ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 35,Issue 8,2009 Table of Contents
2009, 35(8):3-15.
DOI: 10.7519/j.issn.1000-0526.2009.8.001
Abstract:
Supported by the Beijing Municipal Science and Technology Commission key project “Research on the hail suppression, rain mitigation operation during Olympic p eriod”, the technology of the rain mitigation operation during Beijing 2008 Oly mpic opening and closing ceremony was studied since 2002. The rain mitigation te chnological scheme, the rainmitigation working flow was made on the basis of t he study. 18 rain mitigation operation areas were designed according to the weat her characteristics and cloud moving direction during August and September in Be ijing Area, and the preliminary experiment results were also analyzed. Weather characteristics, seeding operation and the evaluation of the operation effect on 8t h August were mainly analyzed in the paper. It shows that the intensity of radar echo is weakened, the height of the radar echo is lowered and the area of inten se radar echo is decreased dramatically after the rain mitigation operation. Esp ecially after the seeding operation between 21:45-22:00, there was a gap obvious ly appeared in the radar echo. In addition, according to the change in the grade of the radar echo intensity we can see that the area of the strong echo was dim inished gradually, while the area of the weak echo was increased. The cloud top height and the cloud effective particle radius over the seeding place retrieved by the satellite also revealed the effect of the seeding operation.
Supported by the Beijing Municipal Science and Technology Commission key project “Research on the hail suppression, rain mitigation operation during Olympic p eriod”, the technology of the rain mitigation operation during Beijing 2008 Oly mpic opening and closing ceremony was studied since 2002. The rain mitigation te chnological scheme, the rainmitigation working flow was made on the basis of t he study. 18 rain mitigation operation areas were designed according to the weat her characteristics and cloud moving direction during August and September in Be ijing Area, and the preliminary experiment results were also analyzed. Weather characteristics, seeding operation and the evaluation of the operation effect on 8t h August were mainly analyzed in the paper. It shows that the intensity of radar echo is weakened, the height of the radar echo is lowered and the area of inten se radar echo is decreased dramatically after the rain mitigation operation. Esp ecially after the seeding operation between 21:45-22:00, there was a gap obvious ly appeared in the radar echo. In addition, according to the change in the grade of the radar echo intensity we can see that the area of the strong echo was dim inished gradually, while the area of the weak echo was increased. The cloud top height and the cloud effective particle radius over the seeding place retrieved by the satellite also revealed the effect of the seeding operation.
2 Numerical Simulation on the Process of Tropical Storm
（Tom） Transformation to Extratropical Cyclone
2009, 35(8):16-26.
DOI: 10.7519/j.issn.1000-0526.2009.8.002
Abstract:
By using MM5, the transition of Tom (a tropical storm in 1996 in North western Pacific Ocean) from the tropical storm to the extratropical cyclone is s imulated. The result shows that: (1) when Tom entered midhigh latitude of baro c linic zone, it interacted with the 500hPa westerly trough. The coupling of the w arm and moist air of low level at the east of the storm and the positive vortici ty advection before the trough made it possible for the cyclone to develop. The cold advection after the trough and warm advection before the trough made Tom wi th cold feature in the west and warm feature in the east. And this thermodynamic structure transformed Tom into a baroclinic cyclone. (2) The cyclonic shear left to the upperlevel jet stream e ntrance and the anticyclonic shear right to the upperlevel jet stream exit w ere favorable for the upward movement right to Tom and downward movement left to Tom, which made Tom transform from a barotropical structure to a baroclinic one . (3) The invasion of the cold and dry air in 700hPa level into Tom's warm core made the storm axis tilt NWSE from lower to upper level and destructed Tom's w arm core. (4) Because of the invasion of the cold and dry air in 700hPa level, t wo warm cores appeared. At the north of the northern warm core a significant war m front was born and a cold front seemed to appear near the northwest warm core. (5) The subtropical cyclone's reintensification was related to the downward t ransmission of high potential vortex from stratosphere.
