ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 34,Issue 1,2008 Table of Contents
2008, 34(1):3-11.
DOI: 10.7519/j.issn.1000-0526.2008.01.001
Abstract:
Making nowcasting and severe weather warning by New Generation Weather Radar nee d to Start from radar observations. Different weather systems must to use diffe rent methods of radar observations. Different observation methods and different f orcast objects must to use different process methods of radar data for stressin g echo characters. Nowcasting and severe weather warning are producted on the bas is of radar echo analyses. Radar echo analyses need to grasp whole process of ec ho evolutions. Synoptic systems of impacting local weather are resolved accordin g to the echo analyses. Severe weathers are distinguished with [JP2]echo charact ers, future development trends of echo are understood by echo evolutions. For identified severe weathers with radar echos, signature recognitions and discerning means are built by the researches and the statistics of radar echoes. The main nowcasting method is the extrapolation, but the forcast experience is most important. The conclusion of the nowcasting is drawn by the forecasters bas ed on their forecast experiences. Nowcasting technological processes needs to be formulated for better nowcasting and severe weather warning.
Making nowcasting and severe weather warning by New Generation Weather Radar nee d to Start from radar observations. Different weather systems must to use diffe rent methods of radar observations. Different observation methods and different f orcast objects must to use different process methods of radar data for stressin g echo characters. Nowcasting and severe weather warning are producted on the bas is of radar echo analyses. Radar echo analyses need to grasp whole process of ec ho evolutions. Synoptic systems of impacting local weather are resolved accordin g to the echo analyses. Severe weathers are distinguished with [JP2]echo charact ers, future development trends of echo are understood by echo evolutions. For identified severe weathers with radar echos, signature recognitions and discerning means are built by the researches and the statistics of radar echoes. The main nowcasting method is the extrapolation, but the forcast experience is most important. The conclusion of the nowcasting is drawn by the forecasters bas ed on their forecast experiences. Nowcasting technological processes needs to be formulated for better nowcasting and severe weather warning.
2008, 34(1):12-17.
DOI: 10.7519/j.issn.1000-0526.2008.01.002
Abstract:
By using 19952005 lightning disaster data and 19952002 LIS/OTD light ning data over Beijing, a contrast analysis of lightning activity with lightning di saster in temporal and spatial characteristics over Beijing was conducted. Resu lts show that the diurnal variation of lightning activity and lightning disaster is generally agreement. The disagreement might be a result of human behavior an d electrical/magnetical environment. The seasonal variation is also generally a ccordant. In summer, the peak period of lightning disaster is in August, but mos t lightning activity occurs in July. This research also shows that the spatial c haracteristics of lightning activity withlightning disaster are obviously different. There are more lightning act ivities in the north of Beijing but less lightning disasters. By contraries, there are less lightning activities but more lightning disasters over the periphery of the city. Based on the economic and population data of eighteen boroughs, further analy sis shows that lightning activity is only one of reasons which lead to lightning d isasters. The lightning disaster is also related to economic development and popu lation density.
By using 19952005 lightning disaster data and 19952002 LIS/OTD light ning data over Beijing, a contrast analysis of lightning activity with lightning di saster in temporal and spatial characteristics over Beijing was conducted. Resu lts show that the diurnal variation of lightning activity and lightning disaster is generally agreement. The disagreement might be a result of human behavior an d electrical/magnetical environment. The seasonal variation is also generally a ccordant. In summer, the peak period of lightning disaster is in August, but mos t lightning activity occurs in July. This research also shows that the spatial c haracteristics of lightning activity withlightning disaster are obviously different. There are more lightning act ivities in the north of Beijing but less lightning disasters. By contraries, there are less lightning activities but more lightning disasters over the periphery of the city. Based on the economic and population data of eighteen boroughs, further analy sis shows that lightning activity is only one of reasons which lead to lightning d isasters. The lightning disaster is also related to economic development and popu lation density.
