Volume 37,Issue 3,2009 Table of Contents
2009, 37(3):257-262.
Abstract:
The researches on theory and application of climatic probability distribution have been made great advances along with the increasing global warming and climate change studies. A brief summary is made of advances in theory and application of climatic probability distribution from the following aspects: the distribution fitting of observational data; the formation mechanisms of climatic probability distribution; indication of climatic change: changes of probability distribution; climate extreme distribution models under global climate change; and the climatic probability distribution models of climatic variables in various spatial domains.
The researches on theory and application of climatic probability distribution have been made great advances along with the increasing global warming and climate change studies. A brief summary is made of advances in theory and application of climatic probability distribution from the following aspects: the distribution fitting of observational data; the formation mechanisms of climatic probability distribution; indication of climatic change: changes of probability distribution; climate extreme distribution models under global climate change; and the climatic probability distribution models of climatic variables in various spatial domains.
2009, 37(3):263-270.
Abstract:
The major advances in the researches on the relationship between the Eurasia snowcover and Asian monsoon are summarized. The varying area and thickness of the Eurasia snowcover can exert remarkably influences on the thermal characteristics and hydrologic processes of the land surface, and thus influences the onset and development of Asian monsoon. It is generally thought that there is an inverse relationship between Eurasia snowcover and Asian monsoon, in both diagnostic and model researches, but the relationship is very complex, including interannual or decadal variability. Snowcover in different regions and seasons has different impacts on the monsoon, and some factors such as ENSO, NAO can also affect the relationship. There exist still many differences and questions in the present studies of the relationship between snowcover and monsoon, as well as the mechanisms that how snow influences climate.
The major advances in the researches on the relationship between the Eurasia snowcover and Asian monsoon are summarized. The varying area and thickness of the Eurasia snowcover can exert remarkably influences on the thermal characteristics and hydrologic processes of the land surface, and thus influences the onset and development of Asian monsoon. It is generally thought that there is an inverse relationship between Eurasia snowcover and Asian monsoon, in both diagnostic and model researches, but the relationship is very complex, including interannual or decadal variability. Snowcover in different regions and seasons has different impacts on the monsoon, and some factors such as ENSO, NAO can also affect the relationship. There exist still many differences and questions in the present studies of the relationship between snowcover and monsoon, as well as the mechanisms that how snow influences climate.
2009, 37(3):271-275.
Abstract:
Based on the PSU/NCAR mesoscale model version WRF 2.2, the SeaFog Numerical Prediction System for the Yellow Sea and Bohai Sea is constructed by choosing optimally optional microphysical processes and boundary layer schemes, with the sea fog diagnostic equation coupled into the WRF model. Continuous operational seafog prediction experiments and verifications are made from 30 June to 1 August of 2007.Several testing schemes are devised according to the characteristics of the data from coastal conventional stations and satellite monitoring data. The results show that the numerical prediction system is able to predict sea fog with a satisfactory precision, especially heavy fog, which can provide helpful guidance for operational heavy fog prediction. The testing schemes are useful attempts for solving the problems for the scarcity of meteorological data on the sea areas, which is helpful to the quality control and application of numerical predictions.
Based on the PSU/NCAR mesoscale model version WRF 2.2, the SeaFog Numerical Prediction System for the Yellow Sea and Bohai Sea is constructed by choosing optimally optional microphysical processes and boundary layer schemes, with the sea fog diagnostic equation coupled into the WRF model. Continuous operational seafog prediction experiments and verifications are made from 30 June to 1 August of 2007.Several testing schemes are devised according to the characteristics of the data from coastal conventional stations and satellite monitoring data. The results show that the numerical prediction system is able to predict sea fog with a satisfactory precision, especially heavy fog, which can provide helpful guidance for operational heavy fog prediction. The testing schemes are useful attempts for solving the problems for the scarcity of meteorological data on the sea areas, which is helpful to the quality control and application of numerical predictions.
2009, 37(3):276-280.
Abstract:
Using the weather forecasting product evaluation system, the results of MM5 and T213 numerical prediction are verified and analyzed, respectively. The verification is conducted based on historical and current data, with verified elements including precipitation, temperature, and circulation patterns at 500 hPa. The results show that MM5 is better than T213 in precipitation and temperature prediction, but T213 is more trustworthy in circulation pattern prediction.
