Volume 36,Issue 1,2008 Table of Contents
2008, 36(1):1-7.
Abstract:
The status and development of the application of satellite data assimilation in numerical weather forecast is introduced. A large amount of satellite data has already being used in numerical weather forecasts. It occupies major amount of data resources and has great effect on the accuracy improvement of numerical weather forecasts. The attempt to assimilate the satellite data affected greatly by surface emissi vity, cloud and precipitation is being made to fully use satellite observation in existence. At the same time, the application of satellite data assimilation in numerical weather forecasts is developing toward an accommodation with the great amount and new types of satellite measurements brought by the global observation system. Introduction is made to two main joint satellite data assimilation centers: JCSAD (Joint Center of Satellite Data Assimilation) and NWP SAF (Satellite Applications Facility for Numerical Weather Prediction), which were built to meet the requirements of the status and development of the application of satellite data assimilation in numerical weather forecasts, with a brief discussion on satellite data assimilation in numerical weather forecast in China.
The status and development of the application of satellite data assimilation in numerical weather forecast is introduced. A large amount of satellite data has already being used in numerical weather forecasts. It occupies major amount of data resources and has great effect on the accuracy improvement of numerical weather forecasts. The attempt to assimilate the satellite data affected greatly by surface emissi vity, cloud and precipitation is being made to fully use satellite observation in existence. At the same time, the application of satellite data assimilation in numerical weather forecasts is developing toward an accommodation with the great amount and new types of satellite measurements brought by the global observation system. Introduction is made to two main joint satellite data assimilation centers: JCSAD (Joint Center of Satellite Data Assimilation) and NWP SAF (Satellite Applications Facility for Numerical Weather Prediction), which were built to meet the requirements of the status and development of the application of satellite data assimilation in numerical weather forecasts, with a brief discussion on satellite data assimilation in numerical weather forecast in China.
2008, 36(1):8-14.
Abstract:
The circulation patterns of the typhoon BILIS and GEAMI are described and summarized. Both occurred in July 2006 over the West Pacific Ocean, landed in the southeast coast of China, and caused serious damages. Based on the outputs of the 700 hPa stream field， 900 hPa wind field and rainfall field of AREM (Advanced Regional Eta Model), the predictions of landing time, landing location, moving route and the maximum wind and precipitation of typhoon are analyzed. The results show that Bilis landed at Xiapu, Fujian Province at 12:50 14 July, then moved to west, and there formed a northwest rain zone between 21°N and 28°N; Geami landed at Jinjiang, Fujian Province at 15:50 25 July, moved to west and there formed a southwestnortheast rain zone over Southeast China. Both brought severe meteorological disasters and life and wealth damages to the provinces on the way. As a whole, AREM forecasts of maximum winds around the typhoon center and the position, shape, moving direction, and intensity of typhoon rain belts are satisfactory, and the forecast for some strong rain centers are good, but the bias between fact and simulation are obvious for most strong rain centers. The predictions of the landing times and positions of the typhoons are good; the bias is small; and the predictions of the moving route also basically accord with the facts, but there also are some biases in the positions of the typhoon centers.
The circulation patterns of the typhoon BILIS and GEAMI are described and summarized. Both occurred in July 2006 over the West Pacific Ocean, landed in the southeast coast of China, and caused serious damages. Based on the outputs of the 700 hPa stream field， 900 hPa wind field and rainfall field of AREM (Advanced Regional Eta Model), the predictions of landing time, landing location, moving route and the maximum wind and precipitation of typhoon are analyzed. The results show that Bilis landed at Xiapu, Fujian Province at 12:50 14 July, then moved to west, and there formed a northwest rain zone between 21°N and 28°N; Geami landed at Jinjiang, Fujian Province at 15:50 25 July, moved to west and there formed a southwestnortheast rain zone over Southeast China. Both brought severe meteorological disasters and life and wealth damages to the provinces on the way. As a whole, AREM forecasts of maximum winds around the typhoon center and the position, shape, moving direction, and intensity of typhoon rain belts are satisfactory, and the forecast for some strong rain centers are good, but the bias between fact and simulation are obvious for most strong rain centers. The predictions of the landing times and positions of the typhoons are good; the bias is small; and the predictions of the moving route also basically accord with the facts, but there also are some biases in the positions of the typhoon centers.
2008, 36(1):15-19.
Abstract:
The relationship between thermal wind helicity and severe convective weather is analyzed by calculating the helicity from 1000 hPa to 100 hPa, 1 to 31 July 2006 at Datong of Shanxi Province. The result shows that there was a high value center of thermal wind helicity before the severe weather occurred, and the higher the value was, the severer the weather was. This center appeared 6 hours before severe weather occurred. The thermal wind helicity can be used as an indicator in forecasting severe weather.
The relationship between thermal wind helicity and severe convective weather is analyzed by calculating the helicity from 1000 hPa to 100 hPa, 1 to 31 July 2006 at Datong of Shanxi Province. The result shows that there was a high value center of thermal wind helicity before the severe weather occurred, and the higher the value was, the severer the weather was. This center appeared 6 hours before severe weather occurred. The thermal wind helicity can be used as an indicator in forecasting severe weather.
2008, 36(1):20-24.
