Volume 35,Issue 4,2007 Table of Contents
2007, 35(4):293-596.
Abstract:
The Beijing Meteorological Bureau is the first user for SAFIR3000 (a lightning location system), which imposes very high equirement on real time transmission. There are certain difference for domestic and international communication service; thus, to choose an appropriate communication mode for the application of the lightning location system is very important. There are many kinds of communication modes in use presently, including special line, VPN, and Internet access, which are effective approaches to the realtime collection of meteorological data. The Internet communication mode is discussed, whtich is adopted in the lightning location system of the Beijing Meteorological Bureau.
The Beijing Meteorological Bureau is the first user for SAFIR3000 (a lightning location system), which imposes very high equirement on real time transmission. There are certain difference for domestic and international communication service; thus, to choose an appropriate communication mode for the application of the lightning location system is very important. There are many kinds of communication modes in use presently, including special line, VPN, and Internet access, which are effective approaches to the realtime collection of meteorological data. The Internet communication mode is discussed, whtich is adopted in the lightning location system of the Beijing Meteorological Bureau.
2007, 35(4):453-457.
Abstract:
The primary tool in estimating tropical cyclone intensity is to analyze the imagery of meteorological satellites over the vast tropical ocean, where few in situ observations are available. By using a set of empirical rules, the Dvorak technique relates cloud patterns and particular parameters derived from imagery to current tropical cyclone intensity. An introduction is made to the backg round of the Dvorak Technique and its main methods, and a summary is made of the advancements of the Dvorak technique in both China and other countries besides its advantages and disadvantages in application. It is pointed out that the Dvorak Technique is the main tool in most of the tropical cyclone forecast centers worldwide presently, and the prospects of the Dvorak Technique are also discussed.
The primary tool in estimating tropical cyclone intensity is to analyze the imagery of meteorological satellites over the vast tropical ocean, where few in situ observations are available. By using a set of empirical rules, the Dvorak technique relates cloud patterns and particular parameters derived from imagery to current tropical cyclone intensity. An introduction is made to the backg round of the Dvorak Technique and its main methods, and a summary is made of the advancements of the Dvorak technique in both China and other countries besides its advantages and disadvantages in application. It is pointed out that the Dvorak Technique is the main tool in most of the tropical cyclone forecast centers worldwide presently, and the prospects of the Dvorak Technique are also discussed.
2007, 35(4):458-463.
Abstract:
Numerical experiments on four cumulus parameterization schemes (CPSs) are carried out using the data of a Meiyu heavy rainstorm event occurred over the Changjiang basin in July 2002 with MM5 model. The impacts of different CPSs under the same model horizontal resolutions on rainfall, the mesoscale feature,and the microphysics feature of clouds are discussed. The results indicated that different CPSs have significantly different effects on rainfall intensity, but a little on the location of the rainfall center. The contributions to the total precipitation of four schemes are obviously different. The GR and KF schemes, which include subgrid scale moist downdrafts, are able to reproduce mesoαscale vortex features. The simulated cloud physical characteristics using four CPSs show significant difference.
Numerical experiments on four cumulus parameterization schemes (CPSs) are carried out using the data of a Meiyu heavy rainstorm event occurred over the Changjiang basin in July 2002 with MM5 model. The impacts of different CPSs under the same model horizontal resolutions on rainfall, the mesoscale feature,and the microphysics feature of clouds are discussed. The results indicated that different CPSs have significantly different effects on rainfall intensity, but a little on the location of the rainfall center. The contributions to the total precipitation of four schemes are obviously different. The GR and KF schemes, which include subgrid scale moist downdrafts, are able to reproduce mesoαscale vortex features. The simulated cloud physical characteristics using four CPSs show significant difference.
2007, 35(4):464-469.
Abstract:
The characteristics of the mesoscale numerical forecasting system developed by the Linyi Meteorological Bureau, the interpretation of the model forecast products, and the application of radar data in the model system are introduced. The evaluation of forecasting results was conducted from June to October 2005. The system displays considerable capability in shortrange weather forecast for predicting precipitation and temperature. The system is considered to be valuable for improving the quantification, timeliness, and accuracy of weather forecasting. By using the selfdeveloped SDAF software package in the application of forecasting products, the methods for forecasting heavy rainfall, air quality, extreme temperature, dryhot winds, etc. are generated. The Doppler radar echo intensity is used to modify the humidity field in numerical model, and the forecasting results are improved obviously. The primary experiments on the retrieval of the wind vector fields from the Doppler radial velocity to modify the initial forecast fields are carried out, and some conclusions are obtained.
The characteristics of the mesoscale numerical forecasting system developed by the Linyi Meteorological Bureau, the interpretation of the model forecast products, and the application of radar data in the model system are introduced. The evaluation of forecasting results was conducted from June to October 2005. The system displays considerable capability in shortrange weather forecast for predicting precipitation and temperature. The system is considered to be valuable for improving the quantification, timeliness, and accuracy of weather forecasting. By using the selfdeveloped SDAF software package in the application of forecasting products, the methods for forecasting heavy rainfall, air quality, extreme temperature, dryhot winds, etc. are generated. The Doppler radar echo intensity is used to modify the humidity field in numerical model, and the forecasting results are improved obviously. The primary experiments on the retrieval of the wind vector fields from the Doppler radial velocity to modify the initial forecast fields are carried out, and some conclusions are obtained.
2007, 35(4):470-473.
Abstract:
A method for discriminating cloud precipitation based on a mesoscale model and CINRAD radar in Anhui Province is introduced. The mesoscale model MM5 products are used to extract the index of potential precipitation areas, and then the CINRAD products are used to analyze the precipitation factors relevant to the cloud clusters with the potential for precipitation. The results show that the composite potential index can denote the occurrence probability of convective systems containing abundant water, and therefore can be used to analyze the precipitation potential of convective systems. The precipitation grade index deduced from CINRAD data is in fact devised according to the water resource grades of convective clouds. As the result, the precision of cloud precipitation discrimination could be enhanced by combining these two kinds of parameters.
