Volume 37,Issue 5,2009 Table of Contents
2009, 37(5):513-519.
Abstract:
By selecting of the ECMWF grid fields and using of such methods as differential method, synoptic diagnosis, factor combination, etc, the predictor database that can reflect the local characteristics of synoptic dynamics was established. The “0, 1” linearization was conducted on the predictors and predictands, and the initial selection was based on the PRESS (Prediction Residual Error Sum of Squares) criterion. The 0〖KG-*3〗〖CD*2〗〖KG-*6〗120 hour precipitation prediction equation was established with the optimal subset regression method, and the precipitation probability was predicted with the multifactor probability weighting regression method. The forecast system has been put into operation, and the verification proved that the forecasting performance and the provided prefecturelevel guidance objective forecasting products are satisfactory. The forecast system can be connected with MICAPS to realize the highlevel automation and assure the objective and quantitative forecast products.
By selecting of the ECMWF grid fields and using of such methods as differential method, synoptic diagnosis, factor combination, etc, the predictor database that can reflect the local characteristics of synoptic dynamics was established. The “0, 1” linearization was conducted on the predictors and predictands, and the initial selection was based on the PRESS (Prediction Residual Error Sum of Squares) criterion. The 0〖KG-*3〗〖CD*2〗〖KG-*6〗120 hour precipitation prediction equation was established with the optimal subset regression method, and the precipitation probability was predicted with the multifactor probability weighting regression method. The forecast system has been put into operation, and the verification proved that the forecasting performance and the provided prefecturelevel guidance objective forecasting products are satisfactory. The forecast system can be connected with MICAPS to realize the highlevel automation and assure the objective and quantitative forecast products.
2009, 37(5):520-522.
Abstract:
Based on the dynamical extended range forecast products from 1983 to 2005, the forecast experiment on the interpretation and application of monthly dynamical extended range forecast products was carried out. The results show that the method has better prediction capability for monthly precipitation forecasting in Shaanxi Province, which is located on the northeast side of the Tibetan Plateau. The PS score is higher in summer and autumn and lower in winter and spring; meanwhile, it is unstable during the period of seasonal transition of atmospheric circulation.
Based on the dynamical extended range forecast products from 1983 to 2005, the forecast experiment on the interpretation and application of monthly dynamical extended range forecast products was carried out. The results show that the method has better prediction capability for monthly precipitation forecasting in Shaanxi Province, which is located on the northeast side of the Tibetan Plateau. The PS score is higher in summer and autumn and lower in winter and spring; meanwhile, it is unstable during the period of seasonal transition of atmospheric circulation.
2009, 37(5):523-526.
Abstract:
The Doppler Radar Products during a tornado occurred in Sixian, Anhui Province on 29 Jun 2006 are analyzed. Before the tornado, there were three NESW oriented bowshaped echoes, and the tornado was on the furthest southwest edge of the bowshaped echo. A shortrange heavy rain occurred before the tornado appearing with a rainfall amount of 60 mm in 2 hours. The strong shear of wind direction existed in the front of the bowshaped echo, which resulted in a series of mesocyclones along the front edge of the echo. The southwest bowshaped echo joined the echo in the front of it, 30 min before tornado occurred, and then a large mesocyclone with a diameter of 25.8 km formed. According to the survey, there was a severe wind zone in upstream of the tornado, which was in agreement with the moving path of the south edges of the maximum zones in the mesocyclones. It suggests that along the south edges of the maximum wind zones in the mesocyclones, the mesocyclones and the straight wind behind the bowshaped echoes have the same direction, and the two airflows overlaid together, leading to the occurrence of the severe winds. About 1 hour 40 min before tornado occurred, the radar caught up the mesocyclones, and 12 min before, detected TVS (Tornadic Vortex Signature) products, which are undoubtedly useful for making tornado warning.
The Doppler Radar Products during a tornado occurred in Sixian, Anhui Province on 29 Jun 2006 are analyzed. Before the tornado, there were three NESW oriented bowshaped echoes, and the tornado was on the furthest southwest edge of the bowshaped echo. A shortrange heavy rain occurred before the tornado appearing with a rainfall amount of 60 mm in 2 hours. The strong shear of wind direction existed in the front of the bowshaped echo, which resulted in a series of mesocyclones along the front edge of the echo. The southwest bowshaped echo joined the echo in the front of it, 30 min before tornado occurred, and then a large mesocyclone with a diameter of 25.8 km formed. According to the survey, there was a severe wind zone in upstream of the tornado, which was in agreement with the moving path of the south edges of the maximum zones in the mesocyclones. It suggests that along the south edges of the maximum wind zones in the mesocyclones, the mesocyclones and the straight wind behind the bowshaped echoes have the same direction, and the two airflows overlaid together, leading to the occurrence of the severe winds. About 1 hour 40 min before tornado occurred, the radar caught up the mesocyclones, and 12 min before, detected TVS (Tornadic Vortex Signature) products, which are undoubtedly useful for making tornado warning.
