ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 35,Issue 5,2009 Table of Contents
2009, 35(5):3-9.
DOI: 10.7519/j.issn.1000-0526.2009.5.001
Abstract:
During the January to the early February in 2008, the southern parts of China had suffered from a wide range of heavy snowstorms and frost disasters, w hich were featured by wide area, intense, long duration and disaster consequence s. The disaster information of the covered area of the ground snow is very import ant for public meteorological service, and decisionmaking. Currently, the stud ies of passive microwave monitoring snow carried by European and Americancountries as well as China, are concentrated on the dry snow conditions in the a rea at higher latitudes, or in the polar regions.While there are few research f ocus on the thin snow, wet snow identification. Because the south part is lo cated in the lower latitude, with the day and night temperature which fluctuates aro und 0℃ during the snowstorm and frost disasters, the mixture of rain, snow, and sleet make the snow fall on the ground always wet. The existence of the liquid w ater in the snow layer could greatly change the radiation signal, and a little l iquid water in the snow could cause a sharp rising of the microwave bright tempe rature. Based on the bright temperature difference between the day and night whe n the changes of the snow in freezethaw in the South China, more snow distribu tion information in the lower latitude could be available by using the passive m icrowave data (DMSPSSM/I) to build a compensate way of monitoring the snow in the South China combined with other snow products.
During the January to the early February in 2008, the southern parts of China had suffered from a wide range of heavy snowstorms and frost disasters, w hich were featured by wide area, intense, long duration and disaster consequence s. The disaster information of the covered area of the ground snow is very import ant for public meteorological service, and decisionmaking. Currently, the stud ies of passive microwave monitoring snow carried by European and Americancountries as well as China, are concentrated on the dry snow conditions in the a rea at higher latitudes, or in the polar regions.While there are few research f ocus on the thin snow, wet snow identification. Because the south part is lo cated in the lower latitude, with the day and night temperature which fluctuates aro und 0℃ during the snowstorm and frost disasters, the mixture of rain, snow, and sleet make the snow fall on the ground always wet. The existence of the liquid w ater in the snow layer could greatly change the radiation signal, and a little l iquid water in the snow could cause a sharp rising of the microwave bright tempe rature. Based on the bright temperature difference between the day and night whe n the changes of the snow in freezethaw in the South China, more snow distribu tion information in the lower latitude could be available by using the passive m icrowave data (DMSPSSM/I) to build a compensate way of monitoring the snow in the South China combined with other snow products.
2009, 35(5):10-17.
DOI: 10.7519/j.issn.1000-0526.2009.5.002
Abstract:
To meet the increasing demand of lightning nowcasting and warning serv ices with the rapid development of modern society, Chinese Academy of Meteorolog ical Sciences developed a Lightning Nowcasting and Warning System (CAMS－LNWS) , which integrates multiple observation data, multiple parameters and mult iple algorithms. In the lightning nowcasting and warning method, many observation data such as radar, satellite, lightning monitoring sys tem, surface electrical field mi ll, sounding data, etc., are used. The forecasting products of synoptic situatio n and the numerical simulation of thunderstorm electrification and discharge mode l are also considered. Two basic algorithms are implemented: one is area identif ication, tracking and extrapolating algorithm, and the other is decision tree al gorithm. CAMS－LNWS can provide lightning activity potential prediction produc t and lightning nowcasting and warning products. The latter can be showed in severa l ways to meet various needs of different applications. It is easy to implement applications of CAMS－LNWS in different regions as a result of its friendly ma nmachine interfaces and rich controls parameters. Additionally, CAMS－LNWS has m odular structure design with a flexible expansibility, which can provide convenient way for the continuous upgrading and improving of nowcasting and warning method in the future.
To meet the increasing demand of lightning nowcasting and warning serv ices with the rapid development of modern society, Chinese Academy of Meteorolog ical Sciences developed a Lightning Nowcasting and Warning System (CAMS－LNWS) , which integrates multiple observation data, multiple parameters and mult iple algorithms. In the lightning nowcasting and warning method, many observation data such as radar, satellite, lightning monitoring sys tem, surface electrical field mi ll, sounding data, etc., are used. The forecasting products of synoptic situatio n and the numerical simulation of thunderstorm electrification and discharge mode l are also considered. Two basic algorithms are implemented: one is area identif ication, tracking and extrapolating algorithm, and the other is decision tree al gorithm. CAMS－LNWS can provide lightning activity potential prediction produc t and lightning nowcasting and warning products. The latter can be showed in severa l ways to meet various needs of different applications. It is easy to implement applications of CAMS－LNWS in different regions as a result of its friendly ma nmachine interfaces and rich controls parameters. Additionally, CAMS－LNWS has m odular structure design with a flexible expansibility, which can provide convenient way for the continuous upgrading and improving of nowcasting and warning method in the future.