By using MM5, the transition of Tom (a tropical storm in 1996 in North western Pacific Ocean) from the tropical storm to the extratropical cyclone is s imulated. The result shows that: (1) when Tom entered midhigh latitude of baro c linic zone, it interacted with the 500hPa westerly trough. The coupling of the w arm and moist air of low level at the east of the storm and the positive vortici ty advection before the trough made it possible for the cyclone to develop. The cold advection after the trough and warm advection before the trough made Tom wi th cold feature in the west and warm feature in the east. And this thermodynamic structure transformed Tom into a baroclinic cyclone. (2) The cyclonic shear left to the upperlevel jet stream e ntrance and the anticyclonic shear right to the upperlevel jet stream exit w ere favorable for the upward movement right to Tom and downward movement left to Tom, which made Tom transform from a barotropical structure to a baroclinic one . (3) The invasion of the cold and dry air in 700hPa level into Tom's warm core made the storm axis tilt NWSE from lower to upper level and destructed Tom's w arm core. (4) Because of the invasion of the cold and dry air in 700hPa level, t wo warm cores appeared. At the north of the northern warm core a significant war m front was born and a cold front seemed to appear near the northwest warm core. (5) The subtropical cyclone's reintensification was related to the downward t ransmission of high potential vortex from stratosphere.
2009, 35(8):27-34.
DOI: 10.7519/j.issn.1000-0526.2009.8.003
Abstract:
In order to study the disaster of the heavy drought occurring in SichuanChongq ing Region in midsummer 2006, the atmospheric circulation anomaly over East Asia is analyzed to investigate the causes of the drought. The results sho w that there is a abnormal water vapor transport from northeast to southwest and a negative abnormal belt of the meridional water vapor transport from Sichuan C hongqing Region to IndoChina, which lead to a center of the abnormal divergen ce of the water vapor over SichuanChongqing Region. This kind of situation of the abnormal water vapor field is advantageous to the development of the drought. At the same time, the subtropical high over the western Pacific that is stronger and extends westward and northward far more contrasting to the case of climate mean, together with the extending eastward Iranian high and the abnormal Tibetan high constitute a belt of high pressure. This abnormal situation of high pressu re accelerates the development of the drought to a large degree.
In order to study the disaster of the heavy drought occurring in SichuanChongq ing Region in midsummer 2006, the atmospheric circulation anomaly over East Asia is analyzed to investigate the causes of the drought. The results sho w that there is a abnormal water vapor transport from northeast to southwest and a negative abnormal belt of the meridional water vapor transport from Sichuan C hongqing Region to IndoChina, which lead to a center of the abnormal divergen ce of the water vapor over SichuanChongqing Region. This kind of situation of the abnormal water vapor field is advantageous to the development of the drought. At the same time, the subtropical high over the western Pacific that is stronger and extends westward and northward far more contrasting to the case of climate mean, together with the extending eastward Iranian high and the abnormal Tibetan high constitute a belt of high pressure. This abnormal situation of high pressu re accelerates the development of the drought to a large degree.
2009, 35(8):35-41.
DOI: 10.7519/j.issn.1000-0526.2009.8.004
Abstract:
The contribution of diabatic heating to vertical velocity in ω equation for two Meiyu heavyrainfall events occurring 9-10 June 2008 is calculated by us ing the NECP reanalysis data. The feedback mechanism of latent heat release to the Meiyu heavyrainfall systems is interpreted. It is found that the late nt heat release may enhance the ascending motion above the rainfall area and promo te the development of mesoscale systems. The analysis also shows that there are two different kinds of precipitation in the Meiyu front: one is the largescal e continuous precipitation associated with shear line and low vortex; another is the mesoscale heavy rainfall caused by convective heating. Besides that, the dy namic lifting and friction forcing of mountain to the rainfall amplification can not be ignored.
The contribution of diabatic heating to vertical velocity in ω equation for two Meiyu heavyrainfall events occurring 9-10 June 2008 is calculated by us ing the NECP reanalysis data. The feedback mechanism of latent heat release to the Meiyu heavyrainfall systems is interpreted. It is found that the late nt heat release may enhance the ascending motion above the rainfall area and promo te the development of mesoscale systems. The analysis also shows that there are two different kinds of precipitation in the Meiyu front: one is the largescal e continuous precipitation associated with shear line and low vortex; another is the mesoscale heavy rainfall caused by convective heating. Besides that, the dy namic lifting and friction forcing of mountain to the rainfall amplification can not be ignored.
2009, 35(8):42-48.
