Volume 32,Issue 1,2004 Table of Contents
2004, 32(1):1.
Abstract:
The essential concepts of targeted observations and several atmospheric scientific field experiments carried out overseas for targeted observations and the used methods and the main conclusions obtained during those field experiments are introduced. Emphasis is placed on the sensitivity analysis and the design of targeted observations based on the adjoint model. Some discussions and suggestions are presented.
The essential concepts of targeted observations and several atmospheric scientific field experiments carried out overseas for targeted observations and the used methods and the main conclusions obtained during those field experiments are introduced. Emphasis is placed on the sensitivity analysis and the design of targeted observations based on the adjoint model. Some discussions and suggestions are presented.
2004, 32(1):6-12.
Abstract:
介绍了MM5中的显式云物理方案，详细分析了Goddard,Reisner和Schultz方案的物理过程特点和存在的不足。这些云物理方案的多个微物理过程的描述不是很合理，对粒子的自动转化过程都采用阚值，且对雪、霰和雨的数浓度只进行诊断计算。Reisner方案的物理过程相对全面，预报量也较多，但仍存在一定的不足。通过对1992年Andrew台风个例的模拟，发现尽管Reisner方案的物理过程比Goddard和Schultz方案全面，但模拟的台风眼最低气压和地面最大风速并没有优势。所以单一物理过程描述的改善不一定立即带来模式预报成效的提高，因为预报能力取决于整个模式系统的科技水平以及各子程序之间的匹配。
介绍了MM5中的显式云物理方案，详细分析了Goddard,Reisner和Schultz方案的物理过程特点和存在的不足。这些云物理方案的多个微物理过程的描述不是很合理，对粒子的自动转化过程都采用阚值，且对雪、霰和雨的数浓度只进行诊断计算。Reisner方案的物理过程相对全面，预报量也较多，但仍存在一定的不足。通过对1992年Andrew台风个例的模拟，发现尽管Reisner方案的物理过程比Goddard和Schultz方案全面，但模拟的台风眼最低气压和地面最大风速并没有优势。所以单一物理过程描述的改善不一定立即带来模式预报成效的提高，因为预报能力取决于整个模式系统的科技水平以及各子程序之间的匹配。
2004, 32(1):13-18.
Abstract:
In order to help users familiarize and better use TRMM data products in their atmospheric researches and weather forecast, the instruments and main data products of the Tropical Rainfall Measuring Mission Satellite (TRMM) and the application of its products in heavy rainfall researches, data assimilation, and tropical sea surface temperature retrieval are introduced.
In order to help users familiarize and better use TRMM data products in their atmospheric researches and weather forecast, the instruments and main data products of the Tropical Rainfall Measuring Mission Satellite (TRMM) and the application of its products in heavy rainfall researches, data assimilation, and tropical sea surface temperature retrieval are introduced.
2004, 32(1):19.
Abstract:
The evaporation on the ocean surface in tropical regions is discussed and it is found out that the vapor into the air through evaporation will change the surface pressure field, and that evaporation latent heat is composed of internal latent heat (vapor internal energy) and external latent heat (vapor pressure energy). The former becomes the atmosphere's heat energy directly and the latter applies work to the atmosphere immediately, which enhance the potential energy. The direct effects of large-scale condensation precipitation and cumulus convection condensation precipitation on the ambient pressure field and the geopotential height field are studied. Based on Kuo's method of cumulus convection parameterization, which embodied the effect of condensation internal latent heat on heat the atmosphere, it is suggested that the other effect should be added to reflect the variation of the surface pressure field as well as the upper geopotential height field resulted from the large-scale condensation precipitation and cumulus convection condensation precipitation. The continuity equation considering condensation is introduced so as being able to change the dynamical frame of the numerical forecast model with taking into account of condensation-precipitation in cumulus convection.
The evaporation on the ocean surface in tropical regions is discussed and it is found out that the vapor into the air through evaporation will change the surface pressure field, and that evaporation latent heat is composed of internal latent heat (vapor internal energy) and external latent heat (vapor pressure energy). The former becomes the atmosphere's heat energy directly and the latter applies work to the atmosphere immediately, which enhance the potential energy. The direct effects of large-scale condensation precipitation and cumulus convection condensation precipitation on the ambient pressure field and the geopotential height field are studied. Based on Kuo's method of cumulus convection parameterization, which embodied the effect of condensation internal latent heat on heat the atmosphere, it is suggested that the other effect should be added to reflect the variation of the surface pressure field as well as the upper geopotential height field resulted from the large-scale condensation precipitation and cumulus convection condensation precipitation. The continuity equation considering condensation is introduced so as being able to change the dynamical frame of the numerical forecast model with taking into account of condensation-precipitation in cumulus convection.