A method for discriminating cloud precipitation based on a mesoscale model and CINRAD radar in Anhui Province is introduced. The mesoscale model MM5 products are used to extract the index of potential precipitation areas, and then the CINRAD products are used to analyze the precipitation factors relevant to the cloud clusters with the potential for precipitation. The results show that the composite potential index can denote the occurrence probability of convective systems containing abundant water, and therefore can be used to analyze the precipitation potential of convective systems. The precipitation grade index deduced from CINRAD data is in fact devised according to the water resource grades of convective clouds. As the result, the precision of cloud precipitation discrimination could be enhanced by combining these two kinds of parameters.
2007, 35(4):474-479.
Abstract:
The method for calculating OLR (Outgoing Longwave Radiation) with FY-2C geostationary satellite data is described, including the establishment of the FY-2C OLR inverse model and the detailed procedures of calculating OLR by using the measurements in the FY-2C window and water vapor channels. The quality of FY-2C OLR products is discussed by comparing with NOAA OLR products nearly at the same time on the OLR isoline charts. The difference between the two products ranges from 0 to 20 W/m, with the maximum difference being 20 W/m. An example of FY-2C OLR products and application is also given.
The method for calculating OLR (Outgoing Longwave Radiation) with FY-2C geostationary satellite data is described, including the establishment of the FY-2C OLR inverse model and the detailed procedures of calculating OLR by using the measurements in the FY-2C window and water vapor channels. The quality of FY-2C OLR products is discussed by comparing with NOAA OLR products nearly at the same time on the OLR isoline charts. The difference between the two products ranges from 0 to 20 W/m, with the maximum difference being 20 W/m. An example of FY-2C OLR products and application is also given.
2007, 35(4):480-483.
Abstract:
The statistical method is used to analyze the spatialtemporal distributions of AMDAR (Aircraft Meteorological Data Relay) data. The AMDAR data are also compared with the conventional radiosonde data. The results show that the AMDAR data is one kind of observation with high spatialtemporal density; the quality of the AMDAR data is close to the radiosonde data; and the temporal density of the AMDAR data is nearly ten times of that of the radiosonde data. Therefore, the AMDAR data can be used to monitor weather systems and the fine characteristics of their evolution around the airports, to provide more usefull references for shorttime forecast, especially for nowcasting.
The statistical method is used to analyze the spatialtemporal distributions of AMDAR (Aircraft Meteorological Data Relay) data. The AMDAR data are also compared with the conventional radiosonde data. The results show that the AMDAR data is one kind of observation with high spatialtemporal density; the quality of the AMDAR data is close to the radiosonde data; and the temporal density of the AMDAR data is nearly ten times of that of the radiosonde data. Therefore, the AMDAR data can be used to monitor weather systems and the fine characteristics of their evolution around the airports, to provide more usefull references for shorttime forecast, especially for nowcasting.
2007, 35(4):484-488.
Abstract:
The SST variation characteristics over the South China Sea (SCS) and the Bay of Bengal before and after the onset of summer monsoon and the possible relation with Southwest air current are investigated by means of the NCEP/NCAR weeklymean SST reanalysis data and dailymean surface wind data from 1982 to 1999, using synthetic and correlation analysis technique. The results show that the SST increase on SCS and the Bay of Bengal is not only related to ocean phenomena, but also to atmospheric factors in the two weeks before the monsoon onset. There were great difference in the regional SST variability between SCS and Bay of Bengal in the two weeks after monsoon onset. The SST increased in the east coast and the northwest part of the SCS and the Bay of Bengal, and decreased in the southwest and central parts of the SCS and the Bay of Bengal. The disparity distributions of SST variation are directly related with the surface southwest current variation in the two weeks after monsoon onset.
The SST variation characteristics over the South China Sea (SCS) and the Bay of Bengal before and after the onset of summer monsoon and the possible relation with Southwest air current are investigated by means of the NCEP/NCAR weeklymean SST reanalysis data and dailymean surface wind data from 1982 to 1999, using synthetic and correlation analysis technique. The results show that the SST increase on SCS and the Bay of Bengal is not only related to ocean phenomena, but also to atmospheric factors in the two weeks before the monsoon onset. There were great difference in the regional SST variability between SCS and Bay of Bengal in the two weeks after monsoon onset. The SST increased in the east coast and the northwest part of the SCS and the Bay of Bengal, and decreased in the southwest and central parts of the SCS and the Bay of Bengal. The disparity distributions of SST variation are directly related with the surface southwest current variation in the two weeks after monsoon onset.
2007, 35(4):489-494.
Abstract:
The analysis and summary are made of the 20 rainfall events occurred around the Qilian Mountain from 2002 to 2004 by use of the reanalyzed daytoday 6h NCEP/NCAR data. The results show that there was a upperlevel westerly jet from east to the west at 40°N, 200 hPa; precipitation generally took place in the south side of the jet axis, and there was cold downdrafts on the north side of the jet axis, warm and humid upcurrent on the south side, and the subcirculations beneath; there was strong divergent ascending motion on the right side of the entrance area of the jet axis, and accordingly there existed strong convergence ascending area at the lower levels. The collocation of divergence and convergence at the upper and lower levels is beneficial to the formation of strong convection weather. The existence of the westerly jet axis at high altitudes is of profound influence to the precipitation over the Qilian mountain areas, and the position variation of the jet axis affects the location of the precipitation.
