ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 37,Issue 10,2011 Table of Contents
2011, 37(10):1185-1195.
DOI: 10.7519/j.issn.1000-0526.2011.10.001
Abstract:
By means of 11 year (1999-2009) data, such as infrared cloud image, synoptic chart, lightning and ground dangerous telegram, aiming at the 62 processes of strong convective weathers in Jiangxi, on the basis of analysis of largescale circulation background when convective weather happens, the features of typical clouds from occurrence and development of mesoscale convective cloud band which triggers convective weather were abstracted. It showed that eight types of cloud features are typical cloud patterns forming convective weather in Jiangxi, which include the strong convective cloud type in the edge of subtropical high, the strong convective cloud type in tail of baroclinic disturbance cloud system, MCS in a ground inverted trough， easterly wave （inverted trough of tropical depression）, the strong convective cloud band ahead of cold front, MCC ahead of cold front, the strong convective cloud type behind an uppertrough, tropical cyclone and its peripheral cloud type of squall line. The eight kinds of cloudbased features are closely related to the strength and relative position of affected systems such as low trough, shear, cold air, east wind wave and tropical cyclone, upperair jet and others. The strong convective cloud types in tail of baroclinic disturbance cloud system, the strong convective cloud band ahead of cold front, and MCC ahead of cold front are often related to stronger lower air activities. When 500 hPa trough’s meridional degree is large, and lowlevel warm advection in front of the trough is obvious, baroclinic disturbance clouds are prone to occur, a convective weather easily occurs at its tail. On the other hand, mesoβscale convective cloud clusters are easy to merge into MCC at abnormal warming center before the front and the unstable center. Rear of the upper trough, edge of the subtropical high and easterly wave are related to the interaction between highlevel dry cold air and weather system at mid and lowlatitudes, when highlevel negative temperaturevariation or water vapor “dark zone” moves closely to the lowerlevel convergence system, then an MCS develops. When divergent airflow and divergent cirrus clouds occur at the upper level, the MCS near the convergence line of a ground invertedtrough develops strongly. Additionally tropical cyclone and its peripheral cloud type of squall line are closely related to the typhoon. The predictable indicative of the strong convective cloud type in tail of baroclinic disturbance clouds is the best.
By means of 11 year (1999-2009) data, such as infrared cloud image, synoptic chart, lightning and ground dangerous telegram, aiming at the 62 processes of strong convective weathers in Jiangxi, on the basis of analysis of largescale circulation background when convective weather happens, the features of typical clouds from occurrence and development of mesoscale convective cloud band which triggers convective weather were abstracted. It showed that eight types of cloud features are typical cloud patterns forming convective weather in Jiangxi, which include the strong convective cloud type in the edge of subtropical high, the strong convective cloud type in tail of baroclinic disturbance cloud system, MCS in a ground inverted trough， easterly wave （inverted trough of tropical depression）, the strong convective cloud band ahead of cold front, MCC ahead of cold front, the strong convective cloud type behind an uppertrough, tropical cyclone and its peripheral cloud type of squall line. The eight kinds of cloudbased features are closely related to the strength and relative position of affected systems such as low trough, shear, cold air, east wind wave and tropical cyclone, upperair jet and others. The strong convective cloud types in tail of baroclinic disturbance cloud system, the strong convective cloud band ahead of cold front, and MCC ahead of cold front are often related to stronger lower air activities. When 500 hPa trough’s meridional degree is large, and lowlevel warm advection in front of the trough is obvious, baroclinic disturbance clouds are prone to occur, a convective weather easily occurs at its tail. On the other hand, mesoβscale convective cloud clusters are easy to merge into MCC at abnormal warming center before the front and the unstable center. Rear of the upper trough, edge of the subtropical high and easterly wave are related to the interaction between highlevel dry cold air and weather system at mid and lowlatitudes, when highlevel negative temperaturevariation or water vapor “dark zone” moves closely to the lowerlevel convergence system, then an MCS develops. When divergent airflow and divergent cirrus clouds occur at the upper level, the MCS near the convergence line of a ground invertedtrough develops strongly. Additionally tropical cyclone and its peripheral cloud type of squall line are closely related to the typhoon. The predictable indicative of the strong convective cloud type in tail of baroclinic disturbance clouds is the best.
Xu Yinglong
,
Han Guirong
,
Ma Suhong
,
Cong Chunhua
,
Zhang Jin
,
Yao Lina
,
Qu Anxiang
,
Sun Minghua
2011, 37(10):1196-1205.