2009, 35(5):18-25.
DOI: 10.7519/j.issn.1000-0526.2009.5.003
Abstract:
The southwest vortex (21-23 July, 2008) moved northeastward from east of Sich uan. Henan Meteorological Observatory published rainstorm forecast at 21st with reference to several numerical weather prediction (NWP) commonly used, and the f orecast showed regional deviation. For the further understanding on the mechanis m of the moving route of the southwest vortex, it is discussed in some aspects s uch as atmospheric circulation, thermal, dynamics based on the formal and NCEP d atasets. Synoptic test on numerical forecast products has been done, and the pro cess is simulated by WRF. The results show that: (1) the route of the southwest vortex changes sharply, firstly southward, then northeastward, and then eastward , finally northeastward. (2) The structure of the vortex is of mesoscale charact eristics. K index and axial direction of the vortex have instructions on the moving of the vortex. (3) The main reasons of the deviation are more rely on the NW P and less consideration to the influence of the cool air from northeast. (4) Th e forecast of the vortex’s route by WRF is better.
The southwest vortex (21-23 July, 2008) moved northeastward from east of Sich uan. Henan Meteorological Observatory published rainstorm forecast at 21st with reference to several numerical weather prediction (NWP) commonly used, and the f orecast showed regional deviation. For the further understanding on the mechanis m of the moving route of the southwest vortex, it is discussed in some aspects s uch as atmospheric circulation, thermal, dynamics based on the formal and NCEP d atasets. Synoptic test on numerical forecast products has been done, and the pro cess is simulated by WRF. The results show that: (1) the route of the southwest vortex changes sharply, firstly southward, then northeastward, and then eastward , finally northeastward. (2) The structure of the vortex is of mesoscale charact eristics. K index and axial direction of the vortex have instructions on the moving of the vortex. (3) The main reasons of the deviation are more rely on the NW P and less consideration to the influence of the cool air from northeast. (4) Th e forecast of the vortex’s route by WRF is better.
2009, 35(5):26-34.
DOI: 10.7519/j.issn.1000-0526.2009.5.004
Abstract:
At the beginning of 2008, South China encounters freezing rain disast er which is the most serious freezing rain in the past 100 year. Especially in G uangdong Province, it caused great economic loss and social impact. The results show that this case is associated with La Nina event and anomalous atmo spheric c irculation. The circulation situation of the middle and high levels in Asia and Europe was a pattern of north ridge and south trough circulation pattern and the western Pacific subtropical high was stronger in intensity and northward in pos ition. The cold air moving up against moist s outherly form the Bay of Bengal and the South China Sea produced the lowlevel temperature inversion over South China and the anomalous localmeridional circu lation,which caused the continuous cryogenic freez ing rain and snow weather. When confront the public events that caused by the fr eezing rain, Guangdong Provincial Meteorology Bureau has a good communication w ith the media, authority weather warning information are published in time, whic h has a positive effect in stabilize the popular feelings and society. Rethinkin g of disaster found that the ability of monitoring, evaluating and information p ublishing about freezing rain disaster in mountain area still need to be reinfor ced.
At the beginning of 2008, South China encounters freezing rain disast er which is the most serious freezing rain in the past 100 year. Especially in G uangdong Province, it caused great economic loss and social impact. The results show that this case is associated with La Nina event and anomalous atmo spheric c irculation. The circulation situation of the middle and high levels in Asia and Europe was a pattern of north ridge and south trough circulation pattern and the western Pacific subtropical high was stronger in intensity and northward in pos ition. The cold air moving up against moist s outherly form the Bay of Bengal and the South China Sea produced the lowlevel temperature inversion over South China and the anomalous localmeridional circu lation,which caused the continuous cryogenic freez ing rain and snow weather. When confront the public events that caused by the fr eezing rain, Guangdong Provincial Meteorology Bureau has a good communication w ith the media, authority weather warning information are published in time, whic h has a positive effect in stabilize the popular feelings and society. Rethinkin g of disaster found that the ability of monitoring, evaluating and information p ublishing about freezing rain disaster in mountain area still need to be reinfor ced.