Abstract:
With the development of sounding instruments, various sounding data can be used by numerical weather prediction. The Local Analysis and Prediction System (LAPS) is introduced and localized for the better integration and assimilation of these various sounding data. The numerical experiment results show that the localization of LAPS is successful and LAPS can integrate T213 or NCEP, Doppler radar data, cloudderived wind data, sounding data, etc., to provide the direct mesoscale analysis fields to forecasters, and supply better initial fields to numerical models.
With the development of sounding instruments, various sounding data can be used by numerical weather prediction. The Local Analysis and Prediction System (LAPS) is introduced and localized for the better integration and assimilation of these various sounding data. The numerical experiment results show that the localization of LAPS is successful and LAPS can integrate T213 or NCEP, Doppler radar data, cloudderived wind data, sounding data, etc., to provide the direct mesoscale analysis fields to forecasters, and supply better initial fields to numerical models.
2008, 36(1):25-30.
Abstract:
Using the historical observation data and NCEP reanalysis data, an investigation is conducted on 31 returnflow events occurred over North China. On the basis of the 500 hPa circulation patterns, 31 events are divided into two types. The dynamical conditions and water vapor sources of these weather events, such as vorticity, divergence, vertical velocity, etc, are diagnosed. The results show that: (1) the dynamical conditions for returnflow events are a little different from other rainfall events, with divergence and anticyclonic circulation at lower levels; (2) the air of the returnflow from Northeast China, through the Bohai Sea, then to North China, is relatively dry.
Using the historical observation data and NCEP reanalysis data, an investigation is conducted on 31 returnflow events occurred over North China. On the basis of the 500 hPa circulation patterns, 31 events are divided into two types. The dynamical conditions and water vapor sources of these weather events, such as vorticity, divergence, vertical velocity, etc, are diagnosed. The results show that: (1) the dynamical conditions for returnflow events are a little different from other rainfall events, with divergence and anticyclonic circulation at lower levels; (2) the air of the returnflow from Northeast China, through the Bohai Sea, then to North China, is relatively dry.
2008, 36(1):31-34.
Abstract:
An analysis is made of the relationship between SSTA (Sea Surface Temperature Anomaly) over the offshore waters of the southern Asia and the precipitation in Yunnan from 1961 to 1999. It is discovered that the precipitation in early summer in Yunnan has a distinct negative relationship with SST over the offshore waters of the southern Asia, and the negative relationship is more obvious in the western North Indian Ocean and the Arabian sea than in the Bay of Bengal and South China Sea, but not obvious in middle summer. The results also show that the precipitation in summer in the southwestern Yunnan is positively related with the SST of the previous period over the Bay of Bengal, but the relationship is not obvious in other sea areas. The precipitation in summer in the southeastern Yunnan is positively related only with the SST of the previous period obviously over the South China Sea.
An analysis is made of the relationship between SSTA (Sea Surface Temperature Anomaly) over the offshore waters of the southern Asia and the precipitation in Yunnan from 1961 to 1999. It is discovered that the precipitation in early summer in Yunnan has a distinct negative relationship with SST over the offshore waters of the southern Asia, and the negative relationship is more obvious in the western North Indian Ocean and the Arabian sea than in the Bay of Bengal and South China Sea, but not obvious in middle summer. The results also show that the precipitation in summer in the southwestern Yunnan is positively related with the SST of the previous period over the Bay of Bengal, but the relationship is not obvious in other sea areas. The precipitation in summer in the southeastern Yunnan is positively related only with the SST of the previous period obviously over the South China Sea.
2008, 36(1):35-42.
Abstract:
By using the NCEP/NCAR monthly mean reanalysis data from 1948 to 1999，the characteristic indexes are defined to describe the Mascarene High (MH)， based on the evolution characteristics of the climatological geopotential height and streamline fields at 850 hPa. By calculating the indexes, the features of the MH variations on different time scales are examined. The results show that the seasonal variations of MH were remarkable: it was the strongest and the location is more westward and northward in southern winter, and vice versa in southern summer. The anomaly variations of MH are also studied. It is shown that MH had the obvious interannual and interdecadal variations. On the interdecadal time scale, the area and center intensity of MH increased gradually, and the center location moved eastward and southward slowly in 52 years.
By using the NCEP/NCAR monthly mean reanalysis data from 1948 to 1999，the characteristic indexes are defined to describe the Mascarene High (MH)， based on the evolution characteristics of the climatological geopotential height and streamline fields at 850 hPa. By calculating the indexes, the features of the MH variations on different time scales are examined. The results show that the seasonal variations of MH were remarkable: it was the strongest and the location is more westward and northward in southern winter, and vice versa in southern summer. The anomaly variations of MH are also studied. It is shown that MH had the obvious interannual and interdecadal variations. On the interdecadal time scale, the area and center intensity of MH increased gradually, and the center location moved eastward and southward slowly in 52 years.
2008, 36(1):43-46.
Abstract:
The daily and the monthly precipitation data in Zaozhuang from 1958 to 2005 are analyzed. The results show that the period from the late 1950s to the mid 1960s was relatively wet and that from the early 1960s to the mid 1960s was a short dry period; the period from the mid 1970s to the late 1990s was a long dry period; then, floods occurred in the year of 2000, 2003 and 2005. The concept of “the number of equivalent heary rain days” is introduced, and the correlation of the number of the equivalent heary rain days and serious drought and flood years is studied. The precipitation of serious drought and flood years are closely correlated with the number of the equivalent heary rain days. The quantitative correlation for the number of the equivalent heary rain days and the annual precipitation is given. In a certain extent, drought/flood forecasts can be made according to the days of heavy rain in flood season.
