ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 37,Issue 3,2011 Table of Contents
2011, 37(3):257-262.
DOI: 10.7519/j.issn.1000-0526.2011.3.001
Abstract:
Climate and human are closely related in essence. Human society has a long history of adaptation to the earth climate. Climatology is a science of humankind understanding the nature and applying climate resource. Since the late 1950s, global climate has been very likely impacted by human being. Further, changing climate influences human life and production through a series of complicated processes. It should be alerted that in the 21st century we should actively cope with climate change and its associated with the extreme weather and climate events. It is urgent to further enhance climate system observation and monitoring, to conduct climate research and model development to enhance climate prediction capability. More importantly, it is necessary to establish a climate service system through close cooperation with sector users in order to adapt to increasingly serious climate change and climate variability.
Climate and human are closely related in essence. Human society has a long history of adaptation to the earth climate. Climatology is a science of humankind understanding the nature and applying climate resource. Since the late 1950s, global climate has been very likely impacted by human being. Further, changing climate influences human life and production through a series of complicated processes. It should be alerted that in the 21st century we should actively cope with climate change and its associated with the extreme weather and climate events. It is urgent to further enhance climate system observation and monitoring, to conduct climate research and model development to enhance climate prediction capability. More importantly, it is necessary to establish a climate service system through close cooperation with sector users in order to adapt to increasingly serious climate change and climate variability.
2011, 37(3):263-269.
DOI: 10.7519/j.issn.1000-0526.2011.3.002
Abstract:
With the view of comprehensive understanding of the systematic difference in aircraft and radiosonde temperatures, the paper checks the quality of Chinese aircraft temperature data from January 2006 to December 2009 by use of the quality control method, which consists of four steps: metadata check, validity check, temporal consistency check, and spatial consistency check basing background field of T213 model of National Meteorological Information Center. Statistical method is used to do a comparative analysis between aircraft and radiosonde temperatures in China from January 2006 to December 2009. The analysis content about difference in aircraft and radiosonde temperatures includes the following: frequency of bias, the vertical distribution of bias, the relation of flight level and bias, the relation of flight phase and bias, the difference of bias observed by different type of aircraft, and monthly value difference of aircraft and radiosonde temperature. The data used to analyze are distributed in seventy large and medium cities of the eastcentral China. The statistical result shows that, the frequency of difference is an approximate symmetrical curve. The maximumfrequency of difference is from -0.5 ℃ to 0.5 ℃. The 64% of difference value is in the range from -1 ℃ to 1 ℃. Relative to radiosonde temperature, aircraft temperature is obviously lower on 1000 hPa. The difference from 925 hPa to 700 hPa is smaller. Aircraft temperature is higher than radiosonde temperature on 500 hPa and above level, and the difference has a gradual increase with height. The difference of aircraft and radiosonde temperatures relies on flight phase. From 925 hPa to 700 hPa, aircraft temperature observed in ascent phase is lower than radiosonde, but aircraft temperature observed in descent phase and level flight phase is quite the contrary. On 500 hPa and above level, aircraft temperatue observed in level flight phase is closest to radiosonde. Most aircraft temperature data in China is observerd by B737800 aircraft and B737700 aircraft. From January 2006 to December 2009, the propotion of data observed by B737800 aircraft is about 83.3 percent, and the propotion of data observed by B737700 aircraft is about 7.1 percent. Temperature difference between B737700 aircraft and radiosonde is larger than temperature difference between B737800 aircraft and radiosonde. There is no significant difference between monthly temperature calculated by aircraft temperature on Beijing Capital Airport and radiosonde monthly temperature. Almost all the difference values of monthly temperature are from -1 ℃ to 0.5 ℃.