2009, 37(5):527-532.
Abstract:
With observational data, mesoscale automatic weather station data and NCEP reanalysis data, a diagnostic analysis is made of the causes of a severe heavy rain occurred on 18 July 2007 in Shandong Province. The results show that the rainstorm was caused by the interaction of the westly trough originated from the cold vortex over the northeast China, the quasi eastwest oriented shear line at lower levels, and the warm and wet airflow on the northwest edge of the subtropical high and cold air from northeast. It is found that the continued warming and strong warmwet air transport at lower levels provided excellent thermal conditions and adequate water supply. Meanwhile, the convective unstable stratification was formed over Shandong Province. Along the shear line at 850 hPa, the northeast wind with cold air and the lowlevel southwest jet with warm air converged. Because of the interaction between the two airflows in the low troposphere, the warm front had obvious characteristics of frontogenesis. The uplifting of warm air caused by the weak lowlevel cold air intrusion promoted the development of convection and energy release. The mesoscale convergence center or convergence line activated the mechanisms of rainstorm formation, and the distribution of heavy rainfall had the same direction with the ground convergence line. The strong rainfall intensity and the special terrain topography played an important role in this rainstorminduced disaster.
With observational data, mesoscale automatic weather station data and NCEP reanalysis data, a diagnostic analysis is made of the causes of a severe heavy rain occurred on 18 July 2007 in Shandong Province. The results show that the rainstorm was caused by the interaction of the westly trough originated from the cold vortex over the northeast China, the quasi eastwest oriented shear line at lower levels, and the warm and wet airflow on the northwest edge of the subtropical high and cold air from northeast. It is found that the continued warming and strong warmwet air transport at lower levels provided excellent thermal conditions and adequate water supply. Meanwhile, the convective unstable stratification was formed over Shandong Province. Along the shear line at 850 hPa, the northeast wind with cold air and the lowlevel southwest jet with warm air converged. Because of the interaction between the two airflows in the low troposphere, the warm front had obvious characteristics of frontogenesis. The uplifting of warm air caused by the weak lowlevel cold air intrusion promoted the development of convection and energy release. The mesoscale convergence center or convergence line activated the mechanisms of rainstorm formation, and the distribution of heavy rainfall had the same direction with the ground convergence line. The strong rainfall intensity and the special terrain topography played an important role in this rainstorminduced disaster.
2009, 37(5):533-537.
Abstract:
On the basis of the atmospheric circulation background and the objective diagnosis of physical quantities with newgeneration weather radar data at Xifeng, an analysis is made of the shorttime severe rainstorm event, induced by the Hetao vortex, in Huanxian of Gansu Province on 24 July 2007. The results show that there existed a deep positive vorticity field corresponding to the Hetao vortex in the vertical section; the echo reflectivity factor is greater than 50 dBz before the hail storm, with the strong echo center in the vicinity of the 0 ℃ layer, and there was no obvious “jumping” feature with altitude; the high value centers of horizontal convergence on the radial velocity echo image (≥±20 m/s) were highly active in the layer of 2 to 7 km; there were significant “jumps” of cloud top heights; the area of VIL being greater than 45 kg〖DK〗·m-2 expanded quickly, which has indicative significance for the earlywarning and monitoring of shortrange severe weather and hail suppression operation.
On the basis of the atmospheric circulation background and the objective diagnosis of physical quantities with newgeneration weather radar data at Xifeng, an analysis is made of the shorttime severe rainstorm event, induced by the Hetao vortex, in Huanxian of Gansu Province on 24 July 2007. The results show that there existed a deep positive vorticity field corresponding to the Hetao vortex in the vertical section; the echo reflectivity factor is greater than 50 dBz before the hail storm, with the strong echo center in the vicinity of the 0 ℃ layer, and there was no obvious “jumping” feature with altitude; the high value centers of horizontal convergence on the radial velocity echo image (≥±20 m/s) were highly active in the layer of 2 to 7 km; there were significant “jumps” of cloud top heights; the area of VIL being greater than 45 kg〖DK〗·m-2 expanded quickly, which has indicative significance for the earlywarning and monitoring of shortrange severe weather and hail suppression operation.
2009, 37(5):538-544.
