ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 36,Issue 2,2010 Table of Contents
2010, 36(2):1-12.
DOI: 10.7519/j.issn.1000-0526.2010.2.001
Abstract:
ATOVS data make up for the conventional observations in some areas with scarce stations, and can particularly provide the temperature and humidity data under the condition with cloud for precipitation forecast by model. In order to examine the application and capacity of T213SSI system and evaluate the impact of ATOVS data on numerical forecast of heavy rainfall in China, the T213SSI system is used to assimilate ATOVS data from NOAA16, 17 satellites. Then a heavy rainfall event during July 7 to 9, 2007 over the Huaihe River Basin is simulated with different assimilation schemes in order to compare and analyze the results of assimilation and simulation. The main conclusions to be drawn are as follows: after AMSU data being added into the T213L31 model, the forecast of precipitation is more exact, especially the intensity of precipitation. By continuous assimilation, temperature fields and humidity fields are improved obviously. After eliminating AMSUA terrestrial channel data, the simulating effect is better than assimilating completely on the location and the intensity of the heavy rainfall centre. Especially, the synoptic situation, the temperature, humidity and wind fields are improved much closer to the real states compared with the assimilating AMSUA terrestrial channel data.
ATOVS data make up for the conventional observations in some areas with scarce stations, and can particularly provide the temperature and humidity data under the condition with cloud for precipitation forecast by model. In order to examine the application and capacity of T213SSI system and evaluate the impact of ATOVS data on numerical forecast of heavy rainfall in China, the T213SSI system is used to assimilate ATOVS data from NOAA16, 17 satellites. Then a heavy rainfall event during July 7 to 9, 2007 over the Huaihe River Basin is simulated with different assimilation schemes in order to compare and analyze the results of assimilation and simulation. The main conclusions to be drawn are as follows: after AMSU data being added into the T213L31 model, the forecast of precipitation is more exact, especially the intensity of precipitation. By continuous assimilation, temperature fields and humidity fields are improved obviously. After eliminating AMSUA terrestrial channel data, the simulating effect is better than assimilating completely on the location and the intensity of the heavy rainfall centre. Especially, the synoptic situation, the temperature, humidity and wind fields are improved much closer to the real states compared with the assimilating AMSUA terrestrial channel data.
2010, 36(2):13-21.
DOI: 10.7519/j.issn.1000-0526.2010.2.002
Abstract:
Based on China Homogenized Historical Temperature Datasets, it presents evidence for urban heat island （UHI） effects on regional temperature on a longterm scale in Northeast China, which were estimated by comparing trends of urbanrural temperature series covering two time periods of 1954—2005 and 1979—2005, respectively. Results indicate that the warming trend in Northeast China over the last 50 years is significant, and the magnitude increased for the annual mean minimum temperature is the largest（2.11 ℃）， followed by the annual mean temperature （1.59 ℃）， while the annual mean maximum temperature （1.13 ℃） is the smallest in magnitude. But the contribution of UHI is minor whenever from 1954 or 1979 to present, especially for the regional annual and winter minimum temperature, the warming attributed by UHI is only some 5%, which are both impacted mostly.
Based on China Homogenized Historical Temperature Datasets, it presents evidence for urban heat island （UHI） effects on regional temperature on a longterm scale in Northeast China, which were estimated by comparing trends of urbanrural temperature series covering two time periods of 1954—2005 and 1979—2005, respectively. Results indicate that the warming trend in Northeast China over the last 50 years is significant, and the magnitude increased for the annual mean minimum temperature is the largest（2.11 ℃）， followed by the annual mean temperature （1.59 ℃）， while the annual mean maximum temperature （1.13 ℃） is the smallest in magnitude. But the contribution of UHI is minor whenever from 1954 or 1979 to present, especially for the regional annual and winter minimum temperature, the warming attributed by UHI is only some 5%, which are both impacted mostly.
2010, 36(2):22-27.
DOI: 10.7519/j.issn.1000-0526.2010.2.003
Abstract:
The sounding balloon drift data of 119 stations in China from April 2003 to August 2008 are analyzed in this paper. The results show that the drift distance is much longer in winter than in summer in each level. Usually, the drift distance increases with the rising of the sounding balloon. But in summer, because of the change of wind direction, the drift distance will decrease with sounding height increasing. The standard deviation of drift distance also increases with sounding balloon ascent. The distribution of standard deviation is consistent with the drift distance. In winter, the balloons over most of the stations flow eastward. However, the drift direction is much more complicated in summer. In the lower troposphere, the drift direction in all stations is basically eastward, but in the upper troposphere and stratosphere, the drift direction is eastward in northern China and westward in southern China.
The sounding balloon drift data of 119 stations in China from April 2003 to August 2008 are analyzed in this paper. The results show that the drift distance is much longer in winter than in summer in each level. Usually, the drift distance increases with the rising of the sounding balloon. But in summer, because of the change of wind direction, the drift distance will decrease with sounding height increasing. The standard deviation of drift distance also increases with sounding balloon ascent. The distribution of standard deviation is consistent with the drift distance. In winter, the balloons over most of the stations flow eastward. However, the drift direction is much more complicated in summer. In the lower troposphere, the drift direction in all stations is basically eastward, but in the upper troposphere and stratosphere, the drift direction is eastward in northern China and westward in southern China.
