According to the daily precipitation data in Beijing area from 1985 to 2008,rainstorm weather index （10.4-38.8 mm） and climate index （daily precipitation ≥27.5 mm） in Beijing area were obtained by using the deter...According to the daily precipitation data in Beijing area from 1985 to 2008,rainstorm weather index （10.4-38.8 mm） and climate index （daily precipitation ≥27.5 mm） in Beijing area were obtained by using the determination method of extreme climate event index recommended by IPCC. Based on rainstorm weather index,rainstorm climate index and national rainstorm standard,the number of rainstorm days and rainfall amount in past years were calculated,and the correlation of annual number of rainy days,rainstorm days,precipitation and rainstorm amount with the flood disaster ratio of crop was analyzed,and the results showed that annual number of rainy days and rainstorm days couldn＇t reflect flood disaster ratio of crop truly,while annual precipitation and rainstorm amount had obvious linear positive correlation with the flood disaster ratio of crop. In addition,the correlation degree between rainstorm amount calculated by regional climate index and flood disaster ratio of crop was the highest,so it was suggested that rainstorm amount calculated by regional rainstorm climate index could be used to predict and evaluate flood disaster.展开更多
A rare local rainstorm weather in the midsummer rainy weather process appeared in the northwest of Hubei Province during July 8-13,2009.The circulation situation,the contributions of dynamic,thermal force and water va...A rare local rainstorm weather in the midsummer rainy weather process appeared in the northwest of Hubei Province during July 8-13,2009.The circulation situation,the contributions of dynamic,thermal force and water vapor to this strong precipitation in this process were discussed.The results showed that the cold air which was brought by Lake Balkis cold vortex was the trigger mechanism of local rainstorm,and Lake Baikal low pressure provided the foreign dynamic for the adjustment of East Asia circulation.When the rainstorm occurred,the divergence in the divergence field had the strong 'pumping effect' in the high altitude.The warm wet airflow in the Bay of Bengal and the South China Sea was the water vapor source of rainstorm.The falling zone of rainstorm appeared in the front of energy frontal zone,and the axis line in the top of high-energy tongue deviated to the side of cold air.Q vector divergence and the negative value zone of water vapor helicity had the important indication effect for the short-term forecast of local rainstorm.展开更多
By using observation data,numerical forecast product and non-conventional observation data,the process of a rainstorm happened on July 15th,2008 was analyzed. The evolution process of situation field and the predictio...By using observation data,numerical forecast product and non-conventional observation data,the process of a rainstorm happened on July 15th,2008 was analyzed. The evolution process of situation field and the prediction error by numerical forecast products were mainly analyzed. Some local indices for forecasting rainstorm were obtained,so as to guide rainstorm prediction in the future.展开更多
[Objective] One regional rainstorm weather in the south area of Shaanxi was expounded.[Method] By employing the NCEP/NCAR 1°×1°reanalysis data,routine observation and automatic precipitation station dat...[Objective] One regional rainstorm weather in the south area of Shaanxi was expounded.[Method] By employing the NCEP/NCAR 1°×1°reanalysis data,routine observation and automatic precipitation station data,the large scale circulation background field of regional precipitation in the south area of Shaanxi province from July 16-18 in 2010 was expounded.By dint of physical quantity such as the meridional wind,relative humidity and false relative temperature,the characteristics of dry intrusion and its role in rainstorm were expounded.[Result] The mild and high latitude at 500 hPa was stable.The continental high pressure and subtropical high pressure were stable.The 700 and 850 hPa shear lines or low vortexes were the main influence system that resulted into large scale of rainstorm in south Shaanxi.The landing typhoon had distinct influences on the importance of storm.The influence of typhoon and subtropical high was mutual.It not only formed and strengthened the torrent in the low air,also transmitted water vapor and energy incessantly to the south area of Shaanxi,playing an important role in augment of rainstorm.There were two distinct dry intrusions in the rainstorm process,showing a dense dry layer in the high layer of convective layer.The existence of dry layer was conductive to the accumulation of convective unstable energy in the low layer.The release of convective unstable energy could transmit warm and wet airstream in the low level to the higher level,being conductive to the occurrence of precipitation.The analysis of θse in the warp direction vertical profile suggested that there was frontal zone in this rainstorm process and the dry air activity in this rainstorm process was very strong.[Conclusion] The study provided theoretical reference to the forecast in future.展开更多
