ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 31,Issue 5,2005 Table of Contents
2005, 31(5):3-7.
DOI: 10.7519/j.issn.1000-0526.2005.5.001
Abstract:
On the basis of the review of Asian monsoon indices' defined method, East Asian monsoon intensity and area indices are classified into five classes, such as circulation class, humid-thermal class, land-sea contrast class, equation class and synthesis class. Meanwhile, the difference of varied kinds of monsoon indices is emphasized. Furthermore, some outlooks of this field are put forward.
On the basis of the review of Asian monsoon indices' defined method, East Asian monsoon intensity and area indices are classified into five classes, such as circulation class, humid-thermal class, land-sea contrast class, equation class and synthesis class. Meanwhile, the difference of varied kinds of monsoon indices is emphasized. Furthermore, some outlooks of this field are put forward.
2005, 31(5):8-11.
DOI: 10.7519/j.issn.1000-0526.2005.5.002
Abstract:
Based on the meteorological data in 1954—2002,the trend of sandstorm variation and its space characteristics in China in recent 49 years are analyzed and discussed. And on gale variation's side, the climatic causes of sandstorm variation are discussed tentatively. The results show that all annual and seasonal sandstorms are decreasing in China in the recent 49 years. There is a 73% reduction in sandstorm frequency from 1950s and 1960s to 1980s and 1990s. The decrease trends of sandstorm frequency display obvious space consistency for most part of China. In comparison, the change of sandstorm frequency is close accord with that of gale frequency, their correlation coefficient is 0.92.The result indicates that the sandstorm change in China mainly depends upon gale change, which is mostly responsible for the decrease of sandstorm frequency in China in recent 49 years. Similarly, the increase of sandstorm frequency after 1997 is also attributed to gale weather.
Based on the meteorological data in 1954—2002,the trend of sandstorm variation and its space characteristics in China in recent 49 years are analyzed and discussed. And on gale variation's side, the climatic causes of sandstorm variation are discussed tentatively. The results show that all annual and seasonal sandstorms are decreasing in China in the recent 49 years. There is a 73% reduction in sandstorm frequency from 1950s and 1960s to 1980s and 1990s. The decrease trends of sandstorm frequency display obvious space consistency for most part of China. In comparison, the change of sandstorm frequency is close accord with that of gale frequency, their correlation coefficient is 0.92.The result indicates that the sandstorm change in China mainly depends upon gale change, which is mostly responsible for the decrease of sandstorm frequency in China in recent 49 years. Similarly, the increase of sandstorm frequency after 1997 is also attributed to gale weather.
2005, 31(5):12-16.
DOI: 10.7519/j.issn.1000-0526.2005.5.003
Abstract:
With the winter temperature data of Xinjiang during 1959—1998, the features of winter temperature change for the recant 40 Years in Tianshan Mountain are analyzed and compared with those in the Southern and Northern Xinjiang and the main conclusions are as follows: (1) The similarity of warm-cold stage of winter mean temperature between Tianshan Mountain and the Northern Xinjiang is greater than that between Tianshan Mountain area and the Southern Xinjiang. (2) The synchronous variability of spatial distribution of winter mean temperature is best in the Northern Xinjiang, and better in Southern Xinjiang and Tianshan Mountainous area. The reversed variability of spatial distribution of winter mean temperature is best in Tianshan Mountainous area and the Southern Xinjiang, better in Northern Xinjiang. (3) The change trends of winter mean temperature are different for three large regions during 1960s—1970s, but they all show continual warming from 1970s to 1990s, it is the warmest in the 1990s. (4) As to the extension of spatial distribution of the significant linear warming for the recent 40 years, the minimum temperature show the largest spatial extension, mean temperature larger and maximum temperature small. The warming rate of winter minimum temperature is the greatest for Northern Xinjiang, greater for Southern Xinjiang and the least for Tianshan Mountainous area. There are similar optimal periods of winter mean temperature, 27 and 29 years for Southern and Northern Xinjiang respectively. And the warming rate for Northern Xinjiang is greater than that for Southern Xinjiang. (5) A abrupt change of winter mean temperature, from low to high, occurred for Northern and Southern Xinjiang in 1979.
