Volume 39,Issue 2,2011 Table of Contents
2011, 39(2):129-136.
Abstract:
The simulated results of regional climate model (RgrCM3) are sensitive to initial and lateral boundary conditions, model horizontal resolutions, and different parameterizations. The sensitivity experiments were conducted to improve the regional climate simulation over China with RgrCM3. The experiment results indicate that the regional climate simulation by using RegCM3 beginning from winter is suitable, as the results of simulation are not notably affected by initial bias. The improvement of the simulated results from the increase of horizontal resolution is indistinctive. Nest simulation with higher horizontal resolution is able to improve the simulated results. The exponential relaxation scheme and Grell convective precipitation parameterization are better than others in the regional climate simulation over China.
The simulated results of regional climate model (RgrCM3) are sensitive to initial and lateral boundary conditions, model horizontal resolutions, and different parameterizations. The sensitivity experiments were conducted to improve the regional climate simulation over China with RgrCM3. The experiment results indicate that the regional climate simulation by using RegCM3 beginning from winter is suitable, as the results of simulation are not notably affected by initial bias. The improvement of the simulated results from the increase of horizontal resolution is indistinctive. Nest simulation with higher horizontal resolution is able to improve the simulated results. The exponential relaxation scheme and Grell convective precipitation parameterization are better than others in the regional climate simulation over China.
2011, 39(2):137-140.
Abstract:
Based on the annual maximum diurnal rainfall data from 12 metrological stations over Honghe of Yunnan Province in the recent 48 to 58 years, the extreme value distribution of annual maximum diurnal rainfall is fitted with the PearsonⅢ distribution, Gumbel distribution, and logarithmic distribution, and their extreme values at various reappearance periods are calculated by the best probability distribution. The results show that these three probability distribution models can fit well the distribution of annual maximum diurnal rainfall; the fitting results with Gumbel distribution are the best for 7 stations, PearsonⅢ distribution for 4 stations, and lognormal distribution for 1 stations, and they all reached the standards of significance test. For various given reappearance periods, the distribution characteristics of annual maximum diurnal rainfall over Honghe are very similar, and maximum and minimum centers are consistent, higher in South and lower in north.
Based on the annual maximum diurnal rainfall data from 12 metrological stations over Honghe of Yunnan Province in the recent 48 to 58 years, the extreme value distribution of annual maximum diurnal rainfall is fitted with the PearsonⅢ distribution, Gumbel distribution, and logarithmic distribution, and their extreme values at various reappearance periods are calculated by the best probability distribution. The results show that these three probability distribution models can fit well the distribution of annual maximum diurnal rainfall; the fitting results with Gumbel distribution are the best for 7 stations, PearsonⅢ distribution for 4 stations, and lognormal distribution for 1 stations, and they all reached the standards of significance test. For various given reappearance periods, the distribution characteristics of annual maximum diurnal rainfall over Honghe are very similar, and maximum and minimum centers are consistent, higher in South and lower in north.
2011, 39(2):141-146.
Abstract:
By means of the precipitation data from 34 stations in Zhejiang Province and NCEP/NCAR monthly mean reanalysis data from March to May of 1960 to 2009, the climate characteristics of spring precipitation and the horizontal transportation in the whole atmospheric, the vertical transportation at various levels in the troposphere, and the regional crossboundary transportation of water vapor over Zhejiang Province are investigated, using the methods of trend analysis and correlation analysis and comprehensive analysis. The primary transporting paths and the areas related to vertical transportation of water vapor, as well as the circulation patterns influencing the spring precipitation, are expatiated. It is found that water vapor transportation fluxes through different boundaries have different contributions to spring precipitation in Zhejiang Province.
By means of the precipitation data from 34 stations in Zhejiang Province and NCEP/NCAR monthly mean reanalysis data from March to May of 1960 to 2009, the climate characteristics of spring precipitation and the horizontal transportation in the whole atmospheric, the vertical transportation at various levels in the troposphere, and the regional crossboundary transportation of water vapor over Zhejiang Province are investigated, using the methods of trend analysis and correlation analysis and comprehensive analysis. The primary transporting paths and the areas related to vertical transportation of water vapor, as well as the circulation patterns influencing the spring precipitation, are expatiated. It is found that water vapor transportation fluxes through different boundaries have different contributions to spring precipitation in Zhejiang Province.