Abstract:
With the momentum diagnosis method, an analysis is made of the interaction between plateau vortex and southwest vortex during a heavy rain event in Sichuan on 20 to 22 July 2008. The results show that when the latitudinal distance between plateau vortex center and southwest vortex center was 5°, the updrafts in both vortexes were confined within 500 hPa; when moved eastward and coupled longitudinally, they both developed, with the updraft of the southwest vortex center reached 300 hPa and that of the plateau vortex center reached 200 hPa. The southwest vortex restricted the development of the plateau vortex in some way at the early stage when it appeared in the lower atmosphere. When they were coupled longitudinally, the vertical difference caused by the different vorticity advections between the upper and lower levels excitated the updrafts under 500 hPa and strengthened cyclone vorticity, and then the positive vorticity at 500 hPa and 700 hPa increased by two times The change rate of positive vorticity facilitated the plateau vortex to move eastward. After coupled longitudinally, the interaction of the plateau vortex and basin vortex strengthened the updrafts. As a result, the plateau vortex and southwest vortex influenced each other and developed together.
With the momentum diagnosis method, an analysis is made of the interaction between plateau vortex and southwest vortex during a heavy rain event in Sichuan on 20 to 22 July 2008. The results show that when the latitudinal distance between plateau vortex center and southwest vortex center was 5°, the updrafts in both vortexes were confined within 500 hPa; when moved eastward and coupled longitudinally, they both developed, with the updraft of the southwest vortex center reached 300 hPa and that of the plateau vortex center reached 200 hPa. The southwest vortex restricted the development of the plateau vortex in some way at the early stage when it appeared in the lower atmosphere. When they were coupled longitudinally, the vertical difference caused by the different vorticity advections between the upper and lower levels excitated the updrafts under 500 hPa and strengthened cyclone vorticity, and then the positive vorticity at 500 hPa and 700 hPa increased by two times The change rate of positive vorticity facilitated the plateau vortex to move eastward. After coupled longitudinally, the interaction of the plateau vortex and basin vortex strengthened the updrafts. As a result, the plateau vortex and southwest vortex influenced each other and developed together.
2009, 37(5):545-548.
Abstract:
By means of conventional weather data and new generation weather radar data in June 2008 at Chengde, two coldvortex weather events are compared and analyzed. It is found that an upperlevel cold vortex and a lowerlevel mesoscale shear line are the common influencing systems; severe convective weather caused by the easternMongolia cold vortex is related to the moving track of the cold vortex; the configuration of the wind fields at lower and upper levels and the chimney index are used to determine the size of the vertical wind shear; such factors are highly indicative to severe weather warning as the shape, strength, moving speed, vertical structure characteristics of Doppler radar basic reflectivity, as well as the moving directions of the mesoscale convergence lines, adverse wind areas, vertical shear lines, zerospeed lines on the average radial velocity fields; the jumps and drastic reduction of VIL values have also great significance, VIL increasing gradually with development at the convection stage and decreasing after the beginning of convective weather.
By means of conventional weather data and new generation weather radar data in June 2008 at Chengde, two coldvortex weather events are compared and analyzed. It is found that an upperlevel cold vortex and a lowerlevel mesoscale shear line are the common influencing systems; severe convective weather caused by the easternMongolia cold vortex is related to the moving track of the cold vortex; the configuration of the wind fields at lower and upper levels and the chimney index are used to determine the size of the vertical wind shear; such factors are highly indicative to severe weather warning as the shape, strength, moving speed, vertical structure characteristics of Doppler radar basic reflectivity, as well as the moving directions of the mesoscale convergence lines, adverse wind areas, vertical shear lines, zerospeed lines on the average radial velocity fields; the jumps and drastic reduction of VIL values have also great significance, VIL increasing gradually with development at the convection stage and decreasing after the beginning of convective weather.
2009, 37(5):549-555.
Abstract:
The statistics characteristics of East Asia winter monsoon and atmospheric circulation fields from 1956 to 2005 are analyzed by using the EOF (VEOF) method. Results show that there are two modes in East Asia winter monsoon. The variation of the second mode played a more important role in the interdecadal variations and longterm variations trends of winter monsoon. The interdecadal spatial anomalies of winter monsoon and atmospheric circulation had a sudden change in about 1980. The interdecadal variations of winter monsoon correlate closely to the interdecadal variations of winter temperature and precipitation in China.
The statistics characteristics of East Asia winter monsoon and atmospheric circulation fields from 1956 to 2005 are analyzed by using the EOF (VEOF) method. Results show that there are two modes in East Asia winter monsoon. The variation of the second mode played a more important role in the interdecadal variations and longterm variations trends of winter monsoon. The interdecadal spatial anomalies of winter monsoon and atmospheric circulation had a sudden change in about 1980. The interdecadal variations of winter monsoon correlate closely to the interdecadal variations of winter temperature and precipitation in China.
2009, 37(5):556-559.