By using the data which included the conventional weather chart,the satellite cloud image,the regional automatic meteorological station and the new generation of weather radar,the regional strong precipitation process...By using the data which included the conventional weather chart,the satellite cloud image,the regional automatic meteorological station and the new generation of weather radar,the regional strong precipitation process which happened in Shandong Province during July 8-9 in 2009 was analyzed comprehensively.The results showed that Shandong Province was in the strong convergence zone of atmospheric vorticity in the low layer and the ascent zone of vertical velocity.The shear line was generated in the eastward process of northwest vortex,and the ground inverted trough extended to Shandong,which provided the dynamic condition for the formation of rainstorm.The coupling of jet stream in the high-low altitude enhanced the development of convection.The low-altitude jet stream was the main water vapor transportation channel,which provided the water vapor condition for the generation of rainstorm.The water vapor was mainly from the South China Sea and the Bay of Bengal.展开更多
By using NCEP reanalysis data and the routine observation data,a rainstorm and convective weather process which occurred in Tianjin was analyzed.The results showed that the rainstorm occurred in the favorable large sc...By using NCEP reanalysis data and the routine observation data,a rainstorm and convective weather process which occurred in Tianjin was analyzed.The results showed that the rainstorm occurred in the favorable large scale circulation background.The sounding analysis and the physical quantity field analysis could reveal the plentiful water vapor supply condition.The rainstorm had the obvious concomitance relationship with the low level jet.Meanwhile,the existence of warm ridge on the ground was the important condition of convective weather occurrence.展开更多
Based on the data from 1998 to 2005,area rainfall,flow of main hydrologic stations in Duhe River and upstream water level of the dam of Huanglongtan Reservoir in the lower reaches of Duhe River were analyzed,and the s...Based on the data from 1998 to 2005,area rainfall,flow of main hydrologic stations in Duhe River and upstream water level of the dam of Huanglongtan Reservoir in the lower reaches of Duhe River were analyzed,and the standard of flood-producing rainstorm in Duhe River was given,while temporal and spatial distribution and circulation flow situation characteristic of flood-producing rainstorm in Duhe River were studied.The results showed that the flood-producing rainstorm in Duhe River was mainly continuous intensive precipitation with the characteristic of long duration.There was most rainfall in Zhuxiquan River,Zhushanguandu River and southwest part of the middle and upper reaches of Duhe River,and next came Zhuxi River.Flood-producing rainstorm occurred in Duhe River with some favorable circulation features.For example,it was more favorable in the west Pacific subtropical high,and the convergence zone at northeast-southwest direction was formed between subtropical high and continental high pressure at 700 hPa,while southwest vortex moved eastward.Low pressure system at 850 hPa in south part of plateau developed and moved eastward to Chongqing region and formed low vortex or shear near Duhe River basin.Moreover,the characteristics of physical quantity field were analyzed,the results showed that temperature in plateau area and the south area of Duhe River basin increased obviously before rainstorm,and east pathway was the main path of cold air which affected flood-producing rainstorm in Duhe River.There was a θse intensive belt with NEE-SWW direction at 30°-40° N at 925-500 hPa,and moisture convergence was beneficial to the occurrence of rainstorm in Duhe River.展开更多