The daily and the monthly precipitation data in Zaozhuang from 1958 to 2005 are analyzed. The results show that the period from the late 1950s to the mid 1960s was relatively wet and that from the early 1960s to the mid 1960s was a short dry period; the period from the mid 1970s to the late 1990s was a long dry period; then, floods occurred in the year of 2000, 2003 and 2005. The concept of “the number of equivalent heary rain days” is introduced, and the correlation of the number of the equivalent heary rain days and serious drought and flood years is studied. The precipitation of serious drought and flood years are closely correlated with the number of the equivalent heary rain days. The quantitative correlation for the number of the equivalent heary rain days and the annual precipitation is given. In a certain extent, drought/flood forecasts can be made according to the days of heavy rain in flood season.
2008, 36(1):47-54.
Abstract:
A continuous heavy rain process occurred in South China from 17 to 24 June 2006, during which there existed two rainbands, one in the north and the other in the south. The north rainband (over the north and central part of Fujian Province) was resulted from frontal systems and the south rainband (over the east and central part of Guangdong Province) was in the warm areas before a front. The double rainband phenomenon has attracted much attention of Chinese meteorologists. In order to investigate the causes of frontal and warmarea heavy rains and deepen the knowledge of the two kind heavy rains, the heavy rain case is analyzed in details as a typical example of the double rainband event with hourly surface rainfall and 6hour NCEP reanalysis data. The main physical differences between the frontal and warmarea heavy rains are revealed. It is found that there exist obvious differences not only in the mesoscale rain mass activities, dynamic structure, instability mechanisms, and vertical heating profiles between Meiyu front and warmarea heavy rain systems, but also in the moisture transportation, mesoscale environment and vertical circulation related to heavy rainfall. These differences may be the reason why the heavy rainfall in warm areas before a front is difficult to simulate and forecast.
A continuous heavy rain process occurred in South China from 17 to 24 June 2006, during which there existed two rainbands, one in the north and the other in the south. The north rainband (over the north and central part of Fujian Province) was resulted from frontal systems and the south rainband (over the east and central part of Guangdong Province) was in the warm areas before a front. The double rainband phenomenon has attracted much attention of Chinese meteorologists. In order to investigate the causes of frontal and warmarea heavy rains and deepen the knowledge of the two kind heavy rains, the heavy rain case is analyzed in details as a typical example of the double rainband event with hourly surface rainfall and 6hour NCEP reanalysis data. The main physical differences between the frontal and warmarea heavy rains are revealed. It is found that there exist obvious differences not only in the mesoscale rain mass activities, dynamic structure, instability mechanisms, and vertical heating profiles between Meiyu front and warmarea heavy rain systems, but also in the moisture transportation, mesoscale environment and vertical circulation related to heavy rainfall. These differences may be the reason why the heavy rainfall in warm areas before a front is difficult to simulate and forecast.
2008, 36(1):55-62.
Abstract:
Based the theory of Barnes filtering, an appropriate bandpass filter is designed, with which the mesoscale data were obtained. The heavy rainstorm in Henan in from 21 to 24 July 2005 resulted from the interaction between Typhoon Haitang and midlatitude systems is analyzed. The results show that the mesoscale disturbance low, mesoscale convergence line, and convergence areas within the largescale cyclonic circulation outside the typhoon are the direct influencing systems of the rainfall storm. The largescale circulation provided abundant vapor sources and a potentially unstable condition for heavy rain, but the mesoscale weather system played an important role in the enhancement of vapour convergence and upward transportation.
Based the theory of Barnes filtering, an appropriate bandpass filter is designed, with which the mesoscale data were obtained. The heavy rainstorm in Henan in from 21 to 24 July 2005 resulted from the interaction between Typhoon Haitang and midlatitude systems is analyzed. The results show that the mesoscale disturbance low, mesoscale convergence line, and convergence areas within the largescale cyclonic circulation outside the typhoon are the direct influencing systems of the rainfall storm. The largescale circulation provided abundant vapor sources and a potentially unstable condition for heavy rain, but the mesoscale weather system played an important role in the enhancement of vapour convergence and upward transportation.
2008, 36(1):63-68.
Abstract:
By means of the conventional observation data and NCEP reanalysis data, the sustained torrential rain event caused by the severe tropical storm Bilis (0604) is investigated. The results show that the strong vapor transport and updrafts originated from strong convergence at the low level under the persistent interaction of the tropical storm and southwest monsoon the south of Bilis, as well as the zones of convergence at the low level, divergence at the high level, updraft and highintensity vapor convergence, are rarely reported for recent years, although Bilis is only a severe tropical storm from its intensity. The rainstorm center is well corresponded with the location of the strong vapor convergence. The rainstorm event is closely related to the slow movement of the typhoon lowpressure system and the sustained interaction with southwest monsoon.
By means of the conventional observation data and NCEP reanalysis data, the sustained torrential rain event caused by the severe tropical storm Bilis (0604) is investigated. The results show that the strong vapor transport and updrafts originated from strong convergence at the low level under the persistent interaction of the tropical storm and southwest monsoon the south of Bilis, as well as the zones of convergence at the low level, divergence at the high level, updraft and highintensity vapor convergence, are rarely reported for recent years, although Bilis is only a severe tropical storm from its intensity. The rainstorm center is well corresponded with the location of the strong vapor convergence. The rainstorm event is closely related to the slow movement of the typhoon lowpressure system and the sustained interaction with southwest monsoon.