DOI: 10.7519/j.issn.1000-0526.2011.10.002
Abstract:
During operational forecasting and service for Super Typhoon Muifa (1109) in Central Meteorological Observatory, there are some errors in its track, intensity and precipitation forecasting. The forecast errors partly caused a passive situation in its operational forecasting and service. In this paper, conventional and unconventional meteorological data, operational numerical prediction models, NCEP reanalysis data (1°×1°) and coupled oceanatmosphere model of National Meteorological Centre (NMC) are used to make a preliminary analysis on these forecast errors. The results show that: (1) The track forecast error for Muifa is mainly attributed to the optimistic estimation of the westward movement toward the Yellow Sea of the subtropical high near Japan, while westerly trough and binary typhoons have an important influence on the northward movement of Muifa. And the northeastward movement of Typhoon Merbok (1110) at the east of Muifa has a certain sense of direction for the southward withdraw of the subtropical high. (2) When there are big differences between operational numerical prediction models, it is the key how to better use ensemble and consensus forecast products for further improving the accuracy of typhoon track prediction. (3) The intensity prediction error of Muifa is mainly due to the onesided consideration about the impact of sea surface temperature on typhoon intensity change, while ignoring the influences of dry air and environmental vertical wind shear. (4) In addition to be concerned with the forecast errors of the track and intensity, the precipitation forecast error for Muifa is also related to the underestimation on the character〖CM（46〗istics of dry typhoon about Muifa and the weak interaction between the low and middle latitude〖CM）〗systems.
During operational forecasting and service for Super Typhoon Muifa (1109) in Central Meteorological Observatory, there are some errors in its track, intensity and precipitation forecasting. The forecast errors partly caused a passive situation in its operational forecasting and service. In this paper, conventional and unconventional meteorological data, operational numerical prediction models, NCEP reanalysis data (1°×1°) and coupled oceanatmosphere model of National Meteorological Centre (NMC) are used to make a preliminary analysis on these forecast errors. The results show that: (1) The track forecast error for Muifa is mainly attributed to the optimistic estimation of the westward movement toward the Yellow Sea of the subtropical high near Japan, while westerly trough and binary typhoons have an important influence on the northward movement of Muifa. And the northeastward movement of Typhoon Merbok (1110) at the east of Muifa has a certain sense of direction for the southward withdraw of the subtropical high. (2) When there are big differences between operational numerical prediction models, it is the key how to better use ensemble and consensus forecast products for further improving the accuracy of typhoon track prediction. (3) The intensity prediction error of Muifa is mainly due to the onesided consideration about the impact of sea surface temperature on typhoon intensity change, while ignoring the influences of dry air and environmental vertical wind shear. (4) In addition to be concerned with the forecast errors of the track and intensity, the precipitation forecast error for Muifa is also related to the underestimation on the character〖CM（46〗istics of dry typhoon about Muifa and the weak interaction between the low and middle latitude〖CM）〗systems.
2011, 37(10):1206-1215.
DOI: 10.7519/j.issn.1000-0526.2011.10.003
Abstract:
The eleven persistent heavy rains occurred over southern China during 5 May to 27 June in 2010. By using NCEP/NCAR daily reanalysis data, the causes for persistent heavy rains are analyzed. The results show that the Ural blocking high, Baikal low trough and the West Pacific subtropical high are stronger than the normal, and they are successively and stably maintained. The strong southwest air successively meets with the dry cold air from middle and high latituded in southern China. The low vortex which continued to move eastward is the important heavyrainproducing mesosacle convective system. The strong ascending flow resulting from the instable warm air and the strong vapor flux convergence are the favorable heavyrainproducing conditions.
The eleven persistent heavy rains occurred over southern China during 5 May to 27 June in 2010. By using NCEP/NCAR daily reanalysis data, the causes for persistent heavy rains are analyzed. The results show that the Ural blocking high, Baikal low trough and the West Pacific subtropical high are stronger than the normal, and they are successively and stably maintained. The strong southwest air successively meets with the dry cold air from middle and high latituded in southern China. The low vortex which continued to move eastward is the important heavyrainproducing mesosacle convective system. The strong ascending flow resulting from the instable warm air and the strong vapor flux convergence are the favorable heavyrainproducing conditions.
2011, 37(10):1216-1227.
DOI: 10.7519/j.issn.1000-0526.2011.10.004
Abstract:
Using the CIND3830CC data of CINRAD, the radiosonde and the surface meteorological data, we analyzed the Doppler radar echo features of the mesoscale and microscale strong convective weather system in Pu’er and Xishuangbanna during 2004 to 2009. In addition, we summarized the identification methods and the forecast targets about hail and gale, and shorttime strong rainfall. It may be concluded that the initial echo center intensity of hail cloud is about 40 dBz, and the height of hail cloud is about 5 km, approaching to 0℃ isotherm. The radial velocity of hail cloud ≥10 m·s-1, the moving speed ≥30 km·h-1, the echo center intensity is about 55 to 69 dBz and convergent features are obvious. The hail cloud intensity of the radar echo top is about 45 dBz. The height of 97% of the hail cloud is higher than 7.5 km, and that of 92% of the hail cloud is colder than -20℃. The echo of gale can be divided into 4 types. The radial velocity of 96% of the gale echo is more than 10 m·s-1, the convergent features of 50% of the gale echo are obvious. The moving speed about 85% of gale is more than 30 km·h-1 and the echo center intensity of gale is 30 to 55 dBz. The echo convergent features are obvious.The radial velocity of 79% of echo is less than 10 m·s-1. The moving speed of 85% of echoes is estimated to be less than 30 km·h-1. Then its intensity is 40 to 45 dBz and height is less than 4.5 km.The moving speed of echo is less than 30 km·h-1. And then we got the reference material in the shortterm weather forecast.