2008, 34(1):18-26.
DOI: 10.7519/j.issn.1000-0526.2008.01.003
Abstract:
By use of the next generation mesoscale nonhydrostatic model WRF, a backflow snowstorm over North China on Nov.24-26,2004 was simulated and analyze d. The development mechanisms of backflow precipitation are analyzed with the r easonable simulation results. The results show that dynamical frontogenesis play s a very important role in the development of backflow snowstorm. The frontogene tical secondary circulation directly causes the snowstorm. Mount Tai plays a ver y important role in the case and makes the positive and minus extremes of vertic al velocity in the upslope and lee, respectively. Meanwhile it affects the dist ribution of rain water and cloud water.
By use of the next generation mesoscale nonhydrostatic model WRF, a backflow snowstorm over North China on Nov.24-26,2004 was simulated and analyze d. The development mechanisms of backflow precipitation are analyzed with the r easonable simulation results. The results show that dynamical frontogenesis play s a very important role in the development of backflow snowstorm. The frontogene tical secondary circulation directly causes the snowstorm. Mount Tai plays a ver y important role in the case and makes the positive and minus extremes of vertic al velocity in the upslope and lee, respectively. Meanwhile it affects the dist ribution of rain water and cloud water.
2008, 34(1):27-34.
DOI: 10.7519/j.issn.1000-0526.2008.01.004
Abstract:
With the conventional and intensive observation data and FY-2 satellite products, the mesoscale convective systems (MCSs) that caused th e “7.18" severe heavy rain over Jinan are analyzed. The mesoscale convergence center and line played important roles. Furthermore, the severe heavy rain occurr ed near the center of mesoscale low pressure and accompanied with them. The ne w cloud clusters which generated behind the right rear of the weakened clouds dev eloped from mesoγ to mesoβ scale. Under enough vapor conditions, they expa nded into compacted αscale clouds with a clear edge that directly caused the se vere heavy rain. The maximum precipitation was strongly related to the lowest TBB measured by FY2 satellite, therefore, FY-2 satellite products is very impor tant in nowcasting.
With the conventional and intensive observation data and FY-2 satellite products, the mesoscale convective systems (MCSs) that caused th e “7.18" severe heavy rain over Jinan are analyzed. The mesoscale convergence center and line played important roles. Furthermore, the severe heavy rain occurr ed near the center of mesoscale low pressure and accompanied with them. The ne w cloud clusters which generated behind the right rear of the weakened clouds dev eloped from mesoγ to mesoβ scale. Under enough vapor conditions, they expa nded into compacted αscale clouds with a clear edge that directly caused the se vere heavy rain. The maximum precipitation was strongly related to the lowest TBB measured by FY2 satellite, therefore, FY-2 satellite products is very impor tant in nowcasting.
2008, 34(1):35-40.
DOI: 10.7519/j.issn.1000-0526.2008.01.005
Abstract:
Analysis and identification on seeding opportunity for enhancing rainf all in a convectional precipitation case occurred in northwestern Hubei, a mount ainous area, are introduced. Firstly, based on a fully elastic threedimensiona l and dualparameter cumulus cloud numerical model, a series of sensitive model ing tests on seeding AgI agent in a variety of time is conducted to analyze how various seeding time affects the result of precipitation enhancement and its pre cipitation physical mechanism. It is concluded that the appropriate seeding oppo rtunity is at the earlyperiod when a convective cloud is developing after its ori ginal formation. According to the results of simulation analysis in this case an d based on radar data, the method of detecting appropriate seeding opportunity i s discussed by analyzing forming and developing characteristics of convective ce ll echoes in the entire precipitation process.
