Volume 36,Issue 6,2008 Table of Contents
2008, 36(6):679-685.
Abstract:
Using the continuous data of PM2.5 mass concentration, aerosol absorbing and scattering coefficients collected during March and May 2006 at the Shangdianzi background station, a primary study of the optical properties of aerosol in sanddust weather is conducted. The results indicate: (1) In the selected clear days, the value of PM2.5 mass concentration and daily average absorbing and scattering coefficients were about 10 μg/m3, 7 Mm-1, 20 Mm-1, respectively. The value of singlescattering albedo ranged from 0.71 to 0.78. During the transportation of pollutants from urban area to the background station, the average PM2.5 mass concentration, absorbing and scattering coefficients were 145 μg/m3,445 Mm-1, and 374.3 Mm-1. The value of single scattering albedo ranged from 0.84 to 0.94.While in sanddust weather, the value of PM2.5 mass concentration, aerosol absorbing and scattering coefficients, single scattering albedo ranged from 248.2 μg/m3to 424.1 μg/m3, 10.8 Mm-1 to 44.7 Mm-1, 225.4 Mm-1 to 393.9 Mm-1, and 0.89 to 0.96, respectively. (2) Affected by the sanddust weather, the increasing ranges of aerosol mass concentration and scattering coefficients were much greater than that of absorbing coefficient. (3) Through comparing the results from the three kinds of weather, it is found that the sanddust weather made the concentration of particles increase up to an abnormally high value and fluctuate greatly in a short time. The absorbing coefficient of aerosol in sanddust weather was much higher than in clear days but lower than during the pollutant transporting process from urban area to background station. The scattering coefficient of aerosol in sanddust weather was much higher than in clear days, close to that during the pollution case. The sanddust weather contributed to the scattering effect more greatly than to the absorbing effect of aerosol.
Using the continuous data of PM2.5 mass concentration, aerosol absorbing and scattering coefficients collected during March and May 2006 at the Shangdianzi background station, a primary study of the optical properties of aerosol in sanddust weather is conducted. The results indicate: (1) In the selected clear days, the value of PM2.5 mass concentration and daily average absorbing and scattering coefficients were about 10 μg/m3, 7 Mm-1, 20 Mm-1, respectively. The value of singlescattering albedo ranged from 0.71 to 0.78. During the transportation of pollutants from urban area to the background station, the average PM2.5 mass concentration, absorbing and scattering coefficients were 145 μg/m3,445 Mm-1, and 374.3 Mm-1. The value of single scattering albedo ranged from 0.84 to 0.94.While in sanddust weather, the value of PM2.5 mass concentration, aerosol absorbing and scattering coefficients, single scattering albedo ranged from 248.2 μg/m3to 424.1 μg/m3, 10.8 Mm-1 to 44.7 Mm-1, 225.4 Mm-1 to 393.9 Mm-1, and 0.89 to 0.96, respectively. (2) Affected by the sanddust weather, the increasing ranges of aerosol mass concentration and scattering coefficients were much greater than that of absorbing coefficient. (3) Through comparing the results from the three kinds of weather, it is found that the sanddust weather made the concentration of particles increase up to an abnormally high value and fluctuate greatly in a short time. The absorbing coefficient of aerosol in sanddust weather was much higher than in clear days but lower than during the pollutant transporting process from urban area to background station. The scattering coefficient of aerosol in sanddust weather was much higher than in clear days, close to that during the pollution case. The sanddust weather contributed to the scattering effect more greatly than to the absorbing effect of aerosol.
2008, 36(6):686-691.
Abstract:
The regional weather characteristics in the key and target areas are analyzed to study their effects on air pollution in Tianjin using the NCEP reanalysis data and daily air pollutant observations during the heating season in winters from 2002 to 2005. The results show that high air pollution in heating seasons is associated with climatic characteristics and weather conditions, such as the regional atmospheric circulation and dynamic and thermal characteristics, which affect the diffusion, accumulation, and transportation of air pollutants. Especially, the influence of regional wind velocity on aerial pollutants reflects the contribution of area pollution in North China to air pollution in Tianjin and enhances the transportation convergence of pollutants. The atmosphere diffusion weakens and the pollutants are easy to accumulate while there is wind direction change from north or northwest to west or southwest. The pollution probability increases with the rise of atmosphere instability.
The regional weather characteristics in the key and target areas are analyzed to study their effects on air pollution in Tianjin using the NCEP reanalysis data and daily air pollutant observations during the heating season in winters from 2002 to 2005. The results show that high air pollution in heating seasons is associated with climatic characteristics and weather conditions, such as the regional atmospheric circulation and dynamic and thermal characteristics, which affect the diffusion, accumulation, and transportation of air pollutants. Especially, the influence of regional wind velocity on aerial pollutants reflects the contribution of area pollution in North China to air pollution in Tianjin and enhances the transportation convergence of pollutants. The atmosphere diffusion weakens and the pollutants are easy to accumulate while there is wind direction change from north or northwest to west or southwest. The pollution probability increases with the rise of atmosphere instability.
2008, 36(6):692-696.
Abstract:
The sampling was conducted simultaneously in August 2006 at the levels of 10，120，220 m of the 255 m meteorological tower in Tianjin with the Andersen cascade sampler. The atmospheric aerosol samples are analyzed by IC (Ion Chromatograph) and ICP/MS (Inductively Coupled Plasma Mass Spectrometer). The results indicate that there are three types of size distribution: (1) K particles are mainly in the fine particle section with the peak at 0.43 to 2.1 μm. (2) Mg, Ca, Al, Fe are mainly in the coarse particle section with the peak at 2.1 to 9.0 μm. (3) Na particle distribution exhibits a doublepeak structure with the peaks at 0.65 to 2.1 μm and 3.3 to 5.8 μm. SO2-4, NO-3,NH+4 and Ca2+ are mainly watersoluble ions，which occupy 17.6%，45.7%，18.1% and 13.7% in the total ions，respectively．The total concentration of ion, as well as NO-,3 SO2-4 and NH+4, increases with height. The ion balance values between total cations and total anions at various levels are less than one, which indicates that the aerosol is slightly alkaline, can attributed to the soil properties of Tianjin. The mean concentration ratio of NO-3 to SO2-4 is 0.48，indicating that coal burning，which represents the stationary sources, compared to the mobile sources of vehicle emission，is the main pollution sources of watersoluble ions in Tianjin．
The sampling was conducted simultaneously in August 2006 at the levels of 10，120，220 m of the 255 m meteorological tower in Tianjin with the Andersen cascade sampler. The atmospheric aerosol samples are analyzed by IC (Ion Chromatograph) and ICP/MS (Inductively Coupled Plasma Mass Spectrometer). The results indicate that there are three types of size distribution: (1) K particles are mainly in the fine particle section with the peak at 0.43 to 2.1 μm. (2) Mg, Ca, Al, Fe are mainly in the coarse particle section with the peak at 2.1 to 9.0 μm. (3) Na particle distribution exhibits a doublepeak structure with the peaks at 0.65 to 2.1 μm and 3.3 to 5.8 μm. SO2-4, NO-3,NH+4 and Ca2+ are mainly watersoluble ions，which occupy 17.6%，45.7%，18.1% and 13.7% in the total ions，respectively．The total concentration of ion, as well as NO-,3 SO2-4 and NH+4, increases with height. The ion balance values between total cations and total anions at various levels are less than one, which indicates that the aerosol is slightly alkaline, can attributed to the soil properties of Tianjin. The mean concentration ratio of NO-3 to SO2-4 is 0.48，indicating that coal burning，which represents the stationary sources, compared to the mobile sources of vehicle emission，is the main pollution sources of watersoluble ions in Tianjin．
2008, 36(6):697-700.