The analysis and summary are made of the 20 rainfall events occurred around the Qilian Mountain from 2002 to 2004 by use of the reanalyzed daytoday 6h NCEP/NCAR data. The results show that there was a upperlevel westerly jet from east to the west at 40°N, 200 hPa; precipitation generally took place in the south side of the jet axis, and there was cold downdrafts on the north side of the jet axis, warm and humid upcurrent on the south side, and the subcirculations beneath; there was strong divergent ascending motion on the right side of the entrance area of the jet axis, and accordingly there existed strong convergence ascending area at the lower levels. The collocation of divergence and convergence at the upper and lower levels is beneficial to the formation of strong convection weather. The existence of the westerly jet axis at high altitudes is of profound influence to the precipitation over the Qilian mountain areas, and the position variation of the jet axis affects the location of the precipitation.
2007, 35(4):495-499.
Abstract:
The calculation is made of the Holdridge aridity index to analyze climate tendency and characteristics of drought/wetness changes for the last 50 years by means of the mean air temperature and precipitation at Tengzhou from 1956 to 2005. The results show that under the influence of the obvious increase trend of annual biotemperature and annual potential evapotranspiration，the indistinctive decrease trend of annual precipitation caused the obvious loss trend of annual water budget and the outstanding increase trend of annual aridity index. The aridity index varies periodically, and drought and wetness stages appear alternately. Generally there are three wetness stages and two drought stages. In 1976, the aridity abruptly turned from wet to dry. Climate types changed markedly after the abrupt climate transformation. Through the movingaverage analysis of the aridity index and the standard deviation, it is found that along with the increase of average aridity index，unusual wetness events obviously decreased，but unusual drought events obviously increased. Along with the increase of the standard deviation, the total frequency of unusual drought/wetness events increased obviously.
The calculation is made of the Holdridge aridity index to analyze climate tendency and characteristics of drought/wetness changes for the last 50 years by means of the mean air temperature and precipitation at Tengzhou from 1956 to 2005. The results show that under the influence of the obvious increase trend of annual biotemperature and annual potential evapotranspiration，the indistinctive decrease trend of annual precipitation caused the obvious loss trend of annual water budget and the outstanding increase trend of annual aridity index. The aridity index varies periodically, and drought and wetness stages appear alternately. Generally there are three wetness stages and two drought stages. In 1976, the aridity abruptly turned from wet to dry. Climate types changed markedly after the abrupt climate transformation. Through the movingaverage analysis of the aridity index and the standard deviation, it is found that along with the increase of average aridity index，unusual wetness events obviously decreased，but unusual drought events obviously increased. Along with the increase of the standard deviation, the total frequency of unusual drought/wetness events increased obviously.
11 Evaporation Variation and Its Relationship with Meteorological Factors in Shangqiu from 1961 to 2004
2007, 35(4):500-502.
Abstract:
The interdecadal, interannual and seasonal evaporation variations are analyzed on the basis of the available observation data from 1961 to 2004 from eight stations over Shangqiu. The results show that although the annual mean air temperature showed an increasing trend over the past 44 years, the evaporation of the same time showed a remarkable decreasing trend, which passed the statistical test with a significant level of 99%. The evaporation variation is most obvious in spring, and least in winter. Compared with the 1960s and the 1970s, the annual pan evaporation rate in the 1980s and the 1990s decreased by about 34 mm. The cause is directly correlated to the decreased average wind speed and sunshine.
The interdecadal, interannual and seasonal evaporation variations are analyzed on the basis of the available observation data from 1961 to 2004 from eight stations over Shangqiu. The results show that although the annual mean air temperature showed an increasing trend over the past 44 years, the evaporation of the same time showed a remarkable decreasing trend, which passed the statistical test with a significant level of 99%. The evaporation variation is most obvious in spring, and least in winter. Compared with the 1960s and the 1970s, the annual pan evaporation rate in the 1980s and the 1990s decreased by about 34 mm. The cause is directly correlated to the decreased average wind speed and sunshine.
2007, 35(4):503-508.
Abstract:
The effects of typhoons Haitang and Talim on the precipitation distribution over Hubei Province are studied by using T213 products and conventional data. The result shows that there was no strong precipitation while the inverse trough north of Haitang moving across Hubei Province from east to west in the case of no secondary circulation, and there occurred strong precipitation while the inverse trough north of Talim moving across Hubei Province companying with the appearance of secondary circulations. The secondary circulations were induced by many kinds of factors, and the source areas of the secondary circulations were in agreement with the areas of strong precipitation occurrence.
The effects of typhoons Haitang and Talim on the precipitation distribution over Hubei Province are studied by using T213 products and conventional data. The result shows that there was no strong precipitation while the inverse trough north of Haitang moving across Hubei Province from east to west in the case of no secondary circulation, and there occurred strong precipitation while the inverse trough north of Talim moving across Hubei Province companying with the appearance of secondary circulations. The secondary circulations were induced by many kinds of factors, and the source areas of the secondary circulations were in agreement with the areas of strong precipitation occurrence.
2007, 35(4):509-513.
Abstract:
A dynamical analysis of two torrential rainfall events in June 2005 in Guangzhou is made with the routine meteorological data, automatic weather station data, NCEP reanalysis data and numerical model outputs. The similarities and differences between two torrential rains are found from aspects of environmental conditions and physical mechanisms. It is found that (1) the cold air from east is likely the trigger mechanism of the torrential rain on 5 June; (2) the pulse of the jet in the southwest monsoon flow and the surface mesoscale low pressure may be the trigger mechanisms of the torrential rain on 21 June.
A dynamical analysis of two torrential rainfall events in June 2005 in Guangzhou is made with the routine meteorological data, automatic weather station data, NCEP reanalysis data and numerical model outputs. The similarities and differences between two torrential rains are found from aspects of environmental conditions and physical mechanisms. It is found that (1) the cold air from east is likely the trigger mechanism of the torrential rain on 5 June; (2) the pulse of the jet in the southwest monsoon flow and the surface mesoscale low pressure may be the trigger mechanisms of the torrential rain on 21 June.
2007, 35(4):514-518.
