ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 25,Issue 8,1999 Table of Contents
1999, 25(8):3-5.
DOI: 10.7519/j.issn.1000-0526.1999.8.001
Abstract:
1998 saw the record for the highest annual global temperature since the late nineteenth century.The temperature exceeded the previous,which was established in 1997,and marks the fourth time the record has been broken in the 1990s.The 1998 temperature is the highest on record in many countries.The 1998 was also the warmest year since 1880 in China.Substantial evidence shows that there is a stronger upward trend (of 0.50℃/100 years) than ever estimated for the annual temperature of China during the last hundred years.Enhanced warming trend has occurred in most part of East Asia,the remarkable trend is making the middlehigh continent of East Asia and the rapidest warming region in the world during the last 2 decades as well.
1998 saw the record for the highest annual global temperature since the late nineteenth century.The temperature exceeded the previous,which was established in 1997,and marks the fourth time the record has been broken in the 1990s.The 1998 temperature is the highest on record in many countries.The 1998 was also the warmest year since 1880 in China.Substantial evidence shows that there is a stronger upward trend (of 0.50℃/100 years) than ever estimated for the annual temperature of China during the last hundred years.Enhanced warming trend has occurred in most part of East Asia,the remarkable trend is making the middlehigh continent of East Asia and the rapidest warming region in the world during the last 2 decades as well.
1999, 25(8):6-10.
DOI: 10.7519/j.issn.1000-0526.1999.8.002
Abstract:
The quasigeostrophic Q-vector method was applied to diagnose the southward movement of Kunming Quasistationary Front(KQF) in association with a cold wave in Yunnan province in February 1995.The results show that the convergence of geostrophic wind in east Yunnan at 850hPa is an important factor responsible for the frontogenesis of KQF.When the value of geostrophic frontogenesis function increases greatly at 700hPa,KQF will move southward.Furthermore,it is found that frontal rain area is correlated well to the position of the Q-convergence at the lower level.
The quasigeostrophic Q-vector method was applied to diagnose the southward movement of Kunming Quasistationary Front(KQF) in association with a cold wave in Yunnan province in February 1995.The results show that the convergence of geostrophic wind in east Yunnan at 850hPa is an important factor responsible for the frontogenesis of KQF.When the value of geostrophic frontogenesis function increases greatly at 700hPa,KQF will move southward.Furthermore,it is found that frontal rain area is correlated well to the position of the Q-convergence at the lower level.
1999, 25(8):11-15.
DOI: 10.7519/j.issn.1000-0526.1999.8.003
Abstract:
The variation tendency of river runoff,precipitation and temperature over drainage areas of the major rivers in Qinghai province was analysed by using nearly 38 years observative data.The Influence of dry climate on the surface water resource in Qinghai was mainly discussed.The results show that the inland rivers are mainly supplied by mountain snowmelt and precipitation,and the outflow rivers are mainly supplied by precipitation.The surface water resource in Qinghai tends to decrease and the tendency is more obvious after the 1990s.The temperature and precipitation are primary influent factors on the surface water resource of Qinghai province.Temperature increasing causes evaporation enhancement,drought aggravation and surface runoff reduction.Precipition decrease after the 1990s,especially during flood season,and it leads to a direct reduction of surface runoff.
The variation tendency of river runoff,precipitation and temperature over drainage areas of the major rivers in Qinghai province was analysed by using nearly 38 years observative data.The Influence of dry climate on the surface water resource in Qinghai was mainly discussed.The results show that the inland rivers are mainly supplied by mountain snowmelt and precipitation,and the outflow rivers are mainly supplied by precipitation.The surface water resource in Qinghai tends to decrease and the tendency is more obvious after the 1990s.The temperature and precipitation are primary influent factors on the surface water resource of Qinghai province.Temperature increasing causes evaporation enhancement,drought aggravation and surface runoff reduction.Precipition decrease after the 1990s,especially during flood season,and it leads to a direct reduction of surface runoff.
1999, 25(8):16-21.
DOI: 10.7519/j.issn.1000-0526.1999.8.004
Abstract:
Statistical analysis and double ratio analysis between the radar echo and the rainfall parameters of single cumulus were conducted by use of the 8 years (1979～1986) randomized experiment data of 28 seeded clouds and 20 controlled clouds observed in Hunan province.The results show that the total precipitation,rainfall amount,rainfall intensity and rainfall duration of the seeded clouds increase by a factor of 17%,28%,24% and 7% than those of the controlled clouds respectively.It is not obvious that antiaircraft gun seeding affects on the cloud top height and the cumulus area as well,but it is obvious that the seeding perhaps increases the radar echo strength of cumulus and decreases the echo depth of the strong core in the randomized experiment.
Statistical analysis and double ratio analysis between the radar echo and the rainfall parameters of single cumulus were conducted by use of the 8 years (1979～1986) randomized experiment data of 28 seeded clouds and 20 controlled clouds observed in Hunan province.The results show that the total precipitation,rainfall amount,rainfall intensity and rainfall duration of the seeded clouds increase by a factor of 17%,28%,24% and 7% than those of the controlled clouds respectively.It is not obvious that antiaircraft gun seeding affects on the cloud top height and the cumulus area as well,but it is obvious that the seeding perhaps increases the radar echo strength of cumulus and decreases the echo depth of the strong core in the randomized experiment.