With the view of comprehensive understanding of the systematic difference in aircraft and radiosonde temperatures, the paper checks the quality of Chinese aircraft temperature data from January 2006 to December 2009 by use of the quality control method, which consists of four steps: metadata check, validity check, temporal consistency check, and spatial consistency check basing background field of T213 model of National Meteorological Information Center. Statistical method is used to do a comparative analysis between aircraft and radiosonde temperatures in China from January 2006 to December 2009. The analysis content about difference in aircraft and radiosonde temperatures includes the following: frequency of bias, the vertical distribution of bias, the relation of flight level and bias, the relation of flight phase and bias, the difference of bias observed by different type of aircraft, and monthly value difference of aircraft and radiosonde temperature. The data used to analyze are distributed in seventy large and medium cities of the eastcentral China. The statistical result shows that, the frequency of difference is an approximate symmetrical curve. The maximumfrequency of difference is from -0.5 ℃ to 0.5 ℃. The 64% of difference value is in the range from -1 ℃ to 1 ℃. Relative to radiosonde temperature, aircraft temperature is obviously lower on 1000 hPa. The difference from 925 hPa to 700 hPa is smaller. Aircraft temperature is higher than radiosonde temperature on 500 hPa and above level, and the difference has a gradual increase with height. The difference of aircraft and radiosonde temperatures relies on flight phase. From 925 hPa to 700 hPa, aircraft temperature observed in ascent phase is lower than radiosonde, but aircraft temperature observed in descent phase and level flight phase is quite the contrary. On 500 hPa and above level, aircraft temperatue observed in level flight phase is closest to radiosonde. Most aircraft temperature data in China is observerd by B737800 aircraft and B737700 aircraft. From January 2006 to December 2009, the propotion of data observed by B737800 aircraft is about 83.3 percent, and the propotion of data observed by B737700 aircraft is about 7.1 percent. Temperature difference between B737700 aircraft and radiosonde is larger than temperature difference between B737800 aircraft and radiosonde. There is no significant difference between monthly temperature calculated by aircraft temperature on Beijing Capital Airport and radiosonde monthly temperature. Almost all the difference values of monthly temperature are from -1 ℃ to 0.5 ℃.
2011, 37(3):270-275.
DOI: 10.7519/j.issn.1000-0526.2011.3.003
Abstract:
Simulated storm surge elevation by the oceanic model is strongly dependent on the wind field, thus the correct simulation of wind field is the important prerequisite. Four typical cases are used to test the impacts of the modified Bohai Sea calculated wind field models on the numerical simulation of storm surges. The hourly Bohai Sea elevation fields before and after the correction are obtained by the numerical model driven by the wind field. Compared to the observed values of Tanggu Station, we can conclude that the simulated results are obviously improved. The simulated extreme values, process curves and the elevation correspond well to the observed values. The accuracy of the calculation results is enhanced significantly after the correction. Results show that by using the appropriate method of sealevel wind field correction, the accuracy of the simulated wind field is enhanced and the oceanic model can simulate the strong storm surge elevation that is close to the reality.
Simulated storm surge elevation by the oceanic model is strongly dependent on the wind field, thus the correct simulation of wind field is the important prerequisite. Four typical cases are used to test the impacts of the modified Bohai Sea calculated wind field models on the numerical simulation of storm surges. The hourly Bohai Sea elevation fields before and after the correction are obtained by the numerical model driven by the wind field. Compared to the observed values of Tanggu Station, we can conclude that the simulated results are obviously improved. The simulated extreme values, process curves and the elevation correspond well to the observed values. The accuracy of the calculation results is enhanced significantly after the correction. Results show that by using the appropriate method of sealevel wind field correction, the accuracy of the simulated wind field is enhanced and the oceanic model can simulate the strong storm surge elevation that is close to the reality.
2011, 37(3):276-284.
DOI: 10.7519/j.issn.1000-0526.2011.3.004
Abstract:
In terms of the observed data and NCEP 1°×1° reanalysis data, the vertical characteristics of different feature torrential rain over Huanghuai Basin and Southwest China on 29 August 2009 are studied. Results show that the torrential rain over above two areas happened in the same circulation background, the former belongs to the stable heavy precipitation ahead of or rear of the front and the latter is of convective heavy precipitation in the warm area before the front. They have distinct differences in the vertical distribution of vorticity, divergence, jet stream at higher and lower levels, vertical meridional circulation and moist potential vorticity (MPV). For the stable heavy precipitation, cold trough at higher levels induced the vortex at lower levels and high MPV was transferred from higher level down to the lower level of the troposphere, which resulted in the high MPV at lower levels corresponding to the heavy rain; for the convective heavy precipitation, high MPV at high levels only was transferred down to the middle level of the troposphere together with dry and cold air intruding, which triggered the moist symmetry instability energy leading to the heavy convective rain. There are significant characters of vertical structure in two different feature torrential rains， which can provide some reference for the feature and strength of shorttime precipitation forecast.