Abstract:
Using the observation data of PM10 from April 2001 to May 2006 in Xi’an, an analysis is made of the temporalspatial distribution and seasonal variation of PM10 by means of statistical methods. The results indicate that pollution mainly occurs in winter and spring, and pollution is more serious in urban areas than in rural areas, in industry areas than in resident areas. Over the past five years, the most serious pollution occurred in 2002, and the number of days with PM10 exceeding the standard value was up to 190. A persistent heavy pollution event from 9 to 21 December 2002 in Xi’an is studied in detail, which was resulted from the stable PBL stratification and the local smallscale system in the near surface under the condition that the wind speed was low and the air relative humidity was large in the surface; Xi’an was controlled by the zonal westerlies at 500 hPa; and the surface homogeneous pressure system moved eastward slowly.
Using the observation data of PM10 from April 2001 to May 2006 in Xi’an, an analysis is made of the temporalspatial distribution and seasonal variation of PM10 by means of statistical methods. The results indicate that pollution mainly occurs in winter and spring, and pollution is more serious in urban areas than in rural areas, in industry areas than in resident areas. Over the past five years, the most serious pollution occurred in 2002, and the number of days with PM10 exceeding the standard value was up to 190. A persistent heavy pollution event from 9 to 21 December 2002 in Xi’an is studied in detail, which was resulted from the stable PBL stratification and the local smallscale system in the near surface under the condition that the wind speed was low and the air relative humidity was large in the surface; Xi’an was controlled by the zonal westerlies at 500 hPa; and the surface homogeneous pressure system moved eastward slowly.
2008, 36(6):701-705.
Abstract:
The outputs of four models (Euler numerical model, neural network model, dynamic statistical model, consensus forecast model) for forecasting precipitation pH from May to September 2005 are analyzed and their effectiveness is compared. The analysis concludes that the Euler numerical model often produces data overflow; the four models all has problems in localization; the forecasting accuracy is affected by the local basic precipitation pH level; the formation mechanisms of acid rains in the coast and inland cities differ from each other; in some cities, some models without considering ions performed as well as the models with ions.
The outputs of four models (Euler numerical model, neural network model, dynamic statistical model, consensus forecast model) for forecasting precipitation pH from May to September 2005 are analyzed and their effectiveness is compared. The analysis concludes that the Euler numerical model often produces data overflow; the four models all has problems in localization; the forecasting accuracy is affected by the local basic precipitation pH level; the formation mechanisms of acid rains in the coast and inland cities differ from each other; in some cities, some models without considering ions performed as well as the models with ions.
2008, 36(6):706-711.
Abstract:
The distribution features of acid rain during the recent three years in the Chongqing area are analyzed with the pH data of precipitation measured at 35 weather stations. The results indicate that there are acid rains in most parts of Chongqing, and some of them are very severe. In recent three years, pH values were lower than 4.5 in most areas of Chongqing with the average being 4.07, lower in the western and southeastern areas and higher in the central and northeastern areas. The frequency of precipitation with pH value being lower than 4.5 is very high. The frequency of acid rain in recent three years was 84.05% generally, 27.42% for relatively severe acid rains and 26.23% for severe acid rains in the whole Chongqing. In the downtown area, the frequency of acid rain was 95.42%, 39.54% for acid rains,relatively severe acid rains and 23.86% for severe acid rains. The frequencies of severe acid rains in autumn and winner were higher than those in spring and summer. The seasonal mean pH of precipitation for each season was lower than 4.5. The pH values varied with the season, lower in autumn and winner and higher in spring and summer.
The distribution features of acid rain during the recent three years in the Chongqing area are analyzed with the pH data of precipitation measured at 35 weather stations. The results indicate that there are acid rains in most parts of Chongqing, and some of them are very severe. In recent three years, pH values were lower than 4.5 in most areas of Chongqing with the average being 4.07, lower in the western and southeastern areas and higher in the central and northeastern areas. The frequency of precipitation with pH value being lower than 4.5 is very high. The frequency of acid rain in recent three years was 84.05% generally, 27.42% for relatively severe acid rains and 26.23% for severe acid rains in the whole Chongqing. In the downtown area, the frequency of acid rain was 95.42%, 39.54% for acid rains,relatively severe acid rains and 23.86% for severe acid rains. The frequencies of severe acid rains in autumn and winner were higher than those in spring and summer. The seasonal mean pH of precipitation for each season was lower than 4.5. The pH values varied with the season, lower in autumn and winner and higher in spring and summer.
2008, 36(6):712-716.
Abstract:
Based on the acid precipitation monitoring data from 2003 to 2006 at Weifang Acid Monitoring Station, analyzed are the seasonal variation characteristics of acid precipitation and the relationship between acid precipitation and meteorological conditions. The statistics show that in 186 precipitation samples, there are 39 acid samples with pH>5.6 (21.0%), 147 samples with pH≥5.6 (79.0%). The occurrence frequency of acid precipitation is the highest in autumn, and lower in spring; the acid precipitation occurs more frequently during the night, and the nonacid precipitation occurs usually in the daytime; the acid substances float at middle and upper levels of the atmospheric boundary layer, and the alkali substances at the middle and lower levels. It is concluded that the occurrence of acid precipitation has close relationship with the density of air pollutants, the height of the atmospheric mixed layer, wind direction and speed, precipitation, and the fog.