2010, 36(2):28-32.
DOI: 10.7519/j.issn.1000-0526.2010.2.004
Abstract:
The forecasting equations of severe convective weather were built using the physical variables obtained from Model MM5 and radiosonde data during 2003 to 2007, by the ways of making the statistic space distribution with location of severe convection and collocating parameters．By considering the seasonal variation characteristics of the factors， potential forecasts of severe convection and location are made in the future 0-6 h and 0-12 h．The results show that the skill of potential forecast is higher during March to June than July to September, and regional than nonregional． The method is of good instructive sense to forecast severe convective weather of hail, disastrous gust and so on, although some False Alarm Rate events are produced.
The forecasting equations of severe convective weather were built using the physical variables obtained from Model MM5 and radiosonde data during 2003 to 2007, by the ways of making the statistic space distribution with location of severe convection and collocating parameters．By considering the seasonal variation characteristics of the factors， potential forecasts of severe convection and location are made in the future 0-6 h and 0-12 h．The results show that the skill of potential forecast is higher during March to June than July to September, and regional than nonregional． The method is of good instructive sense to forecast severe convective weather of hail, disastrous gust and so on, although some False Alarm Rate events are produced.
2010, 36(2):33-38.
DOI: 10.7519/j.issn.1000-0526.2010.2.005
Abstract:
Severe convection is a difficult problem in the weather forecast. For the purpose of increasing the forecasting ability of severe convective weather, especially the local severe convective weather, we have calculated lots of dynamical and thermal parameters by using the analysis model of meteorological observing data from 1995 to 2004 in Henan Province. By statistic and diagnostic analyses we chose better atmospheric dynamical or thermal parameters of forecasting ability and indexes as severe convective forecasting predictors, and then established a forecasting equation by using weighted integrating. We applied computer technology to realize autocollecting data, calculating physical parameters, distinguishing threshold value of predictor and operating diagnostic forecasting equation to output forecast conclusions by means of MICAPS figure at last. Based on these we have built the forecasting system of local severe convective weather of Henan. This system has offered a scientific and objective reference for the forecasters and gotten quite perfect predicting effect in the operational running in the latest two years, thus lifted the forecasting ability of severe convective weather in Henan.
Severe convection is a difficult problem in the weather forecast. For the purpose of increasing the forecasting ability of severe convective weather, especially the local severe convective weather, we have calculated lots of dynamical and thermal parameters by using the analysis model of meteorological observing data from 1995 to 2004 in Henan Province. By statistic and diagnostic analyses we chose better atmospheric dynamical or thermal parameters of forecasting ability and indexes as severe convective forecasting predictors, and then established a forecasting equation by using weighted integrating. We applied computer technology to realize autocollecting data, calculating physical parameters, distinguishing threshold value of predictor and operating diagnostic forecasting equation to output forecast conclusions by means of MICAPS figure at last. Based on these we have built the forecasting system of local severe convective weather of Henan. This system has offered a scientific and objective reference for the forecasters and gotten quite perfect predicting effect in the operational running in the latest two years, thus lifted the forecasting ability of severe convective weather in Henan.
2010, 36(2):39-47.
DOI: 10.7519/j.issn.1000-0526.2010.2.006
Abstract:
The midinfrared channel (3.5-4.0 μm) of Geostationary Meteorological Satellite FY-2C is special, at which earth outgoing longwave radiation and solar incoming shortwave radiation are basically of the same intensity. Therefore it is necessary to take into account both the atmospheric scattering and the thermal emission, and detailed researches are conducted on the two processes. Total radiation, thermal radiation and scattering radiation received from the midinfrared channel of FY-2C are simulated by using radiative transfer model SBDART. And the radiation characteristics and sensitivity to cloud droplet particle effective radius are analyzed. Then an empirical relationship was proposed about removing the thermal radiation emitted by the earth’s surface and clouds from the total radiation received in the midinfrared channel of FY-2C.
The midinfrared channel (3.5-4.0 μm) of Geostationary Meteorological Satellite FY-2C is special, at which earth outgoing longwave radiation and solar incoming shortwave radiation are basically of the same intensity. Therefore it is necessary to take into account both the atmospheric scattering and the thermal emission, and detailed researches are conducted on the two processes. Total radiation, thermal radiation and scattering radiation received from the midinfrared channel of FY-2C are simulated by using radiative transfer model SBDART. And the radiation characteristics and sensitivity to cloud droplet particle effective radius are analyzed. Then an empirical relationship was proposed about removing the thermal radiation emitted by the earth’s surface and clouds from the total radiation received in the midinfrared channel of FY-2C.
2010, 36(2):48-53.