Analysis and identification on seeding opportunity for enhancing rainf all in a convectional precipitation case occurred in northwestern Hubei, a mount ainous area, are introduced. Firstly, based on a fully elastic threedimensiona l and dualparameter cumulus cloud numerical model, a series of sensitive model ing tests on seeding AgI agent in a variety of time is conducted to analyze how various seeding time affects the result of precipitation enhancement and its pre cipitation physical mechanism. It is concluded that the appropriate seeding oppo rtunity is at the earlyperiod when a convective cloud is developing after its ori ginal formation. According to the results of simulation analysis in this case an d based on radar data, the method of detecting appropriate seeding opportunity i s discussed by analyzing forming and developing characteristics of convective ce ll echoes in the entire precipitation process.
2008, 34(1):41-47.
DOI: 10.7519/j.issn.1000-0526.2008.01.006
Abstract:
Based upon 3 pairs of cumulus in the Jianghuai area cumulus cloudsee ding experiment，a contrast anal ysis of echo characteristics of CINRAD between the target cloud and the referenc e cloud was performed．It was found that the average lasted time of the target c loud was 51.2% longer than that of the reference cloud and the average echo area of the target cloud was 17% larger than that of the reference．And the average water content of per volumn scanning of the target cloud was larger than that of the reference, with a difference of 46% between the target cloud and the refere nce in the whole life time of clouds． It concluded that the seeded could increa se the area of echo, prolong the lasting time of the echo, and increase the wate r content of clouds in its whole life．Besides, from one pair of cumulus, it was found that the time of seeding was rather important for convective cloud. If the convective cloud is situated in its weakening phase, seeding coul d not increase the water content and couldn't prolong its life as well．
Based upon 3 pairs of cumulus in the Jianghuai area cumulus cloudsee ding experiment，a contrast anal ysis of echo characteristics of CINRAD between the target cloud and the referenc e cloud was performed．It was found that the average lasted time of the target c loud was 51.2% longer than that of the reference cloud and the average echo area of the target cloud was 17% larger than that of the reference．And the average water content of per volumn scanning of the target cloud was larger than that of the reference, with a difference of 46% between the target cloud and the refere nce in the whole life time of clouds． It concluded that the seeded could increa se the area of echo, prolong the lasting time of the echo, and increase the wate r content of clouds in its whole life．Besides, from one pair of cumulus, it was found that the time of seeding was rather important for convective cloud. If the convective cloud is situated in its weakening phase, seeding coul d not increase the water content and couldn't prolong its life as well．
2008, 34(1):48-53.
DOI: 10.7519/j.issn.1000-0526.2008.01.007
Abstract:
By using the NCEP reanalysed data，the conventional observation data and Doppler radar data of the synoptic and mesoscale characteristics of t wo strong convective weather in Hexi Corridor are analyzed. The results show tha t they are differ greatly from each other on the circulation and mesoscale syste m. A rightmoving squallline(cyclone) led to the hail on 7 July 2006. In cont rast, a stong leftmoving (anticyclone) supercell brought on the hail on 10 Aug ust 2006. The value of stormrelative helicity(SRH) for rightmoving squalll ine is positive in the 0-3km layer, while the value of stormrelative helicity (SRH) for leftmoving supercell is negative during development.
By using the NCEP reanalysed data，the conventional observation data and Doppler radar data of the synoptic and mesoscale characteristics of t wo strong convective weather in Hexi Corridor are analyzed. The results show tha t they are differ greatly from each other on the circulation and mesoscale syste m. A rightmoving squallline(cyclone) led to the hail on 7 July 2006. In cont rast, a stong leftmoving (anticyclone) supercell brought on the hail on 10 Aug ust 2006. The value of stormrelative helicity(SRH) for rightmoving squalll ine is positive in the 0-3km layer, while the value of stormrelative helicity (SRH) for leftmoving supercell is negative during development.
2008, 34(1):54-58.