Based on the acid precipitation monitoring data from 2003 to 2006 at Weifang Acid Monitoring Station, analyzed are the seasonal variation characteristics of acid precipitation and the relationship between acid precipitation and meteorological conditions. The statistics show that in 186 precipitation samples, there are 39 acid samples with pH>5.6 (21.0%), 147 samples with pH≥5.6 (79.0%). The occurrence frequency of acid precipitation is the highest in autumn, and lower in spring; the acid precipitation occurs more frequently during the night, and the nonacid precipitation occurs usually in the daytime; the acid substances float at middle and upper levels of the atmospheric boundary layer, and the alkali substances at the middle and lower levels. It is concluded that the occurrence of acid precipitation has close relationship with the density of air pollutants, the height of the atmospheric mixed layer, wind direction and speed, precipitation, and the fog.
2008, 36(6):717-723.
Abstract:
The classification and analysis of fogs at the Beijing Capital International Airport (BCIA) are made based on the statistical analysis of the hourtohour fog observation data and the AWOS (Automatic Weather Observation System) data from BCIA from 1999 to 2006 (including wind, temperature, pressure, relative humidity and visibility). Each type of fog is statistically studied from the aspects of the temporal and background characteristics, pressure and wind variation characteristics, etc., during the occurrence and dissipation of fogs. The results show that radiation fogs occur most frequently at BCIA, before which there appears a gradually increasing humidity with the wind direction being SE or NNE. Advection fogs form generally after the rapid increase of humidity and the rapid decrease of visibility, inducing most serious damage to flighting, of which 81.8% reached the heavy fog standards. Front fogs occur mostly before a cold front, being persistent, mostly along with an advection or radiation process, appear usually earlier than radiation fog, mostly in the later afternoon and evening with a longer duration,and disperse generally after the front.
The classification and analysis of fogs at the Beijing Capital International Airport (BCIA) are made based on the statistical analysis of the hourtohour fog observation data and the AWOS (Automatic Weather Observation System) data from BCIA from 1999 to 2006 (including wind, temperature, pressure, relative humidity and visibility). Each type of fog is statistically studied from the aspects of the temporal and background characteristics, pressure and wind variation characteristics, etc., during the occurrence and dissipation of fogs. The results show that radiation fogs occur most frequently at BCIA, before which there appears a gradually increasing humidity with the wind direction being SE or NNE. Advection fogs form generally after the rapid increase of humidity and the rapid decrease of visibility, inducing most serious damage to flighting, of which 81.8% reached the heavy fog standards. Front fogs occur mostly before a cold front, being persistent, mostly along with an advection or radiation process, appear usually earlier than radiation fog, mostly in the later afternoon and evening with a longer duration,and disperse generally after the front.
2008, 36(6):724-727.
Abstract:
Based on the conventional data, sounding data, AMS (Automatic Meteorological Station) data and air quality data, a haze event happened in the southwestern Shandong Province in June 2007 is analyzed. The results show that the formation of the haze is related to various meteorological factors. The warm continental high pressure moved eastwards into the sea, and the lowtemperature and highhumidity air was transported to Heze by the easterly airflow at its bottom, which were beneficial to the formation of the haze. The wind speed at the midlow level was small, and the wind direction was reverse with altitude, in which the wind field was also beneficial to the formation of the haze. The stable atmospheric stratification and inversion layer existed at lower levels are important factors to the formation of the haze, and the high concentration of pollutants is also the base of the haze.
Based on the conventional data, sounding data, AMS (Automatic Meteorological Station) data and air quality data, a haze event happened in the southwestern Shandong Province in June 2007 is analyzed. The results show that the formation of the haze is related to various meteorological factors. The warm continental high pressure moved eastwards into the sea, and the lowtemperature and highhumidity air was transported to Heze by the easterly airflow at its bottom, which were beneficial to the formation of the haze. The wind speed at the midlow level was small, and the wind direction was reverse with altitude, in which the wind field was also beneficial to the formation of the haze. The stable atmospheric stratification and inversion layer existed at lower levels are important factors to the formation of the haze, and the high concentration of pollutants is also the base of the haze.
2008, 36(6):728-733.
Abstract:
Based on the daytoday sounding data at Xuzhou, Nanjing, and Sheyang in July and August from 2002 to 2006, the models to forecast maximum temperature are established for Xuzhou, Nanjing, and Sheyang using the stepwise regression statistic method and through analyzing and electing some factors influencing temperature. The regression results and forecasts of the model are analyzed thoroughly, and the rationality and credibility are discussed. In combination with dynamical numerical forecast results of ECMWF, using the Gaussian weight interpolation to insert grid data of the forecast field over Jiangsu Province, the maximum temperature quantitative forecasting for Jiansu Province through the PP method is performed.
Based on the daytoday sounding data at Xuzhou, Nanjing, and Sheyang in July and August from 2002 to 2006, the models to forecast maximum temperature are established for Xuzhou, Nanjing, and Sheyang using the stepwise regression statistic method and through analyzing and electing some factors influencing temperature. The regression results and forecasts of the model are analyzed thoroughly, and the rationality and credibility are discussed. In combination with dynamical numerical forecast results of ECMWF, using the Gaussian weight interpolation to insert grid data of the forecast field over Jiangsu Province, the maximum temperature quantitative forecasting for Jiansu Province through the PP method is performed.
2008, 36(6):734-739.
Abstract:
Based on the statistical analysis and the correlation between high temperature days and synchronous circulation, summer monsoon, and meridional circulation in Guangdong from 1967 to 2007, the long endurance of the high temperature event in July 2007 is studied. Results show that the circulation in July 2007 exhibited the typical features of highfrequency years of high temperature, with the intensified East Asia blocking high, southward extension of subtropical frontal zone, and persistent control of subtropical high over South China, which led to the significant positive anomaly of the number of high temperature days. The urbanization effect on summer maximal temperature increased gradually and speeded up significantly in the last decade. The urbanization effect should be put into consideration in the study of summer high temperatures.
Based on the statistical analysis and the correlation between high temperature days and synchronous circulation, summer monsoon, and meridional circulation in Guangdong from 1967 to 2007, the long endurance of the high temperature event in July 2007 is studied. Results show that the circulation in July 2007 exhibited the typical features of highfrequency years of high temperature, with the intensified East Asia blocking high, southward extension of subtropical frontal zone, and persistent control of subtropical high over South China, which led to the significant positive anomaly of the number of high temperature days. The urbanization effect on summer maximal temperature increased gradually and speeded up significantly in the last decade. The urbanization effect should be put into consideration in the study of summer high temperatures.
2008, 36(6):740-744.
