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:
以山西五台山地面观测站为例,对建站(1957年1月)至2005年的年、季节平均气温、最高和最低气温、相对湿度和降水观测资料序列作均一性分析,结合历史沿革变化(包括迁站、仪器变化和观测业务改变等),得出这些因素对不同气候要素均一性的影响情况.从与该站不同要素序列相关性较好、水平距离最近的台站中选取若干站点作为待检台站的参考台站建立了各自的参考序列作为均一性检查的对比序列,采用国际上应用较为广泛的标准正态检验(SNHT)方法分别对各种要素进行了统计学检验.对统计方法得到的不连续点(不均一性产生年份)进行了总结分析,发现台站迁移对于温度、相对湿度观测序列的均一性带来的影响非常明显,其中对最高气温序列影响最为显著,达到5.5℃.深入分析还表明,迁址对各要素的影响程度各有区别:对相对湿度的年均和春季序列也产生了较为明显的非均一性,而对降水量的影响则并不显著.综合分析表明,常用观测要素的均一性检验和订正是局地气候变化检测的基础环节,但不同要素的均一性受到各种因素影响的表现程度各不相同,需要加以区别和深入研究.
以山西五台山地面观测站为例,对建站(1957年1月)至2005年的年、季节平均气温、最高和最低气温、相对湿度和降水观测资料序列作均一性分析,结合历史沿革变化(包括迁站、仪器变化和观测业务改变等),得出这些因素对不同气候要素均一性的影响情况.从与该站不同要素序列相关性较好、水平距离最近的台站中选取若干站点作为待检台站的参考台站建立了各自的参考序列作为均一性检查的对比序列,采用国际上应用较为广泛的标准正态检验(SNHT)方法分别对各种要素进行了统计学检验.对统计方法得到的不连续点(不均一性产生年份)进行了总结分析,发现台站迁移对于温度、相对湿度观测序列的均一性带来的影响非常明显,其中对最高气温序列影响最为显著,达到5.5℃.深入分析还表明,迁址对各要素的影响程度各有区别:对相对湿度的年均和春季序列也产生了较为明显的非均一性,而对降水量的影响则并不显著.综合分析表明,常用观测要素的均一性检验和订正是局地气候变化检测的基础环节,但不同要素的均一性受到各种因素影响的表现程度各不相同,需要加以区别和深入研究.
2008, 36(1):119-122.
Abstract:
以普遍推广的AO文件(即基本观测资料)为基础,经过一定的程序处理,得到各气象要素的气候值,并形成建立方程所需自变量数据文件和预报所需的自变量数据文件.计算自变量与因变量的相关系数,将相关系数较大的因子筛选出来,通过人机交互的方式进行第2次筛选,用相关显著的自变量与因变量建立回归方程.由于输出的自变量相对因变量来说都是前期因子,根据回归方程和预报所需的自变量,就可以得出预报结果.
以普遍推广的AO文件(即基本观测资料)为基础,经过一定的程序处理,得到各气象要素的气候值,并形成建立方程所需自变量数据文件和预报所需的自变量数据文件.计算自变量与因变量的相关系数,将相关系数较大的因子筛选出来,通过人机交互的方式进行第2次筛选,用相关显著的自变量与因变量建立回归方程.由于输出的自变量相对因变量来说都是前期因子,根据回归方程和预报所需的自变量,就可以得出预报结果.
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:
新一代天气雷达系统在基层的建设和使用,对发现局地中小尺度天气系统,提高天气预报准确率,具有非常重要的作用.与此同时,为确保雷达的正常运行,保证资料的有效性、连续性,对设备维护提出了非常严格的要求.
新一代天气雷达系统在基层的建设和使用,对发现局地中小尺度天气系统,提高天气预报准确率,具有非常重要的作用.与此同时,为确保雷达的正常运行,保证资料的有效性、连续性,对设备维护提出了非常严格的要求.
2008, 36(1):123-124.
Abstract:
基于L波段探空GFE(L)1型二次测风雷达资料具有垂直分层密,并从地面开始就可以获取资料的特点,将其用于重庆市主城区边界层特征的分析,用于逆温与能见度、浓雾和空气污染指数的分析.结果表明,L波段探空雷达资料不仅可以用于大气边界层特征分析,还可以在污染气象分析预报、雾的预报、有害气体泄露事件应急气象服务,风能评价等多个领域发挥作用.
基于L波段探空GFE(L)1型二次测风雷达资料具有垂直分层密,并从地面开始就可以获取资料的特点,将其用于重庆市主城区边界层特征的分析,用于逆温与能见度、浓雾和空气污染指数的分析.结果表明,L波段探空雷达资料不仅可以用于大气边界层特征分析,还可以在污染气象分析预报、雾的预报、有害气体泄露事件应急气象服务,风能评价等多个领域发挥作用.
2008, 36(1):125-126.
Abstract:
目前NOAA制作并提供美国本土各州的地面臭氧预报。臭氧是美国本土各大城市空气质量的主要因子。美国国家天气局与美国国家环保局合作已将其业务性臭氧预报与服务扩展到西部11个州及其他6个州（Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, Wyoming 以及 Kansas 西部, Nebraska, North Dakota, Oklahoma, South Dakota, Texas）, 以确保全美国人口密集的城市都能够得到每日需要的空气质量信息。
目前NOAA制作并提供美国本土各州的地面臭氧预报。臭氧是美国本土各大城市空气质量的主要因子。美国国家天气局与美国国家环保局合作已将其业务性臭氧预报与服务扩展到西部11个州及其他6个州（Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, Wyoming 以及 Kansas 西部, Nebraska, North Dakota, Oklahoma, South Dakota, Texas）, 以确保全美国人口密集的城市都能够得到每日需要的空气质量信息。
2008, 36(1):125-126.
Abstract:
建阳新一代天气雷达2001年3月正式投入运行,其后雷达故障频发,而发射机的故障尤其严重,经过反复观察,发现雷达故障与发射机的温度紧密相关:温度高则故障多.
建阳新一代天气雷达2001年3月正式投入运行,其后雷达故障频发,而发射机的故障尤其严重,经过反复观察,发现雷达故障与发射机的温度紧密相关:温度高则故障多.
2008, 36(1):127-128.
Abstract:
新一代全相干多普勒天气雷达具有较高的可靠性、稳定性、可维护性及全天候的连续工作能力,具有自动数据采集、产品生成和显示、数据存储、运行监控和标校等功能.
新一代全相干多普勒天气雷达具有较高的可靠性、稳定性、可维护性及全天候的连续工作能力,具有自动数据采集、产品生成和显示、数据存储、运行监控和标校等功能.
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.
Supported by:Beijing E-Tiller Technology Development Co., Ltd.