2011, 39(2):147-155.
Abstract:
EOSMODIS satellite data on surface albedo (MCD43C3 on Level3) are used to analyze the regional distribution of surface albedo features in China, as well as the interannual and quarterly trends from March 2000 to February 2009. The results show that the regional surface albedo in China was high in the west and low in the east, and varied with altitude and latitude; for nearly 10 years in most areas of China, the annual mean surface albedo had an increase trend, with the southeastern China being most extensive and highaltitude and high latitude regions being growthoriented; in the Hetao region and Songliao Plain, the surface albedo decreased most quickly. As for seasonal change, there was the most extensive area with variation trends in winter. There were sharply increase trends (00005 to 0001 per year) in the southeastern China in four seasons, and significantly decreasing trends in Hetao, except in winter. In autumn and winter, there was the extensive area with significant variation trends in the Tibetan Plateau, decreasing in the western hinterland of the plateau and increasing around the mountain glaciers.
EOSMODIS satellite data on surface albedo (MCD43C3 on Level3) are used to analyze the regional distribution of surface albedo features in China, as well as the interannual and quarterly trends from March 2000 to February 2009. The results show that the regional surface albedo in China was high in the west and low in the east, and varied with altitude and latitude; for nearly 10 years in most areas of China, the annual mean surface albedo had an increase trend, with the southeastern China being most extensive and highaltitude and high latitude regions being growthoriented; in the Hetao region and Songliao Plain, the surface albedo decreased most quickly. As for seasonal change, there was the most extensive area with variation trends in winter. There were sharply increase trends (00005 to 0001 per year) in the southeastern China in four seasons, and significantly decreasing trends in Hetao, except in winter. In autumn and winter, there was the extensive area with significant variation trends in the Tibetan Plateau, decreasing in the western hinterland of the plateau and increasing around the mountain glaciers.
2011, 39(2):156-159.
Abstract:
The water vapor transports and budgets are analyzed by using the NECEP/NCAR reanalysis data from 1994 and 1998. The results show that the Jianghuai valley was mainly controlled by moisture transport from north to south in drought years and east to west transport in flood years. The water vapor inputs in dry summers from the west and south boundaries were obviously less than those in flood years, which is an important cause for droughts and floods in the Jianghuai valley and should be paid great attention in the drought/flood prediction service.
The water vapor transports and budgets are analyzed by using the NECEP/NCAR reanalysis data from 1994 and 1998. The results show that the Jianghuai valley was mainly controlled by moisture transport from north to south in drought years and east to west transport in flood years. The water vapor inputs in dry summers from the west and south boundaries were obviously less than those in flood years, which is an important cause for droughts and floods in the Jianghuai valley and should be paid great attention in the drought/flood prediction service.
2011, 39(2):160-164.
Abstract:
By using the daily precipitation data from 71 stations in Anhui province from 1961 to 2008, the precipitation amount and frequency of annual heavy rainfall are calculated for every station, and then the climatic characteristics of heavy rainfall over Anhui Province are analyzed by such methods as trend analysis, EOF, power spectrum analysis, wavelet analysis, MannKendall test, and so on. The results show that the distribution of heavy rainfall from 1971 to 2000, in accordance with the distribution of the frequency, shows a latitudinal pattern; the high amount and frequency of heavy rainfall appeared mostly around the end of June and the beginning of July. The heavy rainfall in most parts of Anhui had an increase trend, with the highvalue areas in the western Huaibei and the southern Jiangnan regions. The values of first mode of EOF were positive in all the province, with high values in the southwest of Anhui. The second mode of EOF indicates that the distributions of heavy rainfall in the South and North are contrary, greater in the North and less in the south. The third mode of EOF indicates that heavy rainfall was greater in both South and North, and less in the central part. There were periodic variations with the main periods being 9 to 10 years and the secondary period of about 3 years. The heavy rainfall in recent 50 years in Anhui experienced five cycles in the 9 to 10 year time scale. There was a mutation around 1978, and the average rainfall from 1979 to 2008 is 583 mm higher than the average from 1961 to 1978.