Using the CIND3830CC data of CINRAD, the radiosonde and the surface meteorological data, we analyzed the Doppler radar echo features of the mesoscale and microscale strong convective weather system in Pu’er and Xishuangbanna during 2004 to 2009. In addition, we summarized the identification methods and the forecast targets about hail and gale, and shorttime strong rainfall. It may be concluded that the initial echo center intensity of hail cloud is about 40 dBz, and the height of hail cloud is about 5 km, approaching to 0℃ isotherm. The radial velocity of hail cloud ≥10 m·s-1, the moving speed ≥30 km·h-1, the echo center intensity is about 55 to 69 dBz and convergent features are obvious. The hail cloud intensity of the radar echo top is about 45 dBz. The height of 97% of the hail cloud is higher than 7.5 km, and that of 92% of the hail cloud is colder than -20℃. The echo of gale can be divided into 4 types. The radial velocity of 96% of the gale echo is more than 10 m·s-1, the convergent features of 50% of the gale echo are obvious. The moving speed about 85% of gale is more than 30 km·h-1 and the echo center intensity of gale is 30 to 55 dBz. The echo convergent features are obvious.The radial velocity of 79% of echo is less than 10 m·s-1. The moving speed of 85% of echoes is estimated to be less than 30 km·h-1. Then its intensity is 40 to 45 dBz and height is less than 4.5 km.The moving speed of echo is less than 30 km·h-1. And then we got the reference material in the shortterm weather forecast.
2011, 37(10):1228-1232.
DOI: 10.7519/j.issn.1000-0526.2011.10.005
Abstract:
Based on the Beijing Weather Modification Office Xband dual polarization radar’s observations of different types of rainfall in April to October 2009, the characteristics of raindrop size distribution of ZH-ZDR are given out, and can be expressed as a piecewise function, from which the hail parameters HDR are derived. If HDR>0, then there is hail, and if HDR<0, it means no hail. It is also pointed that the attenuation of electromagnetic waves can affect the results of HDR hail identification. By comparing the relations between HDR and the groundobservation hail data, the preliminary results have shown that the HDR above zero region is in good agreement with hail on the ground.
Based on the Beijing Weather Modification Office Xband dual polarization radar’s observations of different types of rainfall in April to October 2009, the characteristics of raindrop size distribution of ZH-ZDR are given out, and can be expressed as a piecewise function, from which the hail parameters HDR are derived. If HDR>0, then there is hail, and if HDR<0, it means no hail. It is also pointed that the attenuation of electromagnetic waves can affect the results of HDR hail identification. By comparing the relations between HDR and the groundobservation hail data, the preliminary results have shown that the HDR above zero region is in good agreement with hail on the ground.
2011, 37(10):1233-1240.
DOI: 10.7519/j.issn.1000-0526.2011.10.006
Abstract:
Using different assimilation methods, data from automatic stations and precipitable water vapor (PWV) data from GPS stations in the Tibetan Plateau and its vicinity are assimilated, in order to investigate the role played by these observations in summer rainfall prediction in China. Through comparing assimilation results and precipitation forecast results of two months in summer of 2008, the main conclusions can be drawn from this paper as follows: Firstly, as the average height of these observational stations is above 2550 m, the positive effects to adjust the background fields are concentrated on the pressure above 500 hPa after assimilating the observations in the Tibetan Plateau and its vicinity; The adjustment using intermittent assimilation is more obvious than using single assimilation, especially above 500 hPa. Secondly, regardless of intermittent assimilation or single assimilation, the improvements of precipitation forecast in North China are less obvious, except for individual precipitation levels. Thirdly, using single assimilation can improve obviously the rainfall forecast in eastern Southwest China; In most cases, precipitation forecast results obtained by assimilating the 7 stations’ observations along 99° E are more accurate than by assimilating the 24 stations’ observations. Fourthly, using intermittent assimilation is more conductive to the precipitation forecast in the Yangtze River areas, especially for the 25-48 h precipitation forecast; At the same time, the precipitation forecast by assimilating 24 stations’ observations is superior to the one by assimilating 7 stations’ mostly.