Abstract:
The statistical characteristics of Tropical Cyclones (TCs) affecting the East China Sea (117°E to 131°E, 22°N to 33°N) are analyzed by means of the TC data from 1961 to 2005. The results indicate that there is obvious annual variation in TCs over East China Sea with 8.6 TCs per year averagely; the numbers of TCs have good correlation with El Nino phenomenon, during which the numbers of TCs are less; TCs appear mostly from June to September, and the durations of TCs are usually less than 5 days; TCs form mostly in the Pacific area east of Philippines and the sea area around Guam, mostly come from south or east with three moving paths: northwest, northeast, and directionturning.
The statistical characteristics of Tropical Cyclones (TCs) affecting the East China Sea (117°E to 131°E, 22°N to 33°N) are analyzed by means of the TC data from 1961 to 2005. The results indicate that there is obvious annual variation in TCs over East China Sea with 8.6 TCs per year averagely; the numbers of TCs have good correlation with El Nino phenomenon, during which the numbers of TCs are less; TCs appear mostly from June to September, and the durations of TCs are usually less than 5 days; TCs form mostly in the Pacific area east of Philippines and the sea area around Guam, mostly come from south or east with three moving paths: northwest, northeast, and directionturning.
2009, 37(5):560-566.
Abstract:
Based on the climatic data of 5 meteorological stations in Hami from 1961 to 2007，the fundamental change characteristics of various climatic element, such as temperatures, precipitation, sunshine hours, wind speed, relative humidity, potential evapotranspiration, and surface aridity are analyzed by using the linear regression, wavelet analysis and abrupt change detection methods in Hami in the resent 47 years. The main results are as follows: (1) The annual mean temperature, precipitation and relative humidity were increasing, but the annual sunshine hours and wind speed were decreasing.（2）The correlation analysis shows that there was significant positive correlation between potential evapotranspiration and annual mean temperature, annual sunshine hour and mean wind speed, and significant negative correlation between potential evapotranspiration and annual rainfall and relative humidity. Owing to the comprehensive influence of the above climatic factors, the potential evapotranspiration and surface aridity were significantly decreasing. (3) The abrupt change examination indicates that the annual mean temperature, precipitation had sudden increases in 1970 and 1965, and average wind speed, annual potential evapotranspiration and surface aridity had sudden decreases in 1980 and 1975, respectively. To sum up the sudden change characteristic of temperature and surface aridity, there occurred a “warmwet” sudden change in 1973〖CD*2〗1975. (4) There existed periodic changes of various time scales in various climatic elements and potential evapotranspiration and surface aridity in Hami.
Based on the climatic data of 5 meteorological stations in Hami from 1961 to 2007，the fundamental change characteristics of various climatic element, such as temperatures, precipitation, sunshine hours, wind speed, relative humidity, potential evapotranspiration, and surface aridity are analyzed by using the linear regression, wavelet analysis and abrupt change detection methods in Hami in the resent 47 years. The main results are as follows: (1) The annual mean temperature, precipitation and relative humidity were increasing, but the annual sunshine hours and wind speed were decreasing.（2）The correlation analysis shows that there was significant positive correlation between potential evapotranspiration and annual mean temperature, annual sunshine hour and mean wind speed, and significant negative correlation between potential evapotranspiration and annual rainfall and relative humidity. Owing to the comprehensive influence of the above climatic factors, the potential evapotranspiration and surface aridity were significantly decreasing. (3) The abrupt change examination indicates that the annual mean temperature, precipitation had sudden increases in 1970 and 1965, and average wind speed, annual potential evapotranspiration and surface aridity had sudden decreases in 1980 and 1975, respectively. To sum up the sudden change characteristic of temperature and surface aridity, there occurred a “warmwet” sudden change in 1973〖CD*2〗1975. (4) There existed periodic changes of various time scales in various climatic elements and potential evapotranspiration and surface aridity in Hami.
2009, 37(5):567-571.
Abstract:
With the recent emphasis on the understanding of the role of clouds in the global radiation budget, the scope of radar meteorology has expanded to include the measurement of cloud properties and structure. The millimeterwavelength radar is recognized as having the potential to provide a more sensitive probe of cloud particles ranging from a few micrometers in diameter to precipitation drops. A radar operating at 35GHz was designed and assembled primarily for observing clouds and precipitation by the State Key Laboratory of Severe Weather (LaSW) of CAMS (Chinese Academy of Meteorological Sciences) in 2006. The parameters and characteristics of the radar system as well as its activities in field experiments are introduced. Some examples of different kinds of clouds (such as Cb，Sc, Ci, Ac) are presented to demonstrate the capability of HMBQ radar.
With the recent emphasis on the understanding of the role of clouds in the global radiation budget, the scope of radar meteorology has expanded to include the measurement of cloud properties and structure. The millimeterwavelength radar is recognized as having the potential to provide a more sensitive probe of cloud particles ranging from a few micrometers in diameter to precipitation drops. A radar operating at 35GHz was designed and assembled primarily for observing clouds and precipitation by the State Key Laboratory of Severe Weather (LaSW) of CAMS (Chinese Academy of Meteorological Sciences) in 2006. The parameters and characteristics of the radar system as well as its activities in field experiments are introduced. Some examples of different kinds of clouds (such as Cb，Sc, Ci, Ac) are presented to demonstrate the capability of HMBQ radar.