Abstract:
To deal with the problem of sparsely distributed meteorological stations in the Dalian area, the simple and practical adjusting methods of monthly mean temperature series are presented. There are seven basic meteorological stations, and their temporal meteorological stations are used as correction stations. A set of onedimensional linear regression equations and differencevalue correction equations for the monthly mean temperature series are built based on the data from 12 temporal meteorological stations and the corresponding basic stations. Comparison analysis is made from the viewpoint of statistics and error correction. The results indicate that there is no remarkable difference between two methods, and both can be applied in adjusting monthly mean temperature series in the Dalian area.
To deal with the problem of sparsely distributed meteorological stations in the Dalian area, the simple and practical adjusting methods of monthly mean temperature series are presented. There are seven basic meteorological stations, and their temporal meteorological stations are used as correction stations. A set of onedimensional linear regression equations and differencevalue correction equations for the monthly mean temperature series are built based on the data from 12 temporal meteorological stations and the corresponding basic stations. Comparison analysis is made from the viewpoint of statistics and error correction. The results indicate that there is no remarkable difference between two methods, and both can be applied in adjusting monthly mean temperature series in the Dalian area.
2008, 36(6):745-749.
Abstract:
The nonparametric MannKendall trend test is applied to examine the trend of diurnal temperature range (DTR) of Dalian from 1961 to 2005．The method of correlative analysis is used to analyze the factors influencing DTR. The results show: (1) The trends of mean DTRs in four seasons showed a statistically significant decrease, especially in autumn and winter, the least significant in summer. But the mean, maximum, and minimum temperatures in four seasons had a statistically significant increasing trend in four seasons, and the trends of minimum temperature were much larger than those of maximum temperature. (2) DTR was negatively correlated with wind speed closely, as well as with minimum temperature, cloud cover, and vapor, but correlated with maximum temperature positively. (3)The factors related to the trends of DTR vary with season. In spring and summer, the trend of DTR is more closely correlated with the trend of maximum temperature than with minimum temperature, but in autumn and winter, the increasing trends of minimum temperature are more significant than those of maximum temperature. In spring, the increasing trends of wind speed and water vapor pressure contribute to the increasing trends of DTR, and in summer and autumn, the increasing trend of cloud cover is another cause of DTR decrease.
The nonparametric MannKendall trend test is applied to examine the trend of diurnal temperature range (DTR) of Dalian from 1961 to 2005．The method of correlative analysis is used to analyze the factors influencing DTR. The results show: (1) The trends of mean DTRs in four seasons showed a statistically significant decrease, especially in autumn and winter, the least significant in summer. But the mean, maximum, and minimum temperatures in four seasons had a statistically significant increasing trend in four seasons, and the trends of minimum temperature were much larger than those of maximum temperature. (2) DTR was negatively correlated with wind speed closely, as well as with minimum temperature, cloud cover, and vapor, but correlated with maximum temperature positively. (3)The factors related to the trends of DTR vary with season. In spring and summer, the trend of DTR is more closely correlated with the trend of maximum temperature than with minimum temperature, but in autumn and winter, the increasing trends of minimum temperature are more significant than those of maximum temperature. In spring, the increasing trends of wind speed and water vapor pressure contribute to the increasing trends of DTR, and in summer and autumn, the increasing trend of cloud cover is another cause of DTR decrease.
2008, 36(6):750-754.
Abstract:
The quantitative 24hour forecasting equation of high temperature for Shenzhen is established through multivariate linear regression, by means of the singlefactor analysis method to find the factors closely related to hightemperature weather in Shenzhen under the influence of the peripheral sinking air of tropical cyclones. The trial operational use proved that the forecasting equation is practical, has small error, and can be put into operation. It can also be used as reference in high temperature weather forecasting for other coast areas of China.
The quantitative 24hour forecasting equation of high temperature for Shenzhen is established through multivariate linear regression, by means of the singlefactor analysis method to find the factors closely related to hightemperature weather in Shenzhen under the influence of the peripheral sinking air of tropical cyclones. The trial operational use proved that the forecasting equation is practical, has small error, and can be put into operation. It can also be used as reference in high temperature weather forecasting for other coast areas of China.
2008, 36(6):755-759.
Abstract:
The synchronously observed air temperature data from the new and old meteorology observation stations at Dongguan are analyzed with the difference method. The characteristics of high temperature weather since 1971 are discussed by means of the corrected observation data from the new station. In combination with the air temperature data observed from densely distributed automatic weather stations, the temporal and spatial patterns of high temperature weather from July to August in 2007 are further analyzed. The indexes for high temperature forecast and early warning are also discussed according to the temporal characteristics of meteorological data from the single weather station. The results show that the monthly mean maximum air temperature at old station was 0.83 ℃ higher than that at the new station, and the monthly extreme high air temperature at old station was also higher than that at new station. The number of high temperature days in summer was almost doubled every 10 years and there were 4 high temperature centers over Dongguan. The trend of air temperature profile curve from the single station can be used as a good indicator in high temperature forecasting and early warning.
The synchronously observed air temperature data from the new and old meteorology observation stations at Dongguan are analyzed with the difference method. The characteristics of high temperature weather since 1971 are discussed by means of the corrected observation data from the new station. In combination with the air temperature data observed from densely distributed automatic weather stations, the temporal and spatial patterns of high temperature weather from July to August in 2007 are further analyzed. The indexes for high temperature forecast and early warning are also discussed according to the temporal characteristics of meteorological data from the single weather station. The results show that the monthly mean maximum air temperature at old station was 0.83 ℃ higher than that at the new station, and the monthly extreme high air temperature at old station was also higher than that at new station. The number of high temperature days in summer was almost doubled every 10 years and there were 4 high temperature centers over Dongguan. The trend of air temperature profile curve from the single station can be used as a good indicator in high temperature forecasting and early warning.
2008, 36(6):760-763.
Abstract:
An analysis is made of the annual, seasonal, and monthly variation characteristics of sunshine duration in recent 50 years and its relationship with total cloudiness, trying to detect the variation of sunshine duration in Chengdu by the abrupt climate change theory. The results indicate that in recent 50 years, the sunshine duration decreased with a tendency of 69.41 hours per ten years; the interannual variation amplitude was obviously greater; and the difference between the sunshine durations in 1963 and in 1989 is up to 662.8 hours. There is obvious seasonal difference in sunshine duration, with bigger decreasing amplitude in summer and winter than those in spring and autumn and a tendency of -29.77 and -20.17, -9.91 and -9.56 hours per ten years, respectively. The decreasing tendency is obviously greater in August and less in April. The annual variation of sunshine duration is consistent with sunshine percentage. The sudden change occurred around 1978, with the annual sunshine duration decreased rapidly.