Using different assimilation methods, data from automatic stations and precipitable water vapor (PWV) data from GPS stations in the Tibetan Plateau and its vicinity are assimilated, in order to investigate the role played by these observations in summer rainfall prediction in China. Through comparing assimilation results and precipitation forecast results of two months in summer of 2008, the main conclusions can be drawn from this paper as follows: Firstly, as the average height of these observational stations is above 2550 m, the positive effects to adjust the background fields are concentrated on the pressure above 500 hPa after assimilating the observations in the Tibetan Plateau and its vicinity; The adjustment using intermittent assimilation is more obvious than using single assimilation, especially above 500 hPa. Secondly, regardless of intermittent assimilation or single assimilation, the improvements of precipitation forecast in North China are less obvious, except for individual precipitation levels. Thirdly, using single assimilation can improve obviously the rainfall forecast in eastern Southwest China; In most cases, precipitation forecast results obtained by assimilating the 7 stations’ observations along 99° E are more accurate than by assimilating the 24 stations’ observations. Fourthly, using intermittent assimilation is more conductive to the precipitation forecast in the Yangtze River areas, especially for the 25-48 h precipitation forecast; At the same time, the precipitation forecast by assimilating 24 stations’ observations is superior to the one by assimilating 7 stations’ mostly.
2011, 37(10):1241-1251.
DOI: 10.7519/j.issn.1000-0526.2011.10.007
Abstract:
A stratiform preicipitation during 20-21 March 2008 is simulated using the mesoscale model MM5V3 coupled with CAMS explicit cloud microphysics scheme. Simulation of rainfall is very similar to observation. Adding artificial ice particles at different area and time can lead to different results. When seeding is maded in areas with high content of supercooled water and low content of ice particles, surface precipitation will be increased. After seeding, supercooled water decreases while ice, snowfall and graupel increases. Above the seeding level, the collection of ice by snow, the conversion of ice to snow are the main source of snow; below the seeding level, the collection of supercooled cloud water to snow is the main source of snow. The collection of snow to supercooled raindrops is the main source of graupel. The main source of raindrops is the collection of raindrops to cloud water.
A stratiform preicipitation during 20-21 March 2008 is simulated using the mesoscale model MM5V3 coupled with CAMS explicit cloud microphysics scheme. Simulation of rainfall is very similar to observation. Adding artificial ice particles at different area and time can lead to different results. When seeding is maded in areas with high content of supercooled water and low content of ice particles, surface precipitation will be increased. After seeding, supercooled water decreases while ice, snowfall and graupel increases. Above the seeding level, the collection of ice by snow, the conversion of ice to snow are the main source of snow; below the seeding level, the collection of supercooled cloud water to snow is the main source of snow. The collection of snow to supercooled raindrops is the main source of graupel. The main source of raindrops is the collection of raindrops to cloud water.
2011, 37(10):1252-1261.
DOI: 10.7519/j.issn.1000-0526.2011.10.008
Abstract:
Based on the integrated analysis of the cloud data obtained by digital radar， and the particle measuring system made by DMT company, the main cloud physical parameters used to identify cloud seedability are proposed. The vertical distribution of cloud supercooled water content from 0℃ layer height (1500 m) is calculated as follows: the cloud water content has a maximum of 0.416 g·m-3 at 400 m height above the 0℃ layer, then as the distance from the 0℃ layer height increases, the supercooled water content in clouds decreases, rapidly reaches to the lowest at the 600 m height above the 0℃ layer, from this height to the cloud top, the cloud maintains low water content. Only when the relevant cloud particle concentration obtained by CDP probe of DMT is larger than 30 cm-3， would the cloud area have certain seedability. Furthermore， when the particle concentration obtained by CIP probe of DMT is less than 10 cm-3， the cloud would be highly seedable and otherwise it is generally seedable.
Based on the integrated analysis of the cloud data obtained by digital radar， and the particle measuring system made by DMT company, the main cloud physical parameters used to identify cloud seedability are proposed. The vertical distribution of cloud supercooled water content from 0℃ layer height (1500 m) is calculated as follows: the cloud water content has a maximum of 0.416 g·m-3 at 400 m height above the 0℃ layer, then as the distance from the 0℃ layer height increases, the supercooled water content in clouds decreases, rapidly reaches to the lowest at the 600 m height above the 0℃ layer, from this height to the cloud top, the cloud maintains low water content. Only when the relevant cloud particle concentration obtained by CDP probe of DMT is larger than 30 cm-3， would the cloud area have certain seedability. Furthermore， when the particle concentration obtained by CIP probe of DMT is less than 10 cm-3， the cloud would be highly seedable and otherwise it is generally seedable.
2011, 37(10):1262-1269.