Using the weather forecasting product evaluation system, the results of MM5 and T213 numerical prediction are verified and analyzed, respectively. The verification is conducted based on historical and current data, with verified elements including precipitation, temperature, and circulation patterns at 500 hPa. The results show that MM5 is better than T213 in precipitation and temperature prediction, but T213 is more trustworthy in circulation pattern prediction.
2009, 37(3):281-286.
Abstract:
A comparative diagnosis of the divergence and frontogenesis fields of the ageostrophic wet Qvector (Q*) and the improved ageostrophic wet Q vector (Qq) is made for a torrential rain process over the eastern QinghaiXizang Plateau occurred on 18 to 19 July 2005. The results show: (1) The convergence field of the Qq reflects the intensity and area of the heavy rainfall more precisely than that of Q*. The lowerlevel atmospheric forcing is the main driving factor of the vertical motion in the heavy rain area, which made the updraft accelerate under the instability stratification and caused strong convection. (2) The frontogenesis function of Qq with all diabatic heating effects reflects the center and area of the heavy rainfall more precisely and has stronger frontogenesis effect. After the rainfall, due to the release of instable energy, there appeared evident frontolysis.
A comparative diagnosis of the divergence and frontogenesis fields of the ageostrophic wet Qvector (Q*) and the improved ageostrophic wet Q vector (Qq) is made for a torrential rain process over the eastern QinghaiXizang Plateau occurred on 18 to 19 July 2005. The results show: (1) The convergence field of the Qq reflects the intensity and area of the heavy rainfall more precisely than that of Q*. The lowerlevel atmospheric forcing is the main driving factor of the vertical motion in the heavy rain area, which made the updraft accelerate under the instability stratification and caused strong convection. (2) The frontogenesis function of Qq with all diabatic heating effects reflects the center and area of the heavy rainfall more precisely and has stronger frontogenesis effect. After the rainfall, due to the release of instable energy, there appeared evident frontolysis.
2009, 37(3):287-293.
Abstract:
A detailed analysis is made of the synoptic features of the 14 thunderstorm events occurred in 2007 summer at Xi’an Xianyang International Airport through the objective analysis of conventional data. The results indicate that the 14 thunderstorm events can be divided into 3 types: cold front, cold vortex, and northwest current, and thunderstorms in 2007 summer have the features of earlier start, increased frequency, longer duration, higher intensity, and being accompanied with severe rainfall. In addition, a case study of the thunderstorm occurred on 8 August 2007, which caused heavy losses for flights delay and communication and navigation equipment destruction, is conducted. The causes for the occurrence and development of this thunderstorm are analyzed from the aspects of weather situation, energy features, physical quantity fields, and radar echoes.
A detailed analysis is made of the synoptic features of the 14 thunderstorm events occurred in 2007 summer at Xi’an Xianyang International Airport through the objective analysis of conventional data. The results indicate that the 14 thunderstorm events can be divided into 3 types: cold front, cold vortex, and northwest current, and thunderstorms in 2007 summer have the features of earlier start, increased frequency, longer duration, higher intensity, and being accompanied with severe rainfall. In addition, a case study of the thunderstorm occurred on 8 August 2007, which caused heavy losses for flights delay and communication and navigation equipment destruction, is conducted. The causes for the occurrence and development of this thunderstorm are analyzed from the aspects of weather situation, energy features, physical quantity fields, and radar echoes.
2009, 37(3):294-300.
Abstract:
Based on the 1949-2006 Tropical Cyclone Yearbooks and the new tropical cyclone (TC) grade standards, a climatological analysis of landfalling TC over China is carried out. Results show that, out of all landfalling TC, severe tropical storm (STS) takes up a maximal proportion of 38.5%, then typhoon (TY), tropical storm (TS), severe typhoon (STY) and super typhoon (SuperTY). The 59% STY and 67% SuperTY land over Taiwan Island. Guangdong is the province that is attacked mostly frequently by TCs, but scarcely by STYs and SuperTYs. The most active period for TCs is from July to September with the strongest mean intensity in August and September. There are obvious interannual and interdecadal changes in the frequency of landfalling TCs, with a weak decrease tendency in the total landfalling TCs and an increase tendency in those categorized as TYs, STYs and SuperTYs. Under the background of global warming, the landfalling TCs, averagely, show a trend of northward movement in the formation source region and weak decrease in intensity in recent several decades. Since the beginning of the 2000s, there is an obvious southward movement in the formation source region and a significant increase in mean intensity for landfalling TCs, especially for the annual maximum central wind and minimal central pressure. There is no obvious change in the mean latitude of landfalling location for all TCs in the past decades, while the annual northernmost latitude moves southwards, mostly below 35°N since the middle 1970s.
