ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 25,Issue 2,1999 Table of Contents
1999, 25(2):3-9.
DOI: 10.7519/j.issn.1000-0526.1999.2.001
Abstract:
Using historical weather maps, typhoon year-books, and wind fields re-analyzed by ECMWF and NMC, the relations between the characters of some synoptic systems in summer, intertropical convergence zone (ITCZ) skipping northward and the interaction between typhoon and westerly though (TT) pattern are studied. The results are as follows. ① The Bohai sea high and the Japan sea high moving westward, quasi-permanent westerly though locating in the west of Hetao, and low-level southeasterly jet are beneficial to the interaction betwen typhoon and westerly though and the precipitation being caused by typhoon more than 400mm.② The ITCZ had skipped northward two times and reached to the most northern part of the whole year in July of three TT pattern years of "75.8","84.8", and "96.8". The first time of the ITCZ skipping northward was in the second pentad while the second time was in the forth or fifth pentad of July. The ITCZ had not skipped northward two times in other six non-TT pattern year.③ The southeast air current of the Australia cold high or the southeast air current of the southwest Pacific warms high affect the ITCZ of the northern hemisphere and skipping the northward. When the cross-equatorial southeast flow reaches to certain latitude of the northern hemisphere under a suitable circulation condition and then a sereis of cyclonic convergence zone will be generated due to the ITCZ northward skipping. The cross-equatorial flow not only causes the ITCZ northward skipping but can also convert the warm low of the ITCZ into typhoon.
Using historical weather maps, typhoon year-books, and wind fields re-analyzed by ECMWF and NMC, the relations between the characters of some synoptic systems in summer, intertropical convergence zone (ITCZ) skipping northward and the interaction between typhoon and westerly though (TT) pattern are studied. The results are as follows. ① The Bohai sea high and the Japan sea high moving westward, quasi-permanent westerly though locating in the west of Hetao, and low-level southeasterly jet are beneficial to the interaction betwen typhoon and westerly though and the precipitation being caused by typhoon more than 400mm.② The ITCZ had skipped northward two times and reached to the most northern part of the whole year in July of three TT pattern years of "75.8","84.8", and "96.8". The first time of the ITCZ skipping northward was in the second pentad while the second time was in the forth or fifth pentad of July. The ITCZ had not skipped northward two times in other six non-TT pattern year.③ The southeast air current of the Australia cold high or the southeast air current of the southwest Pacific warms high affect the ITCZ of the northern hemisphere and skipping the northward. When the cross-equatorial southeast flow reaches to certain latitude of the northern hemisphere under a suitable circulation condition and then a sereis of cyclonic convergence zone will be generated due to the ITCZ northward skipping. The cross-equatorial flow not only causes the ITCZ northward skipping but can also convert the warm low of the ITCZ into typhoon.
1999, 25(2):10-14.
DOI: 10.7519/j.issn.1000-0526.1999.2.002
Abstract:
Based on analysis of varied effect assessment methods, a method of estimating natural precipitation in areas affected by artificial precipitation was suggested. As a matter of fact, the method does not provide an assumption to the spatial and temporal distribution of the natural precipitation at the station, however, through analysis of the feature of natural precipitation during the operation, based on the given criterion, some camparable samples were made. The method can be applied to the assessment of artificial precipitation effect.
Based on analysis of varied effect assessment methods, a method of estimating natural precipitation in areas affected by artificial precipitation was suggested. As a matter of fact, the method does not provide an assumption to the spatial and temporal distribution of the natural precipitation at the station, however, through analysis of the feature of natural precipitation during the operation, based on the given criterion, some camparable samples were made. The method can be applied to the assessment of artificial precipitation effect.
1999, 25(2):15-18.
DOI: 10.7519/j.issn.1000-0526.1999.2.003
Abstract:
The processing and methods of quality control about the Global Maritime Climate Data Set are introduced.