DOI: 10.7519/j.issn.1000-0526.2011.10.009
Abstract:
Based on the daily precipitation data at 110 observational stations during 1961-2008 in South China， the climatic characteristics and variation of torrential rain days， rainstorm intensity and contribution which is in annual， the first and second flood seasons in South China were studied by using statistical and diagnostic methods， such as linear regression analysis， MannKendall test， wavelet analysis and the computation of trend coefficients. The results have shown that the annual mean torrential rain days have a decreasing trend from coastal regions to inland in South China in recent 48 years， the highest center is in Dongxing of Guangxi （14.9 d）， and the lowest center is in Longlin of Guangxi （3.2 d）. About 72% of the total torrential rain days occurred in the flood seasons with about 45% in the first season and 27% in the second season. The mean torrential rain days have increased faintly in annual， the first and second flood seasons in South China， but it is not obvious. There are the characteristics of interannual and interdecadal changes. The mean rainstorm intensity has increased faintly in annual and in the first flood season in South China. However, since 2005 it has become obviously. The mean rainstorm intensity has declined in the second flood season， but it is not obvious. The annual mean rainstorm contribution to the total rainfall has increased obviously， but the mean contribution is not obvious in the first and second flood seasons. The wavelet analysis has shown that the changes of torrential rain days， intensity and contribution which is in annual， the first and second flood seasons in South China have two significant periods of 2-3 a and 3-4 a.
Based on the daily precipitation data at 110 observational stations during 1961-2008 in South China， the climatic characteristics and variation of torrential rain days， rainstorm intensity and contribution which is in annual， the first and second flood seasons in South China were studied by using statistical and diagnostic methods， such as linear regression analysis， MannKendall test， wavelet analysis and the computation of trend coefficients. The results have shown that the annual mean torrential rain days have a decreasing trend from coastal regions to inland in South China in recent 48 years， the highest center is in Dongxing of Guangxi （14.9 d）， and the lowest center is in Longlin of Guangxi （3.2 d）. About 72% of the total torrential rain days occurred in the flood seasons with about 45% in the first season and 27% in the second season. The mean torrential rain days have increased faintly in annual， the first and second flood seasons in South China， but it is not obvious. There are the characteristics of interannual and interdecadal changes. The mean rainstorm intensity has increased faintly in annual and in the first flood season in South China. However, since 2005 it has become obviously. The mean rainstorm intensity has declined in the second flood season， but it is not obvious. The annual mean rainstorm contribution to the total rainfall has increased obviously， but the mean contribution is not obvious in the first and second flood seasons. The wavelet analysis has shown that the changes of torrential rain days， intensity and contribution which is in annual， the first and second flood seasons in South China have two significant periods of 2-3 a and 3-4 a.
2011, 37(10):1270-1276.
DOI: 10.7519/j.issn.1000-0526.2011.10.010
Abstract:
Based on the 62 meteorological stations’ precipitation data of spring in Shanxi Province from 1961 to 2008, and the contemporaneous NCEP/NCAR monthly mean reanalysis data, the different characteristics of water vapor transport between the typical drought and wet years of spring in Shanxi are analyzed by using composite analysis methods. The research shows that in the typical drought years of spring, the water vapor transport of the subtropical west wind over the south side of the Tibetan Plateau (TP) and that of SW wind in the south areas of the Yangtze River which comes from the turning of west wind vapor over the south side of TP are weakened, and so does the westerly vapor transport over the north side of TP, while the west wind vapor transport over the north side of the subtropical high in the West Pacific is strengthened remarkably, and the south wind vapor transport over the west side of the subtropical high is weakened, thus the southwest wind vapor transport from the south areas of the Yangtze River to North China is weakened, the north wind vapor transport in Shanxi is strengthened; Meanwhile， the vapor flux divergence is strengthened over the Yangtze River and the Yellow River Reaches in eastern China and its east coastal areas, while the vapor flux convergence is strengthened over southen China and its coast areas; and vice versa in typical wet years of spring in Shanxi Province. The order of the decrease of west wind vapor flux is equivalent to that of the increase of north wind vapor flux in the typical drought years of spring in Shanxi area, while in the typical wet years of spring, the order of the increase of south wind vapor flux is greater obviously than that of the increase of the west wind vapor flux in Shanxi area.