With the winter temperature data of Xinjiang during 1959—1998, the features of winter temperature change for the recant 40 Years in Tianshan Mountain are analyzed and compared with those in the Southern and Northern Xinjiang and the main conclusions are as follows: (1) The similarity of warm-cold stage of winter mean temperature between Tianshan Mountain and the Northern Xinjiang is greater than that between Tianshan Mountain area and the Southern Xinjiang. (2) The synchronous variability of spatial distribution of winter mean temperature is best in the Northern Xinjiang, and better in Southern Xinjiang and Tianshan Mountainous area. The reversed variability of spatial distribution of winter mean temperature is best in Tianshan Mountainous area and the Southern Xinjiang, better in Northern Xinjiang. (3) The change trends of winter mean temperature are different for three large regions during 1960s—1970s, but they all show continual warming from 1970s to 1990s, it is the warmest in the 1990s. (4) As to the extension of spatial distribution of the significant linear warming for the recent 40 years, the minimum temperature show the largest spatial extension, mean temperature larger and maximum temperature small. The warming rate of winter minimum temperature is the greatest for Northern Xinjiang, greater for Southern Xinjiang and the least for Tianshan Mountainous area. There are similar optimal periods of winter mean temperature, 27 and 29 years for Southern and Northern Xinjiang respectively. And the warming rate for Northern Xinjiang is greater than that for Southern Xinjiang. (5) A abrupt change of winter mean temperature, from low to high, occurred for Northern and Southern Xinjiang in 1979.
2005, 31(5):17-20.
DOI: 10.7519/j.issn.1000-0526.2005.5.004
Abstract:
Hail cloud recognition is a pattern recognition problem of multi-parameter. The recognition result of hail cloud based on single parameter is always non-compatible. The basic thinking of matter elements and extension set is used for changing the non-compatible problem into compatible problem. The comparison study results show that the accuracy of hail cloud recognition by this method is over 86%.
Hail cloud recognition is a pattern recognition problem of multi-parameter. The recognition result of hail cloud based on single parameter is always non-compatible. The basic thinking of matter elements and extension set is used for changing the non-compatible problem into compatible problem. The comparison study results show that the accuracy of hail cloud recognition by this method is over 86%.
2005, 31(5):21-25.
DOI: 10.7519/j.issn.1000-0526.2005.5.005
Abstract:
Based on the data of the regenerated grass and meteorology at Henan and Ganda, Qinghai Province from 1994 to 2001, the impact of the climatic conditions on the graze regeneration is analyzed. A climatic model of the regenerated grass yield is developed.
Based on the data of the regenerated grass and meteorology at Henan and Ganda, Qinghai Province from 1994 to 2001, the impact of the climatic conditions on the graze regeneration is analyzed. A climatic model of the regenerated grass yield is developed.
2005, 31(5):26-31.
DOI: 10.7519/j.issn.1000-0526.2005.5.006
Abstract:
Based on analysis data of EC numerical model, real-time observation and statistical calamitous data, a synoptic analysis of the weather and the circulation situation in 2004 is made. The result shows that the continuous drought happened in North China, Northeast China and South China is closely related to the abnormal of the synoptic circulation. The interaction of the synoptic system under the favorable situation resulted in the calamitous weather such as heavy rain, thunderstorm and sandstorm etc. Having a good understanding of the synoptic situation and evolution character of the affecting weather system is very important to improve forecast accuracy of the calamitous weather and the disaster prevention.
Based on analysis data of EC numerical model, real-time observation and statistical calamitous data, a synoptic analysis of the weather and the circulation situation in 2004 is made. The result shows that the continuous drought happened in North China, Northeast China and South China is closely related to the abnormal of the synoptic circulation. The interaction of the synoptic system under the favorable situation resulted in the calamitous weather such as heavy rain, thunderstorm and sandstorm etc. Having a good understanding of the synoptic situation and evolution character of the affecting weather system is very important to improve forecast accuracy of the calamitous weather and the disaster prevention.
2005, 31(5):32-36.
DOI: 10.7519/j.issn.1000-0526.2005.5.007
Abstract:
By the use of typhoon annual report, best track of JMA, T213 analysis field, satellite image and aerological observation data, the cause of maintenance of Typhoon Rananim (0414) on land is analyzed from diagnostic analyses of synoptic and dynamic conditions. The results show that the water vapour transportation at low layer and the eastern jet and solenoid field generated by the interaction between middle-latitude synoptic system and Rananim are two main reasons of its maintenance on land. Meanwhile its location being under the outflow at the southeast or south direction of intensive divergent field at high layer as well as at low vertical shear regions during its maintenance on land are also two important conditions.