DOI: 10.7519/j.issn.1000-0526.2008.01.008
Abstract:
Based on the data obtained from the Tianjin 255m meteorological tower in recent 10 years, the surface roughness was estimated by using logarith mic wind profile under the condition of neutral stratification. The results show that the surface roughness is increasing with the development of the urb anization in recent decades．The increased amplitude of the surface roughness over urban land surface is not the same in different azimuth, which is acco rded with the urban construction speed． At the same time, the effect of urbaniz ation on the urban wind field structure was studied. It shows that wind directio n especially near the ground is affected most, and the wind speed, especially ne ar the ground, decreased year by year. The thickness of urban canopy increased 10 m during the last 10 years, and now is between 40～60m.
Based on the data obtained from the Tianjin 255m meteorological tower in recent 10 years, the surface roughness was estimated by using logarith mic wind profile under the condition of neutral stratification. The results show that the surface roughness is increasing with the development of the urb anization in recent decades．The increased amplitude of the surface roughness over urban land surface is not the same in different azimuth, which is acco rded with the urban construction speed． At the same time, the effect of urbaniz ation on the urban wind field structure was studied. It shows that wind directio n especially near the ground is affected most, and the wind speed, especially ne ar the ground, decreased year by year. The thickness of urban canopy increased 10 m during the last 10 years, and now is between 40～60m.
2008, 34(1):59-65.
DOI: 10.7519/j.issn.1000-0526.2008.01.009
Abstract:
Taking Olympic weather service as a case, a brand new assessment method of socio economic impact was put forward, which constructs an Assembled Matrix model of Importance Degree and Satisfaction Degree of weather service. The method synth etically combines the Analytic Hierarchy Process (AHP) method and Boston Consult ing Group Matrix (BCG) method together to get quantitative AHP/BCG matrix model and makes the complex thinking process of users mathematic and systematiz ation. Taking “Good Luck Beijing 2007 Qingdao International Regatta" as an practical case, the model tries to measure six chief items: realizing and meeting users' needs, timely and efficient service, and dissemination approaches (websites, users' manual and so on), ability of server, forecast accuracy, and users' future choice after the game. Through this assembled matrix model it coul d measure the current structures and corresponding position on four quadrants in the matrix model of each item, find problems and try to solve them, and forecast th eir development direction.
Taking Olympic weather service as a case, a brand new assessment method of socio economic impact was put forward, which constructs an Assembled Matrix model of Importance Degree and Satisfaction Degree of weather service. The method synth etically combines the Analytic Hierarchy Process (AHP) method and Boston Consult ing Group Matrix (BCG) method together to get quantitative AHP/BCG matrix model and makes the complex thinking process of users mathematic and systematiz ation. Taking “Good Luck Beijing 2007 Qingdao International Regatta" as an practical case, the model tries to measure six chief items: realizing and meeting users' needs, timely and efficient service, and dissemination approaches (websites, users' manual and so on), ability of server, forecast accuracy, and users' future choice after the game. Through this assembled matrix model it coul d measure the current structures and corresponding position on four quadrants in the matrix model of each item, find problems and try to solve them, and forecast th eir development direction.
2008, 34(1):66-71.
DOI: 10.7519/j.issn.1000-0526.2008.01.010
Abstract:
Using fog data and weather observation data around Beijing,Tianji n,Tanggu stations from 1949 to 2002, the characteristic and weather conditions o f fog over JingJinTang expressway are analyzed. Results show that the annual mea n fog days are between 15 and 19 days along the JingJinTang expressway. The int erannual changes of fog between Beijing and Tianjin stations are same. But th ere is a little downtrend for fog days in Beijing, while a little uptrend in Tia nJin and Tanggu. The fog appears easily from wee hours to the time around sunris e, and disappers gradually after sunrise over JingJinTang expressway . There is an index degression correlation between the duration of fog and time. The weather factors such as the surface temperature, relative humidity, wind sp eed and so on have good indications for fog forecasting over the JingJinTang exp ressway. When the surface temperature is between -5℃ and 5℃, the wind speed is less than 4m?s-1 and the relative humidity is between 90% and 100%, fog appears more easily.