Based on the 1949-2006 Tropical Cyclone Yearbooks and the new tropical cyclone (TC) grade standards, a climatological analysis of landfalling TC over China is carried out. Results show that, out of all landfalling TC, severe tropical storm (STS) takes up a maximal proportion of 38.5%, then typhoon (TY), tropical storm (TS), severe typhoon (STY) and super typhoon (SuperTY). The 59% STY and 67% SuperTY land over Taiwan Island. Guangdong is the province that is attacked mostly frequently by TCs, but scarcely by STYs and SuperTYs. The most active period for TCs is from July to September with the strongest mean intensity in August and September. There are obvious interannual and interdecadal changes in the frequency of landfalling TCs, with a weak decrease tendency in the total landfalling TCs and an increase tendency in those categorized as TYs, STYs and SuperTYs. Under the background of global warming, the landfalling TCs, averagely, show a trend of northward movement in the formation source region and weak decrease in intensity in recent several decades. Since the beginning of the 2000s, there is an obvious southward movement in the formation source region and a significant increase in mean intensity for landfalling TCs, especially for the annual maximum central wind and minimal central pressure. There is no obvious change in the mean latitude of landfalling location for all TCs in the past decades, while the annual northernmost latitude moves southwards, mostly below 35°N since the middle 1970s.
2009, 37(3):301-305.
Abstract:
Based on the data of ground temperature, air temperature and precipitation of China from 1957 to 2006, the distributional characteristics of differences between ground and air temperature in spring in China are analyzed. The relationship of differences between ground and air temperature in spring to summer precipitation is studied by means of the correlation analysis and Singular Value Decomposition (SVD) methods. Results show that the distribution of differences between ground and air temperature is similar to the terrain. When droughts occurred in the midlower reaches of the Yangtze River, the differences between ground and air temperature over the Tibetan Plateau is relatively higher, and lower in the Yellow River and Huai River basins in spring. Furthermore, there is significant positive correlation of the differences between ground and air temperature over Tibetan Plateau in spring to the summer precipitation in the midlower reaches of the Yangtze River.
Based on the data of ground temperature, air temperature and precipitation of China from 1957 to 2006, the distributional characteristics of differences between ground and air temperature in spring in China are analyzed. The relationship of differences between ground and air temperature in spring to summer precipitation is studied by means of the correlation analysis and Singular Value Decomposition (SVD) methods. Results show that the distribution of differences between ground and air temperature is similar to the terrain. When droughts occurred in the midlower reaches of the Yangtze River, the differences between ground and air temperature over the Tibetan Plateau is relatively higher, and lower in the Yellow River and Huai River basins in spring. Furthermore, there is significant positive correlation of the differences between ground and air temperature over Tibetan Plateau in spring to the summer precipitation in the midlower reaches of the Yangtze River.
2009, 37(3):306-310.
Abstract:
To understand the characteristics of clouds over Inner Mongolia, the spatialtemporal distribution and change trends of total, high, middle, low cloud amounts and change trends of temperature and rainfall in Inner Mongolia are analyzed with the trend analysis method on the basis of ISCCP D2 data from July 1983 to September 2001 and monthly mean temperature data of the eastern Inner Mongolia. The results show that total, middle, low cloud amounts over Inner Mongolia increased from west to east, and high cloud amount decreased from southwest to northeast; from 1983 to 2001, cloud amount in the eastern Inner Mongolia increased, but decreased in the central and western parts. Analysis indicates that temperature change may be one of causes of the cloud amount change. The change trends of cloud amount and rainfall tend to be accordant in the northeastern Inner Mongolia.