DOI: 10.7519/j.issn.1000-0526.2009.8.005
Abstract:
Typhoon rainstorm can induce geological hazards such as landslides and debris flows and cause serious casualties consequently. Highresolution data a re essential for highresolution geological hazard prediction. Yueqing in Zhejia ng Province is selected as the studied area, which is frequently attacked by typh oons and is seriously influenced by geological hazards. Geological hazards induc ed by typhoon No.0414, No.0505 and No.0509 are taken as samples. Applicabilit y of radar rainfall estimation is assessed for the studied area. Relations betwe en typhoon rainstorms and geological hazard occurrences are carefully studied by use of radarraingauge rainfall estimation. The results show that the radar ra infall estimation can reflect the characteristics of triggering rainfall of geolo gical hazards in great details. Typhoon induced geological hazards need shorter rainfall duration, smaller effective rainfall, but higher critical rainfall inte nsity.
Typhoon rainstorm can induce geological hazards such as landslides and debris flows and cause serious casualties consequently. Highresolution data a re essential for highresolution geological hazard prediction. Yueqing in Zhejia ng Province is selected as the studied area, which is frequently attacked by typh oons and is seriously influenced by geological hazards. Geological hazards induc ed by typhoon No.0414, No.0505 and No.0509 are taken as samples. Applicabilit y of radar rainfall estimation is assessed for the studied area. Relations betwe en typhoon rainstorms and geological hazard occurrences are carefully studied by use of radarraingauge rainfall estimation. The results show that the radar ra infall estimation can reflect the characteristics of triggering rainfall of geolo gical hazards in great details. Typhoon induced geological hazards need shorter rainfall duration, smaller effective rainfall, but higher critical rainfall inte nsity.
2009, 35(8):49-60.
DOI: 10.7519/j.issn.1000-0526.2009.8.006
Abstract:
On the basis of the CLM3 (Community Land Model 3) simulated soil and c anopy evaporation, the climatology and spatialtemporal variations of the land w ater resource in China are investigated. The distribution of annual mean water r esource is similar to that of annual mean precipitation in China, with a patt ern of the largest in the south of Yangtze River and the smallest in Xinjiang, d ecreasing gradually from southeast to northwest. The total evaporation shows a c lose relationship with the precipitation, with the high evaporation region locat ed in south of 35°N and the low evaporation area in north of 35°N, especially in the northwest, where mean annual evaporation may be below 50 mm. From the distr ibution of evaporation index, we can see a different pattern, in which the high regions are located in northern China and the low regions are in southern China. Analyses of the linear trend show that the land water resource has decreased in most regions of China including northern China north of 35°N except northern T ibetan Plateau, western Xinjiang Autonomy Region and Hetao areas, while increased in the Tibetan Plateau and southern China during the past twenty years. The dec reased (increased) atmospheric precipitable water is generally consistent with t he downward (upward) trend of the land water resource and the variation of the p recipitable water is considered as an important cause of water resource change.
On the basis of the CLM3 (Community Land Model 3) simulated soil and c anopy evaporation, the climatology and spatialtemporal variations of the land w ater resource in China are investigated. The distribution of annual mean water r esource is similar to that of annual mean precipitation in China, with a patt ern of the largest in the south of Yangtze River and the smallest in Xinjiang, d ecreasing gradually from southeast to northwest. The total evaporation shows a c lose relationship with the precipitation, with the high evaporation region locat ed in south of 35°N and the low evaporation area in north of 35°N, especially in the northwest, where mean annual evaporation may be below 50 mm. From the distr ibution of evaporation index, we can see a different pattern, in which the high regions are located in northern China and the low regions are in southern China. Analyses of the linear trend show that the land water resource has decreased in most regions of China including northern China north of 35°N except northern T ibetan Plateau, western Xinjiang Autonomy Region and Hetao areas, while increased in the Tibetan Plateau and southern China during the past twenty years. The dec reased (increased) atmospheric precipitable water is generally consistent with t he downward (upward) trend of the land water resource and the variation of the p recipitable water is considered as an important cause of water resource change.
2009, 35(8):61-69.
DOI: 10.7519/j.issn.1000-0526.2009.8.007
Abstract:
Based on NCEP／NCAR daily reanalysis data in July 2004, the moisture a nd wind fields of heavy rain events in Guangxi are analyzed. Results show that t he evaluation of heavy rain has a good correspondence to the variety of moisture and watervapor content increased before the heavy rain happened. The occurren ce and break of heavy rain is closely associated with the strengthening and brea k of summer monsoon. There is a remarkable difference of the vapor inflow and ou tflow between heavy rain period and nonheavy rain period. South China Sea is t he main water vapor source, while the Bengal and the West Pacific Ocean also pla y the important roles in heavy rain period besides South China Sea. And the wate r vapor income of heavy rain period is much more than that of nonheavy rain pe riod.