The processing and methods of quality control about the Global Maritime Climate Data Set are introduced.
1999, 25(2):19-22.
DOI: 10.7519/j.issn.1000-0526.1999.02.004
Abstract:
A probability weight training method was used to analyze the prediction error ratio of some forecasting methods for the position of subtropical high ridge over the western Pacific Ocean both in history and real time. A best prediction method was set up with integrated method step by step. It showed that the error of the prediction of subtropical high ridge was reduced after integration compared with another forecasting method.
A probability weight training method was used to analyze the prediction error ratio of some forecasting methods for the position of subtropical high ridge over the western Pacific Ocean both in history and real time. A best prediction method was set up with integrated method step by step. It showed that the error of the prediction of subtropical high ridge was reduced after integration compared with another forecasting method.
1999, 25(2):22-27.
DOI: 10.7519/j.issn.1000-0526.1999.2.005
Abstract:
Cumulus precipitation days (R≥0.1mm) in Fuzhou, Fujian during summer and autumn drought seasons from 1985 to 1994, were classified to twelve weather patterns, and were simulated respectively by and 1-D time dependent dual-paremeter cumulonimbus cloud model. The precipitation forecast accuracy is more than 75 percent. By artificial seeding simulation, the physical character of cumulus precipitation during drought season in Fujian, the artificial seeding method, the seeding dose and seeding position were determined, Some significant results were achieved. Using NDP FORTRAN and BORLAND C++ program design the cumulus model systems were applied to the system of command of artificial precipitation enhancement.
Cumulus precipitation days (R≥0.1mm) in Fuzhou, Fujian during summer and autumn drought seasons from 1985 to 1994, were classified to twelve weather patterns, and were simulated respectively by and 1-D time dependent dual-paremeter cumulonimbus cloud model. The precipitation forecast accuracy is more than 75 percent. By artificial seeding simulation, the physical character of cumulus precipitation during drought season in Fujian, the artificial seeding method, the seeding dose and seeding position were determined, Some significant results were achieved. Using NDP FORTRAN and BORLAND C++ program design the cumulus model systems were applied to the system of command of artificial precipitation enhancement.
1999, 25(2):28-32.
DOI: 10.7519/j.issn.1000-0526.1999.02.006
Abstract:
The chemical composition of remains in AgI operator was analysed. The sticking rule of remains and the cause of remain formation were studied. The countermeasure to reduce remains was suggested.
The chemical composition of remains in AgI operator was analysed. The sticking rule of remains and the cause of remain formation were studied. The countermeasure to reduce remains was suggested.
1999, 25(2):33-39.
DOI: 10.7519/j.issn.1000-0526.1999.2.007
Abstract:
Using similarity principle and Chebashev Polynomial, the altitude field for three layers at high altitude in the earlier stage of rainstorm was expanded and the field-similarity characteristics of altitude field came into prominence.The Q vector divergence, water vapour flux and flux divergence, potential unstability and other physical quantities closely related to rainstorm were analysed. Also, by futher approximating the main characteristics in field distribution, the optimum analogue forecast and analogue analasis forcast were given.
Using similarity principle and Chebashev Polynomial, the altitude field for three layers at high altitude in the earlier stage of rainstorm was expanded and the field-similarity characteristics of altitude field came into prominence.The Q vector divergence, water vapour flux and flux divergence, potential unstability and other physical quantities closely related to rainstorm were analysed. Also, by futher approximating the main characteristics in field distribution, the optimum analogue forecast and analogue analasis forcast were given.
1999, 25(2):40-44.
DOI: 10.7519/j.issn.1000-0526.1999.2.008
Abstract:
The analysis results show that the continuous rainstorm circulation eigenvalue beyond hstorical record in June 1998. The heavy folld disaster in the north of Fujina is a component part of heavy flood disaster in the Yangtze River basin and the southern area of the Yangtze River, that usually occur in the same year. The example of successful prediction of a rainstorm in JUne 1998 offers forecast for a heavy flood disaster caused by heavy rainstorm.