To understand the characteristics of clouds over Inner Mongolia, the spatialtemporal distribution and change trends of total, high, middle, low cloud amounts and change trends of temperature and rainfall in Inner Mongolia are analyzed with the trend analysis method on the basis of ISCCP D2 data from July 1983 to September 2001 and monthly mean temperature data of the eastern Inner Mongolia. The results show that total, middle, low cloud amounts over Inner Mongolia increased from west to east, and high cloud amount decreased from southwest to northeast; from 1983 to 2001, cloud amount in the eastern Inner Mongolia increased, but decreased in the central and western parts. Analysis indicates that temperature change may be one of causes of the cloud amount change. The change trends of cloud amount and rainfall tend to be accordant in the northeastern Inner Mongolia.
2009, 37(3):311-314.
Abstract:
Based on the glaze data of 83 weather stations，an analysis is made of the glaze weather processes in the past 50 years, and the temporal and spatial distribution of glaze is revealed. By means of the selfdeveloped automatic weather information analysis methods, the historical glaze data are processed, and some key information is extracted, such as the dates of beginning and ending, durations and affected areas of glaze events. The reoccurrence period analysis of glaze is made of the durations, affected areas of glaze weather and the annual numbers of glaze days. The results show: (1) Glaze occurred mainly during winter, especially in February, sometimes in spring or autumn at highaltitude stations. (2) The highest probability of glaze occurrence was along the middle and northern coast of the Poyang Lake, and the least in the northeastern and northwestern Jiangxi Province; there are more glaze events in the mountainous area than in the plain and hilly areas. (3) The largescale and longlasing glaze weather in the early 2008 induced great cold damage, with the affected area and duration breaking the recodes of the recent 50 years.
Based on the glaze data of 83 weather stations，an analysis is made of the glaze weather processes in the past 50 years, and the temporal and spatial distribution of glaze is revealed. By means of the selfdeveloped automatic weather information analysis methods, the historical glaze data are processed, and some key information is extracted, such as the dates of beginning and ending, durations and affected areas of glaze events. The reoccurrence period analysis of glaze is made of the durations, affected areas of glaze weather and the annual numbers of glaze days. The results show: (1) Glaze occurred mainly during winter, especially in February, sometimes in spring or autumn at highaltitude stations. (2) The highest probability of glaze occurrence was along the middle and northern coast of the Poyang Lake, and the least in the northeastern and northwestern Jiangxi Province; there are more glaze events in the mountainous area than in the plain and hilly areas. (3) The largescale and longlasing glaze weather in the early 2008 induced great cold damage, with the affected area and duration breaking the recodes of the recent 50 years.
2009, 37(3):315-322.
Abstract:
By means of monthly rainfall and temperature data from 1953 to 2006 at seven stations in Shiyan， the summer droughts are divided by the traditional method (R index). Considering that besides rainfall, temperature has also important effect on droughts, P index is designed to divide summer droughts. The results indicate that Shiyan is one of areas attacked by droughts frequently; there exists periodicity and continuity in Shiyan droughts; droughts are severer in the northern part than those in the southern part. The main influencing weather systems include the East Asia trough, subtropical high, QinghaiTibet high (mainland high), which influence Shiyan alternately,controlled by East Asia trough in spring, by the subtropical high and mainland high in summer, and by the mainland high and subtropical high in autumn. Detailed forecast indexes are given according to different seasons and drought types.
By means of monthly rainfall and temperature data from 1953 to 2006 at seven stations in Shiyan， the summer droughts are divided by the traditional method (R index). Considering that besides rainfall, temperature has also important effect on droughts, P index is designed to divide summer droughts. The results indicate that Shiyan is one of areas attacked by droughts frequently; there exists periodicity and continuity in Shiyan droughts; droughts are severer in the northern part than those in the southern part. The main influencing weather systems include the East Asia trough, subtropical high, QinghaiTibet high (mainland high), which influence Shiyan alternately,controlled by East Asia trough in spring, by the subtropical high and mainland high in summer, and by the mainland high and subtropical high in autumn. Detailed forecast indexes are given according to different seasons and drought types.
12 Statistical Characteristics of Fog along Qiongzhou Strait Coast and Its Synoptic Forecasting Indexes
2009, 37(3):323-329.