Abstract:
An analysis is made of the temporal and spatial characteristics of the circulation pattern at 500 hPa and vapor field at 700 hPa during the autumn waterlogging in upstream of the Han River in 2005 with NECP data. The results indicate that the height departure field at 500 hPa took on the wave train of “+, -, +". The primary sources of vapor at 700 hPa came from the Bay of Bengal and the South China Sea. The EOF analysis shows that the vapor flux divergence showed the same variation trend in upstream of the Han River and the Bay of Bengal and the South China Sea. The wavelet analysis reveals that the vapor flux divergence has oscillations of quasitwo week and quasione week in upstream of the Han River and the South China Sea. The strong precipitation appears frequently in the period of the superposed negative phase of several different frequency oscillations.
An analysis is made of the temporal and spatial characteristics of the circulation pattern at 500 hPa and vapor field at 700 hPa during the autumn waterlogging in upstream of the Han River in 2005 with NECP data. The results indicate that the height departure field at 500 hPa took on the wave train of “+, -, +". The primary sources of vapor at 700 hPa came from the Bay of Bengal and the South China Sea. The EOF analysis shows that the vapor flux divergence showed the same variation trend in upstream of the Han River and the Bay of Bengal and the South China Sea. The wavelet analysis reveals that the vapor flux divergence has oscillations of quasitwo week and quasione week in upstream of the Han River and the South China Sea. The strong precipitation appears frequently in the period of the superposed negative phase of several different frequency oscillations.
2007, 35(4):519-523.
Abstract:
The mesoscale characteristics of the regional rain storm over the central Shanxi Province on 26, 27 July 2001 are analyzed on the basis of GMS5 infrared imagery and some conventional observation. The results show that (1) This event is caused directly by a newly developed mesoβ scale cloud cluster. (2) There existed a Ωshaped energy field on the surface, and there was a mesoscale convergence line and an anticyclone. The mesoscale rainfall cluster formed to the north of the convergence line and the southeast side of the mesoanticyclone. The convergence area was overlapped with the high energy tongue where there was strong ascending motion, which triggered energy release, was the main dynamic mechanism of the rainstorm. (3) Mesoscale characteristics can be seen in the distribution of frontogenesis function of wet 〖WTHX〗Q〖WTBZ〗vector. The center of strong frontogenesis function lied in the southeast of mesoβ scale cloud cluster, which was the main startup mechanism of the rainstorm. There was positive correlation between the center of frontogenesis function at the lower levels and the rainfall amount with a time lag of 6 hours.
The mesoscale characteristics of the regional rain storm over the central Shanxi Province on 26, 27 July 2001 are analyzed on the basis of GMS5 infrared imagery and some conventional observation. The results show that (1) This event is caused directly by a newly developed mesoβ scale cloud cluster. (2) There existed a Ωshaped energy field on the surface, and there was a mesoscale convergence line and an anticyclone. The mesoscale rainfall cluster formed to the north of the convergence line and the southeast side of the mesoanticyclone. The convergence area was overlapped with the high energy tongue where there was strong ascending motion, which triggered energy release, was the main dynamic mechanism of the rainstorm. (3) Mesoscale characteristics can be seen in the distribution of frontogenesis function of wet 〖WTHX〗Q〖WTBZ〗vector. The center of strong frontogenesis function lied in the southeast of mesoβ scale cloud cluster, which was the main startup mechanism of the rainstorm. There was positive correlation between the center of frontogenesis function at the lower levels and the rainfall amount with a time lag of 6 hours.
2007, 35(4):524-527.
Abstract:
The climatic factors influencing the occurrence of citrus yellow shoot trees are studied by using the climatic data of the Congjang Meteorological Bureau (the daytoday temperature, precipitation, evaporation and number of consecutive rainy days) from May to October, 1981 to 2005. The results indicate that when the tenday average temperatures in three dekads in summer (the third dekad of May, the first and second dekads of June) surpass 27 ℃, the tenday average differences between precipitation and evaporation are positive from middle May to end of June, and the number of consecutive rainy days is greater than five, the citrus yellow shoot is likely to occur. Therefore, the high temperature and humidity from the end of spring to the beginning of summer is the important condition for the occurrence of citrus yellow shoot for citrus tree tops.
The climatic factors influencing the occurrence of citrus yellow shoot trees are studied by using the climatic data of the Congjang Meteorological Bureau (the daytoday temperature, precipitation, evaporation and number of consecutive rainy days) from May to October, 1981 to 2005. The results indicate that when the tenday average temperatures in three dekads in summer (the third dekad of May, the first and second dekads of June) surpass 27 ℃, the tenday average differences between precipitation and evaporation are positive from middle May to end of June, and the number of consecutive rainy days is greater than five, the citrus yellow shoot is likely to occur. Therefore, the high temperature and humidity from the end of spring to the beginning of summer is the important condition for the occurrence of citrus yellow shoot for citrus tree tops.
2007, 35(4):528-530.
Abstract:
An analysis is made of the variation regularity of soil moisture storage by use of the soil moisture storage data of 0 to 50 cm measured at both spring wheat field and atmospheric observation site at Huzhu County from 1977 to 2002. The results show that under the same climate background, the variation characteristics of soil moisture storage are basically consistent. The soil moisture storage of 0 to 50 cm from the atmospheric observation site is about 25 to 27 mm with minimum value being about 24 mm (from June to July) and the peak value being about 28 mm (September), and its annual variation curve shows an “M” shape. In the spring wheat field, the maximum value of 0 to 50 cm is 33 mm (March to April), and the minimum value is 21 mm (July) with the annual variation being about the same with the case of atmospheric observation. The results show that the drying method used in the spring wheat field can replace the neutron apparatus used in the atmospheric observation site.