2009, 37(5):572-575.
Abstract:
In order to test the radiation sounding performance at the infrared channels of the InfraRed Atmospheric Sounder (IRAS) and obtain the reference calibration coefficients so to offer support to the error analysis of the retrieval products, the ground calibration of satellite onboard instruments is a prerequisite task before launching. Based on the correlation of accepted radiance and output digital counts and the lab vacuum calibration experiment data of IRAS, the relation between radiance and output digital counts is set up by means of the statistical regression method. The lab coefficients at the infrared channels are obtained and the nonlinear responses of IRAS output signals to the input radiance are analyzed. The noise equivalent differential radiance at 290 K temperature is computed and compared with specifications. The results reveal that there is nonlinear response to a certain extent for IRAS, and the nonlinear bias values are less than 0.4 K in the range of 220 to 230 K. The noise equivalent differential radiance meets the functional requirements of the IRAS specifications.
In order to test the radiation sounding performance at the infrared channels of the InfraRed Atmospheric Sounder (IRAS) and obtain the reference calibration coefficients so to offer support to the error analysis of the retrieval products, the ground calibration of satellite onboard instruments is a prerequisite task before launching. Based on the correlation of accepted radiance and output digital counts and the lab vacuum calibration experiment data of IRAS, the relation between radiance and output digital counts is set up by means of the statistical regression method. The lab coefficients at the infrared channels are obtained and the nonlinear responses of IRAS output signals to the input radiance are analyzed. The noise equivalent differential radiance at 290 K temperature is computed and compared with specifications. The results reveal that there is nonlinear response to a certain extent for IRAS, and the nonlinear bias values are less than 0.4 K in the range of 220 to 230 K. The noise equivalent differential radiance meets the functional requirements of the IRAS specifications.
2009, 37(5):576-579.
Abstract:
Based on the solar radiation observations from CE318 sunphotometer at the 936 nm channel，the improved Langley technique is used to retrieve the atmospheric column water vapor content over Zhengzhou. The empirical expression of the relation between atmospheric column water vapor content and ground water vapor pressure is derived. The calculating results show that the seasonal variation of the atmospheric column water vapor content was the greatest in summer, the second in autumn, and the least in winter. The diurnal evolution shows that there is a lower value in morning and evening, and higher value appear around noon. There is a good linear relationship between atmospheric column water vapor content and ground water vapor pressure.
Based on the solar radiation observations from CE318 sunphotometer at the 936 nm channel，the improved Langley technique is used to retrieve the atmospheric column water vapor content over Zhengzhou. The empirical expression of the relation between atmospheric column water vapor content and ground water vapor pressure is derived. The calculating results show that the seasonal variation of the atmospheric column water vapor content was the greatest in summer, the second in autumn, and the least in winter. The diurnal evolution shows that there is a lower value in morning and evening, and higher value appear around noon. There is a good linear relationship between atmospheric column water vapor content and ground water vapor pressure.
2009, 37(5):580-583.
Abstract:
Based on the basic principle and structure of Wind Profile Radar (WPR), the observations by WPR are compared with the corresponding radiosonde data. The results suggest that WPR observations of wind speed and direction are consistent, but WPR temperatures are inconsistent. The distribution of the available rate of the wind profiler data within PBL and the effect of different weather on the available rate are discussed. Results show that the available rate within PBL is greater than 80%, and the detecting capability at the lower troposphere and middle PBL is far greater than that at upper levels; the detecting height after rainfall is greater than that before rainfall at upper levels; the available rates in the different weather are almost consistent at lower levels; the available rate in overcast and rainy weather are greater than that in fine weather, while the detecting height in overcast and rainy weather is greater than that in fine weather at upper levels.
Based on the basic principle and structure of Wind Profile Radar (WPR), the observations by WPR are compared with the corresponding radiosonde data. The results suggest that WPR observations of wind speed and direction are consistent, but WPR temperatures are inconsistent. The distribution of the available rate of the wind profiler data within PBL and the effect of different weather on the available rate are discussed. Results show that the available rate within PBL is greater than 80%, and the detecting capability at the lower troposphere and middle PBL is far greater than that at upper levels; the detecting height after rainfall is greater than that before rainfall at upper levels; the available rates in the different weather are almost consistent at lower levels; the available rate in overcast and rainy weather are greater than that in fine weather, while the detecting height in overcast and rainy weather is greater than that in fine weather at upper levels.
2009, 37(5):584-586.