Using fog data and weather observation data around Beijing,Tianji n,Tanggu stations from 1949 to 2002, the characteristic and weather conditions o f fog over JingJinTang expressway are analyzed. Results show that the annual mea n fog days are between 15 and 19 days along the JingJinTang expressway. The int erannual changes of fog between Beijing and Tianjin stations are same. But th ere is a little downtrend for fog days in Beijing, while a little uptrend in Tia nJin and Tanggu. The fog appears easily from wee hours to the time around sunris e, and disappers gradually after sunrise over JingJinTang expressway . There is an index degression correlation between the duration of fog and time. The weather factors such as the surface temperature, relative humidity, wind sp eed and so on have good indications for fog forecasting over the JingJinTang exp ressway. When the surface temperature is between -5℃ and 5℃, the wind speed is less than 4m?s-1 and the relative humidity is between 90% and 100%, fog appears more easily.
2008, 34(1):72-79.
DOI: 10.7519/j.issn.1000-0526.2008.01.011
Abstract:
Standard Effective Temperature (SET) is the best thermal comfort index induced from human heat balance model so far. SET is used to analyze the therma l comfort in nonheating period in Harbin. In actual environment, one person ma y feel too cold or too hot when he/she wears different clothes and takes differen t activity. For lots of people, the environment can't make all of them feel comf ort because every individual has different feeling about the environment and has different standard of comfort. So, discomfort index (DISC) is adopted in this p aper to analyze the degree of discomfort in Harbin. Based on data of hourly temperature, hourly relative humility and hourly wind speed in nonheati ng period (from 20 April to 20 October) in 2005 in Harbin, average threehour te mperature, relative humility and wind speed of every period of ten days from 20 A pril to 30 May and from 1 September to 20 October are calculated. Average three hour temperature, relative humility and wind speed of every month from June to O ctober are calculated too. And based on the thermal comfort figures in the book “Architecture. Climate.Energy", the method of interpolation is applied to obta in the SET and DISC values of everythreehour of every period of ten days. Som e conclusions are: If people in Harbin wear clothes for which clothing thermal res istance is 0.6, such as trousers, semisleeve shirt or longsleeve shirt, from June to August and people wear clothes for which clothing thermal resistance is 0 .9, such as trousers, longsleeve shirt, and jacket in other periods, there are no period to make eighty percent of people feel thermal comfor t when people work at a table in a room. From 10:00 to 18:00 in a day of thelasttenday of May to thefirsttenday of September, seventy per cent of people feel comfort. People can feel cold in 75 percent of a day during the pe riod from thelasttenday of April to thefirsttenday of May. People ca n feel very cold in half a day during the period from thelasttenday of Sep tember to thefirsttenday of October. So, in nonheating period in Harbin, people may wear warmer clothes to offset the discomfort.
Standard Effective Temperature (SET) is the best thermal comfort index induced from human heat balance model so far. SET is used to analyze the therma l comfort in nonheating period in Harbin. In actual environment, one person ma y feel too cold or too hot when he/she wears different clothes and takes differen t activity. For lots of people, the environment can't make all of them feel comf ort because every individual has different feeling about the environment and has different standard of comfort. So, discomfort index (DISC) is adopted in this p aper to analyze the degree of discomfort in Harbin. Based on data of hourly temperature, hourly relative humility and hourly wind speed in nonheati ng period (from 20 April to 20 October) in 2005 in Harbin, average threehour te mperature, relative humility and wind speed of every period of ten days from 20 A pril to 30 May and from 1 September to 20 October are calculated. Average three hour temperature, relative humility and wind speed of every month from June to O ctober are calculated too. And based on the thermal comfort figures in the book “Architecture. Climate.Energy", the method of interpolation is applied to obta in the SET and DISC values of everythreehour of every period of ten days. Som e conclusions are: If people in Harbin wear clothes for which clothing thermal res istance is 0.6, such as trousers, semisleeve shirt or longsleeve shirt, from June to August and people wear clothes for which clothing thermal resistance is 0 .9, such as trousers, longsleeve shirt, and jacket in other periods, there are no period to make eighty percent of people feel thermal comfor t when people work at a table in a room. From 10:00 to 18:00 in a day of thelasttenday of May to thefirsttenday of September, seventy per cent of people feel comfort. People can feel cold in 75 percent of a day during the pe riod from thelasttenday of April to thefirsttenday of May. People ca n feel very cold in half a day during the period from thelasttenday of Sep tember to thefirsttenday of October. So, in nonheating period in Harbin, people may wear warmer clothes to offset the discomfort.