Abstract:
The climatic statistical characteristics of foggy weather along the Qiongzhou Strait coast are analyzed by using the surface observation and radiosonde data of Haikou Station from 1961 to 2006. The result shows that as far as longterm trend are concerned, the foggy days along the Qiongzhou Strait coast show a significant linear decrease trend, and the two climatic abrupt decrease periods are the early 1970s and the early 1990s. The fog days have good negative relation with diurnal minimum temperature; that is, the climate warming is the main reason for fog decrease. Fogs form more frequently in winter and spring, appearing from 06:00 to 07:00 in the morning and disappearing 1 to 2 hours later. Based on the reanalysis of data from NCEP from 1987 to 2006, three weather patterns of fog along the Qiongzhou Strait are summed up and forecasting indexes are put forward as well.
The climatic statistical characteristics of foggy weather along the Qiongzhou Strait coast are analyzed by using the surface observation and radiosonde data of Haikou Station from 1961 to 2006. The result shows that as far as longterm trend are concerned, the foggy days along the Qiongzhou Strait coast show a significant linear decrease trend, and the two climatic abrupt decrease periods are the early 1970s and the early 1990s. The fog days have good negative relation with diurnal minimum temperature; that is, the climate warming is the main reason for fog decrease. Fogs form more frequently in winter and spring, appearing from 06:00 to 07:00 in the morning and disappearing 1 to 2 hours later. Based on the reanalysis of data from NCEP from 1987 to 2006, three weather patterns of fog along the Qiongzhou Strait are summed up and forecasting indexes are put forward as well.
2009, 37(3):330-335.
Abstract:
With the methods of linear analysis and correlation analysis, the tendency rate of the ground temperature for about 50 years in Puyang and the causes are analyzed. The results indicate that the monthly mean ground temperature has an obvious rise trend from December to next April, and a drop trend from May to November, with the tendency rate being 0.01 to 0.32 ℃ per 10 years and -0.04 to 0.83 ℃ per 10 years. The tendency rate of the annual mean ground temperature is -0.23 ℃ per 10 years; that of the monthly mean maximum temperature in November is 0.01 ℃ per 10 years, and -0.46 to -2.16 ℃ per 10 years in the other months; the annual mean temperature -0.23 ℃ per 10 years; the monthly mean minimum ground temperature in November -0.02 ℃ per 10 years, and 0.09 to 0.76 ℃ per 10 years in the other months; the annual variation 0.34 ℃ per 10 years; the monthly mean airground temperature difference is -0.17 to -0.66 ℃ per 10 years, and annual mean airground temperature difference -0.35 ℃ per 10 years. It can be concluded that the average maximum ground temperature has a yearbyyear drop trend, and the average minimum ground temperatures has a yearbyyear rise trend, with the variation range of the former being far greater than that of the latter. The annual mean ground temperature has also has a yearbyyear drop trend, resulting in less airground temperature difference and greater atmospheric stability, which are unfavorable for the spreading of pollutants and water vapor in the near surface. The variations such as the increased foggy days, heavier air pollution, decreased sunshine duration, and less solar radiation, are the direct causes of ground temperature drop, and the variations such as increased air humidity and precipitation and heavier air pollution are the indirect causes.
With the methods of linear analysis and correlation analysis, the tendency rate of the ground temperature for about 50 years in Puyang and the causes are analyzed. The results indicate that the monthly mean ground temperature has an obvious rise trend from December to next April, and a drop trend from May to November, with the tendency rate being 0.01 to 0.32 ℃ per 10 years and -0.04 to 0.83 ℃ per 10 years. The tendency rate of the annual mean ground temperature is -0.23 ℃ per 10 years; that of the monthly mean maximum temperature in November is 0.01 ℃ per 10 years, and -0.46 to -2.16 ℃ per 10 years in the other months; the annual mean temperature -0.23 ℃ per 10 years; the monthly mean minimum ground temperature in November -0.02 ℃ per 10 years, and 0.09 to 0.76 ℃ per 10 years in the other months; the annual variation 0.34 ℃ per 10 years; the monthly mean airground temperature difference is -0.17 to -0.66 ℃ per 10 years, and annual mean airground temperature difference -0.35 ℃ per 10 years. It can be concluded that the average maximum ground temperature has a yearbyyear drop trend, and the average minimum ground temperatures has a yearbyyear rise trend, with the variation range of the former being far greater than that of the latter. The annual mean ground temperature has also has a yearbyyear drop trend, resulting in less airground temperature difference and greater atmospheric stability, which are unfavorable for the spreading of pollutants and water vapor in the near surface. The variations such as the increased foggy days, heavier air pollution, decreased sunshine duration, and less solar radiation, are the direct causes of ground temperature drop, and the variations such as increased air humidity and precipitation and heavier air pollution are the indirect causes.