Based on the 62 meteorological stations’ precipitation data of spring in Shanxi Province from 1961 to 2008, and the contemporaneous NCEP/NCAR monthly mean reanalysis data, the different characteristics of water vapor transport between the typical drought and wet years of spring in Shanxi are analyzed by using composite analysis methods. The research shows that in the typical drought years of spring, the water vapor transport of the subtropical west wind over the south side of the Tibetan Plateau (TP) and that of SW wind in the south areas of the Yangtze River which comes from the turning of west wind vapor over the south side of TP are weakened, and so does the westerly vapor transport over the north side of TP, while the west wind vapor transport over the north side of the subtropical high in the West Pacific is strengthened remarkably, and the south wind vapor transport over the west side of the subtropical high is weakened, thus the southwest wind vapor transport from the south areas of the Yangtze River to North China is weakened, the north wind vapor transport in Shanxi is strengthened; Meanwhile， the vapor flux divergence is strengthened over the Yangtze River and the Yellow River Reaches in eastern China and its east coastal areas, while the vapor flux convergence is strengthened over southen China and its coast areas; and vice versa in typical wet years of spring in Shanxi Province. The order of the decrease of west wind vapor flux is equivalent to that of the increase of north wind vapor flux in the typical drought years of spring in Shanxi area, while in the typical wet years of spring, the order of the increase of south wind vapor flux is greater obviously than that of the increase of the west wind vapor flux in Shanxi area.
2011, 37(10):1277-1282.
DOI: 10.7519/j.issn.1000-0526.2011.10.011
Abstract:
Based on the arranged daily maximum air temperature data from 83 stations in the BeijingTianjinHebei region (Jingjinji) during the summer of 1960-2008, the temporal and spatial distributions of summer high temperature days (SHTD, daily maximum temperature equal to or higher than 35℃) in Jingjinji are studied with a focus on the longtrends. The line trend analysis and moving t test are used in the analysis. The results show that the SHTDs in Jingjinji display a spatial distribution pattern of “more in the south and less in the north”. And the high center is located near the Nangong Station in the south. The SHTDs in Jingjinji have an evolutional trend of increasingdecreasingincreasing, and do not have significant linear trends. But there exist mainly a decreasing linear trend in the south and an increasing linear trend in the north. By using the moving t test, two points of sudden change are detected, which occurred in 1972 and 1996, respectively. However, the SHTDs in the north of Jingjinji have only a change point. Compared with those during 1960-1972, more SHTDs occurred over Jingjinji during 1997-2008 and the years with more SHTDs are more centralized. The SHTDs during 1997-2008 reveal a significant decreasing trend.
Based on the arranged daily maximum air temperature data from 83 stations in the BeijingTianjinHebei region (Jingjinji) during the summer of 1960-2008, the temporal and spatial distributions of summer high temperature days (SHTD, daily maximum temperature equal to or higher than 35℃) in Jingjinji are studied with a focus on the longtrends. The line trend analysis and moving t test are used in the analysis. The results show that the SHTDs in Jingjinji display a spatial distribution pattern of “more in the south and less in the north”. And the high center is located near the Nangong Station in the south. The SHTDs in Jingjinji have an evolutional trend of increasingdecreasingincreasing, and do not have significant linear trends. But there exist mainly a decreasing linear trend in the south and an increasing linear trend in the north. By using the moving t test, two points of sudden change are detected, which occurred in 1972 and 1996, respectively. However, the SHTDs in the north of Jingjinji have only a change point. Compared with those during 1960-1972, more SHTDs occurred over Jingjinji during 1997-2008 and the years with more SHTDs are more centralized. The SHTDs during 1997-2008 reveal a significant decreasing trend.
2011, 37(10):1283-1291.
DOI: 10.7519/j.issn.1000-0526.2011.10.012
Abstract:
Heat resource is one of the most important agricultural climate resources. It will be very helpful for agricultural climate zoning and guiding agriculture development to use scientific methods to make refinement calculation in how the heat resource will change with different topography elements such as position, direction or altitude. In this paper, the data from 651 basic meteorological observation stations were used to calculate the distribution of the national heat resource, which contains the average temperature data and the highest temperature data of January and July between 1998 and 2007. The IDW (inverse distance weighted), GIDW (gradient inverse distance weighted), spline function, kriging and trend surface analysis methods were used in calculating the heat resources, and the different results were compared. It has shown that the minimum error of GIDW is below 5% while using GIDW methods in calculating the heat resource distribution that can reflect the influence from terrain and altitude. Crossvalidation was used to analyze the error and distribution. Based on GIS software platform, the GIDW was used to draw a lot of distribution maps by use of the 1971—2000 heat resource data from 2346 stations all around China. Average temperature distribution maps in tendays, month, season, year scale and the distribution of the beginning date, the ending date, the days between beginning and ending and accumulated temperature of stably passing through 0, 5, 10, 12 and 15 ℃ at spatial resolution of 0.01°.