By using the daily precipitation data from 1961 to 2005 in North China region,the temporal and spatial distribution characteristics of rainstorm process occurrence and the rainstorm intensity during the crops growth p...By using the daily precipitation data from 1961 to 2005 in North China region,the temporal and spatial distribution characteristics of rainstorm process occurrence and the rainstorm intensity during the crops growth period were studied.The results showed that the rainstorm intensity and the rainstorm process during the crops growth period in North China region both had the obvious annual fluctuations and era variation characteristics.Although the rainstorm and heavy rainstorm occurred in North China region every year,the annual variations were great,and the variation coefficients respectively reached 36.9% and 53.1%.The torrential rain occurred once in every 4-5 years,and the rainstorm process occurred once in every 11 years.Although the torrential rain and rainstorm process occurred in fewer years,their annual fluctuations were more obvious.The peak value zones of rainstorm intensity which was greater and the rainstorm process which occurred frequently were in the 1960s.After 1999,the rainstorm intensity and the rainstorm process were in low value zone of historical stage from 1961 to 2005.Moreover,the 1970s-1990s was between high value and low value,and the rainstorms in different intensities which weren't synchronous happened in the period.In addition,the spatial distribution of annual average rainstorm days presented the tendency which increased obviously from northwest to southeast in Northern China,and the variation coefficient of rainstorm days presented the tendency which increased gradually from southeast to northwest.Generally,the more the annual average rainstorm days are,the smaller the variation coefficient is,and vice versa.The statistics results also showed that precipitation in North China had obvious positive correlation relationship with the rainstorm days.展开更多
Due to the common influence of tropical depression,the low pressure trough and the cold air,the strong precipitation synoptic process occurred in Hainan Island on October 22,2009.It caused that the landslide geologica...Due to the common influence of tropical depression,the low pressure trough and the cold air,the strong precipitation synoptic process occurred in Hainan Island on October 22,2009.It caused that the landslide geological disaster happened in several spots in the eastern line highway.By analyzing on the generation reason of landslide,it gained that the landslide which happened in several spots in the eastern line highway was caused by the common effect of special topographical condition,strong wind and rainstorm.The strong precipitation and strong wind which were generated by the tropical depression were the direct reasons which induced the rainstorm type landslide in the eastern line highway.展开更多
The rainstorm weather from July 15,2010 to July 18,2010 is researched by diagnosis analysis method.The results suggest that in the strong and lasting period,the upward air current in the basin is prevail and is above ...The rainstorm weather from July 15,2010 to July 18,2010 is researched by diagnosis analysis method.The results suggest that in the strong and lasting period,the upward air current in the basin is prevail and is above 300 hPa.The convergence layer during strong rainstorm period is not thick.The convergence movement of air current is under 500 hPa.In this rainstorm process,the positive vortex maximum value center of the lower layer of convection layer is perfectly corresponding to rainstorm zone.The air current convergence and divergence intensity is one magnitude larger than the turning intensity.Flux plays a leading role in the system changes process;the non-equilibrium value of the low layer of convection layer during the strong rainstorm period U<0.Strong non-equilibrium is favorable for the movement of convergence.The non-equilibrium value of the high layer of convection layer U>0,and it stimulates the divergence movement of high layer.The divergence of high layer pushes the convergence of the lower layer and thus forms strong upward movement.展开更多
基金Supported by Cultivation Fund for Scientific and Technical innovation Project of Higher Education of Ministry of Education of China(708013)National Key Technology R &D Program in the 11th Five Year Plan of China (2008BAK50B02, 2007BAC29B05)~~
文摘According to the daily precipitation data in Beijing area from 1985 to 2008,rainstorm weather index （10.4-38.8 mm） and climate index （daily precipitation ≥27.5 mm） in Beijing area were obtained by using the determination method of extreme climate event index recommended by IPCC. Based on rainstorm weather index,rainstorm climate index and national rainstorm standard,the number of rainstorm days and rainfall amount in past years were calculated,and the correlation of annual number of rainy days,rainstorm days,precipitation and rainstorm amount with the flood disaster ratio of crop was analyzed,and the results showed that annual number of rainy days and rainstorm days couldn＇t reflect flood disaster ratio of crop truly,while annual precipitation and rainstorm amount had obvious linear positive correlation with the flood disaster ratio of crop. In addition,the correlation degree between rainstorm amount calculated by regional climate index and flood disaster ratio of crop was the highest,so it was suggested that rainstorm amount calculated by regional rainstorm climate index could be used to predict and evaluate flood disaster.