2009, 35(5):35-41.
DOI: 10.7519/j.issn.1000-0526.2009.5.005
Abstract:
By using routine observational data，satellites products，Doppler rada r products, the heaviest rainfall process of Shandong in 2008 is analyzed. The r ole of far distance typhoon in the increase of heavy rain when a westerly rai nfall system affects Shandong is discussed. The main precipitation period is sim ulated with MM5. The results suggest that wind direction and speed convergence z one of southeast air flow on the right side of typhoon Kalmaegi combines with we sterly convergence zone. Water vapor flux convergence makes vertical liquid wate r content increase significantly， and the specific humidity raised in the area southeast flow reached. A backwardtilting trough in westerly causes positive vo rticity advection ahead of upper trough affecting the lowimpact system. Mesosca le meteorological modeling shows that the vertical convection is stable and the s trong symmetry instability makes ascending motion develop in the western region of Shandong in earlier stage. Increasing temperature and humidity in low level, symmetry instability and convective instability exist simultaneously and lead to the sustained torrential rain in Shandong Peninsula in later stage.
By using routine observational data，satellites products，Doppler rada r products, the heaviest rainfall process of Shandong in 2008 is analyzed. The r ole of far distance typhoon in the increase of heavy rain when a westerly rai nfall system affects Shandong is discussed. The main precipitation period is sim ulated with MM5. The results suggest that wind direction and speed convergence z one of southeast air flow on the right side of typhoon Kalmaegi combines with we sterly convergence zone. Water vapor flux convergence makes vertical liquid wate r content increase significantly， and the specific humidity raised in the area southeast flow reached. A backwardtilting trough in westerly causes positive vo rticity advection ahead of upper trough affecting the lowimpact system. Mesosca le meteorological modeling shows that the vertical convection is stable and the s trong symmetry instability makes ascending motion develop in the western region of Shandong in earlier stage. Increasing temperature and humidity in low level, symmetry instability and convective instability exist simultaneously and lead to the sustained torrential rain in Shandong Peninsula in later stage.
2009, 35(5):42-48.
DOI: 10.7519/j.issn.1000-0526.2009.5.006
Abstract:
The heavy rainfall in Changde on 13 May 2002, Hunan Province in 2002 was analyz ed based on Doppler weather radar products, NCEP 1°× 1° reanalysis data, satellite cloud image products, realtime detection data and MM5 numerical simulations. It is found that the rainfall event was caused by joint influences of upperlevel troughs, middlelowlevel shears, southwest jets, ground inverted troughs and a weak cold air. How the jet formed, developed and weakened had a direct impact on the intensity of rainfall. The rainfall center corresponded well to the “U"shaped gap of satellite cloud image and the middlelow jet axis of Doppler base velocity field. When the jet in the Doppler basic velocity field vibra ted, the cold advection above the low level warm advection appeared, lowlayer cyclone vortex field formed and maintained, and l owlevel vertical wind shear changed, it could instruct conspicuously that heavy rainfall would occur. Numerical simulation has proved the mesoscale vortex, jets and convergence to be consistent with those detected by radar. All these results have valuable reference to rainfall nowcasting.
The heavy rainfall in Changde on 13 May 2002, Hunan Province in 2002 was analyz ed based on Doppler weather radar products, NCEP 1°× 1° reanalysis data, satellite cloud image products, realtime detection data and MM5 numerical simulations. It is found that the rainfall event was caused by joint influences of upperlevel troughs, middlelowlevel shears, southwest jets, ground inverted troughs and a weak cold air. How the jet formed, developed and weakened had a direct impact on the intensity of rainfall. The rainfall center corresponded well to the “U"shaped gap of satellite cloud image and the middlelow jet axis of Doppler base velocity field. When the jet in the Doppler basic velocity field vibra ted, the cold advection above the low level warm advection appeared, lowlayer cyclone vortex field formed and maintained, and l owlevel vertical wind shear changed, it could instruct conspicuously that heavy rainfall would occur. Numerical simulation has proved the mesoscale vortex, jets and convergence to be consistent with those detected by radar. All these results have valuable reference to rainfall nowcasting.