By using the daily precipitation data from 71 stations in Anhui province from 1961 to 2008, the precipitation amount and frequency of annual heavy rainfall are calculated for every station, and then the climatic characteristics of heavy rainfall over Anhui Province are analyzed by such methods as trend analysis, EOF, power spectrum analysis, wavelet analysis, MannKendall test, and so on. The results show that the distribution of heavy rainfall from 1971 to 2000, in accordance with the distribution of the frequency, shows a latitudinal pattern; the high amount and frequency of heavy rainfall appeared mostly around the end of June and the beginning of July. The heavy rainfall in most parts of Anhui had an increase trend, with the highvalue areas in the western Huaibei and the southern Jiangnan regions. The values of first mode of EOF were positive in all the province, with high values in the southwest of Anhui. The second mode of EOF indicates that the distributions of heavy rainfall in the South and North are contrary, greater in the North and less in the south. The third mode of EOF indicates that heavy rainfall was greater in both South and North, and less in the central part. There were periodic variations with the main periods being 9 to 10 years and the secondary period of about 3 years. The heavy rainfall in recent 50 years in Anhui experienced five cycles in the 9 to 10 year time scale. There was a mutation around 1978, and the average rainfall from 1979 to 2008 is 583 mm higher than the average from 1961 to 1978.
2011, 39(2):165-171.
Abstract:
Based on the monthly mean temperature and precipitation data of Xigaze in Tibet from 1956 to 2008, the lineartendency function and MannKendall test methods are used to analyze climate changes. The results reveal: the trend of annual mean temperature and extreme temperature increased remarkably in the past 53 years, with the increasing rate of extreme maximum temperature being most obvious, and precipitation increased in an undulating manner. Temperature increased most obvious in winter, then in spring, followed by autumn and summer; precipitation increased in spring and summer, but decreased in autumn. The MannKendall test shows that： the annual mean temperature exhibited an obvious increase trend in the recent 53 years, but the most significant decrease occurred between 1960s and 1970s; an abrupt temperature change happened in 2001; an abrupt change from less to more of annual precipitation occurred in 1958, but ended in the mid1960s.
Based on the monthly mean temperature and precipitation data of Xigaze in Tibet from 1956 to 2008, the lineartendency function and MannKendall test methods are used to analyze climate changes. The results reveal: the trend of annual mean temperature and extreme temperature increased remarkably in the past 53 years, with the increasing rate of extreme maximum temperature being most obvious, and precipitation increased in an undulating manner. Temperature increased most obvious in winter, then in spring, followed by autumn and summer; precipitation increased in spring and summer, but decreased in autumn. The MannKendall test shows that： the annual mean temperature exhibited an obvious increase trend in the recent 53 years, but the most significant decrease occurred between 1960s and 1970s; an abrupt temperature change happened in 2001; an abrupt change from less to more of annual precipitation occurred in 1958, but ended in the mid1960s.
2011, 39(2):172-181.
Abstract:
A hail event with a gale occurred on 5 June 2008 is analyzed from the aspects of the synoptic circulation background, physical quantities, and the characteristics of radar echoes and cloud pictures by means of observational data from the Meteorological Observation Network of China, Doppler weather radar data from the western Chongqing, and NCEP/NCAR 1°×1° reanalysis data. It is demonstrated that the vertical and horizontal wind shear and the clear sky solar radiation, which resulted in uneven surface heating, were apt to the vorticity genesis. The drycold air in the upper troposphere intruded into the lower layer favored the maintenance of convective instability, and the increasing of specific humidity and CAPE in the lower troposphere was essential to the development of the convective storm. The high potential vorticity (greater than 1 PVU) contributed to the genesis and development of the supercell storm (mesocyclone). The features of a supercell storm can be found, such as the strong overhanging echo core, false echo, mesocyclone, weak echo and echo wall, large echo intensity gradient, etc., and there existed the cumulonimbus plume and uprushing cloud top in the visible satellite imagery (VIS). Some forecast clues are concluded for supercell storms.