Heat resource is one of the most important agricultural climate resources. It will be very helpful for agricultural climate zoning and guiding agriculture development to use scientific methods to make refinement calculation in how the heat resource will change with different topography elements such as position, direction or altitude. In this paper, the data from 651 basic meteorological observation stations were used to calculate the distribution of the national heat resource, which contains the average temperature data and the highest temperature data of January and July between 1998 and 2007. The IDW (inverse distance weighted), GIDW (gradient inverse distance weighted), spline function, kriging and trend surface analysis methods were used in calculating the heat resources, and the different results were compared. It has shown that the minimum error of GIDW is below 5% while using GIDW methods in calculating the heat resource distribution that can reflect the influence from terrain and altitude. Crossvalidation was used to analyze the error and distribution. Based on GIS software platform, the GIDW was used to draw a lot of distribution maps by use of the 1971—2000 heat resource data from 2346 stations all around China. Average temperature distribution maps in tendays, month, season, year scale and the distribution of the beginning date, the ending date, the days between beginning and ending and accumulated temperature of stably passing through 0, 5, 10, 12 and 15 ℃ at spatial resolution of 0.01°.
2011, 37(10):1292-1300.
DOI: 10.7519/j.issn.1000-0526.2011.10.013
Abstract:
In order to improve China meteorological observation facility’s operation supporting ability and observation data quality, the CMA Meteorological Observation Centre developed an integrated meteorological observation operational and monitoring system and built the operational and monitoring operations. It is described the meteorological observation equipment’s operation status monitoring, technique supporting management, observation data quality monitoring and the system’s technical framework involving the requirements of the station, province and national users. It also put forward the distribution form of two level layoutthree level applications. The meteorological observation operational and monitoring and analysis system contains five function subsystems, there are the realtime facility operation status monitoring, the equipment maintance information management, the observation data quality monitoring, the basic information management and the operation statistical evaluation. Besides, the general situation of meteorological observation system operational monitoring operations is described, such as the integrated meteorological observation system’s realtime operational status, the monitoring product analysis service, regular assessment of the equipment operation efficiency and data quality status, etc. The meteorological observation operational and monitoring system could ensure the steady operation of these main meteorological observation equipments, such as meteorological radar, and it also plays a main role in the drastically improving meteorological facility’s operation efficiency.
In order to improve China meteorological observation facility’s operation supporting ability and observation data quality, the CMA Meteorological Observation Centre developed an integrated meteorological observation operational and monitoring system and built the operational and monitoring operations. It is described the meteorological observation equipment’s operation status monitoring, technique supporting management, observation data quality monitoring and the system’s technical framework involving the requirements of the station, province and national users. It also put forward the distribution form of two level layoutthree level applications. The meteorological observation operational and monitoring and analysis system contains five function subsystems, there are the realtime facility operation status monitoring, the equipment maintance information management, the observation data quality monitoring, the basic information management and the operation statistical evaluation. Besides, the general situation of meteorological observation system operational monitoring operations is described, such as the integrated meteorological observation system’s realtime operational status, the monitoring product analysis service, regular assessment of the equipment operation efficiency and data quality status, etc. The meteorological observation operational and monitoring system could ensure the steady operation of these main meteorological observation equipments, such as meteorological radar, and it also plays a main role in the drastically improving meteorological facility’s operation efficiency.
2011, 37(10):1301-1308.
DOI: 10.7519/j.issn.1000-0526.2011.10.014
Abstract:
WIS (WMO Information System) is an integrated information system and developed for meeting the requirements of all WMO Programmes, affiliated international organization and programmes with respect to information exchange, management and access. Its main functional components are National Centres, Data Collection or Product Centres, and Global Information System Centres (GISC). As an important influential member of WMO, CMA’s goal is to serve as one of the GISCs which are core communication centers in WIS and responsible for collecting and distributing the information in their areas of responsibility, and exchanging the information meant for routine global dissemination with other GISCs. The paper gives an introduction to the functional architecture of WIS and the key technologies for implementing the services of metadata synchronization, data discovery and data synchronization, also presents their applications in the design and development of GISC Beijing.
WIS (WMO Information System) is an integrated information system and developed for meeting the requirements of all WMO Programmes, affiliated international organization and programmes with respect to information exchange, management and access. Its main functional components are National Centres, Data Collection or Product Centres, and Global Information System Centres (GISC). As an important influential member of WMO, CMA’s goal is to serve as one of the GISCs which are core communication centers in WIS and responsible for collecting and distributing the information in their areas of responsibility, and exchanging the information meant for routine global dissemination with other GISCs. The paper gives an introduction to the functional architecture of WIS and the key technologies for implementing the services of metadata synchronization, data discovery and data synchronization, also presents their applications in the design and development of GISC Beijing.
2011, 37(10):1309-1313.
DOI: 10.7519/j.issn.1000-0526.2011.10.015
Abstract:
Contingent valuation method (CVM) is an important value assessment method that is widely used in ecological (environmental) economics; and it has unique advantages in the quantitative assessment of the value of natural resources. By questionnaire, the CVM reflects the value under the influence of environment, and it is a theory of strong evaluation. This method is used to analyze public weather service. Considering the uncertainty, the effectiveness assessment of public weather service is conducted by establishing dichotomy Logistic model (DLM). Using national sample survey data, we compare it with the method of traditional willingness to pay. The DLM is more objective when using in a quantitative assessment of national public weather service.