In terms of the observed data and NCEP 1°×1° reanalysis data, the vertical characteristics of different feature torrential rain over Huanghuai Basin and Southwest China on 29 August 2009 are studied. Results show that the torrential rain over above two areas happened in the same circulation background, the former belongs to the stable heavy precipitation ahead of or rear of the front and the latter is of convective heavy precipitation in the warm area before the front. They have distinct differences in the vertical distribution of vorticity, divergence, jet stream at higher and lower levels, vertical meridional circulation and moist potential vorticity (MPV). For the stable heavy precipitation, cold trough at higher levels induced the vortex at lower levels and high MPV was transferred from higher level down to the lower level of the troposphere, which resulted in the high MPV at lower levels corresponding to the heavy rain; for the convective heavy precipitation, high MPV at high levels only was transferred down to the middle level of the troposphere together with dry and cold air intruding, which triggered the moist symmetry instability energy leading to the heavy convective rain. There are significant characters of vertical structure in two different feature torrential rains， which can provide some reference for the feature and strength of shorttime precipitation forecast.
2011, 37(3):285-290.
DOI: 10.7519/j.issn.1000-0526.2011.3.005
Abstract:
Rainstorm processes in Hubei Province from years 2007 to 2008 are selected to study the characteristics of the radar echoes. First， thirtytwo regional rainstorm processes are determined according to the rainfall data analysis. Then, by analyzing the Doppler radar reflectivity echo shapes, structures and so on, the four kinds of regional rainstorm radar echo models in Hubei Province are induced. Moreover, the rainstorm region and the major impact system’s synoptic characteristics of each kind of rainstorm echo are comparatively analyzed. The results show that, the four kinds of regional rainstorm radar echo models are the commashaped, the whirlshaped, the complex vortexbelt shaped and the bandshaped, and they are closely related to the mesoαscale cyclone wave disturbance on the front surface, the development of the low vortex systems in eastern Sichuan Province, the combination of the Meiyufront and the low vortex system, and the formation of quasistationary front shear line on the cyclone waves， etc.
Rainstorm processes in Hubei Province from years 2007 to 2008 are selected to study the characteristics of the radar echoes. First， thirtytwo regional rainstorm processes are determined according to the rainfall data analysis. Then, by analyzing the Doppler radar reflectivity echo shapes, structures and so on, the four kinds of regional rainstorm radar echo models in Hubei Province are induced. Moreover, the rainstorm region and the major impact system’s synoptic characteristics of each kind of rainstorm echo are comparatively analyzed. The results show that, the four kinds of regional rainstorm radar echo models are the commashaped, the whirlshaped, the complex vortexbelt shaped and the bandshaped, and they are closely related to the mesoαscale cyclone wave disturbance on the front surface, the development of the low vortex systems in eastern Sichuan Province, the combination of the Meiyufront and the low vortex system, and the formation of quasistationary front shear line on the cyclone waves， etc.
2011, 37(3):291-297.
DOI: 10.7519/j.issn.1000-0526.2011.3.006
Abstract:
A local torrential rain process occurring in Tianjin on September 26, 2009 is diagnosed and a mesoscale analysis of it is performed, based on the conventional and surface densified automatic station observations, data of mesoscale model of TMMB, satellite cloud pictures and Doppler radar data etc. The results show that the heavy rain occurs when the largescale circulation pattern is adjusted from meridional to zonal. The trough of 500 hPa is the major synoptic scale system in this event, while the main mesoscale systems are surface mesoscale convergence line, humidity frontal zone and sea breeze front visible in Doppler radar imagery, which are driven by sealand breeze circulation. And a fully developed thermal instability before the occurrence of the torrential rainfall has being established, the synoptic scale environment has considerable energy storage, favorable dynamic condition and moisture convergence from the Bay of Bengal at 700 hPa and the sea to the east of Tianjin at 850 hPa. The collision of synoptic system driven cumulus convection and sea breeze front triggers the release of instable energy, resulting in the heavy precipitation of the first period. The strong easterlies in the boundary layer indicate the essential role of sealand breeze circulation in this torrential rain event.
A local torrential rain process occurring in Tianjin on September 26, 2009 is diagnosed and a mesoscale analysis of it is performed, based on the conventional and surface densified automatic station observations, data of mesoscale model of TMMB, satellite cloud pictures and Doppler radar data etc. The results show that the heavy rain occurs when the largescale circulation pattern is adjusted from meridional to zonal. The trough of 500 hPa is the major synoptic scale system in this event, while the main mesoscale systems are surface mesoscale convergence line, humidity frontal zone and sea breeze front visible in Doppler radar imagery, which are driven by sealand breeze circulation. And a fully developed thermal instability before the occurrence of the torrential rainfall has being established, the synoptic scale environment has considerable energy storage, favorable dynamic condition and moisture convergence from the Bay of Bengal at 700 hPa and the sea to the east of Tianjin at 850 hPa. The collision of synoptic system driven cumulus convection and sea breeze front triggers the release of instable energy, resulting in the heavy precipitation of the first period. The strong easterlies in the boundary layer indicate the essential role of sealand breeze circulation in this torrential rain event.