An analysis is made of the variation regularity of soil moisture storage by use of the soil moisture storage data of 0 to 50 cm measured at both spring wheat field and atmospheric observation site at Huzhu County from 1977 to 2002. The results show that under the same climate background, the variation characteristics of soil moisture storage are basically consistent. The soil moisture storage of 0 to 50 cm from the atmospheric observation site is about 25 to 27 mm with minimum value being about 24 mm (from June to July) and the peak value being about 28 mm (September), and its annual variation curve shows an “M” shape. In the spring wheat field, the maximum value of 0 to 50 cm is 33 mm (March to April), and the minimum value is 21 mm (July) with the annual variation being about the same with the case of atmospheric observation. The results show that the drying method used in the spring wheat field can replace the neutron apparatus used in the atmospheric observation site.
2007, 35(4):531-534.
Abstract:
The field experiments show that climatic conditions, including temperature, precipitation, sunlight, etc, in the Fuping mountainous area are suitable for the growth of strawberry. Strawberries can blossom, seed and mature naturally in this area. Since the temperature in the Fuping mountainous area is lower than that of the Hebei plain (taking Mancheng County as an example) in the same time, the development periods of strawberries in the Fuping mountainous area are later than those in the Hebei plain, and the maturity period is about one month later. Consequently, owning to the difference of strawberry maturity times between Fuping mountainous area and Hebei plain, farmers can gain higher profits. The unseasonable strawberries produced in the Fuping mountainous area have good quality and high content of dissolubility substance, 1.5 times higher that those produced in the Hebei plain, and the vitamin C content is 18 percent higher. The benefits from the unseasonable planting are higher than those from the ordinary trawberry planting with the gross income being 6.3 times as much as that of the old planting model. The agroclimate similarity analysis shows that it is feasible to introduce strawberry to the Fuping mountainous area from the Hebei plain.
The field experiments show that climatic conditions, including temperature, precipitation, sunlight, etc, in the Fuping mountainous area are suitable for the growth of strawberry. Strawberries can blossom, seed and mature naturally in this area. Since the temperature in the Fuping mountainous area is lower than that of the Hebei plain (taking Mancheng County as an example) in the same time, the development periods of strawberries in the Fuping mountainous area are later than those in the Hebei plain, and the maturity period is about one month later. Consequently, owning to the difference of strawberry maturity times between Fuping mountainous area and Hebei plain, farmers can gain higher profits. The unseasonable strawberries produced in the Fuping mountainous area have good quality and high content of dissolubility substance, 1.5 times higher that those produced in the Hebei plain, and the vitamin C content is 18 percent higher. The benefits from the unseasonable planting are higher than those from the ordinary trawberry planting with the gross income being 6.3 times as much as that of the old planting model. The agroclimate similarity analysis shows that it is feasible to introduce strawberry to the Fuping mountainous area from the Hebei plain.
2007, 35(4):535-540.
Abstract:
The GISbased operation system of weather modification for prefecturelevel institutions consists of such parts as data analysis and transmission, operation control, and effectiveness evaluation, etc. According to the different characteristics of weather modification and hail suppression operation, the system can determine by means of radar images and cannon operation parameters, produce and send operation orders automatically. The receiving unit adopting GPRS (General Packet Radio Service) technology receives weather modification operation orders safely and delaylessly, in the operating mode of the prefecturelevel operational system from the control center directly to an operation site. The system is transplantable and can handle properly the issues existing in remote data sharing and remote transaction processing, so to realize the operationalization of weather modification operation control.
The GISbased operation system of weather modification for prefecturelevel institutions consists of such parts as data analysis and transmission, operation control, and effectiveness evaluation, etc. According to the different characteristics of weather modification and hail suppression operation, the system can determine by means of radar images and cannon operation parameters, produce and send operation orders automatically. The receiving unit adopting GPRS (General Packet Radio Service) technology receives weather modification operation orders safely and delaylessly, in the operating mode of the prefecturelevel operational system from the control center directly to an operation site. The system is transplantable and can handle properly the issues existing in remote data sharing and remote transaction processing, so to realize the operationalization of weather modification operation control.
2007, 35(4):541-545.
Abstract:
An analysis is made the key areas of various weather systems affecting Anhui Province, based on the objective analysis of weather patterns by means of NCEP 500 hPa height and grided wind data, forecasters' experiences, and the conventional precipitation measurements of ten years in nonflood season from 81 stations over Anhui Province. The daytoday weather calendar resulted from automodeling is used in the weather modification forecast system, and objective typing of circulation patterns is realized. The method is practicable and highly automatic,can provide useful references for the control system of precipitation enhancement operation in Anhui.
An analysis is made the key areas of various weather systems affecting Anhui Province, based on the objective analysis of weather patterns by means of NCEP 500 hPa height and grided wind data, forecasters' experiences, and the conventional precipitation measurements of ten years in nonflood season from 81 stations over Anhui Province. The daytoday weather calendar resulted from automodeling is used in the weather modification forecast system, and objective typing of circulation patterns is realized. The method is practicable and highly automatic,can provide useful references for the control system of precipitation enhancement operation in Anhui.
2007, 35(4):546-549.
Abstract:
The aircraft weather modification in largescale stratiform clouds and mixture clouds in North China is one of the important ways to relieve droughts and forest fires and improve the natural environment. The selfdeveloped L-1 Seeding System of Airborne Towed Flame with Multiple Warheads and 19 Pipes can meet the needs of precipitation enhancement operations. The system consists of the multiple warhead ammunition body, AgI catalyst, and launching and power control units. According to the experiments and primary application, the system shows obvious features of stable, easy to operate, and 100% launch rate. The nucleus rate is high up to above 1015 kg AgI at －8 ℃ and the 90% nucleus can be activated in 5 minutes after getting into clouds. The launcher can carry 760 flares so as to seed for 4 hours ceaselessly and can shoot backward. The Long B2 flame seeding system used presently has just 90% launch rate, and the launcher can carries only 200 flares, operating for only 1.5 hours and shoots laterally with less flexibility, so mechanical failures occurs frequently.