By the use of typhoon annual report, best track of JMA, T213 analysis field, satellite image and aerological observation data, the cause of maintenance of Typhoon Rananim (0414) on land is analyzed from diagnostic analyses of synoptic and dynamic conditions. The results show that the water vapour transportation at low layer and the eastern jet and solenoid field generated by the interaction between middle-latitude synoptic system and Rananim are two main reasons of its maintenance on land. Meanwhile its location being under the outflow at the southeast or south direction of intensive divergent field at high layer as well as at low vertical shear regions during its maintenance on land are also two important conditions.
2005, 31(5):37-41.
DOI: 10.7519/j.issn.1000-0526.2005.5.008
Abstract:
A persistent heavy rainfall event struck the northeast part of Sichuan and Chongqing during 2—6 September 2004. The meteorological reason and the relationship between heavy rains and the vortex in the lower-reaches of the Jialing River are analyzed. It is shown that in the east part of the Sichuan Basin, the convergence of the easterly propagating trough from the Tibetan Plateau and warm moisture from the Bengal Bay by Lower Frequency Oscillation (LFO) of the South Asian summer monsoon provides stable large-scale background and fluent moisture for the persistent heavy rains, that strongly development of meso-scale convective systems (MCSs) initiating the rainstorms and the MCSs combining into meso-α-scale vortex provides persistent lifting and available meso-scale background for lasting heavy rains, that warm advection in the lower troposphere and positive vorticity advection in the middle troposphere take advantage of the vortex development.
A persistent heavy rainfall event struck the northeast part of Sichuan and Chongqing during 2—6 September 2004. The meteorological reason and the relationship between heavy rains and the vortex in the lower-reaches of the Jialing River are analyzed. It is shown that in the east part of the Sichuan Basin, the convergence of the easterly propagating trough from the Tibetan Plateau and warm moisture from the Bengal Bay by Lower Frequency Oscillation (LFO) of the South Asian summer monsoon provides stable large-scale background and fluent moisture for the persistent heavy rains, that strongly development of meso-scale convective systems (MCSs) initiating the rainstorms and the MCSs combining into meso-α-scale vortex provides persistent lifting and available meso-scale background for lasting heavy rains, that warm advection in the lower troposphere and positive vorticity advection in the middle troposphere take advantage of the vortex development.
2005, 31(5):42-46.
DOI: 10.7519/j.issn.1000-0526.2005.5.009
Abstract:
A dynamical and mesoscale analysis of a heavy rainfall event on 10 July 2004 in Beijing is made with the routine and densified observation, NCEP data and radar images. It's found that the heavy rainfall occurred under the favorable environmental conditions. Three rain clusters that brought heavy rainfall have the features of meso-β system and the convective echoes are the direct producer. The mesoscale convergence line and the mesoscale low provided favorable triggering effect for the occurrence of the heavy rainfall.
A dynamical and mesoscale analysis of a heavy rainfall event on 10 July 2004 in Beijing is made with the routine and densified observation, NCEP data and radar images. It's found that the heavy rainfall occurred under the favorable environmental conditions. Three rain clusters that brought heavy rainfall have the features of meso-β system and the convective echoes are the direct producer. The mesoscale convergence line and the mesoscale low provided favorable triggering effect for the occurrence of the heavy rainfall.
2005, 31(5):47-51.
DOI: 10.7519/j.issn.1000-0526.2005.5.010
Abstract:
A squall line weather process occurred in Shanghai on July 12 2004 is diagnosed with various kinds of observational data, such as the automatic meteorological station data, satellite water vapor image and Doppler radar echo, and NCEP reanalysis data of 1°×1°with 6h interval. The results show that Shanghai is located in an unstable stratification and the dry and cold intrusion down from the upper troposphere and the strong convergence of the moist and warm air in the boundary layer are the trigger mechanisms. The radar echo shows that the squall line is shaped by the joint type of line of discontinuity and line of rearward continuity. The bow echo belt causing thunderstorm and gust in Shanghai is the connection of the convective cells and the new ones appearing on the right of them.