Abstract:
The HMP45D humidity sensor, an integrated temperature and humidity measuring device, is used widely across China. Because of the vast territory of China, there exists big difference in the environment temperature from south to north, especially in cold seasons. At some stations in the furthest North, temperature can be as low as －40 ℃. In order to understand the influence of environment temperature on the measuring accuracy of humidity, a characteristic experiment was conducted. Three humidity sensors were randomly selected as testing sensors and the output humidity values of the doublepressure humidity generator were used as standard humidity values. Under the different temperature conditions, the testing of the influence degree of temperature on the measuring accuracy of humidity was carried out.
The HMP45D humidity sensor, an integrated temperature and humidity measuring device, is used widely across China. Because of the vast territory of China, there exists big difference in the environment temperature from south to north, especially in cold seasons. At some stations in the furthest North, temperature can be as low as －40 ℃. In order to understand the influence of environment temperature on the measuring accuracy of humidity, a characteristic experiment was conducted. Three humidity sensors were randomly selected as testing sensors and the output humidity values of the doublepressure humidity generator were used as standard humidity values. Under the different temperature conditions, the testing of the influence degree of temperature on the measuring accuracy of humidity was carried out.
16 Design and Implementation of Remote Meteorological Data Acquisition System Based on GPRS Network
2009, 37(5):587-592.
Abstract:
As the realtime meteorological monitoring network is used more and more widely and intensively, it is necessary to design a remote meteorological data acquisition system based on GPRS Network. The GPRS network has the following advantages: wide coverage, realtime online, high quality communication and low maintenance costs. The structure and functions of the system are introduced, and its longrange monitoring terminal hardware configuration is described in detail, with the focuses on the relevant circuit chip use, and the programming of relevant application software by means of Microsoft Visual Studio 6.0. The application of this system in practice is also discussed .
As the realtime meteorological monitoring network is used more and more widely and intensively, it is necessary to design a remote meteorological data acquisition system based on GPRS Network. The GPRS network has the following advantages: wide coverage, realtime online, high quality communication and low maintenance costs. The structure and functions of the system are introduced, and its longrange monitoring terminal hardware configuration is described in detail, with the focuses on the relevant circuit chip use, and the programming of relevant application software by means of Microsoft Visual Studio 6.0. The application of this system in practice is also discussed .
2009, 37(5):593-596.
Abstract:
An introduction is made to the system structure, working flow，and advantage in weather warning information distribution of WAP Push technology, as well as the framework of the Jiangxi Weather Warning Information Distributing Platform, which is composed of the information acquisition layer, information editing/storage layer, and information distribution layer. The platform is safe, steady and maintainable. The working flow and functions of the information distribution layer are descibed in detail. The platform can send both image and text information, can send information to mobile phones at the same time and support group sending. The application and prospects of WAP Push technology in the meteorological field are also discussed.
An introduction is made to the system structure, working flow，and advantage in weather warning information distribution of WAP Push technology, as well as the framework of the Jiangxi Weather Warning Information Distributing Platform, which is composed of the information acquisition layer, information editing/storage layer, and information distribution layer. The platform is safe, steady and maintainable. The working flow and functions of the information distribution layer are descibed in detail. The platform can send both image and text information, can send information to mobile phones at the same time and support group sending. The application and prospects of WAP Push technology in the meteorological field are also discussed.
2009, 37(5):597-600.
Abstract:
An algorithm of area filling based on isoline classification is presented. Based on the relationship between isolines and borderlines, isolines are classified and ranked, and the isoline areas are constructed. The isoline area topology is built by searching the subisolines. The advantages and disadvantages of different ways of color filling are also discussed, and the analysis concludes that it is necessary to use grid data to choose color. This algorithm can be used to fill the areas between regular isolines for less computing time. The algorithm has been applied successfully in the Shanghai Nowcasting & Warning System (NoCAWS).
An algorithm of area filling based on isoline classification is presented. Based on the relationship between isolines and borderlines, isolines are classified and ranked, and the isoline areas are constructed. The isoline area topology is built by searching the subisolines. The advantages and disadvantages of different ways of color filling are also discussed, and the analysis concludes that it is necessary to use grid data to choose color. This algorithm can be used to fill the areas between regular isolines for less computing time. The algorithm has been applied successfully in the Shanghai Nowcasting & Warning System (NoCAWS).
2009, 37(5):601-606.
Abstract:
Based on the data of the flux observation system of the Shouxian National Climate Observatory from July 2007 to June 2008, an analysis is made of the interaction processes between atmosphere and land in the cropland ecosystem over the Huaihe River basin. The absent ratios of the gradient and eddy data are calculated, and the flux gradient and eddy covariance methods are adopted to validate the credibility of the data, and then the seasonal and daily variation of the CO2 flux, latent heat flux and sensible heat flux, as well as the relationship between the surface and those fluxes, are analyzed. Meanwhile the mean surface albedo, energy budget closure rate and drag coefficient are calculated. The results show that the observation data is credible; the original data is objective and useable; there exists seasonal variation obviously in these fluxes; these fluxes have close relationship with the condition of the underlying surface; and the daily variation of fluxes shows a single peak distribution. The mean surface albedo, mean energy budget closure rate and drag coefficient calculated by the data from the flux observation system are 0.18, 0.92, and 0.0092, respectively, in the Huaihe River basin.