DOI: 10.7519/j.issn.1000-0526.2010.2.007
Abstract:
A continuous torrential rain took place in Hubei Province during August 28-29, 2008. Features of moisture transport are studied by applying conventionally observed data, the automatic meteorological station data, the groundbased GPS precipitable water and NCEP reanalyzed data. The results show that the rainfall process strengthened and weakened twice, respectively. The rainfall became large as the GPS precipitable water increased. Direction of vertically integrated moisture transport was mainly southwest, but when it turned to be northwest the rainfall became weak. The rainfall didn’t change simultaneously as the value of vertically integrated moisture transport did. The location of heavy rain moved as zone of vertically integrated moisture convergence moved, precipitation intensity altered as the value of vertically integrated moisture convergence altered though the relation between them wasn’t linear. Both the area and change tendency of vertically integrated moisture convergence should be paid more attention to.
A continuous torrential rain took place in Hubei Province during August 28-29, 2008. Features of moisture transport are studied by applying conventionally observed data, the automatic meteorological station data, the groundbased GPS precipitable water and NCEP reanalyzed data. The results show that the rainfall process strengthened and weakened twice, respectively. The rainfall became large as the GPS precipitable water increased. Direction of vertically integrated moisture transport was mainly southwest, but when it turned to be northwest the rainfall became weak. The rainfall didn’t change simultaneously as the value of vertically integrated moisture transport did. The location of heavy rain moved as zone of vertically integrated moisture convergence moved, precipitation intensity altered as the value of vertically integrated moisture convergence altered though the relation between them wasn’t linear. Both the area and change tendency of vertically integrated moisture convergence should be paid more attention to.
2010, 36(2):54-61.
DOI: 10.7519/j.issn.1000-0526.2010.2.008
Abstract:
Based on datasets of ADTD lightning′s location and graphic system and 714CD Doppler radar echo, characteristics and relationship of cloudtoground lightning and radar echo between the thunderstorm with hail and the strong rainstorm, which happened eight times from 2004 to 2006, are analyzed. The results show that, the radar echo intensity of thunderstorm with hail is between 50 to 60 dBz, while that of rainstorm is between 40 to 55 dBz. The lightning frequency of rainstorm is obviously more than that of thunderstorm with hail. The latter is major to positive lightning, whose ratio is more than 50%, while the former is less than 6%, and the strong lightning may occur during the whole thunderstorm process. Lightning occurs before or at the appearance of blocky single echo. A spot of lightnings can be found at 20-30 km in front of strong echo′s moving direction, which can foretell the direction of strong echo′s moving well. For the rainstorm, lightning can′t forecast the beginning of rainfall well. The increase of lightning frequency means the lasting period of rainstorm, and weaker lightning appears earlier than its echo. When thunderstorm with hail and the lasting period of rainstorm occur, the areas of positive and negative lightning are corresponding to the strong echo of 40 dBz well. When thunderstorm is lasting, lightning frequency increases suddenly. Its change displays a single peak, while two or more peaks and high frequency appear during rainstorm. The onehour lightning frequency of rainstorm is much more than that of the former. The heights of 0 ℃ , -10 ℃ and -20 ℃ and the height of cloud are higher than those of thunderstorm with hail, and the height differences between ΔH-10～0 ℃, ΔH-20～0 ℃ and ΔHct～0℃ are also larger than those of thunderstorm with hail.
Based on datasets of ADTD lightning′s location and graphic system and 714CD Doppler radar echo, characteristics and relationship of cloudtoground lightning and radar echo between the thunderstorm with hail and the strong rainstorm, which happened eight times from 2004 to 2006, are analyzed. The results show that, the radar echo intensity of thunderstorm with hail is between 50 to 60 dBz, while that of rainstorm is between 40 to 55 dBz. The lightning frequency of rainstorm is obviously more than that of thunderstorm with hail. The latter is major to positive lightning, whose ratio is more than 50%, while the former is less than 6%, and the strong lightning may occur during the whole thunderstorm process. Lightning occurs before or at the appearance of blocky single echo. A spot of lightnings can be found at 20-30 km in front of strong echo′s moving direction, which can foretell the direction of strong echo′s moving well. For the rainstorm, lightning can′t forecast the beginning of rainfall well. The increase of lightning frequency means the lasting period of rainstorm, and weaker lightning appears earlier than its echo. When thunderstorm with hail and the lasting period of rainstorm occur, the areas of positive and negative lightning are corresponding to the strong echo of 40 dBz well. When thunderstorm is lasting, lightning frequency increases suddenly. Its change displays a single peak, while two or more peaks and high frequency appear during rainstorm. The onehour lightning frequency of rainstorm is much more than that of the former. The heights of 0 ℃ , -10 ℃ and -20 ℃ and the height of cloud are higher than those of thunderstorm with hail, and the height differences between ΔH-10～0 ℃, ΔH-20～0 ℃ and ΔHct～0℃ are also larger than those of thunderstorm with hail.
2010, 36(2):62-69.
DOI: 10.7519/j.issn.1000-0526.2010.2.009
Abstract:
In order to identify and analyze superrefraction echoes accurately, a nd take great advantage of the Doppler radar， based on the Doppler radar data in Shijiazhuang and the sounding data, the ray path of the superrefraction radar echoes in the dense fog weather occurring in North China Plain during 19-21 Nove mber, 2005 is studied. The results indicate that, the dense fog weather is favor able for the occurrence of atmospheric duct and the formation of 3 layer mode su perrefraction echoes. The superrefraction radar echoes bring about measuring err ors, especially in the height. The superrefraction radar echoes occur when the f og develops or maintains. These present the new means and lay the scientific bas is for the spatial location by radar， and the monitoring and forecast of dense fog weather in North China Plain.