A hail event with a gale occurred on 5 June 2008 is analyzed from the aspects of the synoptic circulation background, physical quantities, and the characteristics of radar echoes and cloud pictures by means of observational data from the Meteorological Observation Network of China, Doppler weather radar data from the western Chongqing, and NCEP/NCAR 1°×1° reanalysis data. It is demonstrated that the vertical and horizontal wind shear and the clear sky solar radiation, which resulted in uneven surface heating, were apt to the vorticity genesis. The drycold air in the upper troposphere intruded into the lower layer favored the maintenance of convective instability, and the increasing of specific humidity and CAPE in the lower troposphere was essential to the development of the convective storm. The high potential vorticity (greater than 1 PVU) contributed to the genesis and development of the supercell storm (mesocyclone). The features of a supercell storm can be found, such as the strong overhanging echo core, false echo, mesocyclone, weak echo and echo wall, large echo intensity gradient, etc., and there existed the cumulonimbus plume and uprushing cloud top in the visible satellite imagery (VIS). Some forecast clues are concluded for supercell storms.
2011, 39(2):182-189.
Abstract:
The causes of abrupt northward shifting, westward turning and extremely slow moving after entering the Taiwan Strait of Typhoon Morakot (0908) are analyzed by using the objective analysis data and numerical simulation methods. The results show: (1) The weakening and eastward withdrawing of the western Pacific subtropical high when the Typhoon moved close to the Taiwan Island made the typhoon slow down for its steering current obviously weakened. After the Typhoon entering the Taiwan Strait, the splitting, the subsequent rebuilding and the reinforcement are the main causes for its northward recurving and slow movement. (2) Typhoon Morakot has the Fujiwara effect of anticlockwise revolving around Typhoon Goni and Etau. Meanwhile, and the formation and development of Typhoon Etau delayed the westward extending of the western Pacific subtropical high. (3) Sensitivity tests to the Taiwan Island orography indicate that the terrain resulted in the asymmetric distribution of the pressure field, dense on the west and sparse on the east, and that the formation of a topographic low made the typhoon turn westward while traversing the Taiwan Island. (4) Typhoons tend to move towards the positive vorticity variation and warm/wet areas. The connecting line between positive vorticity variation center, positive equivalent potential temperature center, and typhoon center coincides with the direction of the typhoon’s abrupt Northward shifting and westward turning afterwards, which has denotative meaning for the shortrange forecast of typhoon tracks.
The causes of abrupt northward shifting, westward turning and extremely slow moving after entering the Taiwan Strait of Typhoon Morakot (0908) are analyzed by using the objective analysis data and numerical simulation methods. The results show: (1) The weakening and eastward withdrawing of the western Pacific subtropical high when the Typhoon moved close to the Taiwan Island made the typhoon slow down for its steering current obviously weakened. After the Typhoon entering the Taiwan Strait, the splitting, the subsequent rebuilding and the reinforcement are the main causes for its northward recurving and slow movement. (2) Typhoon Morakot has the Fujiwara effect of anticlockwise revolving around Typhoon Goni and Etau. Meanwhile, and the formation and development of Typhoon Etau delayed the westward extending of the western Pacific subtropical high. (3) Sensitivity tests to the Taiwan Island orography indicate that the terrain resulted in the asymmetric distribution of the pressure field, dense on the west and sparse on the east, and that the formation of a topographic low made the typhoon turn westward while traversing the Taiwan Island. (4) Typhoons tend to move towards the positive vorticity variation and warm/wet areas. The connecting line between positive vorticity variation center, positive equivalent potential temperature center, and typhoon center coincides with the direction of the typhoon’s abrupt Northward shifting and westward turning afterwards, which has denotative meaning for the shortrange forecast of typhoon tracks.
2011, 39(2):190-196.