Based on the data of the flux observation system of the Shouxian National Climate Observatory from July 2007 to June 2008, an analysis is made of the interaction processes between atmosphere and land in the cropland ecosystem over the Huaihe River basin. The absent ratios of the gradient and eddy data are calculated, and the flux gradient and eddy covariance methods are adopted to validate the credibility of the data, and then the seasonal and daily variation of the CO2 flux, latent heat flux and sensible heat flux, as well as the relationship between the surface and those fluxes, are analyzed. Meanwhile the mean surface albedo, energy budget closure rate and drag coefficient are calculated. The results show that the observation data is credible; the original data is objective and useable; there exists seasonal variation obviously in these fluxes; these fluxes have close relationship with the condition of the underlying surface; and the daily variation of fluxes shows a single peak distribution. The mean surface albedo, mean energy budget closure rate and drag coefficient calculated by the data from the flux observation system are 0.18, 0.92, and 0.0092, respectively, in the Huaihe River basin.
2009, 37(5):607-612.
Abstract:
The phenophase data and climatic element data in the same time period since 1979 are analyzed, and the variation regularity of winter wheat phenophases in the Huaibei Plain is studied. The results show that the five phenophases of reviving, setting, jointing, flowering, and ripening stages show an obvious advance trend, especially reviving, flowering, and ripening stages. It is found that among light, temperature, and water, temperature is the main factor that determines the variation of winter wheat phenophases in the Huaibei Plain. The correlation between precipitation and all local wheat phenophases does not pass the significance test. The sunshine duration has good correlation with the grouting process of wheat only during the grouting stage. The influences of the main climatic elements on the winter wheat phenophases in the Huaibei Plain are studied in detail, and some quantitative results are given.
The phenophase data and climatic element data in the same time period since 1979 are analyzed, and the variation regularity of winter wheat phenophases in the Huaibei Plain is studied. The results show that the five phenophases of reviving, setting, jointing, flowering, and ripening stages show an obvious advance trend, especially reviving, flowering, and ripening stages. It is found that among light, temperature, and water, temperature is the main factor that determines the variation of winter wheat phenophases in the Huaibei Plain. The correlation between precipitation and all local wheat phenophases does not pass the significance test. The sunshine duration has good correlation with the grouting process of wheat only during the grouting stage. The influences of the main climatic elements on the winter wheat phenophases in the Huaibei Plain are studied in detail, and some quantitative results are given.
2009, 37(5):613-617.
Abstract:
An analysis is made of the climatic factors influencing sugar cane yields and sugar contents to provide the bases for taking measures to adapt to climate change for sugar production. The trends and phasic and periodic characteristics of these climatic factors in the recent 45 years are studied. The results indicate that the accumulated temperature of March to October increased obviously; there was obvious phasic feature in the variation of the accumulated temperature and precipitation of March to October; there was obvious periodic variation in the accumulated temperature, precipitation, and sunshine duration of March to October. The average minimum temperature of October to November increased notably, and there was remarkable phasic and periodic variation; there was periodic oscillation in the precipitation in November to next February with the period being 3 to 4 years.
An analysis is made of the climatic factors influencing sugar cane yields and sugar contents to provide the bases for taking measures to adapt to climate change for sugar production. The trends and phasic and periodic characteristics of these climatic factors in the recent 45 years are studied. The results indicate that the accumulated temperature of March to October increased obviously; there was obvious phasic feature in the variation of the accumulated temperature and precipitation of March to October; there was obvious periodic variation in the accumulated temperature, precipitation, and sunshine duration of March to October. The average minimum temperature of October to November increased notably, and there was remarkable phasic and periodic variation; there was periodic oscillation in the precipitation in November to next February with the period being 3 to 4 years.
2009, 37(5):618-620.
Abstract:
On the basis of the MODIS remote sensing images, the bluealga bloom over the Dianchi Lake was monitored by the pseudocolor composition (RGB: 621) and the normalized vegetation index methods, according to the spectral features in the blue, red, and nearinfrared wavebands. Through the satelliteground synchronization experiments, the accuracies of the two methods are verified. The pseudocolor composition method uses color difference to display bluealga bloom, which has better visual effect, while the normalization vegetation index method uses index values to decide bluealga bloom concentration quantitatively, which can be applied to quantitative investigation.
