intensity, the higher the variation rate of the negative oxygen ion concentration becomes.（4） According to the regression model established by the numerical change rate of negative oxygen ion concentration and the intensity of rainfall and lightning, for thunderstorms with a rainfall intensity of greater than 1.0 mm per 5 minutes and a negative lightning intensity of greater than 50 kA, the model has a high accuracy in predicting the change rate of negative oxygen ions. For thunderstorms with a rainfall intensity of less than 1.0 mm per 5 minutes and a negative lightning intensity of less than 45 kA, the ability of the model to predict the change rate of negative oxygen ions is slightly inadequate.
2021, 49(2):291-296.
Abstract:
The hazard information was collected manually for keywords and the occurrence time of geological hazards in the hazard management system of the Chinese Meteorological Administration, which have multiple organization structures in information characteristics and are thus adverse to the realtime property and objectivity of verification for meteorological risk warning to geological hazard. In this study, an objective technique of intelligent analysis for multiple information of geological hazards by computer and a realtime verification objective tool for meteorological risk warning to geological hazard are developed based on the characteristic analysis of hazard reports and a natural language processing software named Jieba. This objective tool can accomplish all the processes of verification by integrating functions of hazard information analysis, verification to objective and subjective meteorological risk warning to geological hazards, and output verification result products automatically. Verification for meteorological risk warning to geological hazards from 2015 to 2019 shows that the objective tool has an accuracy rate of 97% in gathering hazard information, higher efficiency in analyzing hazards and verifying meteorological risk warning, which has obvious advantages of real time and integration compared with similar tools.
The hazard information was collected manually for keywords and the occurrence time of geological hazards in the hazard management system of the Chinese Meteorological Administration, which have multiple organization structures in information characteristics and are thus adverse to the realtime property and objectivity of verification for meteorological risk warning to geological hazard. In this study, an objective technique of intelligent analysis for multiple information of geological hazards by computer and a realtime verification objective tool for meteorological risk warning to geological hazard are developed based on the characteristic analysis of hazard reports and a natural language processing software named Jieba. This objective tool can accomplish all the processes of verification by integrating functions of hazard information analysis, verification to objective and subjective meteorological risk warning to geological hazards, and output verification result products automatically. Verification for meteorological risk warning to geological hazards from 2015 to 2019 shows that the objective tool has an accuracy rate of 97% in gathering hazard information, higher efficiency in analyzing hazards and verifying meteorological risk warning, which has obvious advantages of real time and integration compared with similar tools.
2021, 49(2):297-302.
Abstract:
Meteorological observation data are usually uploaded through the wired broadband of the internal network, but when the wired line is blocked due to equipment failure, human or natural factors, an emergency communication is needed to replace the internal network communication. In addition, due to the lack of fault warning mechanisms such as network disconnection, power or software failure in meteorological observation stations, the fault processing cycle is long, which affects the transmission quality of observation data. In view of the risk of meteorological observation stations, this paper designs and develops a 5Gbased meteorological data backup transmission and monitoring alarm system, which has the functions of network communication monitoring, data automatic transmission, software status monitoring, various information prompts, fault alarm, etc., can improve the reliability of data transmission of meteorological observation stations to a certain extent, and reduce the timeconsuming of the fault removal process for the technical personnel, so as to improve the quality of meteorological information transmission.
Meteorological observation data are usually uploaded through the wired broadband of the internal network, but when the wired line is blocked due to equipment failure, human or natural factors, an emergency communication is needed to replace the internal network communication. In addition, due to the lack of fault warning mechanisms such as network disconnection, power or software failure in meteorological observation stations, the fault processing cycle is long, which affects the transmission quality of observation data. In view of the risk of meteorological observation stations, this paper designs and develops a 5Gbased meteorological data backup transmission and monitoring alarm system, which has the functions of network communication monitoring, data automatic transmission, software status monitoring, various information prompts, fault alarm, etc., can improve the reliability of data transmission of meteorological observation stations to a certain extent, and reduce the timeconsuming of the fault removal process for the technical personnel, so as to improve the quality of meteorological information transmission.