2011, 37(3):298-308.
DOI: 10.7519/j.issn.1000-0526.2011.3.007
Abstract:
In order to improve the level of Chengdu fine weather forecast, using Chengdu fine underlying surface data, the urban meteorological characteristics of Chengdu are simulated by the WRF coupled with singlelayer urban canopy model for a clear day, on July 6, 2008, and those are compared to simulations with old landuse data and slab model. The result shows that because of urban impervious underlying surface area increasing, the surface evaporation and upward moisture flux are significantly reduced, latent heat flux decreases and sensible heat flux increases. Urban buildings can intercept longwave radiation energy, so urban turbulence enhances and boundary layer height becomes higher; With the fine landuse data and singlelayer urban canopy model, both negative bias and rootmeansquare error of 2m temperature decrease; Urban area expansion and more buildings have led to the result that the urban heat island effect strengthens, urban 10m wind speed decreases, heat circulation between urban and suburban areas enhances, and local vertical circulation boosts.
In order to improve the level of Chengdu fine weather forecast, using Chengdu fine underlying surface data, the urban meteorological characteristics of Chengdu are simulated by the WRF coupled with singlelayer urban canopy model for a clear day, on July 6, 2008, and those are compared to simulations with old landuse data and slab model. The result shows that because of urban impervious underlying surface area increasing, the surface evaporation and upward moisture flux are significantly reduced, latent heat flux decreases and sensible heat flux increases. Urban buildings can intercept longwave radiation energy, so urban turbulence enhances and boundary layer height becomes higher; With the fine landuse data and singlelayer urban canopy model, both negative bias and rootmeansquare error of 2m temperature decrease; Urban area expansion and more buildings have led to the result that the urban heat island effect strengthens, urban 10m wind speed decreases, heat circulation between urban and suburban areas enhances, and local vertical circulation boosts.
2011, 37(3):309-317.
DOI: 10.7519/j.issn.1000-0526.2011.3.008
Abstract:
A severe dust storm over northern China in April of 2009 (i.e., 22-24 April) is studied. Firstly, the relationship between the meteorological variables at surface, PM10 and the intensity of dust storm on April 22, 2009 is analyzed. The results show that Mongolian cyclone and its cold front are the main system producing the strong dust storm. The temperature, surface pressure, wind and PM10 are closely related to the intensity of the dust storm. Secondly, an integrated dust storm modeling system is employed to simulate this process. The simulation results show that the modeling system is capable for better describing the main characteristics of dust storm. And the scope of simulated dust concentration value is consistent with the strong dust storm. Comparing with the morning and afternoon dust concentration distribution, we find it has daily change. The dust emission areas with vertical sand flux over 50 mg·m-2·s-1 are Tarim Basin， Gansu Province， western Inner Mongolia and southern Mongolia. The vertical transportation of dust concentration is below 550 hPa, and the horizontal transportation of dust is driven by strong wind in middlelowerlevel troposphere. The particle size which contributes significantly to the dust emission is different due to the variety of land, however, the quantities of particles with diameter from 2 μm<d≤11 μm are predominated. The scope of simulated dust concentration value is consistent with the strong dust storm.
A severe dust storm over northern China in April of 2009 (i.e., 22-24 April) is studied. Firstly, the relationship between the meteorological variables at surface, PM10 and the intensity of dust storm on April 22, 2009 is analyzed. The results show that Mongolian cyclone and its cold front are the main system producing the strong dust storm. The temperature, surface pressure, wind and PM10 are closely related to the intensity of the dust storm. Secondly, an integrated dust storm modeling system is employed to simulate this process. The simulation results show that the modeling system is capable for better describing the main characteristics of dust storm. And the scope of simulated dust concentration value is consistent with the strong dust storm. Comparing with the morning and afternoon dust concentration distribution, we find it has daily change. The dust emission areas with vertical sand flux over 50 mg·m-2·s-1 are Tarim Basin， Gansu Province， western Inner Mongolia and southern Mongolia. The vertical transportation of dust concentration is below 550 hPa, and the horizontal transportation of dust is driven by strong wind in middlelowerlevel troposphere. The particle size which contributes significantly to the dust emission is different due to the variety of land, however, the quantities of particles with diameter from 2 μm<d≤11 μm are predominated. The scope of simulated dust concentration value is consistent with the strong dust storm.