Based on NCEP／NCAR daily reanalysis data in July 2004, the moisture a nd wind fields of heavy rain events in Guangxi are analyzed. Results show that t he evaluation of heavy rain has a good correspondence to the variety of moisture and watervapor content increased before the heavy rain happened. The occurren ce and break of heavy rain is closely associated with the strengthening and brea k of summer monsoon. There is a remarkable difference of the vapor inflow and ou tflow between heavy rain period and nonheavy rain period. South China Sea is t he main water vapor source, while the Bengal and the West Pacific Ocean also pla y the important roles in heavy rain period besides South China Sea. And the wate r vapor income of heavy rain period is much more than that of nonheavy rain pe riod.
2009, 35(8):70-75.
DOI: 10.7519/j.issn.1000-0526.2009.8.008
Abstract:
By using the data observed by Doppler weather radar, duallinear polarization a nd entirephaseparameter weather radar (on 3 cm waveband), lightning locati on net and precipitation observation stations, the effect of 4 seeding experimen ts in eastern Hubei in 2007 are analyzed. The results show that there are incre asing changes of the Doppler echo characteristics of the target cloud in short time after seeding, including the intensity and area of strong ec hoes, echo tops, the value and the area of larger VIL, these factors reach the m aximum in 25 min. Compared with the contrast cloud, the enlargement rate of seed ed cloud is large. The FY2C data cannot reflect the seeding effect on convective cloud, but on stratus cloud, the cloudtop height rises while the cloud top te mperature reduces, supercooled cloud thickness increases, the effective partic le radius maintains the big granule level and the cloud top brightness temperatu re drops. The dualpolarization factors including Ldr and ρhv (area of l arge value), the frequency (maximum appearing at 18th minute) and intensity of l ightning all vary. Main rainfall period is centralized in half an hour from the 10th minute, and the rainfall intensity and duration of seeded cloud are more th an those of contrast cloud.
By using the data observed by Doppler weather radar, duallinear polarization a nd entirephaseparameter weather radar (on 3 cm waveband), lightning locati on net and precipitation observation stations, the effect of 4 seeding experimen ts in eastern Hubei in 2007 are analyzed. The results show that there are incre asing changes of the Doppler echo characteristics of the target cloud in short time after seeding, including the intensity and area of strong ec hoes, echo tops, the value and the area of larger VIL, these factors reach the m aximum in 25 min. Compared with the contrast cloud, the enlargement rate of seed ed cloud is large. The FY2C data cannot reflect the seeding effect on convective cloud, but on stratus cloud, the cloudtop height rises while the cloud top te mperature reduces, supercooled cloud thickness increases, the effective partic le radius maintains the big granule level and the cloud top brightness temperatu re drops. The dualpolarization factors including Ldr and ρhv (area of l arge value), the frequency (maximum appearing at 18th minute) and intensity of l ightning all vary. Main rainfall period is centralized in half an hour from the 10th minute, and the rainfall intensity and duration of seeded cloud are more th an those of contrast cloud.
2009, 35(8):76-84.
DOI: 10.7519/j.issn.1000-0526.2009.8.009
Abstract:
Based on the observational data in August 2006 obtained by buoys, automatic weat her stations and radio sounding in Qingdao Region, a typical landsea breeze ca se is studied in detail, and verified by WRF modeling results. The results indic ate that both sea breeze circulation and land breeze circulation in the vertical direction are closed, and the thickness of seabreeze circulation is much thic ker than land breeze circulation. Seabreeze appears and disappears firstly in the lower level, which is strongest in the afternoon. The wind force decreases w ith height. When the landsea temperature difference between Qingdao Station an d buoy station reaches to 4℃，sea breeze occurs，which can extend to inland about more than 40km. The WRF model successfully captures the sea breeze circulation, and reveals the interaction b etween sea breezes on both sides of the peninsula, which results in the converge nce and ascending in the middle part of the peninsula.
Based on the observational data in August 2006 obtained by buoys, automatic weat her stations and radio sounding in Qingdao Region, a typical landsea breeze ca se is studied in detail, and verified by WRF modeling results. The results indic ate that both sea breeze circulation and land breeze circulation in the vertical direction are closed, and the thickness of seabreeze circulation is much thic ker than land breeze circulation. Seabreeze appears and disappears firstly in the lower level, which is strongest in the afternoon. The wind force decreases w ith height. When the landsea temperature difference between Qingdao Station an d buoy station reaches to 4℃，sea breeze occurs，which can extend to inland about more than 40km. The WRF model successfully captures the sea breeze circulation, and reveals the interaction b etween sea breezes on both sides of the peninsula, which results in the converge nce and ascending in the middle part of the peninsula.