A squall line weather process occurred in Shanghai on July 12 2004 is diagnosed with various kinds of observational data, such as the automatic meteorological station data, satellite water vapor image and Doppler radar echo, and NCEP reanalysis data of 1°×1°with 6h interval. The results show that Shanghai is located in an unstable stratification and the dry and cold intrusion down from the upper troposphere and the strong convergence of the moist and warm air in the boundary layer are the trigger mechanisms. The radar echo shows that the squall line is shaped by the joint type of line of discontinuity and line of rearward continuity. The bow echo belt causing thunderstorm and gust in Shanghai is the connection of the convective cells and the new ones appearing on the right of them.
2005, 31(5):52-54.
DOI: 10.7519/j.issn.1000-0526.2005.5.011
Abstract:
The method of superensemble is used to give the precipitation prediction during the flood season in order to get a better combined result. Weights are calculated with a linear reflected technique and least-squares minimization of the difference between forecasts and observations. The tests show that the ensemble precipitation prediction has a higher skill than single prediction.
The method of superensemble is used to give the precipitation prediction during the flood season in order to get a better combined result. Weights are calculated with a linear reflected technique and least-squares minimization of the difference between forecasts and observations. The tests show that the ensemble precipitation prediction has a higher skill than single prediction.
2005, 31(5):55-58.
DOI: 10.7519/j.issn.1000-0526.2005.5.012
Abstract:
Using hail data at observational stations and in region (including observation stations and nonobservation place) in Shandong Province from 1960 to 2001, the hail climate characteristic of the two data sets is contrasted. The analysis results show that regional hail is obviously more than the hail on the observational stations, but the temporal and special distribution trend is basically consistent and the similar degree is over 86%. The representations of the climate characteristic expressed in the climate chart made with the hail data at observational stations is about 86%.
Using hail data at observational stations and in region (including observation stations and nonobservation place) in Shandong Province from 1960 to 2001, the hail climate characteristic of the two data sets is contrasted. The analysis results show that regional hail is obviously more than the hail on the observational stations, but the temporal and special distribution trend is basically consistent and the similar degree is over 86%. The representations of the climate characteristic expressed in the climate chart made with the hail data at observational stations is about 86%.
2005, 31(5):59-61.
DOI: 10.7519/j.issn.1000-0526.2005.5.013
Abstract:
The relationship between the summer precipitation in Emei Mountain and the physical factors, such as ENSO, the West Pacific subtropical high and the East Asia blocking high and so on, is analyzed. The results show that there are obvious correlations between the summer precipitation in Emei Mountain and the physical factors, and the short-range climate prediction models of precipitation in Emei Mountain during summer are established.
The relationship between the summer precipitation in Emei Mountain and the physical factors, such as ENSO, the West Pacific subtropical high and the East Asia blocking high and so on, is analyzed. The results show that there are obvious correlations between the summer precipitation in Emei Mountain and the physical factors, and the short-range climate prediction models of precipitation in Emei Mountain during summer are established.
2005, 31(5):62-65.
DOI: 10.7519/j.issn.1000-0526.2005.05.014
Abstract:
The problem of no match on time scale between single-time factors and predictor in objective forecast is analyzed, and the necessity and the possibility of using multi-time factors are put forward. Contrast experiment shows that multi-time factors can improve the quality of prediction equations and make effective rate reach 90.0 percents and reduce sum of residual squares 23.8 percents meanly. The reduction appears some regularity in spite of it's variation in various situation. It is also indicated that it is not benefit to contain more time number in multi-time factors in order to avoid “dimension disaster”.
The problem of no match on time scale between single-time factors and predictor in objective forecast is analyzed, and the necessity and the possibility of using multi-time factors are put forward. Contrast experiment shows that multi-time factors can improve the quality of prediction equations and make effective rate reach 90.0 percents and reduce sum of residual squares 23.8 percents meanly. The reduction appears some regularity in spite of it's variation in various situation. It is also indicated that it is not benefit to contain more time number in multi-time factors in order to avoid “dimension disaster”.
2005, 31(5):66-69.
DOI: 10.7519/j.issn.1000-0526.2005.5.015
Abstract:
The analysis of regional heavy rain over Qingdao, Shandong Province during 1961—2002 is made.The results show that the south vortex( 25—35°N,100—110°E ),the north vortex (35—40°N,92—105°E )and the shear vortex are the main synoptic systems of regional heavy rain over Qingdao area. The difference of the route and position of vortex will cause the difference of heavy rain area.