Abstract:
Through analyzing the fields of height, temperature, precipitation, vorticity and other elements, the major features of the circulation pattern causing the freezing rainfall and abnormal low temperature weather, as well the process of the extreme snow and freezing event in January 2008 over Guizhou Province are discussed. The result shows that under the background of strong La Nina, the blocking high persisted in the east of the Ural Mountains, and the polar vortex was abnormally strong and farther eastern; the western Pacific subtropical high became stronger with active south branch trough, which were possibly the major causes of the disaster. The obvious features are that there existed a cold air layer of below 0 ℃ under 850 hPa, a warmer layer near the 700 hPa, and a colder ice layer above. There existed positive relative vorticity advection and a southwest lowlevel jet, which transported beneficial sufficient warmer and wetter air and sustained the steady flow of heat to the melting layer. The difference between upper and lower vorticity advection was favorable for the development of ascending motion, which provided conditions for the occurrence of the snow and freezing rainfall.
Through analyzing the fields of height, temperature, precipitation, vorticity and other elements, the major features of the circulation pattern causing the freezing rainfall and abnormal low temperature weather, as well the process of the extreme snow and freezing event in January 2008 over Guizhou Province are discussed. The result shows that under the background of strong La Nina, the blocking high persisted in the east of the Ural Mountains, and the polar vortex was abnormally strong and farther eastern; the western Pacific subtropical high became stronger with active south branch trough, which were possibly the major causes of the disaster. The obvious features are that there existed a cold air layer of below 0 ℃ under 850 hPa, a warmer layer near the 700 hPa, and a colder ice layer above. There existed positive relative vorticity advection and a southwest lowlevel jet, which transported beneficial sufficient warmer and wetter air and sustained the steady flow of heat to the melting layer. The difference between upper and lower vorticity advection was favorable for the development of ascending motion, which provided conditions for the occurrence of the snow and freezing rainfall.
2011, 39(2):197-201.
Abstract:
The NCEP reanalysis grid data, conventional observations, numerical forecast products, as well as satellite imagery, are used to diagnose and analyze a dense fog event occurred in the central Zhejiang Province and the surrounding areas on 6 April 2009. The results show that the circulation pattern of “the warm ridge behind a trough” is conducive to the surface cooling resulted from longwave radiation and the midlevel warming, which is advantageous to the formation of temperature inversion, so to provide favorable conditions for fog generation. The formation and maintenance of the temperature inversion or isothermal layer in the boundary layer played an important role in the development and sustentation of the fog event. The main reasons for the higher visibility in mountain areas than that in urban areas include more condensation nuclei and stronger turbulent mixing. The crossover temperature can be used to indicate the humidity state of the potential fog layer, and the difference between temperature and crossover temperature can be used as an indicator of the generation, development, and dissipation processes of fogs. The model products can provide the environmental conditions for fog formation, and the satellite images are helpful in predicting the generation, development and dissipation of fogs.
The NCEP reanalysis grid data, conventional observations, numerical forecast products, as well as satellite imagery, are used to diagnose and analyze a dense fog event occurred in the central Zhejiang Province and the surrounding areas on 6 April 2009. The results show that the circulation pattern of “the warm ridge behind a trough” is conducive to the surface cooling resulted from longwave radiation and the midlevel warming, which is advantageous to the formation of temperature inversion, so to provide favorable conditions for fog generation. The formation and maintenance of the temperature inversion or isothermal layer in the boundary layer played an important role in the development and sustentation of the fog event. The main reasons for the higher visibility in mountain areas than that in urban areas include more condensation nuclei and stronger turbulent mixing. The crossover temperature can be used to indicate the humidity state of the potential fog layer, and the difference between temperature and crossover temperature can be used as an indicator of the generation, development, and dissipation processes of fogs. The model products can provide the environmental conditions for fog formation, and the satellite images are helpful in predicting the generation, development and dissipation of fogs.
2011, 39(2):202-206.