On the basis of the MODIS remote sensing images, the bluealga bloom over the Dianchi Lake was monitored by the pseudocolor composition (RGB: 621) and the normalized vegetation index methods, according to the spectral features in the blue, red, and nearinfrared wavebands. Through the satelliteground synchronization experiments, the accuracies of the two methods are verified. The pseudocolor composition method uses color difference to display bluealga bloom, which has better visual effect, while the normalization vegetation index method uses index values to decide bluealga bloom concentration quantitatively, which can be applied to quantitative investigation.
2009, 37(5):621-626.
Abstract:
The factors which are significantly correlated with the 1 hour and 3 h rainfall from the rainfall data of automatic precipitation stations over Anhui Province are selected from the satellite products or model products in the national directive products for weather artificial modification. With the Fisher norm method and the factors, the equations of 1 hour and 3 hour operation condition discrimination are established for all seasons and automatic precipitation stations to judge quantitatively whether there are favorable operation conditions for seeding. The equations are tested and verified with history data, and the results indicate that the forecast accuracy of 1 hour and 3 hour seeding conditions is 70% or so and over 50% respectively, which means that the equations have satisfactory accuracy and can be used to predict seeding conditions. But it has to be noted that the nohitting rate is relatively high in spring, summer and autumn.
The factors which are significantly correlated with the 1 hour and 3 h rainfall from the rainfall data of automatic precipitation stations over Anhui Province are selected from the satellite products or model products in the national directive products for weather artificial modification. With the Fisher norm method and the factors, the equations of 1 hour and 3 hour operation condition discrimination are established for all seasons and automatic precipitation stations to judge quantitatively whether there are favorable operation conditions for seeding. The equations are tested and verified with history data, and the results indicate that the forecast accuracy of 1 hour and 3 hour seeding conditions is 70% or so and over 50% respectively, which means that the equations have satisfactory accuracy and can be used to predict seeding conditions. But it has to be noted that the nohitting rate is relatively high in spring, summer and autumn.
2009, 37(5):627-631.
Abstract:
By analyzing the geological conditions, exterior factors, and antecedent precipitation over the areas where landslides and debris flows happen more frequently, the discrimination standards of geological disaster grades and the prediction method are devised. By means of ArcGIS Engine and MICAPS, a prediction system of landslides and debris flows for Diqing is developed. The hourly and daily automatic weather station (AWS) precipitation data from the antecedent precipitation database are used to forecast the disasters, which provides useful guidance for the prevention of geological disasters.
By analyzing the geological conditions, exterior factors, and antecedent precipitation over the areas where landslides and debris flows happen more frequently, the discrimination standards of geological disaster grades and the prediction method are devised. By means of ArcGIS Engine and MICAPS, a prediction system of landslides and debris flows for Diqing is developed. The hourly and daily automatic weather station (AWS) precipitation data from the antecedent precipitation database are used to forecast the disasters, which provides useful guidance for the prevention of geological disasters.
2009, 37(5):632-637.
Abstract:
The surpass probability of precipitation of different levels during the singlecropping rice growth period in Zhejiang Province is studied using the risk assessment model based on the principle of information spread by means of the precipitation data during the singlecropping rice growth periods from 58 local meteorological stations from 1971 to 2004. With the risk charts of differentlevel precipitation, the risks of droughts and floods for singlecropping rice and their damage to rice yields are evaluated. The results indicate that the highrisk areas with precipitation lower than 400 mm are located in the coastal island areas, Jiaxing, and the JinhuaQuzhou basin, where rice suffers heavier drought damage. The highrisk areas with precipitation higher than 1000 mm are found in the southeastern coastal areas (including Linhai, Wencheng, Wenling, Ninghai, Taishun, etc), where singlecropping rice suffers greater flood damage (typhoon rainstorm). Compared to the drought disasters, which may be relieved by irrigation, floods have greater contribution to rice yield reduction.
The surpass probability of precipitation of different levels during the singlecropping rice growth period in Zhejiang Province is studied using the risk assessment model based on the principle of information spread by means of the precipitation data during the singlecropping rice growth periods from 58 local meteorological stations from 1971 to 2004. With the risk charts of differentlevel precipitation, the risks of droughts and floods for singlecropping rice and their damage to rice yields are evaluated. The results indicate that the highrisk areas with precipitation lower than 400 mm are located in the coastal island areas, Jiaxing, and the JinhuaQuzhou basin, where rice suffers heavier drought damage. The highrisk areas with precipitation higher than 1000 mm are found in the southeastern coastal areas (including Linhai, Wencheng, Wenling, Ninghai, Taishun, etc), where singlecropping rice suffers greater flood damage (typhoon rainstorm). Compared to the drought disasters, which may be relieved by irrigation, floods have greater contribution to rice yield reduction.
2009, 37(5):638-640.
Abstract:
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.