The aircraft weather modification in largescale stratiform clouds and mixture clouds in North China is one of the important ways to relieve droughts and forest fires and improve the natural environment. The selfdeveloped L-1 Seeding System of Airborne Towed Flame with Multiple Warheads and 19 Pipes can meet the needs of precipitation enhancement operations. The system consists of the multiple warhead ammunition body, AgI catalyst, and launching and power control units. According to the experiments and primary application, the system shows obvious features of stable, easy to operate, and 100% launch rate. The nucleus rate is high up to above 1015 kg AgI at －8 ℃ and the 90% nucleus can be activated in 5 minutes after getting into clouds. The launcher can carry 760 flares so as to seed for 4 hours ceaselessly and can shoot backward. The Long B2 flame seeding system used presently has just 90% launch rate, and the launcher can carries only 200 flares, operating for only 1.5 hours and shoots laterally with less flexibility, so mechanical failures occurs frequently.
2007, 35(4):550-557.
Abstract:
The continuous field measurement of some trace gases on the surface air was conducted at Shangdianzi Regional Background Station (117°07′E，40°39′N，293.9 m a.s.l.) in Beijing from September 2003 to February 2004. Some variation characteristics, variation regularity and the present concentrations of O3, NO, NO2, NOx, SO2 and CO were obtained. Primary study shows that the concentrations of O3, NO, NO2, NOx, SO2, CO showed diurnal variation and monthly variation. In general, the ozone concentration was higher in autumn and lower in winter. The relationships between O3, NO, NO2, NOx, SO2, CO and meteorolo gical factors are discussed. Ozone is negatively correlated with NO, NO2, SO2 and CO. There is a good correlation between CO and NOx, SO2. It can be observed that the trends of concentration variations of gaseous pollutants in Shangdianzi are similar to those in the Beijing urban area.
The continuous field measurement of some trace gases on the surface air was conducted at Shangdianzi Regional Background Station (117°07′E，40°39′N，293.9 m a.s.l.) in Beijing from September 2003 to February 2004. Some variation characteristics, variation regularity and the present concentrations of O3, NO, NO2, NOx, SO2 and CO were obtained. Primary study shows that the concentrations of O3, NO, NO2, NOx, SO2, CO showed diurnal variation and monthly variation. In general, the ozone concentration was higher in autumn and lower in winter. The relationships between O3, NO, NO2, NOx, SO2, CO and meteorolo gical factors are discussed. Ozone is negatively correlated with NO, NO2, SO2 and CO. There is a good correlation between CO and NOx, SO2. It can be observed that the trends of concentration variations of gaseous pollutants in Shangdianzi are similar to those in the Beijing urban area.
2007, 35(4):558-562.
Abstract:
The spatialtemporal variations of wind power over Hexi Corridor are studied by means of wind data over the corridor from 1970 to 2004 and the 10minute interval intensive observation data from seven wind towers in the Gobi.The results show that the wind speed was relatively stable over Hexi Corridor; there is an obvious decreasing trend in wind speed within Oasis; there is regional difference in the distribution of wind power with two high power areas. Within 10 m above the surface, the wind power density is greater than 100 W/m2, mostly 150 W/m2 with the maximum being over 200 W/m2; and in the layer of 10 to 70 m, the wind power density increases with altitude linearly, 28 W/m2 per 10 m, over 300 W/m2 at 70 m. There are diurnal and monthly wind power variations in Hexi Corridor with the higher density in the period of February to June. The wind power density is the lowest at about 10 m above the surface around 07:00, then increases gradually from 08:00, reaches the maximum at about 18:00, then decreases again. There is abundant wind resources in Hexi Corridor area. The duration of effective wind in Hexi Corridor can be up to 6000 hours or higher, even to 7500 hours.
The spatialtemporal variations of wind power over Hexi Corridor are studied by means of wind data over the corridor from 1970 to 2004 and the 10minute interval intensive observation data from seven wind towers in the Gobi.The results show that the wind speed was relatively stable over Hexi Corridor; there is an obvious decreasing trend in wind speed within Oasis; there is regional difference in the distribution of wind power with two high power areas. Within 10 m above the surface, the wind power density is greater than 100 W/m2, mostly 150 W/m2 with the maximum being over 200 W/m2; and in the layer of 10 to 70 m, the wind power density increases with altitude linearly, 28 W/m2 per 10 m, over 300 W/m2 at 70 m. There are diurnal and monthly wind power variations in Hexi Corridor with the higher density in the period of February to June. The wind power density is the lowest at about 10 m above the surface around 07:00, then increases gradually from 08:00, reaches the maximum at about 18:00, then decreases again. There is abundant wind resources in Hexi Corridor area. The duration of effective wind in Hexi Corridor can be up to 6000 hours or higher, even to 7500 hours.
24 Application of Grey Correlation Degree to Disaster Loss Evaluation of Strong Wind and Heavy Rainfall
2007, 35(4):563-566.
Abstract:
The grey correlation degree is a measure of relation among various factors, can be used to evaluate natural disaster loss. By using the grey correlation degree method, the disaster loss assessing indexes and correlation degrees of 19 severe weather events (strong winds and heavy rainfall) are calculated. The results show that the grey correlation method is reasonable in the grading of disaster situation and the ranking of disaster loss correlation degree, with the results basically in agreement with the actual situation, being applicable for natural disaster evaluation. It can identify the disaster lost difference among different meteorological disasters, as well as the differences among the meteorological disasters of the same class. It can be used to the operational disaster loss evaluation service.