2009, 37(3):336-340.
Abstract:
Through releasing three sets of radiosonde tied by a same balloon, the performance of the Finland Vaisala sounding system was tested. The results indicate that the consistency of pressure and humidity is in accordance with the technical specifications of RS92 GPS radiosonde, so is temperature except in the 10 hPa layer in the daytime; humidity and wind meet basically the requirements of WMO for the GCOS (Global Climate Observing System); geopotential height can well satisfy the WMO GCOS requirements. The analysis of the radiative characteristics shows that the influence of solar radiation is small below 70 hPa and great above 20 hPa. The experiment suggests that the radiosonde can also sensitively detect humidity with good measuring performance within clouds; the coordination between temperature and humidity is reasonable; the data losses of RS9GPS2 are significantly less than those of RS80, but improvements are still needed in stability, examination and software.
Through releasing three sets of radiosonde tied by a same balloon, the performance of the Finland Vaisala sounding system was tested. The results indicate that the consistency of pressure and humidity is in accordance with the technical specifications of RS92 GPS radiosonde, so is temperature except in the 10 hPa layer in the daytime; humidity and wind meet basically the requirements of WMO for the GCOS (Global Climate Observing System); geopotential height can well satisfy the WMO GCOS requirements. The analysis of the radiative characteristics shows that the influence of solar radiation is small below 70 hPa and great above 20 hPa. The experiment suggests that the radiosonde can also sensitively detect humidity with good measuring performance within clouds; the coordination between temperature and humidity is reasonable; the data losses of RS9GPS2 are significantly less than those of RS80, but improvements are still needed in stability, examination and software.
2009, 37(3):341-344.
Abstract:
The frequency characteristics of excitationsignals from the newgeneration weather radar at Urumchi before and after equipped with a bandpass filter are discussed, and the constituent structure and impedance transformation functions of the band pass filter are analyzed. Fourier transform is conducted on the excitationsignal function and responsesignal function, respectively, to gain the corresponding frequency function, which is then compared with the measurements. It is found out that that the installation of the bandpass filter brought about a satisfactory result, which can avoid radar microwave signal disturbance to other local microwave equipments due to the frequency band width of the radar.
The frequency characteristics of excitationsignals from the newgeneration weather radar at Urumchi before and after equipped with a bandpass filter are discussed, and the constituent structure and impedance transformation functions of the band pass filter are analyzed. Fourier transform is conducted on the excitationsignal function and responsesignal function, respectively, to gain the corresponding frequency function, which is then compared with the measurements. It is found out that that the installation of the bandpass filter brought about a satisfactory result, which can avoid radar microwave signal disturbance to other local microwave equipments due to the frequency band width of the radar.
2009, 37(3):345-348.
Abstract:
By means of the CINRAD/CD and WSR88D hail indexes, the hail data from January 2005 to August 2007 is analyzed. The hail indexes, such as warning threshold, relative radar height, missing report rate, false alarm rate, POD/FAR/CSI (Probability of Detection/False Acceptance Rate/Critical Success Index), are calculated and compared with SHI (Severe Hail Index), which is used as a prediction factor of the hail size, and the actual and predicted hail sizes are compared. Considering the local environment and climate characteristics, attempts to improve FAR are made (inputting the correct heights of 0 ℃ (-20 ℃), and increasing the reflectivity), and a method for reducing FAR is discussed. Using the method, the hail events from January 2007 to August 2007 are analyzed and tested, and the results show that FARs are reduced, and the forecast sizes of hailstones are closer to the actual sizes.
By means of the CINRAD/CD and WSR88D hail indexes, the hail data from January 2005 to August 2007 is analyzed. The hail indexes, such as warning threshold, relative radar height, missing report rate, false alarm rate, POD/FAR/CSI (Probability of Detection/False Acceptance Rate/Critical Success Index), are calculated and compared with SHI (Severe Hail Index), which is used as a prediction factor of the hail size, and the actual and predicted hail sizes are compared. Considering the local environment and climate characteristics, attempts to improve FAR are made (inputting the correct heights of 0 ℃ (-20 ℃), and increasing the reflectivity), and a method for reducing FAR is discussed. Using the method, the hail events from January 2007 to August 2007 are analyzed and tested, and the results show that FARs are reduced, and the forecast sizes of hailstones are closer to the actual sizes.