2008, 36(1):69-73.
Abstract:
On the basis of the routine weather charts, numerical prediction products, satellite cloud pictures and the V3θ diagram from the breakingupevolving theory, the regional continual rainstorm process occurred in Gansu to the northeast of the Tibetan Plateau from 30 June to 2 July 2005 is diagnosed and analyzed. The results show that during the heavy rainfall,the subtropical high pressure extended to west and lifted the external southwest current to north, which controlled the northeast party of the QinghaiXizang Plateau; when the Mongolia vortex, the westerly cold airflow and the southwest wind converged, a strong convection was triggered; there was a deep water vapor level between 850 hPa and 200 hPa and a stable vortex shear on 700 hPa, providing continuously strong rising movement for the heavy rainfall; and several Mesoscale Convective Systems (MCSs) appeared successively on the satellite cloud pictures. It is concluded that the prediction method based on the breakingupevolving theory is capable of forecasting the beginning, ending and areas of continuous heavy rainfall in the Northwest China.
On the basis of the routine weather charts, numerical prediction products, satellite cloud pictures and the V3θ diagram from the breakingupevolving theory, the regional continual rainstorm process occurred in Gansu to the northeast of the Tibetan Plateau from 30 June to 2 July 2005 is diagnosed and analyzed. The results show that during the heavy rainfall,the subtropical high pressure extended to west and lifted the external southwest current to north, which controlled the northeast party of the QinghaiXizang Plateau; when the Mongolia vortex, the westerly cold airflow and the southwest wind converged, a strong convection was triggered; there was a deep water vapor level between 850 hPa and 200 hPa and a stable vortex shear on 700 hPa, providing continuously strong rising movement for the heavy rainfall; and several Mesoscale Convective Systems (MCSs) appeared successively on the satellite cloud pictures. It is concluded that the prediction method based on the breakingupevolving theory is capable of forecasting the beginning, ending and areas of continuous heavy rainfall in the Northwest China.
2008, 36(1):74-77.
Abstract:
A largescale drought and high temperature weather occurred in the rainy season (July and August) of 2006 over Shanxi Province, resulting in severe drinking water difficulty and agricultural disasters. Particularly, there occurred much less heavy rainfall processes in the usual rainy period from July 21 to August 10 of the year. It seldom occurred in history. The data of atmospheric circulation at 500 hPa and the indexes of subtropical high are analyzed and primary causes mainly include the activity of cold air, the location of subtropical high, the disposition status of weather systems and so on.
A largescale drought and high temperature weather occurred in the rainy season (July and August) of 2006 over Shanxi Province, resulting in severe drinking water difficulty and agricultural disasters. Particularly, there occurred much less heavy rainfall processes in the usual rainy period from July 21 to August 10 of the year. It seldom occurred in history. The data of atmospheric circulation at 500 hPa and the indexes of subtropical high are analyzed and primary causes mainly include the activity of cold air, the location of subtropical high, the disposition status of weather systems and so on.
2008, 36(1):78-81.
Abstract:
By means of the daytoday precipitation data from 1951 to 2004 in Jilin Province, the characteristics of major rainfall events are analyzed and the single and synthetical evaluating indexes that can reflect the severity of heavy rainfall are built. The evaluation grades of heavy rainfall events are devised. The normality test of the synthetical evaluation index is conducted by using the kurtosis and skewness coefficients of the synthetical evaluating indexes. The synthetical evaluation indexes obey the normal distribution, so the evaluation indexes for the recurrence period of abnormal climate are given. By using the indexes of evaluation grades and the evaluation indexes for the recurrence period of abnormal climate, the heavy rainfall events from 2005 to 2006 are evaluated. The results show that the method is feasible and can satisfy the requirements of operational application.
By means of the daytoday precipitation data from 1951 to 2004 in Jilin Province, the characteristics of major rainfall events are analyzed and the single and synthetical evaluating indexes that can reflect the severity of heavy rainfall are built. The evaluation grades of heavy rainfall events are devised. The normality test of the synthetical evaluation index is conducted by using the kurtosis and skewness coefficients of the synthetical evaluating indexes. The synthetical evaluation indexes obey the normal distribution, so the evaluation indexes for the recurrence period of abnormal climate are given. By using the indexes of evaluation grades and the evaluation indexes for the recurrence period of abnormal climate, the heavy rainfall events from 2005 to 2006 are evaluated. The results show that the method is feasible and can satisfy the requirements of operational application.
2008, 36(1):82-86.
Abstract:
The analysis of potential evaporation and dry/wet indexes is meaningful to the utilization of water resources and the prevention of agricultural droughts. By using the 34year data from the Fuzhou weather station, the distribution characteristics of potential evaporation and humid indexes are analyzed. The results show that: (1) from 1980, the potential evaporation has been increasing; the year of 1991 was the climate jump point, with the anomaly being negative before it and positive after it; (2) the humid index decreased obviously because of the decrease of precipitation and the increase of potential evaporation, so the natural rain cannot meet the water demands of crops and droughts occurred frequently, and the annual mean humid index had no clear climate jump; (3) according to the humid indexes, the autumn was the driest season, then the summer and winter.