2008, 34(1):80-85.
DOI: 10.7519/j.issn.1000-0526.2008.01.012
Abstract:
According to the data of daily precipitation in Hunan from 1961 to 200 4, the climatic changes and the catastrophe of extreme precipitation events are analysed. The results show that the amount and days of extreme precipitation ha s significantly increased in the recent 44 years. 1993 is the mutational site o f significant increase. Between 1994-2004 and 1991-1993 the difference of extrem e precipitation amount is 126.4 mm and the difference of extreme precipitation days is 2.05 d. The intensity of extreme precipitation has no significant mutat ion but there is an upward trend after 1993. The increase of the intensity of e xtreme precipitation is 2.25mm?d-1 between 1994-2004 and 1991-1993. In addition to the south of Yongzhou and the west of Hunan,the spacing from one to five days of extreme precipitation events showed an upw ard trend in the most areas, the Dongting Lake and the Xiangjiang River Basin in creased significantly. Extreme precipitation events mainly occurred in the secon d and third ten days of June and the first and second ten days of May. Since 199 0s, extreme precipitation events frequently occurred in the second ten days of July.
According to the data of daily precipitation in Hunan from 1961 to 200 4, the climatic changes and the catastrophe of extreme precipitation events are analysed. The results show that the amount and days of extreme precipitation ha s significantly increased in the recent 44 years. 1993 is the mutational site o f significant increase. Between 1994-2004 and 1991-1993 the difference of extrem e precipitation amount is 126.4 mm and the difference of extreme precipitation days is 2.05 d. The intensity of extreme precipitation has no significant mutat ion but there is an upward trend after 1993. The increase of the intensity of e xtreme precipitation is 2.25mm?d-1 between 1994-2004 and 1991-1993. In addition to the south of Yongzhou and the west of Hunan,the spacing from one to five days of extreme precipitation events showed an upw ard trend in the most areas, the Dongting Lake and the Xiangjiang River Basin in creased significantly. Extreme precipitation events mainly occurred in the secon d and third ten days of June and the first and second ten days of May. Since 199 0s, extreme precipitation events frequently occurred in the second ten days of July.
2008, 34(1):86-93.
DOI: 10.7519/j.issn.1000-0526.2008.01.013
Abstract:
Using American National Centre of Environmental Prediction reanalysis data and monthly precipitation data at 64 observational stations of Shanxi Province， the precipitation and temperature anomalies variation and tempora l/spatial distribution patterns in 1960-2003 summer was studied with EOF, wavelet analyse s and composite analyses methods. The first rainfall pattern over Shanxi Province was concurrent rich/seldom rain pattern. The distinctive years were selected an d the corresponding spatial distributions were made out. Summer precipitation tr ends appeared the same trend pattern with the first rainfall pattern and showed that precipitation in 43 years decreased mainly over whole Shanxi Province. With the first rainfall pattern, analyzed were the general circulation anomalies and meridional winds on 500hPa potential height field, 850hPa wind vector anomalous fields, 700hPa water vapor field and sea surface temperature anomalies and so o n. The results showed that concurrent rich rainfall pattern in Shanxi Province c orresponded to strong East Asian summer monsoon, normally appeared at the year w hen La Nina event was happening and El Nino event had happened during last winte r. While at midand high latitudes there was latitudinal+-+-anomalous circ ulation pattern, and over Asian continent there were one trough around Baikal an d two ridges around Ural Mountain and Okhotsk Sea respectively. Concurrent poor rainfall pattern corresponded to weak East Asian summer monsoon, normally appear ed at the year when El Nino event was happening and La Nina event had happened d uring last winter. At the same time, at midand high latitudes there was lati tu dinal-+-+anomalous circulation pattern, and over Asian continent there we re two troughs and one ridge. Therefore, The first rainfall pattern in Shanxi Pr ovince is strong related to the anomalous latitudinal wave train happened at mid and high latitudes and SSTA over the equatorial Pacific Ocean.