Abstract:
The development history and present state of spacebased GPS occultation, as well as the advancements of spacebased occultation sounding and the brief merits and demerits of different occultation inversion methods, are introduced. The emphasis is put on the latest researches and advancements of GPS occultation sounding in China. A detailed introduction is made to the research achievements of mountainbased GPS occultation sounding. The prospects of the research emphases and development tendency of GPS occultation sounding in China are discussed. It is pointed out that GPS occultation sounding will develop towards the constellation and comprehensive application, and China will certainly rank among GPS occultation sounding developers.
The development history and present state of spacebased GPS occultation, as well as the advancements of spacebased occultation sounding and the brief merits and demerits of different occultation inversion methods, are introduced. The emphasis is put on the latest researches and advancements of GPS occultation sounding in China. A detailed introduction is made to the research achievements of mountainbased GPS occultation sounding. The prospects of the research emphases and development tendency of GPS occultation sounding in China are discussed. It is pointed out that GPS occultation sounding will develop towards the constellation and comprehensive application, and China will certainly rank among GPS occultation sounding developers.
2011, 39(2):207-211.
Abstract:
Based on the principles of earth rotation and revolution, the effects of the obliquity of the ecliptic plane, solar declination, longitude, and solar elevation angle on the formation of the sunlight line on a dark tube sunshine recorder are analyzed. The principles of sunlightline location displacement with seasonal variation are described, and the regularities of sunlightline formation at spring equinox, autumnal equinox, winter solstice and summer solstice are discussed. Under the condition of the fixed earth motion trajectory, the daytoday sunshine path line can be obtained. With the theoretical basis, the software for sunlight line formation are designed and introduced.
Based on the principles of earth rotation and revolution, the effects of the obliquity of the ecliptic plane, solar declination, longitude, and solar elevation angle on the formation of the sunlight line on a dark tube sunshine recorder are analyzed. The principles of sunlightline location displacement with seasonal variation are described, and the regularities of sunlightline formation at spring equinox, autumnal equinox, winter solstice and summer solstice are discussed. Under the condition of the fixed earth motion trajectory, the daytoday sunshine path line can be obtained. With the theoretical basis, the software for sunlight line formation are designed and introduced.
2011, 39(2):212-216.
Abstract:
A detailed instruction about the CINRAD/SB digital Servo Control power structures and the antennastate signal process is made, and three reasons are discussed for the CINRAD/SB servo poweroff failure: the protective poweroff of the air switch resulted from overloading, abnormal poweroff signals of the server systems, and abnormal temperature induced by the overflow of the brake. The analysis methods and diagnosis process of that the CINRAD/SB servo system poweroff failure are summed up, and the detailed explanation is given about how to find out and get rid of the faults in two complex cases of the CINRAD/SB servo system poweroff failure and the methods for restoring radar operation in emergency case without spare parts available by making full use of the existing facilities according to the features of the radar lines.
A detailed instruction about the CINRAD/SB digital Servo Control power structures and the antennastate signal process is made, and three reasons are discussed for the CINRAD/SB servo poweroff failure: the protective poweroff of the air switch resulted from overloading, abnormal poweroff signals of the server systems, and abnormal temperature induced by the overflow of the brake. The analysis methods and diagnosis process of that the CINRAD/SB servo system poweroff failure are summed up, and the detailed explanation is given about how to find out and get rid of the faults in two complex cases of the CINRAD/SB servo system poweroff failure and the methods for restoring radar operation in emergency case without spare parts available by making full use of the existing facilities according to the features of the radar lines.
2011, 39(2):217-221.
Abstract:
Through analyzing and studying the principles of PTB220 pressure sensors, the analog value adjustment of tolerance pressure sensors is achieved by means of super terminal technology, the Keithley 2000 Digital Multimeter, and the linear equation. The problem that the digital adjustment influences the analog output is resolved, so to avoid the effect of the channel errors resulted from the collectors in automatic weather stations on calibration accuracy, and thereby to ensure the accuracy of the pressure data from automatic weather stations.
Through analyzing and studying the principles of PTB220 pressure sensors, the analog value adjustment of tolerance pressure sensors is achieved by means of super terminal technology, the Keithley 2000 Digital Multimeter, and the linear equation. The problem that the digital adjustment influences the analog output is resolved, so to avoid the effect of the channel errors resulted from the collectors in automatic weather stations on calibration accuracy, and thereby to ensure the accuracy of the pressure data from automatic weather stations.