The analysis of potential evaporation and dry/wet indexes is meaningful to the utilization of water resources and the prevention of agricultural droughts. By using the 34year data from the Fuzhou weather station, the distribution characteristics of potential evaporation and humid indexes are analyzed. The results show that: (1) from 1980, the potential evaporation has been increasing; the year of 1991 was the climate jump point, with the anomaly being negative before it and positive after it; (2) the humid index decreased obviously because of the decrease of precipitation and the increase of potential evaporation, so the natural rain cannot meet the water demands of crops and droughts occurred frequently, and the annual mean humid index had no clear climate jump; (3) according to the humid indexes, the autumn was the driest season, then the summer and winter.
2008, 36(1):87-90.
Abstract:
The meteorological and lightning strike data, as well as forest fire data from 1981 to 2004 are used to study the effects of climatic conditions on the occurrence of forest fires induced by lightning strikes in the forest region of Daxinganling Mountain, Inner Mongolia, and the climatic causes of the frequent lightninginduced forest fires are analyzed. The results reveal that: (1) the occurrence frequency of lightninginduced forest fires in Daxinganling had a increasing trend and occurred mostly in the period from 12 May to 16 July, 10:00 to 17:00; (2) the occurrence of lightninginduced forest fires has close relations with temperature increase, especially the increase of temperature from May to July and ground temperature; (3) the gradual decrease of precipitation and relative humidity led to greater drought damages and more lightninginduced forest fires after 1999; (4) the leading climatic cause of the frequent occurrence of lightninginduced forest fires in Daxinganling Mountain are the drier and warmer climate and frequent extreme climatic events.
The meteorological and lightning strike data, as well as forest fire data from 1981 to 2004 are used to study the effects of climatic conditions on the occurrence of forest fires induced by lightning strikes in the forest region of Daxinganling Mountain, Inner Mongolia, and the climatic causes of the frequent lightninginduced forest fires are analyzed. The results reveal that: (1) the occurrence frequency of lightninginduced forest fires in Daxinganling had a increasing trend and occurred mostly in the period from 12 May to 16 July, 10:00 to 17:00; (2) the occurrence of lightninginduced forest fires has close relations with temperature increase, especially the increase of temperature from May to July and ground temperature; (3) the gradual decrease of precipitation and relative humidity led to greater drought damages and more lightninginduced forest fires after 1999; (4) the leading climatic cause of the frequent occurrence of lightninginduced forest fires in Daxinganling Mountain are the drier and warmer climate and frequent extreme climatic events.
17 Calculation Method and Distributional Characteristics of Solar Global Radiation in Guizhou Province
2008, 36(1):91-94.
Abstract:
By using the observation data from only three solar radiation stations in Guizhou Province, comparison is made between the calculation errors from two methods (sunlight percentage and nationwide universal formula). The results indicate that the absolute error values of the monthly and annual mean solar radiation calculated by the sunlight percentage method are less then 10%, and the sunlight percentage model is better than the universal method obviously. Since solar radiation increases with increasing altitude, the model is set up according to the altitude of each station by means of the sunlight percentage method. From the related data from 1971 to 2000, the solar radiation is calculated, and the distributional characteristic are analyzed.
By using the observation data from only three solar radiation stations in Guizhou Province, comparison is made between the calculation errors from two methods (sunlight percentage and nationwide universal formula). The results indicate that the absolute error values of the monthly and annual mean solar radiation calculated by the sunlight percentage method are less then 10%, and the sunlight percentage model is better than the universal method obviously. Since solar radiation increases with increasing altitude, the model is set up according to the altitude of each station by means of the sunlight percentage method. From the related data from 1971 to 2000, the solar radiation is calculated, and the distributional characteristic are analyzed.
2008, 36(1):95-99.
Abstract:
The significance of designing a new realtime meteorological radar monitor system is discussed, and the design of the newtype realtime monitoring system of meteorological radar based on the wideband network technology is introduced. The structure mode and functions of this new system are described, and the feasibility of this design based on the wideband communication system is studied by discussing the TCP/IP and calculating the information quantity of meteorological radar data and the occupied bandwidth. The characteristics of the structure and storage of the realtime monitoring information from CINRAD/SA meteorological radar are analyzed, and the monitoring, receiving, sending, and storing methods of meteorological radar information are introduced. The emphasis is put on the programming of software for information transmitting and storing. According to two basic protocols of the TCP/IP (TCP & UDP) and ADO database programming technology, the longdistance control of the operation of the meteorological radar can be realized in real time based on the existing wideband technology.
The significance of designing a new realtime meteorological radar monitor system is discussed, and the design of the newtype realtime monitoring system of meteorological radar based on the wideband network technology is introduced. The structure mode and functions of this new system are described, and the feasibility of this design based on the wideband communication system is studied by discussing the TCP/IP and calculating the information quantity of meteorological radar data and the occupied bandwidth. The characteristics of the structure and storage of the realtime monitoring information from CINRAD/SA meteorological radar are analyzed, and the monitoring, receiving, sending, and storing methods of meteorological radar information are introduced. The emphasis is put on the programming of software for information transmitting and storing. According to two basic protocols of the TCP/IP (TCP & UDP) and ADO database programming technology, the longdistance control of the operation of the meteorological radar can be realized in real time based on the existing wideband technology.
2008, 36(1):100-104.