The grey correlation degree is a measure of relation among various factors, can be used to evaluate natural disaster loss. By using the grey correlation degree method, the disaster loss assessing indexes and correlation degrees of 19 severe weather events (strong winds and heavy rainfall) are calculated. The results show that the grey correlation method is reasonable in the grading of disaster situation and the ranking of disaster loss correlation degree, with the results basically in agreement with the actual situation, being applicable for natural disaster evaluation. It can identify the disaster lost difference among different meteorological disasters, as well as the differences among the meteorological disasters of the same class. It can be used to the operational disaster loss evaluation service.
2007, 35(4):567-570.
Abstract:
It is always difficult for a lightning protection project to build a qualified and economical earthing device for the areas with high soil resistance. Considering the relation of the shape of earthing electrodes to the utilization efficiency of materials and the difficulty in construction, the polygonal divergent earthing electrode technique is presented. The experiments on the technique were conducted at three sites with different environments. The comparison with common earthing devices indicates that the polygonal divergent earthing electrode technique is superior in the areas with high soil resistance. Comparisons are also made between the different installation distances and different dosages of resistance reducing agents. Thus, the optimal installation method is found out; the parallel connection coefficient is calculated on the basis of the experiment data; and the estimating method of engineering work load is obtained.
It is always difficult for a lightning protection project to build a qualified and economical earthing device for the areas with high soil resistance. Considering the relation of the shape of earthing electrodes to the utilization efficiency of materials and the difficulty in construction, the polygonal divergent earthing electrode technique is presented. The experiments on the technique were conducted at three sites with different environments. The comparison with common earthing devices indicates that the polygonal divergent earthing electrode technique is superior in the areas with high soil resistance. Comparisons are also made between the different installation distances and different dosages of resistance reducing agents. Thus, the optimal installation method is found out; the parallel connection coefficient is calculated on the basis of the experiment data; and the estimating method of engineering work load is obtained.
2007, 35(4):571-573.
Abstract:
An analysis is made of the data of solar ultraviolet radiation (UV) observed at Taiyan for three years. The results show that UV is the highest in sunny midday, obvious higher in summer than in winter, and the occurrence time of the highest UV is earlier in summer than in winter. Some meteorological factors and air pollution of the same time is also analyzed, and the results shows that UV is influenced by cloud form, cloud cover, air pressure, air temperature, visibility, humidity, air pollution, etc. The ratio of UV to the global radiation is higher in summer than in winter, and the attenuation is not synchronous in cloudy days. It is suggested that halfhour averaged maximum UV and averaged UV from 10:00 to 14: 00 have the same importance for UV forecasting, so to estimate the possible harm of UV to human bodies.
An analysis is made of the data of solar ultraviolet radiation (UV) observed at Taiyan for three years. The results show that UV is the highest in sunny midday, obvious higher in summer than in winter, and the occurrence time of the highest UV is earlier in summer than in winter. Some meteorological factors and air pollution of the same time is also analyzed, and the results shows that UV is influenced by cloud form, cloud cover, air pressure, air temperature, visibility, humidity, air pollution, etc. The ratio of UV to the global radiation is higher in summer than in winter, and the attenuation is not synchronous in cloudy days. It is suggested that halfhour averaged maximum UV and averaged UV from 10:00 to 14: 00 have the same importance for UV forecasting, so to estimate the possible harm of UV to human bodies.
2007, 35(4):574-578.
Abstract:
The advantages and disadvantages of the relevant drought remote sensing techniques are analyzed in detail on the basis of three kinds of different underlying surfaces (bare surface, partly and fully covered surface by vegetation). In the case of the bare underlying surface, the microwave remote sensing method has great potential; in the case of the partly covered underlying surface, the double model method is better, which is, however, complicated, and in which the emphasis should be put on the simplification of the classic layer model. In the case of the fully covered underlying surface, each monitoring method has both good and bad sides. Meanwhile, the developing trend and application prospects of the remote sensing techniques are discussed, so to provide useful reference to drought monitoring service.
The advantages and disadvantages of the relevant drought remote sensing techniques are analyzed in detail on the basis of three kinds of different underlying surfaces (bare surface, partly and fully covered surface by vegetation). In the case of the bare underlying surface, the microwave remote sensing method has great potential; in the case of the partly covered underlying surface, the double model method is better, which is, however, complicated, and in which the emphasis should be put on the simplification of the classic layer model. In the case of the fully covered underlying surface, each monitoring method has both good and bad sides. Meanwhile, the developing trend and application prospects of the remote sensing techniques are discussed, so to provide useful reference to drought monitoring service.
2007, 35(4):579-582.
Abstract:
In order to understand of the dynamical changes and causes of the main lakes over Jiangsu Province to provide the accurate references for flood/drought and water environment control departments in decisionmaking, the dynamical remote sensing of the lakes over the northern Jiangsu Province was conducted by means of the EOS/MODIS satellite dataset in summer of 2005. The threechannel colorized synthetic images are obtained, and the water borderlines of these lakes are extracted with the threshold method. An analysis is made of the area variation of the lakes from the viewpoint of meteorology. It can be seen from the remote sensing images and the statistical results that the areas of the lakes decreased because of the previous drought and then increased because of the subsequent abundant precipitation. The meteorological factors such as sunshine duration, precipitation, etc., have great influence on the areas of lakes.
In order to understand of the dynamical changes and causes of the main lakes over Jiangsu Province to provide the accurate references for flood/drought and water environment control departments in decisionmaking, the dynamical remote sensing of the lakes over the northern Jiangsu Province was conducted by means of the EOS/MODIS satellite dataset in summer of 2005. The threechannel colorized synthetic images are obtained, and the water borderlines of these lakes are extracted with the threshold method. An analysis is made of the area variation of the lakes from the viewpoint of meteorology. It can be seen from the remote sensing images and the statistical results that the areas of the lakes decreased because of the previous drought and then increased because of the subsequent abundant precipitation. The meteorological factors such as sunshine duration, precipitation, etc., have great influence on the areas of lakes.
2007, 35(4):583-588.