Using American National Centre of Environmental Prediction reanalysis data and monthly precipitation data at 64 observational stations of Shanxi Province， the precipitation and temperature anomalies variation and tempora l/spatial distribution patterns in 1960-2003 summer was studied with EOF, wavelet analyse s and composite analyses methods. The first rainfall pattern over Shanxi Province was concurrent rich/seldom rain pattern. The distinctive years were selected an d the corresponding spatial distributions were made out. Summer precipitation tr ends appeared the same trend pattern with the first rainfall pattern and showed that precipitation in 43 years decreased mainly over whole Shanxi Province. With the first rainfall pattern, analyzed were the general circulation anomalies and meridional winds on 500hPa potential height field, 850hPa wind vector anomalous fields, 700hPa water vapor field and sea surface temperature anomalies and so o n. The results showed that concurrent rich rainfall pattern in Shanxi Province c orresponded to strong East Asian summer monsoon, normally appeared at the year w hen La Nina event was happening and El Nino event had happened during last winte r. While at midand high latitudes there was latitudinal+-+-anomalous circ ulation pattern, and over Asian continent there were one trough around Baikal an d two ridges around Ural Mountain and Okhotsk Sea respectively. Concurrent poor rainfall pattern corresponded to weak East Asian summer monsoon, normally appear ed at the year when El Nino event was happening and La Nina event had happened d uring last winter. At the same time, at midand high latitudes there was lati tu dinal-+-+anomalous circulation pattern, and over Asian continent there we re two troughs and one ridge. Therefore, The first rainfall pattern in Shanxi Pr ovince is strong related to the anomalous latitudinal wave train happened at mid and high latitudes and SSTA over the equatorial Pacific Ocean.
2008, 34(1):94-99.
DOI: 10.7519/j.issn.1000-0526.2008.01.014
Abstract:
For partitioning precipitation of tropical cyclone(TC) in China, an Objective Sy noptic Analysis Technique（OSAT）was used on six TCs affecting China in 2005. Th e results were compared with those results using subjective technique. It showed that some station observations caused by other weather systems or interaction b etween TC and other weather systems were included because the radius D1 of cir culation around maximum TC area was set too big. So the distinguish error is hig h, but missed unlikely. In order to reduce the distinguish error, a method of se tting D1 by realtime observations circulation radius and cloud and so on was proposed. Finallythe distinguish error was reduced, but missed a little more . The new result showed that rain station numbers partitioned by improved objectiv e technique could be less than that of subjective technique because the effect o f interaction between TC and other weather systems (cold front, west wind trough etc.) was not taken into account. Shortly, the accuracy of partition was improv ed after D1 was reset by integration of observation data and cloud image and s o on instead of intensity of TC. The precision of TC precipitation partitioned b y the objective method could be accepted in operation. It could be applied in op eration.