An analysis is made of the annual, seasonal, and monthly variation characteristics of sunshine duration in recent 50 years and its relationship with total cloudiness, trying to detect the variation of sunshine duration in Chengdu by the abrupt climate change theory. The results indicate that in recent 50 years, the sunshine duration decreased with a tendency of 69.41 hours per ten years; the interannual variation amplitude was obviously greater; and the difference between the sunshine durations in 1963 and in 1989 is up to 662.8 hours. There is obvious seasonal difference in sunshine duration, with bigger decreasing amplitude in summer and winter than those in spring and autumn and a tendency of -29.77 and -20.17, -9.91 and -9.56 hours per ten years, respectively. The decreasing tendency is obviously greater in August and less in April. The annual variation of sunshine duration is consistent with sunshine percentage. The sudden change occurred around 1978, with the annual sunshine duration decreased rapidly.
2008, 36(6):764-767.
Abstract:
The variation characteristics of average maximum temperature, the number of high temperature days, and the dates of the first and last days of high temperature occurrence are analyzed with the observational data from 1953 to 2005 in Hefei, based on the moving t test technique, etc. The results indicate that the changes of the average maximum temperature shows an increasingdecreasingincreasing trend, with the abrupt changes taking place in 1968 and 1988. The change of the number of high temperature days shows an increasingdecreasingincreasing trend, without evident abrupt change. High temperature days occurred mainly from May to September, most frequently in July (49.7%) and secondly in August (40.5%). The high temperature duration in Hefei underwent a longshortlong change, with the shortest in the early 1980s.
The variation characteristics of average maximum temperature, the number of high temperature days, and the dates of the first and last days of high temperature occurrence are analyzed with the observational data from 1953 to 2005 in Hefei, based on the moving t test technique, etc. The results indicate that the changes of the average maximum temperature shows an increasingdecreasingincreasing trend, with the abrupt changes taking place in 1968 and 1988. The change of the number of high temperature days shows an increasingdecreasingincreasing trend, without evident abrupt change. High temperature days occurred mainly from May to September, most frequently in July (49.7%) and secondly in August (40.5%). The high temperature duration in Hefei underwent a longshortlong change, with the shortest in the early 1980s.
2008, 36(6):768-771.
Abstract:
The temperature and other meteorological elements of 36 years at Beijing Observatory are analyzed, so to understand the extent and temporal variation of hightemperature weather in midsummer (dog days) in Beijing. The results indicate: (1) The mean temperature and relative humidity in dogdays are 0.8 ℃ and 5% higher than those of the whole summer, respectively. (2) The mean temperature of “short dogdays” is 0.6 ℃ higher than that of “long dogdays”; meanwhile, the mean relative humidity of “short dogdays” is 5% lower than that of “long dogdays”. (3) The variation rates of the mean temperature, mean relative humidity, and mean rainfall are 0.42 ℃,－3.13%, and －11.25 mm per year, respectively. The findings can provide scientific bases for meteorological service for water resources, power supply, and traffic management departments, as well as the health care of people in Beijing.
The temperature and other meteorological elements of 36 years at Beijing Observatory are analyzed, so to understand the extent and temporal variation of hightemperature weather in midsummer (dog days) in Beijing. The results indicate: (1) The mean temperature and relative humidity in dogdays are 0.8 ℃ and 5% higher than those of the whole summer, respectively. (2) The mean temperature of “short dogdays” is 0.6 ℃ higher than that of “long dogdays”; meanwhile, the mean relative humidity of “short dogdays” is 5% lower than that of “long dogdays”. (3) The variation rates of the mean temperature, mean relative humidity, and mean rainfall are 0.42 ℃,－3.13%, and －11.25 mm per year, respectively. The findings can provide scientific bases for meteorological service for water resources, power supply, and traffic management departments, as well as the health care of people in Beijing.
19 Causalative Analysis of Urban Waterlogging Induced by Severe Rainfall in Xi’an with Numerical Model
2008, 36(6):772-775.
Abstract:
The hourtohour precipitation data in the recent 10 to 40 years in Xi’an and waterlogging information from the local government are used to analyze the formation causes of waterlogging induced by severe rainfall. The shorttime severe rain, or rain with large amount, is the direct cause for Xi’an’s waterlogging, and the drainage capacity is also a key factor. Along with the development of Xi’an’s urbanization, both the intensity of severe rainfall and the number of severe rains with 1hour precipitation being greater than 10 mm increase. The increased frequency of severe rains increased the frequency and intensity of waterlogging, and the urbanization is the main cause of the enhanced urban waterlogging. The simulation analysis using the Waterlogging Numerical Model reveals that the thresholds of rain intensity for waterlogging in Xi’an are relatively low, 3 mm/h for waterlogging and 13 mm/h for severe waterlogging. The northwestern part of Xi’an is the most critical zone for weather forecasting, disaster monitoring and municipal waterlogging defense departments. Generally speaking, to shorten the distances between drainage wells is an effective approach.
The hourtohour precipitation data in the recent 10 to 40 years in Xi’an and waterlogging information from the local government are used to analyze the formation causes of waterlogging induced by severe rainfall. The shorttime severe rain, or rain with large amount, is the direct cause for Xi’an’s waterlogging, and the drainage capacity is also a key factor. Along with the development of Xi’an’s urbanization, both the intensity of severe rainfall and the number of severe rains with 1hour precipitation being greater than 10 mm increase. The increased frequency of severe rains increased the frequency and intensity of waterlogging, and the urbanization is the main cause of the enhanced urban waterlogging. The simulation analysis using the Waterlogging Numerical Model reveals that the thresholds of rain intensity for waterlogging in Xi’an are relatively low, 3 mm/h for waterlogging and 13 mm/h for severe waterlogging. The northwestern part of Xi’an is the most critical zone for weather forecasting, disaster monitoring and municipal waterlogging defense departments. Generally speaking, to shorten the distances between drainage wells is an effective approach.
2008, 36(6):776-778.
Abstract:
By using of daily temperature from 1951 to 2003 during heating periods in Taiyuan, the variation characteristics of mean temperatures during heating periods and elements about energy consumption (the dates of first and last days of heating periods, heating degree days, etc.) are analyzed. The result indicates that: the temperatures in heating periods increased significantly, having a jump at the end of the 1980’s; the dates of first days delayed year after year, and the dates of last days show an advanced tendency since the 1990s and remarkable interdecadal changes, thus heating periods shortened year by year; heating degree days showed an obvious decreasing tendency. Based on heating indexes, an analysis of energy saving effect is made, which shows that there is high potential in energy saving in Taiyuan and it is necessary to change the traditional heating pattern.