In order to identify and analyze superrefraction echoes accurately, a nd take great advantage of the Doppler radar， based on the Doppler radar data in Shijiazhuang and the sounding data, the ray path of the superrefraction radar echoes in the dense fog weather occurring in North China Plain during 19-21 Nove mber, 2005 is studied. The results indicate that, the dense fog weather is favor able for the occurrence of atmospheric duct and the formation of 3 layer mode su perrefraction echoes. The superrefraction radar echoes bring about measuring err ors, especially in the height. The superrefraction radar echoes occur when the f og develops or maintains. These present the new means and lay the scientific bas is for the spatial location by radar， and the monitoring and forecast of dense fog weather in North China Plain.
2010, 36(2):70-75.
DOI: 10.7519/j.issn.1000-0526.2010.2.010
Abstract:
In order to augment the precipitation on the ground, cloud seeding experiments have been carried out for more than 60 years. However， it remains to be very difficult to evaluate the seeding effect because of the large nature variations of the cloud. By the use of GPS and CINRAD techniques, a physical test was made for the operation of weather modification in Guangxi on 16 February, 2008. It shows that after the cloud seeding, microphysical changes in the supercooled clouds may lead to the enhancement of the basic reflectivity on radar in both of the supercooled cloud layer and the warm cloud and rain layer, and be more quickly in reaching the maximum value than the nonoperated clouds which are under the similar conditions, and last for a longer period. After the cloud seeding, the maximum enhancement rates of the echo reflectivity in the supercooled cloud layer and in the low and warm region may reach 200% and 100%, respectively.
In order to augment the precipitation on the ground, cloud seeding experiments have been carried out for more than 60 years. However， it remains to be very difficult to evaluate the seeding effect because of the large nature variations of the cloud. By the use of GPS and CINRAD techniques, a physical test was made for the operation of weather modification in Guangxi on 16 February, 2008. It shows that after the cloud seeding, microphysical changes in the supercooled clouds may lead to the enhancement of the basic reflectivity on radar in both of the supercooled cloud layer and the warm cloud and rain layer, and be more quickly in reaching the maximum value than the nonoperated clouds which are under the similar conditions, and last for a longer period. After the cloud seeding, the maximum enhancement rates of the echo reflectivity in the supercooled cloud layer and in the low and warm region may reach 200% and 100%, respectively.
2010, 36(2):76-80.
DOI: 10.7519/j.issn.1000-0526.2010.2.011
Abstract:
In the context of natural disaster data in China during 1989-2008, a composite index of meteorological disaster is estimated by the integration method. The cluster analysis is used to classify the losses during the 20 years and the change of losses is further discussed. The results show that the composite index of losses is greater in 1989-1998 than that in 1999-2008. The number of death people caused by meteorological disasters shows a significant decreasing trend during the past 20 years. As for composite index, the years with serious grade occurred in 1991,1994,1996 and 1998.
In the context of natural disaster data in China during 1989-2008, a composite index of meteorological disaster is estimated by the integration method. The cluster analysis is used to classify the losses during the 20 years and the change of losses is further discussed. The results show that the composite index of losses is greater in 1989-1998 than that in 1999-2008. The number of death people caused by meteorological disasters shows a significant decreasing trend during the past 20 years. As for composite index, the years with serious grade occurred in 1991,1994,1996 and 1998.
2010, 36(2):81-86.
DOI: 10.7519/j.issn.1000-0526.2010.2.012
Abstract:
The research status of debris flow at home and abroad is reviewed. On this basis, the research advance of relationship among the debris flow, effective antecedent precipitation and ecoenvironment factors is briefly summarized. It is discussed from four aspects, i.e. the ways of the use of precipitation, the estimation of precipitation, the analysis model of relation between precipitation and debris, and the ecoenvironment factor. The applying of intense rain gauge, radar and satellite gauge made the rainfall estimating of debris flow position more precise. The study is developed from the analysis about the impact of the critical rainfall on debris flow to effective antecedent rainfall, rain rate triggered debris flow and the type of precipitation on debris flow. At present, there are deterministic model and probability model which analyze the relationship between the rainfall and the debris flow occurrence. The study of the applying of ecoenvironment factors developed forward to two directions: one is that the debris flow model is developed in elementary area on the basis of finer definition of geological hazardous region. The other is that the ecoenvironmental factor is used as one of the variables in the model. Besides, more analyses are needed to solve the problem found in the present debris flow study.