2011, 39(2):222-226.
Abstract:
The microwave devices of the radar system play different roles in various channels. It is very important for maintenance personnel to know their shapes, functions, principles, and fault identification. The working principles, specifications, fault identification of microwave devices in the CINRAD/SA radar system, such as receiver protector, BAW microwave delay line, passive limiter and so on, are discussed, so as to further understand those devices and identify the faults in the CINRAD/SA radar system.
The microwave devices of the radar system play different roles in various channels. It is very important for maintenance personnel to know their shapes, functions, principles, and fault identification. The working principles, specifications, fault identification of microwave devices in the CINRAD/SA radar system, such as receiver protector, BAW microwave delay line, passive limiter and so on, are discussed, so as to further understand those devices and identify the faults in the CINRAD/SA radar system.
2011, 39(2):227-230.
Abstract:
The data of daily rainfall from 54 weather stations in 2004, 2005, 2007 are used to analyze the difference and correlativity between automatic and selfrecording observation rainfall. Results indicate that the average daily rain amount observed by dual tippingbucket pluviographs is 012 mm less than those by the automatic observation, with the standard deviation of the difference being 093 mm; the average daily rain amount observed by hydroconetype pluviographs is 039 mm less than the automatic observation, with the standard deviation of the difference being 15 mm. The application of the automatic rain sensors has certain influence on the statistical results of rainy days. The daily rain amount observed by the selfrecording observation is obviously linearly related to that by the automatic observation. The correlation coefficient of daily rainfall measurements by the tipping bucket pluviograph and the automatic rain sensor is 0996 and the correlation coefficient of daily rainfall measurements by hydrocone type pluviograph and the automatic rain sensor is 0994. The selfrecording rainfall also is obviously linearly related to the manual observation.
The data of daily rainfall from 54 weather stations in 2004, 2005, 2007 are used to analyze the difference and correlativity between automatic and selfrecording observation rainfall. Results indicate that the average daily rain amount observed by dual tippingbucket pluviographs is 012 mm less than those by the automatic observation, with the standard deviation of the difference being 093 mm; the average daily rain amount observed by hydroconetype pluviographs is 039 mm less than the automatic observation, with the standard deviation of the difference being 15 mm. The application of the automatic rain sensors has certain influence on the statistical results of rainy days. The daily rain amount observed by the selfrecording observation is obviously linearly related to that by the automatic observation. The correlation coefficient of daily rainfall measurements by the tipping bucket pluviograph and the automatic rain sensor is 0996 and the correlation coefficient of daily rainfall measurements by hydrocone type pluviograph and the automatic rain sensor is 0994. The selfrecording rainfall also is obviously linearly related to the manual observation.
2011, 39(2):231-235.
Abstract:
Vertical distributions of cloud condensation nuclei (CCN) in a cloudless sky were observed by the DMT (Droplet Measurement Technologies) CCN counter mounted on an AN26 airplane in the western Guanzhong area of Shaanxi Province on 13 October 2009. The results of observation show that the ground average concentration of CCN was more than 10000 cm-3 (supersaturation was 02%) under a cloudless sky condition, and the ground CCN concentration for foggy days on 7 October 2009 was significantly higher. The CCN concentration tends to decrease with height. CCN concentration was high below 1500 m, with the mean CCN concentration being 8827 /cm3, 4439 /cm3 , 456 /cm3, 504/ cm3 (supersaturation equals 04%) at the levels of 1000 m, 1550 m, 4100 m, 5500 m, respectively.