2009, 35(5):49-54.
DOI: 10.7519/j.issn.1000-0526.2009.5.007
Abstract:
A strong convection event on 21 July 2008 in Chongqing City was diagno sed. The developing mechanism of the strong convection weather was studied with the background of weather, the echoes of radar and the wind field computed by 4D VAR technique. The results indicate that the strong storm was caused by atmo spheric convergence, which was brought by upper cold air inrush and lower warmwet airflow intersection. Observation of radar shows that there were a weak echo fie ld and “adverse wind region". Low level wind field computed by 4DVAR shows that there was a convergence band before strong echoes. The convergence band is super posed with strong echoes in the middlelevel. And the upperlevel is divergen ce field. At the vertical section, there was an inflow at the rear of strong convection area. In the middle o f squall line there was a strong rising motion, which produced strong echoes. Th e strong rainfall in the front of weak echo produced the outflow, which converge d with warm and wet air and formed a thin outflow border line.
A strong convection event on 21 July 2008 in Chongqing City was diagno sed. The developing mechanism of the strong convection weather was studied with the background of weather, the echoes of radar and the wind field computed by 4D VAR technique. The results indicate that the strong storm was caused by atmo spheric convergence, which was brought by upper cold air inrush and lower warmwet airflow intersection. Observation of radar shows that there were a weak echo fie ld and “adverse wind region". Low level wind field computed by 4DVAR shows that there was a convergence band before strong echoes. The convergence band is super posed with strong echoes in the middlelevel. And the upperlevel is divergen ce field. At the vertical section, there was an inflow at the rear of strong convection area. In the middle o f squall line there was a strong rising motion, which produced strong echoes. Th e strong rainfall in the front of weak echo produced the outflow, which converge d with warm and wet air and formed a thin outflow border line.
2009, 35(5):55-60.
DOI: 10.7519/j.issn.1000-0526.2009.5.008
Abstract:
The weather environments and radar echo features of thunderstorm occu rred on April 27th and 28th 2008 in Lhasa are analyzed by using Doppler radar da ta, lightning data and ECMWF data and conventional meteorological data and so on . The result showed that this thunderstorm in Lhasa was engendered by the cold a ir which came southward from Ural and strengthened the development of the unstab le level and turbulence in Lhasa. Radial velocity map and VAD wind profiler both showed that there were obviously the lowlevel warm advection structure, low le vel jet and vertical wind shears. The interaction between the γmesoscale cycl on ic vortex disturbance and the environment vertical wind shears led to the develo pments of thunderstorm cloud and rising of echo top, of which the height of ech o of 40 dBz reached to 7 km. The value of CAPE, the γmesoscale cyclonic vort ex disturbance, vertical wind shears and lowlevel warm advection structure are good indices to the forecasting and warning of Lhasa th understorm. This paper gives the notion and the emphasis of the forecasting of t hunderstorm in Lhasa.
The weather environments and radar echo features of thunderstorm occu rred on April 27th and 28th 2008 in Lhasa are analyzed by using Doppler radar da ta, lightning data and ECMWF data and conventional meteorological data and so on . The result showed that this thunderstorm in Lhasa was engendered by the cold a ir which came southward from Ural and strengthened the development of the unstab le level and turbulence in Lhasa. Radial velocity map and VAD wind profiler both showed that there were obviously the lowlevel warm advection structure, low le vel jet and vertical wind shears. The interaction between the γmesoscale cycl on ic vortex disturbance and the environment vertical wind shears led to the develo pments of thunderstorm cloud and rising of echo top, of which the height of ech o of 40 dBz reached to 7 km. The value of CAPE, the γmesoscale cyclonic vort ex disturbance, vertical wind shears and lowlevel warm advection structure are good indices to the forecasting and warning of Lhasa th understorm. This paper gives the notion and the emphasis of the forecasting of t hunderstorm in Lhasa.
2009, 35(5):61-65.