The research status of debris flow at home and abroad is reviewed. On this basis, the research advance of relationship among the debris flow, effective antecedent precipitation and ecoenvironment factors is briefly summarized. It is discussed from four aspects, i.e. the ways of the use of precipitation, the estimation of precipitation, the analysis model of relation between precipitation and debris, and the ecoenvironment factor. The applying of intense rain gauge, radar and satellite gauge made the rainfall estimating of debris flow position more precise. The study is developed from the analysis about the impact of the critical rainfall on debris flow to effective antecedent rainfall, rain rate triggered debris flow and the type of precipitation on debris flow. At present, there are deterministic model and probability model which analyze the relationship between the rainfall and the debris flow occurrence. The study of the applying of ecoenvironment factors developed forward to two directions: one is that the debris flow model is developed in elementary area on the basis of finer definition of geological hazardous region. The other is that the ecoenvironmental factor is used as one of the variables in the model. Besides, more analyses are needed to solve the problem found in the present debris flow study.
2010, 36(2):87-92.
DOI: 10.7519/j.issn.1000-0526.2010.2.013
Abstract:
Flood risk can, in general terms, be defined as probability time conse quence. It consists of flood hazard analysis, vulnerability analysis and damage evaluation. At present, there are many studies on the flood disaster risk assess ment, which is mainly by constructing evaluation system or regional torrent risk zonation based on GIS, but few researches are by using the combination. The GIS has been chosen to quantitatively represent the influencing fact ors, spatialize the data into the uniform grid system, and transfer all the data items into the effect degrees on the probability of flooding, and based on cons tructing evaluation system and combining GIS, the flood risk assessment and regi onal torrent risk zonation are analyzed. Finally, a categorical model for flood risk zonation has been put forward. The approach has been applied to the Henan P rovince flood disaster risk zonation. The accuracy of evaluation system by givin g weight and the significance of regionalization map are provided. The case stud y shows that the GISbased category model is effective in flood risk zonation. Therefore the paper has a certain theoretical and practical significance. The re sults of zonation show that the possibility of flood disaster risk is the bigges t in the three urban districts of Xinyang, Zhumadian and Zhoukou because the ind exes of rainfall on flooding and vulnerability of socioeconomic properties are relatively high. Because of the higher influence indexes of river density in Ji aozuo, Kaifeng, Zhengzhou, Anyang and Puyang in the reaches of the Yellow River, the flood disaster risk in these areas is higher. However occurrence of floods in other areas is very few.
Flood risk can, in general terms, be defined as probability time conse quence. It consists of flood hazard analysis, vulnerability analysis and damage evaluation. At present, there are many studies on the flood disaster risk assess ment, which is mainly by constructing evaluation system or regional torrent risk zonation based on GIS, but few researches are by using the combination. The GIS has been chosen to quantitatively represent the influencing fact ors, spatialize the data into the uniform grid system, and transfer all the data items into the effect degrees on the probability of flooding, and based on cons tructing evaluation system and combining GIS, the flood risk assessment and regi onal torrent risk zonation are analyzed. Finally, a categorical model for flood risk zonation has been put forward. The approach has been applied to the Henan P rovince flood disaster risk zonation. The accuracy of evaluation system by givin g weight and the significance of regionalization map are provided. The case stud y shows that the GISbased category model is effective in flood risk zonation. Therefore the paper has a certain theoretical and practical significance. The re sults of zonation show that the possibility of flood disaster risk is the bigges t in the three urban districts of Xinyang, Zhumadian and Zhoukou because the ind exes of rainfall on flooding and vulnerability of socioeconomic properties are relatively high. Because of the higher influence indexes of river density in Ji aozuo, Kaifeng, Zhengzhou, Anyang and Puyang in the reaches of the Yellow River, the flood disaster risk in these areas is higher. However occurrence of floods in other areas is very few.
HONG Shengmao
,
JIAO Li
,
HE Xi
,
SUN Hongliang
,
XU Hong
,
YANG Le
,
HE Jiping
,
YE Xianman
,
ZANG Tian
,
YAO Han
2010, 36(2):93-101.
DOI: 10.7519/j.issn.1000-0526.2010.2.014
Abstract:
Based on the monitoring data of air pollutants from 2002 to 2007 over Hangzhou, according to ambient air quality every day in surrounding cities of Hangzhou, combined with different types of pollution and meteorological data, the characteristics of air pollutants and its relationship with weather conditions are analyzed. The results show that the frequency of pollution days in air quality is decreased year by year, and the air quality has been improved step by step, because the concentrations of PM10 that is the primary pollutant are decreased by degrees. The day of heavier level pollution in largescale continual pollution is half more than that of other two types of pollution, and the highest concentration of PM10 appears in largescale continual pollution, and lowest in the individual pollution, there are 0.253 mg·m-3 and 0.177 mg·m-3, respectively. The different types of pollution are affected by various weather situations, their pollution level is also changed. The rates of different pollution types have an obvious seasonal variation, which is highest in winter, lowest in summer, there are 25.6% and 3.6%, respectively. Among the different types of pollution, the rates of individual pollution and local continual pollution are 40.7% and 29.9%, respectively. The rates of different pollution types in four seasons are very obvious,showing a higher rate of local pollution type in winter, that of individual pollution in spring , and that of the largescale continuous pollution in autumn. The air quality in summer, that appears to be few of local pollution days, is the best in four seasons. The levels of different pollution are different, presenting the grades of III1(level of slight pollution) is mainly the type of local pollution, the grades of III2 (lightly pollution) and IV1 (moderat pollution) are mainly the largescale continual pollution type, the grades of IV2 (moderat heavier pollution level) and V (heavy pollution level) are mostly the individual pollution type that affected by the duststorm or firework in the Spring Festival.