1999, 25(8):22-25.
DOI: 10.7519/j.issn.1000-0526.1999.8.005
Abstract:
The cloud motion wind vectors provided by the National Satellite Meteorological Center are applied to the numerical weather prediction system of typhoon tracks at the National Meteorological Center.Numerical experiments of the prediction of typhoon tracks are done for initially inquiring into the method of using cloud motion wind vectors in improving typhoon model. The experiments consist of two forecast trials. The first one is to take cloud motion wind vectors as observation data to do optimum interpolation objective analysis. Based on the first test, the second one is to put cloud motion wind into the axisymmetric vortex wind field to form asymmetric wind field of bogus vortex.The result indicates that the first one can distinctly reduce the prediction errors of typhoon tracks and the second one can further improve the prediction precision.
The cloud motion wind vectors provided by the National Satellite Meteorological Center are applied to the numerical weather prediction system of typhoon tracks at the National Meteorological Center.Numerical experiments of the prediction of typhoon tracks are done for initially inquiring into the method of using cloud motion wind vectors in improving typhoon model. The experiments consist of two forecast trials. The first one is to take cloud motion wind vectors as observation data to do optimum interpolation objective analysis. Based on the first test, the second one is to put cloud motion wind into the axisymmetric vortex wind field to form asymmetric wind field of bogus vortex.The result indicates that the first one can distinctly reduce the prediction errors of typhoon tracks and the second one can further improve the prediction precision.
1999, 25(8):26-30.
DOI: 10.7519/j.issn.1000-0526.1999.08.006
Abstract:
The forecast of rainstorm fall area was done by the rainstorm station number prediction combined with the rainfall forecast of one station.The TS grade of a operational forecast for rainstorm fall area from July to August of 1998 was up to 224%,and more than both HLAFS and subjective forecast.Further,the analysis results show that the method is an effective forecast for rainstorm fall area,and makes the best use of the spatial distribution of rainfall forecast.
The forecast of rainstorm fall area was done by the rainstorm station number prediction combined with the rainfall forecast of one station.The TS grade of a operational forecast for rainstorm fall area from July to August of 1998 was up to 224%,and more than both HLAFS and subjective forecast.Further,the analysis results show that the method is an effective forecast for rainstorm fall area,and makes the best use of the spatial distribution of rainfall forecast.
1999, 25(8):31-33.
DOI: 10.7519/j.issn.1000-0526.1999.08.007
Abstract:
Flood and waterlogging are main calamities during flood season in Lixiahe area of Jiangsu province.The calamity occurrence is closely related to the water level before precipitation.The relationship between rainfall amount and water level was determined on the basis of the special river system and topography in Lixiahe area.The forecast value of the highest water level was given according to the rainfall forecast.The essential measures can be taken in advance in term of the forecast result and therefor the flood and waterlogging damage could be reduced.
Flood and waterlogging are main calamities during flood season in Lixiahe area of Jiangsu province.The calamity occurrence is closely related to the water level before precipitation.The relationship between rainfall amount and water level was determined on the basis of the special river system and topography in Lixiahe area.The forecast value of the highest water level was given according to the rainfall forecast.The essential measures can be taken in advance in term of the forecast result and therefor the flood and waterlogging damage could be reduced.
1999, 25(8):34-36.
DOI: 10.7519/j.issn.1000-0526.1999.08.008
Abstract:
The transmitter is one of important upper-air sounding instruments.A volume tube as a key element of the transmitter has been used for a long period,it has become a reality that the volume tube is replaced by a transistor in the transmitter.The transistor transmitter Type GPZ5-3 has been used in all upper-air sounding stations since the beginning of 1997.The information of this instrument including its principle,specifications test and the right operation was described.
The transmitter is one of important upper-air sounding instruments.A volume tube as a key element of the transmitter has been used for a long period,it has become a reality that the volume tube is replaced by a transistor in the transmitter.The transistor transmitter Type GPZ5-3 has been used in all upper-air sounding stations since the beginning of 1997.The information of this instrument including its principle,specifications test and the right operation was described.
9 The Short-range Weather Forecast for Heavy Snow in Chuanxi Plateau by BP Artificial Neural Network
1999, 25(8):37-39.
DOI: 10.7519/j.issn.1000-0526.1999.08.009
Abstract:
The weather forecast system for heavy snow over Chuanxi Plateau in Sichuan province was developed by using the historical weather records of heavy snow on Aba grass land and combining an elementary model with BP artificial neural network.The system is automated to collect the interrelated factors and output the conclusion by using the data information from the Project 9210.Then new factors were automatically added to the data base, and the forecast accruacy for heavy snow of the forecast system was improved.