Abstract:
The Microtops Ⅱ is a handheld multiband sunphotometer capable of measuring the aerosol optical depth (AOD). Some experiences and tips for use are given. The principles of application, major features, the calculation of AOD and the calibration method of the instrument are introduced. An analysis is made of a set of data the on contrasting observation at the National Nanling Forest Park on 19 September 2004. The results show that the AOD values differ by 0.01 at most at the 500 nm channel, and the calibration constants are suitable for the two instruments.
The Microtops Ⅱ is a handheld multiband sunphotometer capable of measuring the aerosol optical depth (AOD). Some experiences and tips for use are given. The principles of application, major features, the calculation of AOD and the calibration method of the instrument are introduced. An analysis is made of a set of data the on contrasting observation at the National Nanling Forest Park on 19 September 2004. The results show that the AOD values differ by 0.01 at most at the 500 nm channel, and the calibration constants are suitable for the two instruments.
2007, 35(4):589-592.
Abstract:
The strategy for data sharing on meteorological scientific data storage and search servce for the society via Internet is studied on the basis of the analysis of meteorological scientific data and the reference of the relevant technology development at home and abroad, according to the needs of the society and users. Some suggestions on storage and search strategy are given, including storage on line, storage in files associated with databases, as well as diversification, visualization and humanity in storage and search.
The strategy for data sharing on meteorological scientific data storage and search servce for the society via Internet is studied on the basis of the analysis of meteorological scientific data and the reference of the relevant technology development at home and abroad, according to the needs of the society and users. Some suggestions on storage and search strategy are given, including storage on line, storage in files associated with databases, as well as diversification, visualization and humanity in storage and search.
2007, 35(4):597-601.
Abstract:
A new technique of remote MICAPS data transmission based on automatic compression, transmission, decompression, and processing technology is presented according to the needs of the countylevel meteorological service and network development. It can be used in countylevel stations to share meteorological information with provincial or prefecturallevel bureaus. The technique can satisfy the needs of integrated application of meteorological data, and plays a significant role in avoiding equipment redundancy and reducing the maintenance cost of countylevel stations.
A new technique of remote MICAPS data transmission based on automatic compression, transmission, decompression, and processing technology is presented according to the needs of the countylevel meteorological service and network development. It can be used in countylevel stations to share meteorological information with provincial or prefecturallevel bureaus. The technique can satisfy the needs of integrated application of meteorological data, and plays a significant role in avoiding equipment redundancy and reducing the maintenance cost of countylevel stations.
32 Contrastive Analysis of Observation Data between Automatic Weather Station and Conventional Station
2007, 35(4):602-606.
Abstract:
The contrastive analysis is made based on the data from automatic weather stations (AWS) and conventional stations from January 2003 to December 2004 at Yanzhou Weather Station. All the essential meteorological elements are compared and analyzed, and the reasons for discrepancy are discussed. The result shows that though there is certain discrepancy in data from two observation approaches, the errors are within the permitted limits. The discrepancies in average ground minimum temperature, average ground maximum temperature, ground extreme minimum temperature, and ground extreme maximum temperature are relatively greater. The causes of the discrepancies (except for those resulted from the design and capability of the instruments), the changes of observation environment, and factors relevant to artificial operating and special weather phenomenon are also discussed. The findings are of significance to the application studies of automatic weather stations and the precision of AWS observation data.
The contrastive analysis is made based on the data from automatic weather stations (AWS) and conventional stations from January 2003 to December 2004 at Yanzhou Weather Station. All the essential meteorological elements are compared and analyzed, and the reasons for discrepancy are discussed. The result shows that though there is certain discrepancy in data from two observation approaches, the errors are within the permitted limits. The discrepancies in average ground minimum temperature, average ground maximum temperature, ground extreme minimum temperature, and ground extreme maximum temperature are relatively greater. The causes of the discrepancies (except for those resulted from the design and capability of the instruments), the changes of observation environment, and factors relevant to artificial operating and special weather phenomenon are also discussed. The findings are of significance to the application studies of automatic weather stations and the precision of AWS observation data.
2007, 35(4):607-609.
Abstract:
The typhoon message from the Comprehensive Operational System of Meteorological Satellite (9210 project) can be searched with C++ langue and transformed into the realtime typhoon position information stored in the database, which can be plotted at the same time automatically on the web by using the VML (Vector Markup Language) technique in order to create the realtime typhoon track map and the related information on the web. The technique has the characteristics of realtime, automatic and visualized in typhoon track display and can provide users with much more visual information about typhoon, etc. on the web. This technique has been successfully used in the Web page of the Quanzhou Meteorological Bureau.
The typhoon message from the Comprehensive Operational System of Meteorological Satellite (9210 project) can be searched with C++ langue and transformed into the realtime typhoon position information stored in the database, which can be plotted at the same time automatically on the web by using the VML (Vector Markup Language) technique in order to create the realtime typhoon track map and the related information on the web. The technique has the characteristics of realtime, automatic and visualized in typhoon track display and can provide users with much more visual information about typhoon, etc. on the web. This technique has been successfully used in the Web page of the Quanzhou Meteorological Bureau.
2007, 35(4):610-612.
Abstract:
Based on the government administrative network, the Nanping Meteorological Bureau established a videobased system of weather consultation. The system can cascade the weather consulting systems of different types (from the provincial center to various prefectures, and from the prefecturelevel center to various counties) to release in real time the consulting results to the countylevel weather bureaus. The system can also be used as a platform for weather information exchanging, video meeting and professional training for weather forecasters.
Based on the government administrative network, the Nanping Meteorological Bureau established a videobased system of weather consultation. The system can cascade the weather consulting systems of different types (from the provincial center to various prefectures, and from the prefecturelevel center to various counties) to release in real time the consulting results to the countylevel weather bureaus. The system can also be used as a platform for weather information exchanging, video meeting and professional training for weather forecasters.
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.