DOI: 10.7519/j.issn.1000-0526.2009.5.009
Abstract:
In order to obtain the important land surface ecological parameter—land sur face temperature (LST) quickl y, macroscopically, and to avoid the more parameters estimation and the limitati on of the parameters applicability range of the splitwindow algorithm, a stati stical model to retrieve LST was built up by using 13 clear air earth surface MO DIS data and 24 autoweather station data in 2005-2007. The new model can enhan ce the calculation speed and make more efficient use of the “threestations an d four nets” products built by China Meteorological Administration. The results indicate that after introducing the related parameters, the model relevance and accuracy were improved obviously, the combination of the water vapor channel of MODIS with the enhanced vegetation index (EVI) can obtain an optimal effect. Compared with the splitwindow algorithm, the statistical model is simple and feasible. It does not need to estimate the atmospheric transmissivity and the land surface emissivity. Compar ed with the AWS data, the actual error in 70% retrieved LST is within 4.0℃.
In order to obtain the important land surface ecological parameter—land sur face temperature (LST) quickl y, macroscopically, and to avoid the more parameters estimation and the limitati on of the parameters applicability range of the splitwindow algorithm, a stati stical model to retrieve LST was built up by using 13 clear air earth surface MO DIS data and 24 autoweather station data in 2005-2007. The new model can enhan ce the calculation speed and make more efficient use of the “threestations an d four nets” products built by China Meteorological Administration. The results indicate that after introducing the related parameters, the model relevance and accuracy were improved obviously, the combination of the water vapor channel of MODIS with the enhanced vegetation index (EVI) can obtain an optimal effect. Compared with the splitwindow algorithm, the statistical model is simple and feasible. It does not need to estimate the atmospheric transmissivity and the land surface emissivity. Compar ed with the AWS data, the actual error in 70% retrieved LST is within 4.0℃.
2009, 35(5):66-73.
DOI: 10.7519/j.issn.1000-0526.2009.5.010
Abstract:
with the reanalysis data f rom the National Centers of Environmental Prediction/National Centers for Atmosp heric Research (NCEP/NCAR) during the same period. The reanalysis data can captu re much of the synopticscale variability in daily mean pressure, temperature a n d relative humidity. Among them, the reanalyzed pressure is more confident than temperature and relative humidity at the Col of Zhadang Glacier and Nam Co Stati on. Differences between the reanalyzed and observational daily mean pressure and relative humidity are large in winter and less in summer, while differences bet ween the reanalyzed and observational daily mean temperature are opposite. Relia bility of reanalysis data is better at the Col of Zhadang Glacier than at Nam Co Station. The reanalyzed data can be used to study the trends of climate change in the glacier and lake area in the Nam Co Basin, and more attentions should be given to influences of topography.
with the reanalysis data f rom the National Centers of Environmental Prediction/National Centers for Atmosp heric Research (NCEP/NCAR) during the same period. The reanalysis data can captu re much of the synopticscale variability in daily mean pressure, temperature a n d relative humidity. Among them, the reanalyzed pressure is more confident than temperature and relative humidity at the Col of Zhadang Glacier and Nam Co Stati on. Differences between the reanalyzed and observational daily mean pressure and relative humidity are large in winter and less in summer, while differences bet ween the reanalyzed and observational daily mean temperature are opposite. Relia bility of reanalysis data is better at the Col of Zhadang Glacier than at Nam Co Station. The reanalyzed data can be used to study the trends of climate change in the glacier and lake area in the Nam Co Basin, and more attentions should be given to influences of topography.
2009, 35(5):74-82.
DOI: 10.7519/j.issn.1000-0526.2009.5.011
Abstract:
Considering different solar radiation between various areas and terrain, and att enuation by terrain, atmosphere and other factors, along with the newly research trends, based on slope, aspect and shadow derived by DEM, a model of p otential solar radiation in Shanxi Plateau is established. By comparing with the daily solar radiation observed in three observation stations in 5 years, the re sults show that the model is feasible. The model was used to analyze the spatial and temporal distributions and variation of potential solar radiation in Shanxi Plateau. The model could also provide critical foundation for research of microc limate variation and microclimate index.
Considering different solar radiation between various areas and terrain, and att enuation by terrain, atmosphere and other factors, along with the newly research trends, based on slope, aspect and shadow derived by DEM, a model of p otential solar radiation in Shanxi Plateau is established. By comparing with the daily solar radiation observed in three observation stations in 5 years, the re sults show that the model is feasible. The model was used to analyze the spatial and temporal distributions and variation of potential solar radiation in Shanxi Plateau. The model could also provide critical foundation for research of microc limate variation and microclimate index.