2011, 37(3):318-324.
DOI: 10.7519/j.issn.1000-0526.2011.3.009
Abstract:
AIRS(Atmospheric Infrared Sounder), the first high spectral atmospheric infrared detector, started a new era of satellite sounding atmosphere. The samples, composed of the radiosonde observations and the AIRS brightness temperature value simulated by the SARTA (StandAlone Radiative Transfer Algorithm)v1.05 forward mode, were inversed to the atmospheric humidity profiles using neural network. The results show that, compared with the result of eigenvector statistics, the neural network inversion is of higher precision, and the humidity profiles obtained are closer to the true profiles. AIRS displays the fine structure of the atmosphere because of its high spectral resolution (high vertical resolution).Neural network has a strong nonliner processing capability in the issue that the inversion of the atmospheric humidity profiles is based on high spectral data.
AIRS(Atmospheric Infrared Sounder), the first high spectral atmospheric infrared detector, started a new era of satellite sounding atmosphere. The samples, composed of the radiosonde observations and the AIRS brightness temperature value simulated by the SARTA (StandAlone Radiative Transfer Algorithm)v1.05 forward mode, were inversed to the atmospheric humidity profiles using neural network. The results show that, compared with the result of eigenvector statistics, the neural network inversion is of higher precision, and the humidity profiles obtained are closer to the true profiles. AIRS displays the fine structure of the atmosphere because of its high spectral resolution (high vertical resolution).Neural network has a strong nonliner processing capability in the issue that the inversion of the atmospheric humidity profiles is based on high spectral data.
LI Rui
,
NIU Shengjie
,
WANG Lingling
,
LV Jingjing
,
WANG Yan
,
XIE Zhenzhen
,
KE Yiming
,
YANG Zhibiao
,
XIONG Shouquan
2011, 37(3):325-333.
DOI: 10.7519/j.issn.1000-0526.2011.3.010
Abstract:
Based on the observations of three different kinds of underlying surface temperatures and the automatic meteorological sensor measurements during January and February of 2009 winter in Enshi and Jinsha, Hubei Province, this paper studies the relationship of the three kinds of underlying surface temperatures and the air temperature by establishing multi〖HJ*3/7〗ple regressions accordingly with the statistic analysis method as well as the meteorological conditions of icy underlying surface. The results show that the range of soil and concrete road surface temperature is less than asphalt, and the former two variation trends are highly consistent. Air temperature is one of the most important factors influencing the underlying surface temperature. The underlying surface temperature in different weather conditions predicted by multiple regression are well validated, with 0.9 above correlated with observations except for 0.88 of asphalt underlying surface in Jinsha. Besides, the revealed close relationship between the low temperature around 0 ℃ on the underlying surface and the wet state for the road ice development will benefit the meteorological departments for their practical operation to some extent.
Based on the observations of three different kinds of underlying surface temperatures and the automatic meteorological sensor measurements during January and February of 2009 winter in Enshi and Jinsha, Hubei Province, this paper studies the relationship of the three kinds of underlying surface temperatures and the air temperature by establishing multi〖HJ*3/7〗ple regressions accordingly with the statistic analysis method as well as the meteorological conditions of icy underlying surface. The results show that the range of soil and concrete road surface temperature is less than asphalt, and the former two variation trends are highly consistent. Air temperature is one of the most important factors influencing the underlying surface temperature. The underlying surface temperature in different weather conditions predicted by multiple regression are well validated, with 0.9 above correlated with observations except for 0.88 of asphalt underlying surface in Jinsha. Besides, the revealed close relationship between the low temperature around 0 ℃ on the underlying surface and the wet state for the road ice development will benefit the meteorological departments for their practical operation to some extent.
2011, 37(3):334-338.