The weather forecast system for heavy snow over Chuanxi Plateau in Sichuan province was developed by using the historical weather records of heavy snow on Aba grass land and combining an elementary model with BP artificial neural network.The system is automated to collect the interrelated factors and output the conclusion by using the data information from the Project 9210.Then new factors were automatically added to the data base, and the forecast accruacy for heavy snow of the forecast system was improved.
1999, 25(8):40-43.
DOI: 10.7519/j.issn.1000-0526.1999.8.010
Abstract:
The statistical analysis of the radar-713 observation data was conducted.The climatic features of the radar echoes of severe and convective weather from April to August in Shandong province were revealed:spatial and time distribution,occurring location,moving track and parameter characteristic.The result is useful to the shorttime forecast for severe and convective weather.
The statistical analysis of the radar-713 observation data was conducted.The climatic features of the radar echoes of severe and convective weather from April to August in Shandong province were revealed:spatial and time distribution,occurring location,moving track and parameter characteristic.The result is useful to the shorttime forecast for severe and convective weather.
1999, 25(8):44-46.
DOI: 10.7519/j.issn.1000-0526.1999.8.011
Abstract:
On the basis of analysis of the satellite cloud picture,combined with routine meteorological information and the product of T106 mathematical forecast,the mechanic of a local torrential rain in Beijing on 23 July,1998 and the character of mesoscale structure about IR cloud atlas were analyzed.It is shown that the advantageous conditions are favorable to the birth and development of the mesoscale system including the favorable synoptic condition,the water vapor convergence and high instability energy.
On the basis of analysis of the satellite cloud picture,combined with routine meteorological information and the product of T106 mathematical forecast,the mechanic of a local torrential rain in Beijing on 23 July,1998 and the character of mesoscale structure about IR cloud atlas were analyzed.It is shown that the advantageous conditions are favorable to the birth and development of the mesoscale system including the favorable synoptic condition,the water vapor convergence and high instability energy.
1999, 25(8):47-50.
DOI: 10.7519/j.issn.1000-0526.1999.08.012
Abstract:
The characteristic of lightning data and radar echo of the heavy torrential rain happened in southwest of Hebei during August 3—5 in 1996 was analyzed by the lighting data,713 radar echo and nonconventional observational data every hour.The results show that the rainfall process is a mixed rainfall,and the number of cloudtoground lightning,lightning intensity,and the intensity of radar echo have a instructive meaning on rainfall intensity,rainfall distribution and the development of the mesoscale convective system.
The characteristic of lightning data and radar echo of the heavy torrential rain happened in southwest of Hebei during August 3—5 in 1996 was analyzed by the lighting data,713 radar echo and nonconventional observational data every hour.The results show that the rainfall process is a mixed rainfall,and the number of cloudtoground lightning,lightning intensity,and the intensity of radar echo have a instructive meaning on rainfall intensity,rainfall distribution and the development of the mesoscale convective system.
1999, 25(8):51-54.
DOI: 10.7519/j.issn.1000-0526.1999.08.013
Abstract:
Based on the T63 model data,the torrential rainfall over Hebei province during August 1996 (‘96.8’event) was analysed by filtering low layer stream field.The results are as follows:within the east-north quadrant of Typhoon 9608 low,there was a convergence line whose moving trend was northeast to southwest.It resulted from the interaction of the typhoon low air pressure and the cold air in the westerly wind bnad,while the former was moving northward.Its life period extremely coincided with the heavy rain's,so it was one of the meso-scale synthetic system that caused ‘96.8’event.The convergence line had some features of an easterly wave,and extreme rainfall zone appeared at the east-south side of the convergence line.
Based on the T63 model data,the torrential rainfall over Hebei province during August 1996 (‘96.8’event) was analysed by filtering low layer stream field.The results are as follows:within the east-north quadrant of Typhoon 9608 low,there was a convergence line whose moving trend was northeast to southwest.It resulted from the interaction of the typhoon low air pressure and the cold air in the westerly wind bnad,while the former was moving northward.Its life period extremely coincided with the heavy rain's,so it was one of the meso-scale synthetic system that caused ‘96.8’event.The convergence line had some features of an easterly wave,and extreme rainfall zone appeared at the east-south side of the convergence line.
1999, 25(8):55-57.
DOI: 10.7519/j.issn.1000-0526.1999.8.014
Abstract:
The precipitation amount comparing to water requirement of crops can be used to assesse the agricultural drought.Ratio of irrigated and tillable field area is used to evaluate the drought resistant abilities of regional farming.Both of them are combined with the NOAA/AVHRR data in ordar to estimate the summer-drought damage to agriculture in Hebei provincial.It gave well results during the application in 1997 and 1998.
The precipitation amount comparing to water requirement of crops can be used to assesse the agricultural drought.Ratio of irrigated and tillable field area is used to evaluate the drought resistant abilities of regional farming.Both of them are combined with the NOAA/AVHRR data in ordar to estimate the summer-drought damage to agriculture in Hebei provincial.It gave well results during the application in 1997 and 1998.
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ISSN:1000-0526 CN:11-2282/P