基金Supported by The Special Project of National Public Welfare Industry(Meteorology)(GYHY200806002)The Key Project of Science and Technology Development Fund of Wuhan Regional Meteorological Center of China Meteorological Administration(QY-Z-200801)
文摘A rare local rainstorm weather in the midsummer rainy weather process appeared in the northwest of Hubei Province during July 8-13,2009.The circulation situation,the contributions of dynamic,thermal force and water vapor to this strong precipitation in this process were discussed.The results showed that the cold air which was brought by Lake Balkis cold vortex was the trigger mechanism of local rainstorm,and Lake Baikal low pressure provided the foreign dynamic for the adjustment of East Asia circulation.When the rainstorm occurred,the divergence in the divergence field had the strong 'pumping effect' in the high altitude.The warm wet airflow in the Bay of Bengal and the South China Sea was the water vapor source of rainstorm.The falling zone of rainstorm appeared in the front of energy frontal zone,and the axis line in the top of high-energy tongue deviated to the side of cold air.Q vector divergence and the negative value zone of water vapor helicity had the important indication effect for the short-term forecast of local rainstorm.
文摘By using observation data,numerical forecast product and non-conventional observation data,the process of a rainstorm happened on July 15th,2008 was analyzed. The evolution process of situation field and the prediction error by numerical forecast products were mainly analyzed. Some local indices for forecasting rainstorm were obtained,so as to guide rainstorm prediction in the future.
文摘[Objective] One regional rainstorm weather in the south area of Shaanxi was expounded.[Method] By employing the NCEP/NCAR 1°×1°reanalysis data,routine observation and automatic precipitation station data,the large scale circulation background field of regional precipitation in the south area of Shaanxi province from July 16-18 in 2010 was expounded.By dint of physical quantity such as the meridional wind,relative humidity and false relative temperature,the characteristics of dry intrusion and its role in rainstorm were expounded.[Result] The mild and high latitude at 500 hPa was stable.The continental high pressure and subtropical high pressure were stable.The 700 and 850 hPa shear lines or low vortexes were the main influence system that resulted into large scale of rainstorm in south Shaanxi.The landing typhoon had distinct influences on the importance of storm.The influence of typhoon and subtropical high was mutual.It not only formed and strengthened the torrent in the low air,also transmitted water vapor and energy incessantly to the south area of Shaanxi,playing an important role in augment of rainstorm.There were two distinct dry intrusions in the rainstorm process,showing a dense dry layer in the high layer of convective layer.The existence of dry layer was conductive to the accumulation of convective unstable energy in the low layer.The release of convective unstable energy could transmit warm and wet airstream in the low level to the higher level,being conductive to the occurrence of precipitation.The analysis of θse in the warp direction vertical profile suggested that there was frontal zone in this rainstorm process and the dry air activity in this rainstorm process was very strong.[Conclusion] The study provided theoretical reference to the forecast in future.
文摘By using the data which included the conventional weather chart,the satellite cloud image,the regional automatic meteorological station and the new generation of weather radar,the regional strong precipitation process which happened in Shandong Province during July 8-9 in 2009 was analyzed comprehensively.The results showed that Shandong Province was in the strong convergence zone of atmospheric vorticity in the low layer and the ascent zone of vertical velocity.The shear line was generated in the eastward process of northwest vortex,and the ground inverted trough extended to Shandong,which provided the dynamic condition for the formation of rainstorm.The coupling of jet stream in the high-low altitude enhanced the development of convection.The low-altitude jet stream was the main water vapor transportation channel,which provided the water vapor condition for the generation of rainstorm.The water vapor was mainly from the South China Sea and the Bay of Bengal.
基金Supported by The Science Research Item of Civil Aviation North China Air Management Bureau(201012)
文摘By using NCEP reanalysis data and the routine observation data,a rainstorm and convective weather process which occurred in Tianjin was analyzed.The results showed that the rainstorm occurred in the favorable large scale circulation background.The sounding analysis and the physical quantity field analysis could reveal the plentiful water vapor supply condition.The rainstorm had the obvious concomitance relationship with the low level jet.Meanwhile,the existence of warm ridge on the ground was the important condition of convective weather occurrence.