DOI: 10.7519/j.issn.1000-0526.2011.3.011
Abstract:
AMSR-E soil moisture products have been gradually used in meteorology, agriculture and other fields. Studying soil moisture has important significance, especially in arid and semiarid regions. In order to investigate AMSRE soil moisture products in Xilinhot grassland applicability, this paper utilizes field experiments in Xilinhot grassland, which is a 3 km× 3 km area within the AMSRE retrieval region with the same ninepoint latitude and longitude ground soil moisture compared to validate product precision. Because the relationship between precipitation and surface soil moisture is most closely, the soil moisture inversed from AMSR-E and precipitation data for comparison can validate soil moisture product reliability indirectly. Compared with the ground data, it shows that the AMSRE retrieval value and the groundbased measured average soil volumetric water content are 13.3% and 11.8% respectively, and their RMSE is 3.7%.
AMSR-E soil moisture products have been gradually used in meteorology, agriculture and other fields. Studying soil moisture has important significance, especially in arid and semiarid regions. In order to investigate AMSRE soil moisture products in Xilinhot grassland applicability, this paper utilizes field experiments in Xilinhot grassland, which is a 3 km× 3 km area within the AMSRE retrieval region with the same ninepoint latitude and longitude ground soil moisture compared to validate product precision. Because the relationship between precipitation and surface soil moisture is most closely, the soil moisture inversed from AMSR-E and precipitation data for comparison can validate soil moisture product reliability indirectly. Compared with the ground data, it shows that the AMSRE retrieval value and the groundbased measured average soil volumetric water content are 13.3% and 11.8% respectively, and their RMSE is 3.7%.
2011, 37(3):339-344.
DOI: 10.7519/j.issn.1000-0526.2011.3.012
Abstract:
By virtue of the daily surface temperature data at 753 stations from the National Climate Center in China during 1957 to 2007, the 51 stations within the area of 27.5°-32.5°N, 112°-123°E are selected for the Middle and Lower Reaches of the Yangtze River, and the characteristics of the similar cold wave frequency in the area are analyzed. The main conclusions reached are that the frequency in the area is reducing due to the global warming. From decadal changes, the frequency of the similar cold wave is gradually reduced in 1960s-1980s of the twentieth century and slightly increased in the 1990s. Abrupt change occurs around 1973. Cyclic changes of the 5a signal and the 14a signal are the main in the area and months are March and November each year, in which the highest frequency of the similar cold wave occurred. However, there are interannual differences for these changes. And the greatest different regions are in the southern Anhui, northern Jiangxi and western Zhejiang.
By virtue of the daily surface temperature data at 753 stations from the National Climate Center in China during 1957 to 2007, the 51 stations within the area of 27.5°-32.5°N, 112°-123°E are selected for the Middle and Lower Reaches of the Yangtze River, and the characteristics of the similar cold wave frequency in the area are analyzed. The main conclusions reached are that the frequency in the area is reducing due to the global warming. From decadal changes, the frequency of the similar cold wave is gradually reduced in 1960s-1980s of the twentieth century and slightly increased in the 1990s. Abrupt change occurs around 1973. Cyclic changes of the 5a signal and the 14a signal are the main in the area and months are March and November each year, in which the highest frequency of the similar cold wave occurred. However, there are interannual differences for these changes. And the greatest different regions are in the southern Anhui, northern Jiangxi and western Zhejiang.
2011, 37(3):345-351.
DOI: 10.7519/j.issn.1000-0526.2011.3.013
Abstract:
Heat waves appear usually accompanied by both the abnormal high temperature (or high temperature and muggy weather) and a persistent period of high temperature weather. According to these two characteristics, heat wave index is designed as an identification index of heat wave weather to show the torridity extent and accumulative effect of high temperature process, and the classification standard of heat waves is established. Heat wave index and meteorological grades were tested by daily numbers of heatstroke sufferers in Wuhan during July to August of 1994 and 1995 and daily numbers of death in Shanghai during July to August of 2003. The results show that the heat wave index is a valid index to predict heat wave weather. The method on grading of heat wave can be applied to the actual operation.
Heat waves appear usually accompanied by both the abnormal high temperature (or high temperature and muggy weather) and a persistent period of high temperature weather. According to these two characteristics, heat wave index is designed as an identification index of heat wave weather to show the torridity extent and accumulative effect of high temperature process, and the classification standard of heat waves is established. Heat wave index and meteorological grades were tested by daily numbers of heatstroke sufferers in Wuhan during July to August of 1994 and 1995 and daily numbers of death in Shanghai during July to August of 2003. The results show that the heat wave index is a valid index to predict heat wave weather. The method on grading of heat wave can be applied to the actual operation.