2009, 35(5):83-90.
DOI: 10.7519/j.issn.1000-0526.2009.5.012
Abstract:
Based on the relevant reference data of the tropical cyclone (TC) in NorthWest Pacific (NWP) regions and the sea surface temperature (SST) from 1 950 to 2005, the general climatic features of the TC in NWP, the seasonal and interannual variations and the relationship with SST were analyzed. The TC int ensity, track, the formation regions and their relations were als o investigated. In NWP there are four areas where TCs frequently occur, i.e., th e northeastern area of South China Sea, eastern Philippine Sea, adjacent sea are as of t he Guam and the Marshall Islands. Among them the Guam area is the main origin wh ere the TC frequently occurs. The seasonal and interannual variations of TC ov e r NWP are obvious and closely associated with the local SST. The TC formation re gions shift westward and northward in warm years of SST and eastward and southwa rd in cold years. The northwest line of the TC formation location is well matche d to the monthly mean SST isotherm of 27.5℃. Most of TCs are formed in the area s where the monthly mean SST is equal to or higher than 27.5℃. The intensity an d the track of TC are associated with the TC formation regions. When the TC form ation regions move westward and northward, the TC intensity is lower and the TC tracks move northwestward, the number of TCs affecting eastern and northern Chin a seas may be increased. On the contrary, when the TC formation regions move eas tward and southward, the TC intensity is higher and the TC tracks move eastward and southward too, and the number of TCs affecting the southern China seas and t he seas of Japan may be increased accordingly.
Based on the relevant reference data of the tropical cyclone (TC) in NorthWest Pacific (NWP) regions and the sea surface temperature (SST) from 1 950 to 2005, the general climatic features of the TC in NWP, the seasonal and interannual variations and the relationship with SST were analyzed. The TC int ensity, track, the formation regions and their relations were als o investigated. In NWP there are four areas where TCs frequently occur, i.e., th e northeastern area of South China Sea, eastern Philippine Sea, adjacent sea are as of t he Guam and the Marshall Islands. Among them the Guam area is the main origin wh ere the TC frequently occurs. The seasonal and interannual variations of TC ov e r NWP are obvious and closely associated with the local SST. The TC formation re gions shift westward and northward in warm years of SST and eastward and southwa rd in cold years. The northwest line of the TC formation location is well matche d to the monthly mean SST isotherm of 27.5℃. Most of TCs are formed in the area s where the monthly mean SST is equal to or higher than 27.5℃. The intensity an d the track of TC are associated with the TC formation regions. When the TC form ation regions move westward and northward, the TC intensity is lower and the TC tracks move northwestward, the number of TCs affecting eastern and northern Chin a seas may be increased. On the contrary, when the TC formation regions move eas tward and southward, the TC intensity is higher and the TC tracks move eastward and southward too, and the number of TCs affecting the southern China seas and t he seas of Japan may be increased accordingly.
2009, 35(5):91-96.
DOI: 10.7519/j.issn.1000-0526.2009.5.013
Abstract:
By using Doppler weather radar data on 46 thunderstorms from 2002 to 2 007 in Tianjin and observing data of AWS, according to the echo characters on th e data, there are four kinds of echo characters, including bow echo, gust, strip echo and isolated echo. Especially, bow echo can cause great losses. Meanwhile, the sources of thunderstorm have the following four aspects, including north pa th, northwest path, west path and others. The situation mentioned above can be a pplied for warning of thunderstorm in Bohai bay and others area.
By using Doppler weather radar data on 46 thunderstorms from 2002 to 2 007 in Tianjin and observing data of AWS, according to the echo characters on th e data, there are four kinds of echo characters, including bow echo, gust, strip echo and isolated echo. Especially, bow echo can cause great losses. Meanwhile, the sources of thunderstorm have the following four aspects, including north pa th, northwest path, west path and others. The situation mentioned above can be a pplied for warning of thunderstorm in Bohai bay and others area.
2009, 35(5):97-104.