By using of daily temperature from 1951 to 2003 during heating periods in Taiyuan, the variation characteristics of mean temperatures during heating periods and elements about energy consumption (the dates of first and last days of heating periods, heating degree days, etc.) are analyzed. The result indicates that: the temperatures in heating periods increased significantly, having a jump at the end of the 1980’s; the dates of first days delayed year after year, and the dates of last days show an advanced tendency since the 1990s and remarkable interdecadal changes, thus heating periods shortened year by year; heating degree days showed an obvious decreasing tendency. Based on heating indexes, an analysis of energy saving effect is made, which shows that there is high potential in energy saving in Taiyuan and it is necessary to change the traditional heating pattern.
2008, 36(6):779-781.
Abstract:
With the enhancement of people’s living standards, indoor air pollution attracts broad concern. The ventilation index (VI) began to be released to the public operationally from June 2006. By testing and analyzing 1790 data records, including pressure, temperature, humidity, wind, visibility, and weather phenomena, apparent temperature is selected as a main forecasting factor. Different forecasting formulas of summer VI in seven periods (05:00 to 08:00, 08:00 to 11:00, 11:00 to 14:00, 14:00 to 17:00, 17:00 to 20:00, 20:00 to 23:00, 23:00 to 05:00) are developed, considering the influences of summer unusual weather phenomena and wind speed, and the corresponding grades of VI are classified.
With the enhancement of people’s living standards, indoor air pollution attracts broad concern. The ventilation index (VI) began to be released to the public operationally from June 2006. By testing and analyzing 1790 data records, including pressure, temperature, humidity, wind, visibility, and weather phenomena, apparent temperature is selected as a main forecasting factor. Different forecasting formulas of summer VI in seven periods (05:00 to 08:00, 08:00 to 11:00, 11:00 to 14:00, 14:00 to 17:00, 17:00 to 20:00, 20:00 to 23:00, 23:00 to 05:00) are developed, considering the influences of summer unusual weather phenomena and wind speed, and the corresponding grades of VI are classified.
2008, 36(6):782-786.
Abstract:
The similarity analysis of kiwifruit growing ecoclimate conditions between Guizhou and New Zealand is conducted. The results indicate that the ecoclimate is favorable for the growth and development of kiwifruit in Guizhou. Through experiment and investigation, the general ecoclimatic requirements of kiwifruit growing and the ecoclimatic indices for its main growth period are determined. After having considering comprehensively the ecoclimatic adaptability and geographical factors such as landform, topography, altitude, the secondary and the critical indices of ecoclimatic regionalization are determined. According to the agroclimatic similarity principle，the region that kiwifruit may growth in Guizhou is divided into three climate regions: favorable region (I), hypofavorable region (Ⅱ), and unfavorable region (Ⅲ). In addition，the ecoclimatic features are discussed for different ecoclimatic regions．
The similarity analysis of kiwifruit growing ecoclimate conditions between Guizhou and New Zealand is conducted. The results indicate that the ecoclimate is favorable for the growth and development of kiwifruit in Guizhou. Through experiment and investigation, the general ecoclimatic requirements of kiwifruit growing and the ecoclimatic indices for its main growth period are determined. After having considering comprehensively the ecoclimatic adaptability and geographical factors such as landform, topography, altitude, the secondary and the critical indices of ecoclimatic regionalization are determined. According to the agroclimatic similarity principle，the region that kiwifruit may growth in Guizhou is divided into three climate regions: favorable region (I), hypofavorable region (Ⅱ), and unfavorable region (Ⅲ). In addition，the ecoclimatic features are discussed for different ecoclimatic regions．
2008, 36(6):787-790.
Abstract:
By using the data of monthly mean temperature and humidity from 1971 to 2000 in Zhejiang Province, as well as the times and routes of migratory birds’ passing through Zhejiang Province, an analysis is made of the main periods of Avian Influenza (AI) prevailing in Zhejiang Province, according to the weather condition assessment standards such as temperature and humidity indexes presented by previous researchers, and the crucial periods with high risk for AI prevailing are identified. The results show that the climatic conditions from November of the current year to March of the next year are favorable to the surviving and spreading of AI in Zhejiang Province, especially in February and March. December and January is the middle risk period.
By using the data of monthly mean temperature and humidity from 1971 to 2000 in Zhejiang Province, as well as the times and routes of migratory birds’ passing through Zhejiang Province, an analysis is made of the main periods of Avian Influenza (AI) prevailing in Zhejiang Province, according to the weather condition assessment standards such as temperature and humidity indexes presented by previous researchers, and the crucial periods with high risk for AI prevailing are identified. The results show that the climatic conditions from November of the current year to March of the next year are favorable to the surviving and spreading of AI in Zhejiang Province, especially in February and March. December and January is the middle risk period.
2008, 36(6):791-794.
Abstract:
Based on the relation between biological characteristics of dairy cows and meteorological conditions and the 30year meteorological data from Yanqing Station (Beijing), the climatic advantages of developing dairy cow industry in Yanqing are analyzed compared with the plain area of Beijing in aspects of geographical conditions, climatic characteristics, height at withers of dairy cows, suitable/unsuitable temperature, temperaturehumidity index, relative humidity, sunshine duration, wind chill index, and cow feed. The results show that compared with the Beijing plain area, there obviously are climate advantages in Yanqing in developing dairy cow breeding.
Based on the relation between biological characteristics of dairy cows and meteorological conditions and the 30year meteorological data from Yanqing Station (Beijing), the climatic advantages of developing dairy cow industry in Yanqing are analyzed compared with the plain area of Beijing in aspects of geographical conditions, climatic characteristics, height at withers of dairy cows, suitable/unsuitable temperature, temperaturehumidity index, relative humidity, sunshine duration, wind chill index, and cow feed. The results show that compared with the Beijing plain area, there obviously are climate advantages in Yanqing in developing dairy cow breeding.
2008, 36(6):795-800.
Abstract:
The variation characteristics of daily electrical loads from 2000 to 2006 in Hebei are analyzed. Taking Shijiazhuang as an example, a series of correlative indexes between peak loads and meteorological elements are presented, such as maximum, minimum and average temperatures, as well as average relative humidity, precipitation,etc. The results show that the meteorological elements affecting directly electric loads vary with time. An analysis is made of the variation of the electric loads when temperature rise 1 ℃ from June to September and in November,and the variation of the electric loads when precipitation is above 10 mm/d from March to August. The weatherbased electric load forecast equation is set up according to meteorological conditions.
The variation characteristics of daily electrical loads from 2000 to 2006 in Hebei are analyzed. Taking Shijiazhuang as an example, a series of correlative indexes between peak loads and meteorological elements are presented, such as maximum, minimum and average temperatures, as well as average relative humidity, precipitation,etc. The results show that the meteorological elements affecting directly electric loads vary with time. An analysis is made of the variation of the electric loads when temperature rise 1 ℃ from June to September and in November,and the variation of the electric loads when precipitation is above 10 mm/d from March to August. The weatherbased electric load forecast equation is set up according to meteorological conditions.