20 Design and Implementation of Automatic Generation System for C-Band Weather Radar Inspection Reports
2021, 49(2):303-307.
Abstract:
Every year, before the start of the flood season, the new generation weather radar needs to test and calibrate the radar technical indexes, repair and maintain the radar components, and at the end of the radar inspection, also needs to make an inspection report. The Cband weather radar inspection before overhaul has three shortcomings: when a part of test data transforms into technical indexes, manual calculating is needed, so the degree of automatic is not high enough; there are no prompts that show whether the radar inspection items are completed or not, and also there are no prompts that show whether the radar technical indexes are qualified or not, so it is easy to leave out unfinished inspection items and uncorrected technical indexes; there is no online help document, so technical staff conduct inspection items based on their experience; therefore, it is prone to irregular operations. In view of the above situation, to design and implement an automatic generation system for Cband weather radar inspection reports, automatically process test data to get the result of indexes, reveal the completion status of radar inspection items and the qualification status of technical indexes, and provide the help document for measurement, will improve the efficiency and intelligence level of radar inspection.
Every year, before the start of the flood season, the new generation weather radar needs to test and calibrate the radar technical indexes, repair and maintain the radar components, and at the end of the radar inspection, also needs to make an inspection report. The Cband weather radar inspection before overhaul has three shortcomings: when a part of test data transforms into technical indexes, manual calculating is needed, so the degree of automatic is not high enough; there are no prompts that show whether the radar inspection items are completed or not, and also there are no prompts that show whether the radar technical indexes are qualified or not, so it is easy to leave out unfinished inspection items and uncorrected technical indexes; there is no online help document, so technical staff conduct inspection items based on their experience; therefore, it is prone to irregular operations. In view of the above situation, to design and implement an automatic generation system for Cband weather radar inspection reports, automatically process test data to get the result of indexes, reveal the completion status of radar inspection items and the qualification status of technical indexes, and provide the help document for measurement, will improve the efficiency and intelligence level of radar inspection.
2021, 49(2):308-314.
Abstract:
In order to meet the needs of users for specialized, refined and personalized meteorological services, solve the release problem of crossplatform meteorological information and realize the automatic push of mobile terminal information, a meteorological crossplatform release system of specialized meteorological service is established with the aid of Enterprise WeChat of the Jiangmen Meteorological Public Service Center and the Sina cloud server SAE (Sina App Engine), adopting the PHP network programming language. The key technologies of the system are expounded：(1) the SAE and multiple application API of Enterprise WeChat are connected to achieve the unified management of multiple applications. (2) Access tokens based on the KVDB cache are established, which improves the efficiency of information publish. (3) Timed tasks and asynchronous execution of messages are used to realize the automatic release of the superthreshold messages and to reduce the blocking and delay while sending messages in groups. (4) Messages push mechanisms of different threshold conditions are used to realize the synchronous release of various kinds of meteorological products. To a certain extent, this system improves the capability of specialized meteorological service and had creates economic benefits for users.
In order to meet the needs of users for specialized, refined and personalized meteorological services, solve the release problem of crossplatform meteorological information and realize the automatic push of mobile terminal information, a meteorological crossplatform release system of specialized meteorological service is established with the aid of Enterprise WeChat of the Jiangmen Meteorological Public Service Center and the Sina cloud server SAE (Sina App Engine), adopting the PHP network programming language. The key technologies of the system are expounded：(1) the SAE and multiple application API of Enterprise WeChat are connected to achieve the unified management of multiple applications. (2) Access tokens based on the KVDB cache are established, which improves the efficiency of information publish. (3) Timed tasks and asynchronous execution of messages are used to realize the automatic release of the superthreshold messages and to reduce the blocking and delay while sending messages in groups. (4) Messages push mechanisms of different threshold conditions are used to realize the synchronous release of various kinds of meteorological products. To a certain extent, this system improves the capability of specialized meteorological service and had creates economic benefits for users.
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.