Based on the monitoring data of air pollutants from 2002 to 2007 over Hangzhou, according to ambient air quality every day in surrounding cities of Hangzhou, combined with different types of pollution and meteorological data, the characteristics of air pollutants and its relationship with weather conditions are analyzed. The results show that the frequency of pollution days in air quality is decreased year by year, and the air quality has been improved step by step, because the concentrations of PM10 that is the primary pollutant are decreased by degrees. The day of heavier level pollution in largescale continual pollution is half more than that of other two types of pollution, and the highest concentration of PM10 appears in largescale continual pollution, and lowest in the individual pollution, there are 0.253 mg·m-3 and 0.177 mg·m-3, respectively. The different types of pollution are affected by various weather situations, their pollution level is also changed. The rates of different pollution types have an obvious seasonal variation, which is highest in winter, lowest in summer, there are 25.6% and 3.6%, respectively. Among the different types of pollution, the rates of individual pollution and local continual pollution are 40.7% and 29.9%, respectively. The rates of different pollution types in four seasons are very obvious,showing a higher rate of local pollution type in winter, that of individual pollution in spring , and that of the largescale continuous pollution in autumn. The air quality in summer, that appears to be few of local pollution days, is the best in four seasons. The levels of different pollution are different, presenting the grades of III1(level of slight pollution) is mainly the type of local pollution, the grades of III2 (lightly pollution) and IV1 (moderat pollution) are mainly the largescale continual pollution type, the grades of IV2 (moderat heavier pollution level) and V (heavy pollution level) are mostly the individual pollution type that affected by the duststorm or firework in the Spring Festival.
2010, 36(2):102-108.
DOI: 10.7519/j.issn.1000-0526.2010.2.015
Abstract:
The data in the second year of relative humidity from Sichuan 135 stations observed by automatic and manual in parallel, are used to analyze the difference between the relative humidity information by automatic and manual observations, and the reasons for the differences. The parallel comparison observations indicated that the average daily relative humidity observed by automatic way was 2.727% less than that by manual way, the average monthly relative humidity observed by automatic way was 2.797% less than that by manual way, and the average annual relative humidity observed by automatic way was 2.7472% less than that by manual way. There were 56.35% stations whose difference values in relative humidity respectively observed in the two ways were less than 5%, the difference values were below 10% at 86.66% stations, and the difference values were above 20% at 2.61% stations. The relative humidity Dvalue between automatic and manual observations has no significant regional difference. Some factors may affect the results, even make the significant difference between manual and automated observations, such as the irregular use of wetbulb gauze, uncleanness of gauze, the error that people read drybulb thermometer and wetbulb thermometer, the state of ventilation drybulb thermometer and wetbulb thermometer, inconsistently observation time, the automated observation nonlinear in high humidity and so on.
The data in the second year of relative humidity from Sichuan 135 stations observed by automatic and manual in parallel, are used to analyze the difference between the relative humidity information by automatic and manual observations, and the reasons for the differences. The parallel comparison observations indicated that the average daily relative humidity observed by automatic way was 2.727% less than that by manual way, the average monthly relative humidity observed by automatic way was 2.797% less than that by manual way, and the average annual relative humidity observed by automatic way was 2.7472% less than that by manual way. There were 56.35% stations whose difference values in relative humidity respectively observed in the two ways were less than 5%, the difference values were below 10% at 86.66% stations, and the difference values were above 20% at 2.61% stations. The relative humidity Dvalue between automatic and manual observations has no significant regional difference. Some factors may affect the results, even make the significant difference between manual and automated observations, such as the irregular use of wetbulb gauze, uncleanness of gauze, the error that people read drybulb thermometer and wetbulb thermometer, the state of ventilation drybulb thermometer and wetbulb thermometer, inconsistently observation time, the automated observation nonlinear in high humidity and so on.
2010, 36(2):109-112.
DOI: 10.7519/j.issn.1000-0526.2010.2.016
Abstract:
RHI scan mode is widely used in weather modification field because it can provide more detailed vertical structures of cloud and rain echoes. The traditional RHI mode needs so many manual operations to select its crosssection orientations one by one, and the information obtained is very limited. Therefore, CINRAD automatic detection functions are limited by these disadvantages. The developed algorithm introduces how the combined RHI products are autoimplemented based on current volume scan mode, to enhance the CINRAD operational functions.
RHI scan mode is widely used in weather modification field because it can provide more detailed vertical structures of cloud and rain echoes. The traditional RHI mode needs so many manual operations to select its crosssection orientations one by one, and the information obtained is very limited. Therefore, CINRAD automatic detection functions are limited by these disadvantages. The developed algorithm introduces how the combined RHI products are autoimplemented based on current volume scan mode, to enhance the CINRAD operational functions.
2010, 36(2):113-119.