14 A Neural Network Model Based on Principal Component Analysis for Ensemble Precipitation Prediction
2011, 37(3):352-355.
DOI: 10.7519/j.issn.1000-0526.2011.03.014
Abstract:
Using the method of artificial neural network and principal component analysis (PCA) to study a variety of numerical forecast products for the same precipitation forecast. The results show that the fitting accuracy of the principal component analysis artificial neural network ensemble model is better than each sub product, and the experimental results of the independent sample also show its better prediction accuracy and stability. The model is a good prospect for operational applications.
Using the method of artificial neural network and principal component analysis (PCA) to study a variety of numerical forecast products for the same precipitation forecast. The results show that the fitting accuracy of the principal component analysis artificial neural network ensemble model is better than each sub product, and the experimental results of the independent sample also show its better prediction accuracy and stability. The model is a good prospect for operational applications.
2011, 37(3):356-362.
DOI: 10.7519/j.issn.1000-0526.2011.03.015
Abstract:
A new generation of national meteorological communication system is established in China Meteorological Administration. For the high demand of data transmission time, the huge amount of information data, complex and irregular transmission, incomprehensive monitoring and other problems, the provincial and national level unified management platform is established with the data transmission and processing and system monitoring function based on the Symantec VCS (VERITAS Cluster Server) technology. The meteorological communication system to achieve high availability, easy scalability, and the standardization of business processes, improves data processing capacity and transmition capacity. In the business operational test, all observation data can be transmitted to the National Meteorological Information Center within the prescribed time, and the system can still function properly when an exception occurs on any node. The test results show that: the system is stable, monitoring is comprehensive, so as to meet the design objective. This paper describes the construction of the system, the background and purpose, overall system architecture, implementation details, and other key technologies.
A new generation of national meteorological communication system is established in China Meteorological Administration. For the high demand of data transmission time, the huge amount of information data, complex and irregular transmission, incomprehensive monitoring and other problems, the provincial and national level unified management platform is established with the data transmission and processing and system monitoring function based on the Symantec VCS (VERITAS Cluster Server) technology. The meteorological communication system to achieve high availability, easy scalability, and the standardization of business processes, improves data processing capacity and transmition capacity. In the business operational test, all observation data can be transmitted to the National Meteorological Information Center within the prescribed time, and the system can still function properly when an exception occurs on any node. The test results show that: the system is stable, monitoring is comprehensive, so as to meet the design objective. This paper describes the construction of the system, the background and purpose, overall system architecture, implementation details, and other key technologies.
2011, 37(3):363-368.
DOI: 10.7519/j.issn.1000-0526.2011.03.016
Abstract:
The following are the main characteristics of the general atmospheric circulation in December 2010. There was one weak polar vortex center in the Northern Hemisphere, which was extending to middle latitudes in East Asia, guided cold air going down south. The circulation presents a four wave pattern in middle high latitudes. The subtropical high is more easterly than normal years. The south branch trough is slightly stronger than normal years. The monthly mean precipitation (18.0 mm) is 83.7% above normal, but is 80% less than normal in North China, central west Huang Huai Plain etc., and increases drought in these areas. There were four cold air processes affecting most areas of China, including part of Northeast China, and Inner Mongolia and northern Xinjiang suffered snow disasters.
The following are the main characteristics of the general atmospheric circulation in December 2010. There was one weak polar vortex center in the Northern Hemisphere, which was extending to middle latitudes in East Asia, guided cold air going down south. The circulation presents a four wave pattern in middle high latitudes. The subtropical high is more easterly than normal years. The south branch trough is slightly stronger than normal years. The monthly mean precipitation (18.0 mm) is 83.7% above normal, but is 80% less than normal in North China, central west Huang Huai Plain etc., and increases drought in these areas. There were four cold air processes affecting most areas of China, including part of Northeast China, and Inner Mongolia and northern Xinjiang suffered snow disasters.
2011, 37(3):373-378.
DOI: 10.7519/j.issn.1000-0526.2011.03.017
Abstract:
With the development of weather modification operation and the increase in operation information data, the operation information submission and statistics are playing an increasingly outstanding role in the business of weather modification. By using Visual Basic 6.0 and Microsoft Office Excel, the information acquisition system of anti hail on the ground is developed to accomplish operation information submission, data statistics and chart analysis. The system has the function of data construction, data management, communication transmission, inquiry statistics and chart analysis, and can conduct the statistics and application of operation days, operation stations, operation times and operation dosage. It can not only meet the needs of operation information submission, but also improves the capacity of data statistics, analysis and application, offering users Excel and BMP bitmap and providing more help for the business, service and scientific reasearch of weather modification.