The analysis results show that the continuous rainstorm circulation eigenvalue beyond hstorical record in June 1998. The heavy folld disaster in the north of Fujina is a component part of heavy flood disaster in the Yangtze River basin and the southern area of the Yangtze River, that usually occur in the same year. The example of successful prediction of a rainstorm in JUne 1998 offers forecast for a heavy flood disaster caused by heavy rainstorm.
1999, 25(2):44-48.
DOI: 10.7519/j.issn.1000-0526.1999.2.009
Abstract:
A statistical resultant analysis of the shear line heavy rain in the middle west Inner Mongolia from July to August between 1994 and 1995 was presented. The synoptic characteristics and physics elements field features during the shear line heavy rain were discussed. These revealed the genetic and developing mechanism of the heavy rain. Results are referential to routine operational prediction.
A statistical resultant analysis of the shear line heavy rain in the middle west Inner Mongolia from July to August between 1994 and 1995 was presented. The synoptic characteristics and physics elements field features during the shear line heavy rain were discussed. These revealed the genetic and developing mechanism of the heavy rain. Results are referential to routine operational prediction.
1999, 25(2):48-52.
DOI: 10.7519/j.issn.1000-0526.1999.2.010
Abstract:
The climatic characteristics of snow, glaze and rime in Huangshan mountain were analysed with the meteorological data obtained from 1956 to 1996. The results show that: a) the days of snow, glaze and rime in a year are characterized by a time varying feature of multi wave fluctuation, and their interannual change is periodical and there is a 12 years quasi period of low frequency fluctuation;b) It is possible that snow, snow cover, glaze and rime generate in the period from October to next May, most the days of snow, glaze and rime are in Winter, the days in March are less than in the months of winter, and the days of glaze in March are more than that in December; c) the first day of snow is on 17 September and the end day is on 26 May, the first days of glaze and rime are in October and the end days are in the first or second dekad of May; d) the daily maximum snow is 30mm in the second dekad of March, the maximum weight of snow cover on wire is 12.148kg; e) the air temperature during glaze is -0.45~0.8℃, more than that during rime and glaze/rime. The generating frequence of snow, glaze and rime in wind direction distribution is not obviousely different, and the frequence of glaze and rime in NW wind direction is the most.
The climatic characteristics of snow, glaze and rime in Huangshan mountain were analysed with the meteorological data obtained from 1956 to 1996. The results show that: a) the days of snow, glaze and rime in a year are characterized by a time varying feature of multi wave fluctuation, and their interannual change is periodical and there is a 12 years quasi period of low frequency fluctuation;b) It is possible that snow, snow cover, glaze and rime generate in the period from October to next May, most the days of snow, glaze and rime are in Winter, the days in March are less than in the months of winter, and the days of glaze in March are more than that in December; c) the first day of snow is on 17 September and the end day is on 26 May, the first days of glaze and rime are in October and the end days are in the first or second dekad of May; d) the daily maximum snow is 30mm in the second dekad of March, the maximum weight of snow cover on wire is 12.148kg; e) the air temperature during glaze is -0.45~0.8℃, more than that during rime and glaze/rime. The generating frequence of snow, glaze and rime in wind direction distribution is not obviousely different, and the frequence of glaze and rime in NW wind direction is the most.
1999, 25(2):53-55.
DOI: 10.7519/j.issn.1000-0526.1999.2.011
Abstract:
Using the data of the Huanan coastal area under the condition of fog in February, March and April during the period of 1978～1995, the variable rules of fog were analysed. The weather systems, circulation background and forecast indicators were given.
Using the data of the Huanan coastal area under the condition of fog in February, March and April during the period of 1978～1995, the variable rules of fog were analysed. The weather systems, circulation background and forecast indicators were given.
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ISSN:1000-0526 CN:11-2282/P