DOI: 10.7519/j.issn.1000-0526.2010.2.017
Abstract:
The wind energy resource assessment in a complex terrain is very important for the development of wind power generation field. Wind energy resource assessment software WindSim based on the Computational Fluid Dynamics (CFD) method is applied to simulate the wind energy resources of wind farm area in Toksun, Xinjiang in 2007. By comparing simulation results and observation data measured by anemometer towers, it is shown that the software WindSim provides good simulation results of mean wind speed in a complex terrain area, and the mean relative errors of monthly mean wind speed at 10 m, 40 m, 50 m and 70 m are 12.91%, 10.21%, 9.68% and 12.91% respectively. Moreover, the WindSim is able to accurately simulate the predominant wind direction at 40 m and 70 m height. At the same time, the WindSim can also obtain good results of effective wind speed frequency in a complex terrain area. The simulation results of wind energy resources in wind farm show that the area has rich wind energy resources which can be used by wind power generation. It is further indicated that WindSim software can be utilized in the assessment of wind energy resources of complex terrain and has further research value in the future.
The wind energy resource assessment in a complex terrain is very important for the development of wind power generation field. Wind energy resource assessment software WindSim based on the Computational Fluid Dynamics (CFD) method is applied to simulate the wind energy resources of wind farm area in Toksun, Xinjiang in 2007. By comparing simulation results and observation data measured by anemometer towers, it is shown that the software WindSim provides good simulation results of mean wind speed in a complex terrain area, and the mean relative errors of monthly mean wind speed at 10 m, 40 m, 50 m and 70 m are 12.91%, 10.21%, 9.68% and 12.91% respectively. Moreover, the WindSim is able to accurately simulate the predominant wind direction at 40 m and 70 m height. At the same time, the WindSim can also obtain good results of effective wind speed frequency in a complex terrain area. The simulation results of wind energy resources in wind farm show that the area has rich wind energy resources which can be used by wind power generation. It is further indicated that WindSim software can be utilized in the assessment of wind energy resources of complex terrain and has further research value in the future.
2010, 36(2):120-125.
DOI: 10.7519/j.issn.1000-0526.2010.2.018
Abstract:
Both the angle of solar altitude and the orientation of the sun at sunrise and sunset in the observing stations located in the Equator, stations between the Equator and the Tropic of Cancer, stations at the Tropic of Cancer, and stations north to the Tropic of Cancer are calculated and analyzed respectively. The scale of sunshine records affected by the obstruction is decided on the basis of the above analysis. In an example of Yichang observing station（30°42′N，111°18′E）, the procedures to analyze the scale of sunshine records affected by the obstructions are given, which will not only be a helpful guidance for observing stations to calculate the scale of sunshine record affected by the obstruction, and but also be a useful example for deciding the location of solar radiation and sunshine duration observing instrument. In the examples of Guangzhou （23°10′N，113°20′E）, Yichang（ 30°42′N，111°18′E） and Beijing （39°48′N，116°28′E） observing stations, the days and dates when the sunshine records are affected, and annual maximum sunshine duration and sunshine percentage which are possibly affected are also calculated, and therefore, the rules how the obstruction affects the record in different directions and with the change of latitude are found. The result shows that the azimuth of the sun in China varies from 37°to 143° at sunrise and from 217°to 323° at sunset. Any obstructions located in the azimuth between 323°and 37° （northeast or northwest） can not affect the sunshine record. Obstructions located in a certain area in the south, southwest or southeast are not prone to affect the sunshine record since the solar altitude angle is usually very high. Maximum sunshine duration affected by obstructions which have the same altitude and the orientation increases with the increasing latitude. The degree that obstructions located in the mostly affected direction affect annual sunshine percentage is basically similar.
Both the angle of solar altitude and the orientation of the sun at sunrise and sunset in the observing stations located in the Equator, stations between the Equator and the Tropic of Cancer, stations at the Tropic of Cancer, and stations north to the Tropic of Cancer are calculated and analyzed respectively. The scale of sunshine records affected by the obstruction is decided on the basis of the above analysis. In an example of Yichang observing station（30°42′N，111°18′E）, the procedures to analyze the scale of sunshine records affected by the obstructions are given, which will not only be a helpful guidance for observing stations to calculate the scale of sunshine record affected by the obstruction, and but also be a useful example for deciding the location of solar radiation and sunshine duration observing instrument. In the examples of Guangzhou （23°10′N，113°20′E）, Yichang（ 30°42′N，111°18′E） and Beijing （39°48′N，116°28′E） observing stations, the days and dates when the sunshine records are affected, and annual maximum sunshine duration and sunshine percentage which are possibly affected are also calculated, and therefore, the rules how the obstruction affects the record in different directions and with the change of latitude are found. The result shows that the azimuth of the sun in China varies from 37°to 143° at sunrise and from 217°to 323° at sunset. Any obstructions located in the azimuth between 323°and 37° （northeast or northwest） can not affect the sunshine record. Obstructions located in a certain area in the south, southwest or southeast are not prone to affect the sunshine record since the solar altitude angle is usually very high. Maximum sunshine duration affected by obstructions which have the same altitude and the orientation increases with the increasing latitude. The degree that obstructions located in the mostly affected direction affect annual sunshine percentage is basically similar.