With the development of weather modification operation and the increase in operation information data, the operation information submission and statistics are playing an increasingly outstanding role in the business of weather modification. By using Visual Basic 6.0 and Microsoft Office Excel, the information acquisition system of anti hail on the ground is developed to accomplish operation information submission, data statistics and chart analysis. The system has the function of data construction, data management, communication transmission, inquiry statistics and chart analysis, and can conduct the statistics and application of operation days, operation stations, operation times and operation dosage. It can not only meet the needs of operation information submission, but also improves the capacity of data statistics, analysis and application, offering users Excel and BMP bitmap and providing more help for the business, service and scientific reasearch of weather modification.
2011, 37(3):373-378.
DOI: 10.7519/j.issn.1000-0526.2011.03.018
Abstract:
The use and safeguard of radar klystron are one of the main links in improving operation quality and reducing the cost in radar station, because the performance of klystron directly affects the quality of radar echo, operating costs and the lifetime of use. It is very important and necessary to use and safeguard the klystron better in the case of Yunnan 6 CINRAD/CC radars’ operations in recent years. For example, in Dehong and Pu’er radars, based on both klystron operation principle and practical experience, the operating performance of klystron is determined by the change of collecting waveform, transmission power and anomalous propagation. Based on years of experience, it is shown that the electron gun of klystron is usually considered vulnerable and easy aging. It should be appropriately increased the klystron electron gun filament current so that the full activation of the filament and the new tube keeping with good vacuum during the initial klystron operational period. It should be slightly lowered filament current during the medium klystron operation period. During later period, it should be increased the filament current to ensure the quality of radar echo because klystron cathode emission capability may be decreased at this period. Based on the above operation initiatives and proposals on klystron, it could extend the use lifetime of klystron without affecting the quality of detection. The method should also be good reference for other CINRAD radars.
The use and safeguard of radar klystron are one of the main links in improving operation quality and reducing the cost in radar station, because the performance of klystron directly affects the quality of radar echo, operating costs and the lifetime of use. It is very important and necessary to use and safeguard the klystron better in the case of Yunnan 6 CINRAD/CC radars’ operations in recent years. For example, in Dehong and Pu’er radars, based on both klystron operation principle and practical experience, the operating performance of klystron is determined by the change of collecting waveform, transmission power and anomalous propagation. Based on years of experience, it is shown that the electron gun of klystron is usually considered vulnerable and easy aging. It should be appropriately increased the klystron electron gun filament current so that the full activation of the filament and the new tube keeping with good vacuum during the initial klystron operational period. It should be slightly lowered filament current during the medium klystron operation period. During later period, it should be increased the filament current to ensure the quality of radar echo because klystron cathode emission capability may be decreased at this period. Based on the above operation initiatives and proposals on klystron, it could extend the use lifetime of klystron without affecting the quality of detection. The method should also be good reference for other CINRAD radars.
2011, 37(3):379-384.
DOI: 10.7519/j.issn.1000-0526.2011.03.019
Abstract:
Based on the online calibration correction principle of CINRAD return intensity and combined with the return intensity reception, calibration and transmitting power online measurement signal process of CINRAD/SA&SB, this paper analyzes and classifies anomalous phenomena of CINRAD return intensity in detail. In addition, it summarizes and puts forward analysis and handling methods for anomalous problems such as stronger or weaker returns, and the decreased return area of CINRAD. Moreover, it enumerates examples to solve CINRAD return intensity anomalies effectively. The result shows that using this method can improve timeliness and reliability of handling CINRAD return intensity anomalies.
Based on the online calibration correction principle of CINRAD return intensity and combined with the return intensity reception, calibration and transmitting power online measurement signal process of CINRAD/SA&SB, this paper analyzes and classifies anomalous phenomena of CINRAD return intensity in detail. In addition, it summarizes and puts forward analysis and handling methods for anomalous problems such as stronger or weaker returns, and the decreased return area of CINRAD. Moreover, it enumerates examples to solve CINRAD return intensity anomalies effectively. The result shows that using this method can improve timeliness and reliability of handling CINRAD return intensity anomalies.
Mobile website
® 2024 All Rights Reserved
Supported by:Beijing E-Tiller Technology Development Co., Ltd.
ISSN:1000-0526 CN:11-2282/P