2009, 37(3):349-352.
Abstract:
An introduction is made to the routine test and debugging methods of the control circuit of the CINRAD/SA radar at Jinan, with emphasis on the module 3A10 of the return charge control circuit system for the transmitter. Some major malfunctions, which frequently occur in operation, and their causes and solutions are discussed, which can provide technicalsupport engineers with references in the debugging and testing of malfunctions.
An introduction is made to the routine test and debugging methods of the control circuit of the CINRAD/SA radar at Jinan, with emphasis on the module 3A10 of the return charge control circuit system for the transmitter. Some major malfunctions, which frequently occur in operation, and their causes and solutions are discussed, which can provide technicalsupport engineers with references in the debugging and testing of malfunctions.
2009, 37(3):353-355.
Abstract:
An analysis is made of a failure in the CINRAD/SA radar switching subassembly at Guangzhou, considering the signal flow and circuit principles. A detailed expatiation is conducted on the fault location, detection and elimination, as well as the analysis of the failure causes. Some maintenance experiences are summed up, which can be used as reference for radar maintenance staffs.
An analysis is made of a failure in the CINRAD/SA radar switching subassembly at Guangzhou, considering the signal flow and circuit principles. A detailed expatiation is conducted on the fault location, detection and elimination, as well as the analysis of the failure causes. Some maintenance experiences are summed up, which can be used as reference for radar maintenance staffs.
2009, 37(3):356-359.
Abstract:
An autoadapted method for drawing up contour maps for multiisland areas is devised by means of the powerful and unique capability of Sufer. Through analyzing various flaws in contour drawing with Surfer (incapability of whitening outward the multiislands maps and poor adaptability), the methods for improving and making the grid documents, whitening documents, and block level documents are given. In combination with the calling of the Automation interface, the algorithm diagram and main codes of the entire process are designed. Taking the 30year meteorological data of Zhejiang Province as an example, the meteorological element contour map superposed on the ZheJiang Province map is obtained by the autoadapted method, which prove that the method has good comparability, expandability, and applicability
An autoadapted method for drawing up contour maps for multiisland areas is devised by means of the powerful and unique capability of Sufer. Through analyzing various flaws in contour drawing with Surfer (incapability of whitening outward the multiislands maps and poor adaptability), the methods for improving and making the grid documents, whitening documents, and block level documents are given. In combination with the calling of the Automation interface, the algorithm diagram and main codes of the entire process are designed. Taking the 30year meteorological data of Zhejiang Province as an example, the meteorological element contour map superposed on the ZheJiang Province map is obtained by the autoadapted method, which prove that the method has good comparability, expandability, and applicability
2009, 37(3):360-362.
Abstract:
In order to enhance the accuracy of the records observed by small evaporation pans, an analysis is made of the false evaporation records from January 1998 to December 2007, including negativevalue, greaterthannormal, and missing records, in combination with weather conditions. The results show that the negative occupies 54.8% in false records, mostly in November and next February, under the conditions of light rain (snow), continuous rain, and bad fog weather; greaterthannormal and missing records appear mostly in June, July, and August under the conditions of showery heavy rainfall, small humidity, strong sunshine, and high wind weather. The causes of false records include improper and unreasonable operations and special weather. Some suggestions to avoid false records are presented corresponding different weather conditions.
In order to enhance the accuracy of the records observed by small evaporation pans, an analysis is made of the false evaporation records from January 1998 to December 2007, including negativevalue, greaterthannormal, and missing records, in combination with weather conditions. The results show that the negative occupies 54.8% in false records, mostly in November and next February, under the conditions of light rain (snow), continuous rain, and bad fog weather; greaterthannormal and missing records appear mostly in June, July, and August under the conditions of showery heavy rainfall, small humidity, strong sunshine, and high wind weather. The causes of false records include improper and unreasonable operations and special weather. Some suggestions to avoid false records are presented corresponding different weather conditions.