Vertical distributions of cloud condensation nuclei (CCN) in a cloudless sky were observed by the DMT (Droplet Measurement Technologies) CCN counter mounted on an AN26 airplane in the western Guanzhong area of Shaanxi Province on 13 October 2009. The results of observation show that the ground average concentration of CCN was more than 10000 cm-3 (supersaturation was 02%) under a cloudless sky condition, and the ground CCN concentration for foggy days on 7 October 2009 was significantly higher. The CCN concentration tends to decrease with height. CCN concentration was high below 1500 m, with the mean CCN concentration being 8827 /cm3, 4439 /cm3 , 456 /cm3, 504/ cm3 (supersaturation equals 04%) at the levels of 1000 m, 1550 m, 4100 m, 5500 m, respectively.
2011, 39(2):236-241.
Abstract:
Radar echo extrapolation is an effective way to select the operation time in rocket weather modification. The radar echo extrapolation method of TREC (Tracking Radar Echoes by Correlation) is described. Based on the echo shifting and moving speeds, echoes are extrapolated linearly within the range of the rocket shot, then calculating the time that the echoes arrives at the rocket shot to provide reference for the selection of operation time. The test indicates that the extrapolated time for echoes to reach the rocket shot is in consistent with the actual echoes.
Radar echo extrapolation is an effective way to select the operation time in rocket weather modification. The radar echo extrapolation method of TREC (Tracking Radar Echoes by Correlation) is described. Based on the echo shifting and moving speeds, echoes are extrapolated linearly within the range of the rocket shot, then calculating the time that the echoes arrives at the rocket shot to provide reference for the selection of operation time. The test indicates that the extrapolated time for echoes to reach the rocket shot is in consistent with the actual echoes.
2011, 39(2):242-246.
Abstract:
The establishment of meteorological disaster emergency assessment systems can reinforce the government’s capability of management and emergency response when disasters occur. From the view of system sciences, the Analytic Hierarchy Process (AHP) method is used to give weights for different assessment indicators, and the assessment model of emergency responding capability to meteorological disasters is established. The model can be used to assess the emergency management capability for meteorological disasters, and some reasonable suggestions for government are given.
The establishment of meteorological disaster emergency assessment systems can reinforce the government’s capability of management and emergency response when disasters occur. From the view of system sciences, the Analytic Hierarchy Process (AHP) method is used to give weights for different assessment indicators, and the assessment model of emergency responding capability to meteorological disasters is established. The model can be used to assess the emergency management capability for meteorological disasters, and some reasonable suggestions for government are given.
2011, 39(2):247-252.
Abstract:
The energysaving solar greenhouse is the agricultural facility with the fastest growth speed and the largest occupying area in North China. The establishment of a greenhouse weathermonitoring and disasterwarning system is described in detail, including the automatic monitoring of greenhouse microclimate, data remote collection, greenhouse climate modeling, product production and delivery, and disaster warning. The application of the system is briefly introduced. The system, put to use from 2007, combines midrange and shortrange forecasting with nowcasting, monitoring and forecasting with postdisaster assessment together, and performs satisfactorily in meteorological service.
The energysaving solar greenhouse is the agricultural facility with the fastest growth speed and the largest occupying area in North China. The establishment of a greenhouse weathermonitoring and disasterwarning system is described in detail, including the automatic monitoring of greenhouse microclimate, data remote collection, greenhouse climate modeling, product production and delivery, and disaster warning. The application of the system is briefly introduced. The system, put to use from 2007, combines midrange and shortrange forecasting with nowcasting, monitoring and forecasting with postdisaster assessment together, and performs satisfactorily in meteorological service.
2011, 39(2):253-256.
Abstract:
The generating system of CAAC (Civil Aviation Administration of China) annual and monthly general meteorological records using the Crystal Report technique is established in the Visual Studio.NET development platform. The production, output, preview, printing， and remodifying of the report form are discussed in details. The resulted records are in accordance with the new edition of CAAC ground meteorological observation criterions. The system has been formally applied in nearly 20 airports in East China, which has received good responses.
The generating system of CAAC (Civil Aviation Administration of China) annual and monthly general meteorological records using the Crystal Report technique is established in the Visual Studio.NET development platform. The production, output, preview, printing， and remodifying of the report form are discussed in details. The resulted records are in accordance with the new edition of CAAC ground meteorological observation criterions. The system has been formally applied in nearly 20 airports in East China, which has received good responses.
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.