2009, 35(8):85-90.
DOI: 10.7519/j.issn.1000-0526.2009.8.010
Abstract:
Based on the daily observation data of rain rime and fog rime in Jinhu a during 1953-2008, characters of wire icing, such as the variatio n in the age, year, season, month, and the beginning and ending time, the durati on, the largest diameter were analyzed. At the same time, the analyses of the fo rmation conditions and characters of the disaster of wire icing in Jinhua were carried out. Th e results showed that the average day of wire icing in Jinhua was 0.8 d each year , which concentrated in winter. The maximum appeared in January, followed by Febr uary, and the minimum appeared in December. Wire icing can occur at any time in one day. The first date of the appearance of wire icing was on December 10, and the latest date was on February 19. The longest duration was 64 h, and the largest diameter was 16 mm. The formation conditions of rain rime and fog rime were different. The disaster of rain rime was worse than the fog rime when thelargest diameter of them was the same. And the ice disaster in electric power was more serious in high mountains than in hills or basins. Finally, specific measures a bout the defense of the disaster were put forward based on the analysis of chara cteristics of wire icing.
Based on the daily observation data of rain rime and fog rime in Jinhu a during 1953-2008, characters of wire icing, such as the variatio n in the age, year, season, month, and the beginning and ending time, the durati on, the largest diameter were analyzed. At the same time, the analyses of the fo rmation conditions and characters of the disaster of wire icing in Jinhua were carried out. Th e results showed that the average day of wire icing in Jinhua was 0.8 d each year , which concentrated in winter. The maximum appeared in January, followed by Febr uary, and the minimum appeared in December. Wire icing can occur at any time in one day. The first date of the appearance of wire icing was on December 10, and the latest date was on February 19. The longest duration was 64 h, and the largest diameter was 16 mm. The formation conditions of rain rime and fog rime were different. The disaster of rain rime was worse than the fog rime when thelargest diameter of them was the same. And the ice disaster in electric power was more serious in high mountains than in hills or basins. Finally, specific measures a bout the defense of the disaster were put forward based on the analysis of chara cteristics of wire icing.
2009, 35(8):91-97.
DOI: 10.7519/j.issn.1000-0526.2009.8.011
Abstract:
Three upper air sounding stations of Jilin Province, Changchun, Linjia ng, and Yanji, are located on middle plain, south mountain area, and east basin of the province, respectively. Temporal and spatial distribution characteristics , statistical characteristics, synoptic and climatic features, and causes of tem perature inversion occurring in the winter of Jilin Province are analyzed on the basis of the data from three stations mentioned above. Analysis results indicat e that (1) the inversion is of high frequency in the middle plain, median in the mountain area, and low in the east basin, but the frequency of severe inversion is on the opposite; (2) the inversion base often lies near the surface in the middle plain, below 400m in the mountain area, and below 200m in the basin; (3) the thickness of the severe inversion on surface is usually less than 1000m; ( 4) inversions in the plain and mountain area are mainly caused by radiation and subsidence, whileinversions in the basin can be caused by radiation and subside nce, or advection. The situation field characteristics of different inversions a re also studied.
Three upper air sounding stations of Jilin Province, Changchun, Linjia ng, and Yanji, are located on middle plain, south mountain area, and east basin of the province, respectively. Temporal and spatial distribution characteristics , statistical characteristics, synoptic and climatic features, and causes of tem perature inversion occurring in the winter of Jilin Province are analyzed on the basis of the data from three stations mentioned above. Analysis results indicat e that (1) the inversion is of high frequency in the middle plain, median in the mountain area, and low in the east basin, but the frequency of severe inversion is on the opposite; (2) the inversion base often lies near the surface in the middle plain, below 400m in the mountain area, and below 200m in the basin; (3) the thickness of the severe inversion on surface is usually less than 1000m; ( 4) inversions in the plain and mountain area are mainly caused by radiation and subsidence, whileinversions in the basin can be caused by radiation and subside nce, or advection. The situation field characteristics of different inversions a re also studied.
He Junjie
,
Wang Yingshun
,
Guo Lizhi
,
Ji Gang
,
Chen Li
,
Huang Fengru
,
Li Wei
,
Wang Ruojing
,
Zhao Haijie
2009, 35(8):98-103.