Abstract:
The forest fire monitoring is a new application of unmanned aerial vehicle (UAV). An introduction is made to a miniature UAV system for forestfire monitoring. It is composed of three parts: the miniature meteorological UAV, the digital image system (including two CCD cameras and a set of RF transmitter), and its software. In the test flight, the system successfully detected the fire targets on the ground. It is proved that the system has the ability to accomplish forestfire monitoring mission within a radius of 30 km (about 80 to 100 km2). The application of UAV in forest fire prevention is lowcost, feasible and promising. Some problems encountered the system development are discussed.
The forest fire monitoring is a new application of unmanned aerial vehicle (UAV). An introduction is made to a miniature UAV system for forestfire monitoring. It is composed of three parts: the miniature meteorological UAV, the digital image system (including two CCD cameras and a set of RF transmitter), and its software. In the test flight, the system successfully detected the fire targets on the ground. It is proved that the system has the ability to accomplish forestfire monitoring mission within a radius of 30 km (about 80 to 100 km2). The application of UAV in forest fire prevention is lowcost, feasible and promising. Some problems encountered the system development are discussed.
2008, 36(1):105-107.
Abstract:
The Lband GFE(L) 1 radar radiosonde can provide dense data in vertical, and the measurements are available from the ground to high altitude. The characteristics of the Lband radar in gathering data can be used in analyzing the characteristics of Atmosphere Boundary Layer (ABL) in the main urban area of Chongqing. The temperature inversion, visibility, thick fog and air pollutant indexes are analyzed by means of the radiosonde data. The results indicate that the Lband radar radiosonde data can be applied not only in the analysis of the characteristics of ABL but also in meteorological service fields such as air pollution forecasting, fog forecasting, emergent meteorological service (such as the leakiness of harmful gases), evaluation of wind energy resources, etc.
The Lband GFE(L) 1 radar radiosonde can provide dense data in vertical, and the measurements are available from the ground to high altitude. The characteristics of the Lband radar in gathering data can be used in analyzing the characteristics of Atmosphere Boundary Layer (ABL) in the main urban area of Chongqing. The temperature inversion, visibility, thick fog and air pollutant indexes are analyzed by means of the radiosonde data. The results indicate that the Lband radar radiosonde data can be applied not only in the analysis of the characteristics of ABL but also in meteorological service fields such as air pollution forecasting, fog forecasting, emergent meteorological service (such as the leakiness of harmful gases), evaluation of wind energy resources, etc.
2008, 36(1):108-111.
Abstract:
The spectrum characteristics of TM band 1 to 5 and band 7, as well as Normalized Difference Vegetation Index, Normalized Difference Water Index, Normalized Difference Moisture Index, and Modified Normalized Difference Water Index, are analyzed by using TM images of 4 August 1994 and 16 September 2004. The falsecolor images with bands 7, 4 and 3 combined are used to identify the wetland with human eye and the signs of the Ruoergai wetland on the TM imagery are established．The analysis shows that the band 7 can be used to distinguish sandy lands from the other land cover types, and the difference of Modified Normalized Difference Water Index and Normalized Difference Vegetation Index can be used to identify water bodies effectively with the threshold being greater than 0. The better classification result can be obtained automatically. The result shows that compared with in 1984, the area of lake and wetland in 1994 is less obviously, and the area of sandy land is larger.
The spectrum characteristics of TM band 1 to 5 and band 7, as well as Normalized Difference Vegetation Index, Normalized Difference Water Index, Normalized Difference Moisture Index, and Modified Normalized Difference Water Index, are analyzed by using TM images of 4 August 1994 and 16 September 2004. The falsecolor images with bands 7, 4 and 3 combined are used to identify the wetland with human eye and the signs of the Ruoergai wetland on the TM imagery are established．The analysis shows that the band 7 can be used to distinguish sandy lands from the other land cover types, and the difference of Modified Normalized Difference Water Index and Normalized Difference Vegetation Index can be used to identify water bodies effectively with the threshold being greater than 0. The better classification result can be obtained automatically. The result shows that compared with in 1984, the area of lake and wetland in 1994 is less obviously, and the area of sandy land is larger.
2008, 36(1):112-118.
Abstract:
According to the metadata of in situ observation at Wutaishan (53588) of Shanxi Province, including information about station relocation, instrumentation change, and observing and data processing procedure changes, etc., the homogeneities of annual and seasonal mean, maximum and minimum temperatures, relative humidity, and precipitation time series are analyzed from January 1957 to 2005. The reference series for different meteorological variables are constructed by combining the corresponding observed data at five nearby stations with the largest correlation in candidate stations, and then based on the Standard Normal Homogeneity Test (SNHT) technique, each meteorological variable is statistically tested, respectively. The discontinuous points obtained from SNHT are analyzed and compared. Results indicate that the influence of station relocation on 1 January 1998 on the homogeneities of different meteorological variables mentioned above is very obvious, and that on the maximum temperature time series is the most significant, being 5.5 ℃. Further analysis shows that this station relocation has different effects on the other meteorological variables time series; for example, the influence on the homogeneities of annual and spring relative humidity time series are also obvious, but not on precipitation. The tests and adjustment of the in situ climatic data series used frequently are important to local climate change researches. The effects of various “nonclimate” factors on different meteorological variables vary, so more careful distinction and further research are needed.