2009, 37(3):363-368.
Abstract:
In order to integrate the current different application systems and databases and enhance the construction of data storage and sharing capability, considering the requirements of integrating the existing data resources and establishing the uniform information platform, the basic skeleton of the J2EEbased meteorological information system is devised, using the JDBC (Java Database Connectivity) technology to manage the consolidated operation among the heteromerous and dispersive databases. The application of the J2EE technology to the construction of the distributed and dynamic meteorological information system is discussed.
In order to integrate the current different application systems and databases and enhance the construction of data storage and sharing capability, considering the requirements of integrating the existing data resources and establishing the uniform information platform, the basic skeleton of the J2EEbased meteorological information system is devised, using the JDBC (Java Database Connectivity) technology to manage the consolidated operation among the heteromerous and dispersive databases. The application of the J2EE technology to the construction of the distributed and dynamic meteorological information system is discussed.
2009, 37(3):369-373.
Abstract:
Considering the problems existing in prefecturelevel TV weather forecast program making, with the VB programming tool and the reflectivity factor data from newgerenration radar, a TGA document series with an Alpha channel is generated, by means of the cubic convolution interpolation algorithm scaling. The TGA document series can be broadcasted by most nonlinear editing software. The background pictures and the video frequency can be added through the Alpha channel. The radar products can be broadcasted in TV weather forecast programs. It indicates that the interpolation precision of the cubic convolution resampling method, as well as the colour continuity and picture quality, is satisfactory. The pictures accord the broadcast standards and the high frequency component can be retained well.
Considering the problems existing in prefecturelevel TV weather forecast program making, with the VB programming tool and the reflectivity factor data from newgerenration radar, a TGA document series with an Alpha channel is generated, by means of the cubic convolution interpolation algorithm scaling. The TGA document series can be broadcasted by most nonlinear editing software. The background pictures and the video frequency can be added through the Alpha channel. The radar products can be broadcasted in TV weather forecast programs. It indicates that the interpolation precision of the cubic convolution resampling method, as well as the colour continuity and picture quality, is satisfactory. The pictures accord the broadcast standards and the high frequency component can be retained well.
2009, 37(3):374-376.
Abstract:
To improve the inquiring efficiency of regional weather station rain data, a program is compiled with the TSQL clause under VB. The rain data can be obtained with the program from the central database of regional weather stations at the given periods as a background task. The redundancy can be removed from the original database, and the volume of the database is reduced greatly through creating a middle database of hour, day, and month tables. When the longterm accumulation rainfall is inquired, the inquiry is divided into 5 parts, with each part running separately, so the inquiring efficiency is improved greatly. The system can well satisfy the needs of floodcontrol and droughtrelief departments.
To improve the inquiring efficiency of regional weather station rain data, a program is compiled with the TSQL clause under VB. The rain data can be obtained with the program from the central database of regional weather stations at the given periods as a background task. The redundancy can be removed from the original database, and the volume of the database is reduced greatly through creating a middle database of hour, day, and month tables. When the longterm accumulation rainfall is inquired, the inquiry is divided into 5 parts, with each part running separately, so the inquiring efficiency is improved greatly. The system can well satisfy the needs of floodcontrol and droughtrelief departments.
2009, 37(3):377-379.
Abstract:
Software is developed with the tool of Visual Basic 6.0, aiming at the statistic and application problems about the groundbased observation data relevant to the operational agrometeorological service. The system can extract data from surface observation data and save them into a database. From the database, some useful data can obtained such as the accumulated temperature, the normal means for a certain week in history, the precipitation data in the table of soil moisture observation, and the relative data from natural phenological observation, as well as the data needed in crop meteorological condition appraisal and climate assessment.
Software is developed with the tool of Visual Basic 6.0, aiming at the statistic and application problems about the groundbased observation data relevant to the operational agrometeorological service. The system can extract data from surface observation data and save them into a database. From the database, some useful data can obtained such as the accumulated temperature, the normal means for a certain week in history, the precipitation data in the table of soil moisture observation, and the relative data from natural phenological observation, as well as the data needed in crop meteorological condition appraisal and climate assessment.
2009, 37(3):380-382.
Abstract:
2009, 37(3):383-384.
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.
Supported by:Beijing E-Tiller Technology Development Co., Ltd.