文摘Based on the data from 1998 to 2005,area rainfall,flow of main hydrologic stations in Duhe River and upstream water level of the dam of Huanglongtan Reservoir in the lower reaches of Duhe River were analyzed,and the standard of flood-producing rainstorm in Duhe River was given,while temporal and spatial distribution and circulation flow situation characteristic of flood-producing rainstorm in Duhe River were studied.The results showed that the flood-producing rainstorm in Duhe River was mainly continuous intensive precipitation with the characteristic of long duration.There was most rainfall in Zhuxiquan River,Zhushanguandu River and southwest part of the middle and upper reaches of Duhe River,and next came Zhuxi River.Flood-producing rainstorm occurred in Duhe River with some favorable circulation features.For example,it was more favorable in the west Pacific subtropical high,and the convergence zone at northeast-southwest direction was formed between subtropical high and continental high pressure at 700 hPa,while southwest vortex moved eastward.Low pressure system at 850 hPa in south part of plateau developed and moved eastward to Chongqing region and formed low vortex or shear near Duhe River basin.Moreover,the characteristics of physical quantity field were analyzed,the results showed that temperature in plateau area and the south area of Duhe River basin increased obviously before rainstorm,and east pathway was the main path of cold air which affected flood-producing rainstorm in Duhe River.There was a θse intensive belt with NEE-SWW direction at 30°-40° N at 925-500 hPa,and moisture convergence was beneficial to the occurrence of rainstorm in Duhe River.
基金Supported by The National "The 11 th Five-Year" Science and Technology Support Project (2008BAK50B02)The Major Projects Cultivation Funds of Science and Technology Innovation Project in High Education Institutions of Education Ministry (708013 )The Science and Technology Commission Project in Beijing City (J08050503260803)
文摘By using the daily precipitation data from 1961 to 2005 in North China region,the temporal and spatial distribution characteristics of rainstorm process occurrence and the rainstorm intensity during the crops growth period were studied.The results showed that the rainstorm intensity and the rainstorm process during the crops growth period in North China region both had the obvious annual fluctuations and era variation characteristics.Although the rainstorm and heavy rainstorm occurred in North China region every year,the annual variations were great,and the variation coefficients respectively reached 36.9% and 53.1%.The torrential rain occurred once in every 4-5 years,and the rainstorm process occurred once in every 11 years.Although the torrential rain and rainstorm process occurred in fewer years,their annual fluctuations were more obvious.The peak value zones of rainstorm intensity which was greater and the rainstorm process which occurred frequently were in the 1960s.After 1999,the rainstorm intensity and the rainstorm process were in low value zone of historical stage from 1961 to 2005.Moreover,the 1970s-1990s was between high value and low value,and the rainstorms in different intensities which weren't synchronous happened in the period.In addition,the spatial distribution of annual average rainstorm days presented the tendency which increased obviously from northwest to southeast in Northern China,and the variation coefficient of rainstorm days presented the tendency which increased gradually from southeast to northwest.Generally,the more the annual average rainstorm days are,the smaller the variation coefficient is,and vice versa.The statistics results also showed that precipitation in North China had obvious positive correlation relationship with the rainstorm days.
基金Supported by The Spreading Scheme of China Meteorological Administration (CMATG2009MS18)Hainan Natural Fund Project (40883)
文摘Due to the common influence of tropical depression,the low pressure trough and the cold air,the strong precipitation synoptic process occurred in Hainan Island on October 22,2009.It caused that the landslide geological disaster happened in several spots in the eastern line highway.By analyzing on the generation reason of landslide,it gained that the landslide which happened in several spots in the eastern line highway was caused by the common effect of special topographical condition,strong wind and rainstorm.The strong precipitation and strong wind which were generated by the tropical depression were the direct reasons which induced the rainstorm type landslide in the eastern line highway.
基金Supported by Sichuan Meteorology Subject Fund(2010-Youth-02)~~
文摘The rainstorm weather from July 15,2010 to July 18,2010 is researched by diagnosis analysis method.The results suggest that in the strong and lasting period,the upward air current in the basin is prevail and is above 300 hPa.The convergence layer during strong rainstorm period is not thick.The convergence movement of air current is under 500 hPa.In this rainstorm process,the positive vortex maximum value center of the lower layer of convection layer is perfectly corresponding to rainstorm zone.The air current convergence and divergence intensity is one magnitude larger than the turning intensity.Flux plays a leading role in the system changes process;the non-equilibrium value of the low layer of convection layer during the strong rainstorm period U<0.Strong non-equilibrium is favorable for the movement of convergence.The non-equilibrium value of the high layer of convection layer U>0,and it stimulates the divergence movement of high layer.The divergence of high layer pushes the convergence of the lower layer and thus forms strong upward movement.