2008, 36(6):801-805.
Abstract:
The daily power peak loads are highly correlated with weather conditions. Base on the analysis of daily meteorological data and power peak load data in the summer (from 1 May to 30 September) of 2002 to 2004 in the Beijing area, the temporal characteristics of the power peak loads are studied. The power peak loads in the Beijing area have obvious seasonal and weekly variation trends. By using the regression and artificial neural network methods, the power peak loads are simulated and forecasted with weather data. The results show that these methods can be used to forecast the daily power peak loads, and the artificial neural networks method is better.
The daily power peak loads are highly correlated with weather conditions. Base on the analysis of daily meteorological data and power peak load data in the summer (from 1 May to 30 September) of 2002 to 2004 in the Beijing area, the temporal characteristics of the power peak loads are studied. The power peak loads in the Beijing area have obvious seasonal and weekly variation trends. By using the regression and artificial neural network methods, the power peak loads are simulated and forecasted with weather data. The results show that these methods can be used to forecast the daily power peak loads, and the artificial neural networks method is better.
2008, 36(6):806-810.
Abstract:
The risk assessment of gale damage in Beijing Olympic Games is conducted according to the 36year wind data in Beijing. The results indicate that there are more strong wind days in spring compared with other seasons, with the most in April and the lest in September. The average number of strong wind days from June to October is usually two or three with the maximum being five. By calculating the number of stations with strong wind from 1971 to 2006, the spatial distribution of risk grades of gale damage during the Beijing Olympic Games (June to October) is worked out. The risk level of gale damage is about the same over the whole Beijing area, and the high risk area spreads in the southtonorth direction with the highest risk in the south, especially the southwest, which may be attributed to the frequent summer rainstorms and the topography of the areas.
The risk assessment of gale damage in Beijing Olympic Games is conducted according to the 36year wind data in Beijing. The results indicate that there are more strong wind days in spring compared with other seasons, with the most in April and the lest in September. The average number of strong wind days from June to October is usually two or three with the maximum being five. By calculating the number of stations with strong wind from 1971 to 2006, the spatial distribution of risk grades of gale damage during the Beijing Olympic Games (June to October) is worked out. The risk level of gale damage is about the same over the whole Beijing area, and the high risk area spreads in the southtonorth direction with the highest risk in the south, especially the southwest, which may be attributed to the frequent summer rainstorms and the topography of the areas.
2008, 36(6):811-813.
Abstract:
Using the wind data at onehour interval of 12 CAWS600 sets and the data of BJANC and AWS, the occurrence frequencies of various level winds over the Olympic RowingCanoeing Park in August 2007 are statistically analyzed. Meanwhile, the features of wind speeds and directions are also analyzed. The results show that from 08:00 to 18:00 (Beijing Time), the frequency of wind speed being 0 to 2 m/s accounts for 82% with the maximum at 08:00, and that being 3 to 5 m/s accounts for 41% at 09:00, then 6 to 8 m/s accounts for only 14% at 15:00, that of more than 9 m/s is very small, which are related to strong convective weather. The analysis shows that the weak and narrow echo bands in BJANC reflectivity products can be used to predict wind direction variation. When a weak and narrow echo band moves through the Olympic RowingCanoeing Park, there will variation in wind speed and direction; when two weak and narrow echo bands run into each other, the storm will intensify, which is of significance to the meteorological support of Olympic rowing races.
Using the wind data at onehour interval of 12 CAWS600 sets and the data of BJANC and AWS, the occurrence frequencies of various level winds over the Olympic RowingCanoeing Park in August 2007 are statistically analyzed. Meanwhile, the features of wind speeds and directions are also analyzed. The results show that from 08:00 to 18:00 (Beijing Time), the frequency of wind speed being 0 to 2 m/s accounts for 82% with the maximum at 08:00, and that being 3 to 5 m/s accounts for 41% at 09:00, then 6 to 8 m/s accounts for only 14% at 15:00, that of more than 9 m/s is very small, which are related to strong convective weather. The analysis shows that the weak and narrow echo bands in BJANC reflectivity products can be used to predict wind direction variation. When a weak and narrow echo band moves through the Olympic RowingCanoeing Park, there will variation in wind speed and direction; when two weak and narrow echo bands run into each other, the storm will intensify, which is of significance to the meteorological support of Olympic rowing races.
2008, 36(6):814-817.
Abstract:
Using oneyear meteorological observation data from the observation towers at the Zuoquan and Wangqu power plants of Shanxi Province and the conventional meteorological data from neighboring weather stations in same time, some technical issues, such as the selection of typical years and contrast stations with good correlation, are discussed. Through analyzing the gradient meteorological data around the aircooling systems, in combination with the longrange meteorological element series of the selected contrast meteorology stations, the wind and temperature fields around the power plants are reconstructed by means of the related statistical methods. Some problems existed in the wind data transformation are discussed. The results indicate that when there is poor correlation between two wind data series, it is better to add and revises the wind data by using conditional probability, linear regression, and wind vector methods. The findings are of certain significance to the reconstruction of historical wind and temperature fields.
Using oneyear meteorological observation data from the observation towers at the Zuoquan and Wangqu power plants of Shanxi Province and the conventional meteorological data from neighboring weather stations in same time, some technical issues, such as the selection of typical years and contrast stations with good correlation, are discussed. Through analyzing the gradient meteorological data around the aircooling systems, in combination with the longrange meteorological element series of the selected contrast meteorology stations, the wind and temperature fields around the power plants are reconstructed by means of the related statistical methods. Some problems existed in the wind data transformation are discussed. The results indicate that when there is poor correlation between two wind data series, it is better to add and revises the wind data by using conditional probability, linear regression, and wind vector methods. The findings are of certain significance to the reconstruction of historical wind and temperature fields.
2008, 36(6):818-821.
Abstract:
The present situation of geological hazard forecasting and warning research and system development is introduced, and the design ideas, system components, main functions and features of the meteorological forecasting and warning system of geological hazards for the mountainous areas of Hebei Province is expounded. The design of the system is reasonable, considering the such information as the geological hazard regionalization, GIS data, meteorological observation (including intensive regional precipitation observation, Doppler radar products, cloud satellite images, lightning position, etc), numerical forecasting products of precipitation, etc. Adopting the mathematical statistical, synopticdynamic method, and advanced computer technology, it is able to create forecasting and warning products conveniently. The operational application in the flood season of 2007 proved that this forecasting and warning system of geological hazards performed well with considerable accuracy and less nohitting and falsehitting rates.