According to the metadata of in situ observation at Wutaishan (53588) of Shanxi Province, including information about station relocation, instrumentation change, and observing and data processing procedure changes, etc., the homogeneities of annual and seasonal mean, maximum and minimum temperatures, relative humidity, and precipitation time series are analyzed from January 1957 to 2005. The reference series for different meteorological variables are constructed by combining the corresponding observed data at five nearby stations with the largest correlation in candidate stations, and then based on the Standard Normal Homogeneity Test (SNHT) technique, each meteorological variable is statistically tested, respectively. The discontinuous points obtained from SNHT are analyzed and compared. Results indicate that the influence of station relocation on 1 January 1998 on the homogeneities of different meteorological variables mentioned above is very obvious, and that on the maximum temperature time series is the most significant, being 5.5 ℃. Further analysis shows that this station relocation has different effects on the other meteorological variables time series; for example, the influence on the homogeneities of annual and spring relative humidity time series are also obvious, but not on precipitation. The tests and adjustment of the in situ climatic data series used frequently are important to local climate change researches. The effects of various “nonclimate” factors on different meteorological variables vary, so more careful distinction and further research are needed.
2008, 36(1):112-118.
Abstract:
以山西五臺山地面觀測站為例,對建站(1957年1月)至2005年的年、季節平均氣溫、最高和最低氣溫、相對濕度和降水觀測資料序列作均一性分析,結合歷史沿革變化(包括遷站、儀器變化和觀測業務改變等),得出這些因素對不同氣候要素均一性的影響情況.從與該站不同要素序列相關性較好、水平距離最近的臺站中選取若干站點作為待檢臺站的參考臺站建立了各自的參考序列作為均一性檢查的對比序列,采用國際上應用較為廣泛的標準正態檢驗(SNHT)方法分別對各種要素進行了統計學檢驗.對統計方法得到的不連續點(不均一性產生年份)進行了總結分析,發現臺站遷移對于溫度、相對濕度觀測序列的均一性帶來的影響非常明顯,其中對最高氣溫序列影響最為顯著,達到5.5℃.深入分析還表明,遷址對各要素的影響程度各有區別:對相對濕度的年均和春季序列也產生了較為明顯的非均一性,而對降水量的影響則并不顯著.綜合分析表明,常用觀測要素的均一性檢驗和訂正是局地氣候變化檢測的基礎環節,但不同要素的均一性受到各種因素影響的表現程度各不相同,需要加以區別和深入研究.
以山西五臺山地面觀測站為例,對建站(1957年1月)至2005年的年、季節平均氣溫、最高和最低氣溫、相對濕度和降水觀測資料序列作均一性分析,結合歷史沿革變化(包括遷站、儀器變化和觀測業務改變等),得出這些因素對不同氣候要素均一性的影響情況.從與該站不同要素序列相關性較好、水平距離最近的臺站中選取若干站點作為待檢臺站的參考臺站建立了各自的參考序列作為均一性檢查的對比序列,采用國際上應用較為廣泛的標準正態檢驗(SNHT)方法分別對各種要素進行了統計學檢驗.對統計方法得到的不連續點(不均一性產生年份)進行了總結分析,發現臺站遷移對于溫度、相對濕度觀測序列的均一性帶來的影響非常明顯,其中對最高氣溫序列影響最為顯著,達到5.5℃.深入分析還表明,遷址對各要素的影響程度各有區別:對相對濕度的年均和春季序列也產生了較為明顯的非均一性,而對降水量的影響則并不顯著.綜合分析表明,常用觀測要素的均一性檢驗和訂正是局地氣候變化檢測的基礎環節,但不同要素的均一性受到各種因素影響的表現程度各不相同,需要加以區別和深入研究.
2008, 36(1):119-122.
Abstract:
以普遍推廣的AO文件(即基本觀測資料)為基礎,經過一定的程序處理,得到各氣象要素的氣候值,并形成建立方程所需自變量數據文件和預報所需的自變量數據文件.計算自變量與因變量的相關系數,將相關系數較大的因子篩選出來,通過人機交互的方式進行第2次篩選,用相關顯著的自變量與因變量建立回歸方程.由于輸出的自變量相對因變量來說都是前期因子,根據回歸方程和預報所需的自變量,就可以得出預報結果.
以普遍推廣的AO文件(即基本觀測資料)為基礎,經過一定的程序處理,得到各氣象要素的氣候值,并形成建立方程所需自變量數據文件和預報所需的自變量數據文件.計算自變量與因變量的相關系數,將相關系數較大的因子篩選出來,通過人機交互的方式進行第2次篩選,用相關顯著的自變量與因變量建立回歸方程.由于輸出的自變量相對因變量來說都是前期因子,根據回歸方程和預報所需的自變量,就可以得出預報結果.
2008, 36(1):119-122.
Abstract:
By using the specifically processed basic meteorological observation data, the climatic parameters of various meteorological elements are obtained, and the data files of various independent variables needed for establishing the regression equation and forecasting (each independent variable corresponding to a dependent variable is a predictor) are established. The correlation coefficients of independent variables and dependent variable are computed. Through selecting greater correlation coefficient independent variables in a manmachine interactive way, the regression equations are established. According to the regression equation, forecasts can be obtained from the needed independent variables.
By using the specifically processed basic meteorological observation data, the climatic parameters of various meteorological elements are obtained, and the data files of various independent variables needed for establishing the regression equation and forecasting (each independent variable corresponding to a dependent variable is a predictor) are established. The correlation coefficients of independent variables and dependent variable are computed. Through selecting greater correlation coefficient independent variables in a manmachine interactive way, the regression equations are established. According to the regression equation, forecasts can be obtained from the needed independent variables.