DOI: 10.7519/j.issn.1000-0526.2009.8.012
Abstract:
According to the ecological and agrometeorological service demand, th e monitoring and evaluation service system of ecologicalagrometeorology in reg ional level was developed and applied. The system can transfer all kinds of ecol ogical and agricultural observed data rapidly in different stations, and store d ata efficiently. It provides functions such as analyzing the input data, control ling data quality, making various tables and figures of service information on t ime based on communications network, by adopting the Client/Server (C/S) p lot structure and by fully using database management technology, network communi cation and multimedia. This system will provide the efficient information servic es for government and production manager.
According to the ecological and agrometeorological service demand, th e monitoring and evaluation service system of ecologicalagrometeorology in reg ional level was developed and applied. The system can transfer all kinds of ecol ogical and agricultural observed data rapidly in different stations, and store d ata efficiently. It provides functions such as analyzing the input data, control ling data quality, making various tables and figures of service information on t ime based on communications network, by adopting the Client/Server (C/S) p lot structure and by fully using database management technology, network communi cation and multimedia. This system will provide the efficient information servic es for government and production manager.
2009, 35(8):104-108.
DOI: 10.7519/j.issn.1000-0526.2009.8.013
Abstract:
The related equations and characteristic equation were established on the basis of Changsha Doppler radar echo and surface rainfall parameter. S u rface rainfall data of 27 summer cumulus were calculated to test the established relationships, then some estimation equations about single factor or multiple fa ctors were gained. The results show that the most rain intensity is correlated w e ll with echo height in the range of 50～100 kilometers, in multiple factors corr elated equations, the surface rainfall is proportional to the horizontal scale and echo height, and is inversely proportional to the echo moving speed.
The related equations and characteristic equation were established on the basis of Changsha Doppler radar echo and surface rainfall parameter. S u rface rainfall data of 27 summer cumulus were calculated to test the established relationships, then some estimation equations about single factor or multiple fa ctors were gained. The results show that the most rain intensity is correlated w e ll with echo height in the range of 50～100 kilometers, in multiple factors corr elated equations, the surface rainfall is proportional to the horizontal scale and echo height, and is inversely proportional to the echo moving speed.
2009, 35(8):109-111.
DOI: 10.7519/j.issn.1000-0526.2009.8.014
Abstract:
There are a lot of disputatious problems on the lightning prevention dome of gas station, such as the installation space between two surge protective device (SP D), the length of earth conductor, as well as the abnormal resistance of earth e lectrode. These complicated and confusing problems are investigated by ap plying the modern electrical knowledge and combining with a lot of lightning pre vention practices. It is important to correctly understand and apply the lightni ng prevention regulations.
There are a lot of disputatious problems on the lightning prevention dome of gas station, such as the installation space between two surge protective device (SP D), the length of earth conductor, as well as the abnormal resistance of earth e lectrode. These complicated and confusing problems are investigated by ap plying the modern electrical knowledge and combining with a lot of lightning pre vention practices. It is important to correctly understand and apply the lightni ng prevention regulations.
2009, 35(8):112-117.
DOI: 10.7519/j.issn.1000-0526.2009.8.015
Abstract:
In order to better apply the mediumrange forecast products of the T639 model， s ome synoptic verification from March to May 2009 are made in comparison with ECM WF and Japan models. The result shows that three models all have good forecastin g performanes. Comparably, the ECMWF is better than T639 and Japan models in forecasting the evolution and modification of the atmosphere circulation in middle and highlatitude, and the trend of temperature in 850hPa. Taking the sandstorm process during the period of 23-25th in April as a case, T639 mo del can predict well in aspect of forcecasting surface strong wind in the proces s of the sandstorm compared with Japan and ECMWF models.
In order to better apply the mediumrange forecast products of the T639 model， s ome synoptic verification from March to May 2009 are made in comparison with ECM WF and Japan models. The result shows that three models all have good forecastin g performanes. Comparably, the ECMWF is better than T639 and Japan models in forecasting the evolution and modification of the atmosphere circulation in middle and highlatitude, and the trend of temperature in 850hPa. Taking the sandstorm process during the period of 23-25th in April as a case, T639 mo del can predict well in aspect of forcecasting surface strong wind in the proces s of the sandstorm compared with Japan and ECMWF models.
Mobile website
® 2024 All Rights Reserved
Supported by:Beijing E-Tiller Technology Development Co., Ltd.
ISSN:1000-0526 CN:11-2282/P