DOI: 10.7519/j.issn.1000-0526.2009.5.014
Abstract:
With the development of society and economy, lightning disasters becom e more and more influential in the economic losses and society. In order to inve stigate the distribution characteristics and development law of lightning disast ers and realize the visualization analysis of lightning disasters, a visual anal ysis system for lightning disaster data, named VASLDD, was established by means of the rapid rendering method for Doppler radar figure based on user draw layer , the drawing strategy of lighting density figure and polarity figure based on d atabase, rapid merging display technology of Doppler radar data and lightning direction finder data. By means of graph, thematic map of GIS, contour map and choroplethic map etc, the system re alizes the visual analysis of lightning disasters, thunderstorms day, lightning etc. VASLDD has become a powerful tool for operational and research work.
With the development of society and economy, lightning disasters becom e more and more influential in the economic losses and society. In order to inve stigate the distribution characteristics and development law of lightning disast ers and realize the visualization analysis of lightning disasters, a visual anal ysis system for lightning disaster data, named VASLDD, was established by means of the rapid rendering method for Doppler radar figure based on user draw layer , the drawing strategy of lighting density figure and polarity figure based on d atabase, rapid merging display technology of Doppler radar data and lightning direction finder data. By means of graph, thematic map of GIS, contour map and choroplethic map etc, the system re alizes the visual analysis of lightning disasters, thunderstorms day, lightning etc. VASLDD has become a powerful tool for operational and research work.
2009, 35(5):105-111.
DOI: 10.7519/j.issn.1000-0526.2009.5.015
Abstract:
The paper introduced the structure and production, localization parameter settin g, transporting processing of data and services of the system on disaster weathe r warning and nowcasting by new generation weather radar in the flood season of 2007. The system was developed by Chinese Academy of Meteorological Sciences and introduced by Henan Meteorological Observatory in 2007, which could not only di splay the commonly used production but also create a series of services producti on such as identification of reverse wind region, mesocyclone, rainstorm echoes, squall line, storm and heavy hail, nowcasting of precipitation from 1 to 3 hours, extrapolation forecast of echoes, area rainfall using radarraingaug e and the consensus of estimating rainfall by fully using the base data of the n ew generation weather radar. Therefore, it has obvious guiding and warning funct ion in monitoring and early warning the severe convection weather and is one of the indispensable tools in our practical operations.
The paper introduced the structure and production, localization parameter settin g, transporting processing of data and services of the system on disaster weathe r warning and nowcasting by new generation weather radar in the flood season of 2007. The system was developed by Chinese Academy of Meteorological Sciences and introduced by Henan Meteorological Observatory in 2007, which could not only di splay the commonly used production but also create a series of services producti on such as identification of reverse wind region, mesocyclone, rainstorm echoes, squall line, storm and heavy hail, nowcasting of precipitation from 1 to 3 hours, extrapolation forecast of echoes, area rainfall using radarraingaug e and the consensus of estimating rainfall by fully using the base data of the n ew generation weather radar. Therefore, it has obvious guiding and warning funct ion in monitoring and early warning the severe convection weather and is one of the indispensable tools in our practical operations.
2009, 35(5):112-119.
DOI: 10.7519/j.issn.1000-0526.2009.5.016
Abstract:
It was verified and compared that the performance of T639, ECMWF and Japan model about their mediumrange forecasting during Dec. 2008 to Feb. 2009. The result shows that the three models have good performances for the evolvement and adjus tment of atmospheric circulation situation in Asia middle and high latitude area , and also for the temperature trends of 850hPa. The prediction error of ECMWF m odel is minimal in that of the three models. They all show significant indicatio n to forecast the transition and disaster weather processes, and have successful ly predicted the atmospheric circulation situation and main effecting synoptic s ystems of the three cold wave processes on a national scale, and continuous rain fall weather process occurring in the middlelower reaches of Yangtze River.
It was verified and compared that the performance of T639, ECMWF and Japan model about their mediumrange forecasting during Dec. 2008 to Feb. 2009. The result shows that the three models have good performances for the evolvement and adjus tment of atmospheric circulation situation in Asia middle and high latitude area , and also for the temperature trends of 850hPa. The prediction error of ECMWF m odel is minimal in that of the three models. They all show significant indicatio n to forecast the transition and disaster weather processes, and have successful ly predicted the atmospheric circulation situation and main effecting synoptic s ystems of the three cold wave processes on a national scale, and continuous rain fall weather process occurring in the middlelower reaches of Yangtze River.
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