The present situation of geological hazard forecasting and warning research and system development is introduced, and the design ideas, system components, main functions and features of the meteorological forecasting and warning system of geological hazards for the mountainous areas of Hebei Province is expounded. The design of the system is reasonable, considering the such information as the geological hazard regionalization, GIS data, meteorological observation (including intensive regional precipitation observation, Doppler radar products, cloud satellite images, lightning position, etc), numerical forecasting products of precipitation, etc. Adopting the mathematical statistical, synopticdynamic method, and advanced computer technology, it is able to create forecasting and warning products conveniently. The operational application in the flood season of 2007 proved that this forecasting and warning system of geological hazards performed well with considerable accuracy and less nohitting and falsehitting rates.
2008, 36(6):822-825.
Abstract:
Using the precipitation data of 10 heavy rainfall events over the drainage area of the Panjiakou reservoir and the corresponding surface rainfall forecasts of the MM5 in Hebei Provincial Meteorological Bureau, combining the the precipitation forecast gridpoint data with the hydrological flood forecasts, the flood forecasting and water resources mangement experiment for the reservoir was conducted, in which the forecast period of hydrological flood forecasting was increased. With the increased forecast lead time of the floods, it is possible to make the reservoir play a significant role in converting floods into water resources in flooding season without additional investment and without increasing the risk of the upper and lower reaches of the river.
Using the precipitation data of 10 heavy rainfall events over the drainage area of the Panjiakou reservoir and the corresponding surface rainfall forecasts of the MM5 in Hebei Provincial Meteorological Bureau, combining the the precipitation forecast gridpoint data with the hydrological flood forecasts, the flood forecasting and water resources mangement experiment for the reservoir was conducted, in which the forecast period of hydrological flood forecasting was increased. With the increased forecast lead time of the floods, it is possible to make the reservoir play a significant role in converting floods into water resources in flooding season without additional investment and without increasing the risk of the upper and lower reaches of the river.
2008, 36(6):826-829.
Abstract:
With a large area of forest, Linfen is one of fireprone regions in Shaanxi Province. Using the meteorological and forestfire data from 1986 to 2003, an analysis is made of the relation between forestfire occurrence and meteorological conditions, fire hazard conditions, and forest moisture content. The synthesis forecast index of forest fire risk is calculated, and a synthesis multifactor fire risk forecast equation is established. The application proved that it has satisfactory effectiveness and certain capability of forest fire forecasting and early warning.
With a large area of forest, Linfen is one of fireprone regions in Shaanxi Province. Using the meteorological and forestfire data from 1986 to 2003, an analysis is made of the relation between forestfire occurrence and meteorological conditions, fire hazard conditions, and forest moisture content. The synthesis forecast index of forest fire risk is calculated, and a synthesis multifactor fire risk forecast equation is established. The application proved that it has satisfactory effectiveness and certain capability of forest fire forecasting and early warning.
2008, 36(6):830-833.
Abstract:
The key technical points of lightning protection for solar water heaters are presented through the theoretical analysis of lightning disasters and the related researches on various lightning protection standards from the following three aspects: the protection of direct lightning strokes for solar collectors, the LEMP (Lightning electromagnetic impulse) protection of electric and automatic control systems, and the protection of user’s personal safety. It is suggested that the risk of lightning damage should be estimated according to the heights of the buildings on which solar water heaters are installed and the annual mean numbers of lightning days in the related areas to decide whether it is necessary to install a lightning arrester around the collector. For the LEMP protection of electric and automatic control systems, the oneoff investment and the ratio of maintenance fee to equipment cost should be considered in determining whether such measures is necessary as shielding, equipotential bonding, flashover protection (rational wiring), and SPD (Surge Protective Device) installation.
The key technical points of lightning protection for solar water heaters are presented through the theoretical analysis of lightning disasters and the related researches on various lightning protection standards from the following three aspects: the protection of direct lightning strokes for solar collectors, the LEMP (Lightning electromagnetic impulse) protection of electric and automatic control systems, and the protection of user’s personal safety. It is suggested that the risk of lightning damage should be estimated according to the heights of the buildings on which solar water heaters are installed and the annual mean numbers of lightning days in the related areas to decide whether it is necessary to install a lightning arrester around the collector. For the LEMP protection of electric and automatic control systems, the oneoff investment and the ratio of maintenance fee to equipment cost should be considered in determining whether such measures is necessary as shielding, equipotential bonding, flashover protection (rational wiring), and SPD (Surge Protective Device) installation.
2008, 36(6):834-836.
Abstract:
The concentration of air negative ions is one of indicators in representative of air quality. The WIMDA series automatic air negative ion observation instruments, which meet the national recommended standards, were developed to satisfy the requirements of air negative ion monitoring. The instrument realizes the automation from data collection to data processing, and can work normally at a relative humidity from 0 to 100%, even under supersaturation condition. The results of operational running show that it is reliable and has high stability, and can reduce the workloads of observers greatly.
The concentration of air negative ions is one of indicators in representative of air quality. The WIMDA series automatic air negative ion observation instruments, which meet the national recommended standards, were developed to satisfy the requirements of air negative ion monitoring. The instrument realizes the automation from data collection to data processing, and can work normally at a relative humidity from 0 to 100%, even under supersaturation condition. The results of operational running show that it is reliable and has high stability, and can reduce the workloads of observers greatly.
2008, 36(6):837-839.
Abstract:
An introduction is made to the design, development, and core technology of an expressway weather forecasting and service system based on GIS, taking Shaanxi Province as an example. The system adopts the SQL Server 2000 management system database, developed by VB, ADO technology and MapObjects Active technology, which makes the weather query, webpublishing and other GISbased functions realizable and enhances the capability of expressway weather service greatly. Meanwhile, the system has a good portability and can be applied easily in other provinces.
An introduction is made to the design, development, and core technology of an expressway weather forecasting and service system based on GIS, taking Shaanxi Province as an example. The system adopts the SQL Server 2000 management system database, developed by VB, ADO technology and MapObjects Active technology, which makes the weather query, webpublishing and other GISbased functions realizable and enhances the capability of expressway weather service greatly. Meanwhile, the system has a good portability and can be applied easily in other provinces.
External LinksChina Meteorological AdministrationCMA Meteorological Observation CentreChinese Academy of Meteorological SciencesBeijing Meteorological ServiceNational Satellite Meteorological Center
You are thevisitors
Supported by:Beijing E-Tiller Technology Development Co., Ltd.
Supported by:Beijing E-Tiller Technology Development Co., Ltd.