For partitioning precipitation of tropical cyclone(TC) in China, an Objective Sy noptic Analysis Technique（OSAT）was used on six TCs affecting China in 2005. Th e results were compared with those results using subjective technique. It showed that some station observations caused by other weather systems or interaction b etween TC and other weather systems were included because the radius D1 of cir culation around maximum TC area was set too big. So the distinguish error is hig h, but missed unlikely. In order to reduce the distinguish error, a method of se tting D1 by realtime observations circulation radius and cloud and so on was proposed. Finallythe distinguish error was reduced, but missed a little more . The new result showed that rain station numbers partitioned by improved objectiv e technique could be less than that of subjective technique because the effect o f interaction between TC and other weather systems (cold front, west wind trough etc.) was not taken into account. Shortly, the accuracy of partition was improv ed after D1 was reset by integration of observation data and cloud image and s o on instead of intensity of TC. The precision of TC precipitation partitioned b y the objective method could be accepted in operation. It could be applied in op eration.
2008, 34(1):100-106.
DOI: 10.7519/j.issn.1000-0526.2008.01.015
Abstract:
Using the data of the thunderstorm days of Danzhou stations in Ha inan province from 1971 to 2000, the basic climatic characteristics of thunderstorm in Danzhou are analyzed. It is shown that the annual averaged days of thundersto rm in Danzhou are 111. Thunderstorm occurs frequently from May to August, most f requently from 13-17 in the afternoon . The general trend of the annual thunde rstorm in Danzhou has been reducing in the last 30 years. Based on the thunders torm data from 1991 to 2000, the related circulation patterns and synoptic syste ms are also studied. The synoptic patterns of thunderstorm can be divided into f ive types, which are affected by the cold air, indifferent cold high, the subtro pical high ,the tropical cyclone or related to tropical low systems respectively. The proportion of each type varies in different seasons.
Using the data of the thunderstorm days of Danzhou stations in Ha inan province from 1971 to 2000, the basic climatic characteristics of thunderstorm in Danzhou are analyzed. It is shown that the annual averaged days of thundersto rm in Danzhou are 111. Thunderstorm occurs frequently from May to August, most f requently from 13-17 in the afternoon . The general trend of the annual thunde rstorm in Danzhou has been reducing in the last 30 years. Based on the thunders torm data from 1991 to 2000, the related circulation patterns and synoptic syste ms are also studied. The synoptic patterns of thunderstorm can be divided into f ive types, which are affected by the cold air, indifferent cold high, the subtro pical high ,the tropical cyclone or related to tropical low systems respectively. The proportion of each type varies in different seasons.
2008, 34(1):107-113.
DOI: 10.7519/j.issn.1000-0526.2008.01.016
Abstract:
In order to enhance automatization of rocket operation in weather modifi cation, a longrange controlled automated rocket operation system of weather modificati on was constructed based on GIS, GPS and GPRS technology. The system takes radar as its main command means and integrates radar image analysis, early warning, o peration command, rocket state, data communication and rocket management togethe r. This system transfers operation instructions formed from command centre to th e operating rocket site by wireless communication, and realizes automatic azimut h and elevation circumvolution and automatic launch of the longrange controlle d rockets. Meanwhile some problems are well solved, such as complicated rocket o peration, unscientific parameters design, incomplete operation record, slow inst ructions transmission and so on. The application of this system provides authent ic and reliable data for operation effect test. It fills up the blank of ground automated operation instrument in the field of weather modification in China.
In order to enhance automatization of rocket operation in weather modifi cation, a longrange controlled automated rocket operation system of weather modificati on was constructed based on GIS, GPS and GPRS technology. The system takes radar as its main command means and integrates radar image analysis, early warning, o peration command, rocket state, data communication and rocket management togethe r. This system transfers operation instructions formed from command centre to th e operating rocket site by wireless communication, and realizes automatic azimut h and elevation circumvolution and automatic launch of the longrange controlle d rockets. Meanwhile some problems are well solved, such as complicated rocket o peration, unscientific parameters design, incomplete operation record, slow inst ructions transmission and so on. The application of this system provides authent ic and reliable data for operation effect test. It fills up the blank of ground automated operation instrument in the field of weather modification in China.
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