Contingent valuation method (CVM) is an important value assessment method that is widely used in ecological (environmental) economics; and it has unique advantages in the quantitative assessment of the value of natural resources. By questionnaire, the CVM reflects the value under the influence of environment, and it is a theory of strong evaluation. This method is used to analyze public weather service. Considering the uncertainty, the effectiveness assessment of public weather service is conducted by establishing dichotomy Logistic model (DLM). Using national sample survey data, we compare it with the method of traditional willingness to pay. The DLM is more objective when using in a quantitative assessment of national public weather service.
2011, 37(10):1314-1319.
DOI: 10.7519/j.issn.1000-0526.2011.10.016
Abstract:
The following are the main characteristics of the general atmospheric circulation in July 2011. There were several polar vortex centers in the Northern Hemisphere. The West Pacific subtropical high is weaker than normal years. In middlehigh latitudes of Eurasia, the zonal circulation is prevailing with activities of many shortwave troughs. The monthly mean precipitation is 105.8 mm, and is 8.7% less than normal (115.9 mm). The monthly mean temperature is 22.1℃, and is 0.7℃ higher than normal (21.4℃). The main weather events in July include seven times of heavy rainfalls. There were 4 tropical cyclones generated but only one landing China. Extreme high temperature weather consecutively occurred in Xinjiang, western Inner Monglia, South of the Yangtze River, South China, Yangtze River, Hanshui Basin, Yangtze RiverHuaihe Basin, Yellow RiverHuaihe Basin, North China, etc.
The following are the main characteristics of the general atmospheric circulation in July 2011. There were several polar vortex centers in the Northern Hemisphere. The West Pacific subtropical high is weaker than normal years. In middlehigh latitudes of Eurasia, the zonal circulation is prevailing with activities of many shortwave troughs. The monthly mean precipitation is 105.8 mm, and is 8.7% less than normal (115.9 mm). The monthly mean temperature is 22.1℃, and is 0.7℃ higher than normal (21.4℃). The main weather events in July include seven times of heavy rainfalls. There were 4 tropical cyclones generated but only one landing China. Extreme high temperature weather consecutively occurred in Xinjiang, western Inner Monglia, South of the Yangtze River, South China, Yangtze River, Hanshui Basin, Yangtze RiverHuaihe Basin, Yellow RiverHuaihe Basin, North China, etc.
2011, 37(10):1320-1328.
DOI: 10.7519/j.issn.1000-0526.2011.10.017
Abstract:
According to the Typhoon Operation and Service Requirements, forecast errors of the 14 typhoon cases in 2010 (1001-1014) were evaluated and analyzed. Generally, the average distance errors of domestic operational stations in 24 h, 48 h and 72 h forecasts are 110.0 km (1392 times), 210.6 km (945 times) and 322.4 km (364 times) respectively. Comparing with the results of the corresponding forecasting in 2009, the average errors of typhoon track forecast in different forecast time length in 2010 are decreased in different degrees. By the homogeneous comparison between different numerical models, ECMWF dominates the best track forecast performance and the Japanese model (JAPN) is the second best in 24 h, 48 h and 72 h forecasts. And these two models show some superiority comparing with the domestic models in the typhoon track forecasts. Further analysis of the homogeneous comparison to ECMWF shows that domestic numerical models have more obvious difference in the typhoon movement direction forecast while JAPN shows larger difference in the forecast of movement speed. On the other hand, the forecast difference between the domestic models and ECMWF model seems much larger in the initial forecast time (12-24 h) than that of the later forecast time (36-48 h). In other words, the forecast differences between them are gradually reduced with the extension of forecast time.
According to the Typhoon Operation and Service Requirements, forecast errors of the 14 typhoon cases in 2010 (1001-1014) were evaluated and analyzed. Generally, the average distance errors of domestic operational stations in 24 h, 48 h and 72 h forecasts are 110.0 km (1392 times), 210.6 km (945 times) and 322.4 km (364 times) respectively. Comparing with the results of the corresponding forecasting in 2009, the average errors of typhoon track forecast in different forecast time length in 2010 are decreased in different degrees. By the homogeneous comparison between different numerical models, ECMWF dominates the best track forecast performance and the Japanese model (JAPN) is the second best in 24 h, 48 h and 72 h forecasts. And these two models show some superiority comparing with the domestic models in the typhoon track forecasts. Further analysis of the homogeneous comparison to ECMWF shows that domestic numerical models have more obvious difference in the typhoon movement direction forecast while JAPN shows larger difference in the forecast of movement speed. On the other hand, the forecast difference between the domestic models and ECMWF model seems much larger in the initial forecast time (12-24 h) than that of the later forecast time (36-48 h). In other words, the forecast differences between them are gradually reduced with the extension of forecast time.
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