2010, 36(2):126-129.
DOI: 10.7519/j.issn.1000-0526.2010.2.019
Abstract:
The statistical 73 breakdowns for 5 CINRAD/CC radars at Yunnan in the recent 5 years have discovered that the failure from launching system magnetic field power reaches 21 times, relatively speaking, the failure rate of magnetic field power source is high. Through analyzing and inducing the elimination processes of 21 magnetic field power failures, we summarize, examines and analyzes the computing technique for the magnetic field power failure, have given the essential test point profile, the debugging target, as well as causes for radar parameters and emission power, klystron change situations and the debug method, which can be references for the technical support personnel. Meanwhile, take a Wenshan CINRAD/CC typical fault analysis and the eliminaton as an example, has presented the above method and the target specifically, and use the practical experience obtained through the elimination process of failure many times, then replace the primary device often possibly to bring some radar performance parameters to change, easy to cause other breakdowns, therefore after proposing the trouble shooting, the paddingsystem related is very important.
The statistical 73 breakdowns for 5 CINRAD/CC radars at Yunnan in the recent 5 years have discovered that the failure from launching system magnetic field power reaches 21 times, relatively speaking, the failure rate of magnetic field power source is high. Through analyzing and inducing the elimination processes of 21 magnetic field power failures, we summarize, examines and analyzes the computing technique for the magnetic field power failure, have given the essential test point profile, the debugging target, as well as causes for radar parameters and emission power, klystron change situations and the debug method, which can be references for the technical support personnel. Meanwhile, take a Wenshan CINRAD/CC typical fault analysis and the eliminaton as an example, has presented the above method and the target specifically, and use the practical experience obtained through the elimination process of failure many times, then replace the primary device often possibly to bring some radar performance parameters to change, easy to cause other breakdowns, therefore after proposing the trouble shooting, the paddingsystem related is very important.
2010, 36(2):130-135.
DOI: 10.7519/j.issn.1000-0526.2010.2.020
Abstract:
In order to improve the ability to use the products of T639, some syno ptic verification on its mediumrange forecasting in 2009 autumn is made in comparison with the NWP of ECMWF and Japan models. The results show that the thr ee models have good performances in the aspect of predicting the largescale ci rculation evolution and adjustment in Asian middle and high latitude areas. As a whole, ECMWF model is better in forecasting most weather systems compared with the T639 and Japan models. Taking tropical storm No.0917 (Parma) as a case, it is found that ECMWF model gets the most correct results, and that T639 model has poor stability, whereas Japan model completely failed in forecasting the track and the intensity of Parma.
In order to improve the ability to use the products of T639, some syno ptic verification on its mediumrange forecasting in 2009 autumn is made in comparison with the NWP of ECMWF and Japan models. The results show that the thr ee models have good performances in the aspect of predicting the largescale ci rculation evolution and adjustment in Asian middle and high latitude areas. As a whole, ECMWF model is better in forecasting most weather systems compared with the T639 and Japan models. Taking tropical storm No.0917 (Parma) as a case, it is found that ECMWF model gets the most correct results, and that T639 model has poor stability, whereas Japan model completely failed in forecasting the track and the intensity of Parma.
2010, 36(2):136-141.
DOI: 10.7519/j.issn.1000-0526.2010.2.021
Abstract:
The 18th International Congress of Biometeorology, ICB2008, was held in Tokyo, Japan. on 22-26 September 2008 The ICB2008 and the advances of biometeorological researches in recent years are summarized. The reports and discussions in ICB2008 indicate that the important issues of future biometeorology studies mainly include the following six aspects: (1) researches and applications in the realm of human biometeorology on the topics of heat health warning systems, medical meteorology, assessment of thermal stress and strain at work in outdoor climates, and medweather forecast; (2) the characteristics and assessment of urban climate, and the mitigation measurements; (3) the impacts of climate change on extreme weather and climate events; (4) the impacts of climate change on agriculture; (5) responses of animals to meteorological conditions and climate change; and (6) transboundary air pollutions and international environmental cooperation. Strengthening biometeorological research in China meets the needs of combating with climate change, humanoriented policy, and harmonious society, and could provide the scientific foundation and advisory for societal sustainable development.
The 18th International Congress of Biometeorology, ICB2008, was held in Tokyo, Japan. on 22-26 September 2008 The ICB2008 and the advances of biometeorological researches in recent years are summarized. The reports and discussions in ICB2008 indicate that the important issues of future biometeorology studies mainly include the following six aspects: (1) researches and applications in the realm of human biometeorology on the topics of heat health warning systems, medical meteorology, assessment of thermal stress and strain at work in outdoor climates, and medweather forecast; (2) the characteristics and assessment of urban climate, and the mitigation measurements; (3) the impacts of climate change on extreme weather and climate events; (4) the impacts of climate change on agriculture; (5) responses of animals to meteorological conditions and climate change; and (6) transboundary air pollutions and international environmental cooperation. Strengthening biometeorological research in China meets the needs of combating with climate change, humanoriented policy, and harmonious society, and could provide the scientific foundation and advisory for societal sustainable development.
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