2008, 36(1):123-124.
Abstract:
新一代天氣雷達系統在基層的建設和使用,對發現局地中小尺度天氣系統,提高天氣預報準確率,具有非常重要的作用.與此同時,為確保雷達的正常運行,保證資料的有效性、連續性,對設備維護提出了非常嚴格的要求.
新一代天氣雷達系統在基層的建設和使用,對發現局地中小尺度天氣系統,提高天氣預報準確率,具有非常重要的作用.與此同時,為確保雷達的正常運行,保證資料的有效性、連續性,對設備維護提出了非常嚴格的要求.
2008, 36(1):123-124.
Abstract:
基于L波段探空GFE(L)1型二次測風雷達資料具有垂直分層密,并從地面開始就可以獲取資料的特點,將其用于重慶市主城區邊界層特征的分析,用于逆溫與能見度、濃霧和空氣污染指數的分析.結果表明,L波段探空雷達資料不僅可以用于大氣邊界層特征分析,還可以在污染氣象分析預報、霧的預報、有害氣體泄露事件應急氣象服務,風能評價等多個領域發揮作用.
基于L波段探空GFE(L)1型二次測風雷達資料具有垂直分層密,并從地面開始就可以獲取資料的特點,將其用于重慶市主城區邊界層特征的分析,用于逆溫與能見度、濃霧和空氣污染指數的分析.結果表明,L波段探空雷達資料不僅可以用于大氣邊界層特征分析,還可以在污染氣象分析預報、霧的預報、有害氣體泄露事件應急氣象服務,風能評價等多個領域發揮作用.
2008, 36(1):125-126.
Abstract:
目前NOAA制作并提供美國本土各州的地面臭氧預報。臭氧是美國本土各大城市空氣質量的主要因子。美國國家天氣局與美國國家環保局合作已將其業務性臭氧預報與服務擴展到西部11個州及其他6個州（Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, Wyoming 以及 Kansas 西部, Nebraska, North Dakota, Oklahoma, South Dakota, Texas）, 以確保全美國人口密集的城市都能夠得到每日需要的空氣質量信息。
目前NOAA制作并提供美國本土各州的地面臭氧預報。臭氧是美國本土各大城市空氣質量的主要因子。美國國家天氣局與美國國家環保局合作已將其業務性臭氧預報與服務擴展到西部11個州及其他6個州（Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, Wyoming 以及 Kansas 西部, Nebraska, North Dakota, Oklahoma, South Dakota, Texas）, 以確保全美國人口密集的城市都能夠得到每日需要的空氣質量信息。
2008, 36(1):125-126.
Abstract:
建陽新一代天氣雷達2001年3月正式投入運行,其后雷達故障頻發,而發射機的故障尤其嚴重,經過反復觀察,發現雷達故障與發射機的溫度緊密相關:溫度高則故障多.
建陽新一代天氣雷達2001年3月正式投入運行,其后雷達故障頻發,而發射機的故障尤其嚴重,經過反復觀察,發現雷達故障與發射機的溫度緊密相關:溫度高則故障多.
2008, 36(1):127-128.
Abstract:
新一代全相干多普勒天氣雷達具有較高的可靠性、穩定性、可維護性及全天候的連續工作能力,具有自動數據采集、產品生成和顯示、數據存儲、運行監控和標校等功能.
新一代全相干多普勒天氣雷達具有較高的可靠性、穩定性、可維護性及全天候的連續工作能力,具有自動數據采集、產品生成和顯示、數據存儲、運行監控和標校等功能.
2008, 36(1):127-128.
Abstract:
The spectrum characteristics of TM band 1 to 5 and band 7, as well as Normalized Difference Vegetation Index, Normalized Difference Water Index, Normalized Difference Moisture Index, and Modified Normalized Difference Water Index, are analyzed by using TM images of 4 August 1994 and 16 September 2004. The false-color images with bands 7, 4 and 3 combined are used to identify the wetland with human eye and the signs of the Ruoergai wetland on the TM imagery are established. The analysis shows that the band 7 can be used to distinguish sandy lands from the other land cover types, and the difference of Modified Normalized Difference Water Index and Normalized Difference Vegetation Index can be used to identify water bodies effectively with the threshold being greater than 0. The better classification result can be obtained automatically. The result shows that compared with in 1984, the area of lake and wetland in 1994 is less obviously, and the area of sandy land is larger.
The spectrum characteristics of TM band 1 to 5 and band 7, as well as Normalized Difference Vegetation Index, Normalized Difference Water Index, Normalized Difference Moisture Index, and Modified Normalized Difference Water Index, are analyzed by using TM images of 4 August 1994 and 16 September 2004. The false-color images with bands 7, 4 and 3 combined are used to identify the wetland with human eye and the signs of the Ruoergai wetland on the TM imagery are established. The analysis shows that the band 7 can be used to distinguish sandy lands from the other land cover types, and the difference of Modified Normalized Difference Water Index and Normalized Difference Vegetation Index can be used to identify water bodies effectively with the threshold being greater than 0. The better classification result can be obtained automatically. The result shows that compared with in 1984, the area of lake and wetland in 1994 is less obviously, and the area of sandy land is larger.
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.