The analysis of regional heavy rain over Qingdao, Shandong Province during 1961—2002 is made.The results show that the south vortex( 25—35°N,100—110°E ),the north vortex (35—40°N,92—105°E )and the shear vortex are the main synoptic systems of regional heavy rain over Qingdao area. The difference of the route and position of vortex will cause the difference of heavy rain area.
2005, 31(5):70-73.
DOI: 10.7519/j.issn.1000-0526.2005.05.016
Abstract:
The typhoon activities in the west of 125°E of West Pacific Ocean during 1961 to 2003 and the autumnal rains in the central Shaanxi are investigated. It shows that the typhoon track of the corresponding period is mainly westward in the more autumn rainfall years, but mainly northward and turning around in the less autumn rainfall years.
The typhoon activities in the west of 125°E of West Pacific Ocean during 1961 to 2003 and the autumnal rains in the central Shaanxi are investigated. It shows that the typhoon track of the corresponding period is mainly westward in the more autumn rainfall years, but mainly northward and turning around in the less autumn rainfall years.
2005, 31(5):74-76.
DOI: 10.7519/j.issn.1000-0526.2005.5.017
Abstract:
Based on the routine data and numerial model, “0418”heavy rain is analyzed and compared with heavy rain in flood season. The results show that the vorticity, divergence and vertical velocity are stronger in the flood season, but the cold wave and the low level jet are stronger in the non-flood season.
Based on the routine data and numerial model, “0418”heavy rain is analyzed and compared with heavy rain in flood season. The results show that the vorticity, divergence and vertical velocity are stronger in the flood season, but the cold wave and the low level jet are stronger in the non-flood season.
2005, 31(5):77-79.
DOI: 10.7519/j.issn.1000-0526.2005.5.018
Abstract:
The relationships between days of Hefei lower temperature and Meiyu rainfall and length in Anhui province is analyzed. It shows that cold wave is an important rule in Meiyu rainfall. When strong air waves are frequent, the Meiyu rainfall and is more and the Meiyu duration is longer. On the contrary, Meiyu rainfall is less and Meiyu length is shorter in the year of weak cold wave.
The relationships between days of Hefei lower temperature and Meiyu rainfall and length in Anhui province is analyzed. It shows that cold wave is an important rule in Meiyu rainfall. When strong air waves are frequent, the Meiyu rainfall and is more and the Meiyu duration is longer. On the contrary, Meiyu rainfall is less and Meiyu length is shorter in the year of weak cold wave.
2005, 31(5):80-82.
DOI: 10.7519/j.issn.1000-0526.2005.5.019
Abstract:
The temperature-measuring radio-acoustic sounding system combined with wind profile radar to measure atmospheric temperature at heights of 100—1500 m is developed and its precision is 0.5K. The system is controlled by chip microprocessor 8031 and can transmit standard sinusoidal waves with various frequencies and arbitrary time intervals according to various requirements. The device has a compact structure and it is completely designed on one printed circuit card, which is directly plugged in the expanding groove of personal computer (PC). It mainly contains CPU (chip microprocessor 8031), four-channel 12-bit D/A converters and four-channel sinusoidal wave generators. When working smoothly, the system can receive orders from personal computer (PC) at any time, and then radio-acoustic signals can be transmitted out via isolated circuit, outside connected power amplifier and loudspeaker.
The temperature-measuring radio-acoustic sounding system combined with wind profile radar to measure atmospheric temperature at heights of 100—1500 m is developed and its precision is 0.5K. The system is controlled by chip microprocessor 8031 and can transmit standard sinusoidal waves with various frequencies and arbitrary time intervals according to various requirements. The device has a compact structure and it is completely designed on one printed circuit card, which is directly plugged in the expanding groove of personal computer (PC). It mainly contains CPU (chip microprocessor 8031), four-channel 12-bit D/A converters and four-channel sinusoidal wave generators. When working smoothly, the system can receive orders from personal computer (PC) at any time, and then radio-acoustic signals can be transmitted out via isolated circuit, outside connected power amplifier and loudspeaker.
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ISSN:1000-0526 CN:11-2282/P