2004, 32(1):25-28.
Abstract:
Using the modified MASS model and terrain data of Liaoning, the effect of terrain on diurnal variation of the wind field in the ground layer is simulated. The result shows that the Bohai Sea and the northern Yellow Sea have significant effect on the diurnal variation of the wind field in the ground layer in Liaoning Province, and that differences in heating rate and terrain may result in the diurnal variation of the wind field in the ground layer.
Using the modified MASS model and terrain data of Liaoning, the effect of terrain on diurnal variation of the wind field in the ground layer is simulated. The result shows that the Bohai Sea and the northern Yellow Sea have significant effect on the diurnal variation of the wind field in the ground layer in Liaoning Province, and that differences in heating rate and terrain may result in the diurnal variation of the wind field in the ground layer.
2004, 32(1):29-33.
Abstract:
Through synoptic and dynamical diagnostic methods and the contrast analysis of the background atmospheric circulation, the main influencing systems and characteristics of weather element fields, as well as the similarities and differences of two heavy rain events happened in the northern Sichuan Basin,are analyzed. It is shown that the low-level jet and the steady circulation pattern are the key factors.
Through synoptic and dynamical diagnostic methods and the contrast analysis of the background atmospheric circulation, the main influencing systems and characteristics of weather element fields, as well as the similarities and differences of two heavy rain events happened in the northern Sichuan Basin,are analyzed. It is shown that the low-level jet and the steady circulation pattern are the key factors.
2004, 32(1):34-38.
Abstract:
In order to improve TC track and landfall forecast and to reduce the loss caused by TC, some nonlinear mathematic models of tropical cyclones are built. The results of research and experiments of more than 5 years show that TC track forecast with the exponential curve model has higher accuracy. The 24-hour average error of TC track forecast for 199 forecasts is about 123 km, which reaches an advanced level in TC track forecasting in China. Nonlinear forecasts such as multinomial curve models have been applied for 3 years in forecasting the number of TC in Guangdong Province. The accuracy can be as high as 70% to 90%. By means of the nonlinear model to analyze the long-term forecasts of day-to-day pressure and precipitation fields to make the landfall time and location forecast of TC, as well as the time forecast of TC appearing in South China Sea. The accuracy can be as high as 70% to 80%. The way of integrating medium and long term, numerical and statistical forecasting methods to forecast the TC track and landing time and location has been proved successful in 2002 TC forecasting practice.
In order to improve TC track and landfall forecast and to reduce the loss caused by TC, some nonlinear mathematic models of tropical cyclones are built. The results of research and experiments of more than 5 years show that TC track forecast with the exponential curve model has higher accuracy. The 24-hour average error of TC track forecast for 199 forecasts is about 123 km, which reaches an advanced level in TC track forecasting in China. Nonlinear forecasts such as multinomial curve models have been applied for 3 years in forecasting the number of TC in Guangdong Province. The accuracy can be as high as 70% to 90%. By means of the nonlinear model to analyze the long-term forecasts of day-to-day pressure and precipitation fields to make the landfall time and location forecast of TC, as well as the time forecast of TC appearing in South China Sea. The accuracy can be as high as 70% to 80%. The way of integrating medium and long term, numerical and statistical forecasting methods to forecast the TC track and landing time and location has been proved successful in 2002 TC forecasting practice.
2004, 32(1):39-43.
Abstract:
The resources of solar radiation, temperature and wind energy are analyzed according to the records of 54 representative weather stations from 1961 to 1995. In general, climatic resources in Liaoning Province are abundant and have the characteristics of: precipitation mainly concentrates in summer and is relatively stable in accordance with the peaks of the water need of crops; heat resources are very plenty with high guaranteed accumulated temperature during the periods of crop growth and development except in the eastern mountain areas; and the solar and wind resources are also abundant in Liaoning Province.
The resources of solar radiation, temperature and wind energy are analyzed according to the records of 54 representative weather stations from 1961 to 1995. In general, climatic resources in Liaoning Province are abundant and have the characteristics of: precipitation mainly concentrates in summer and is relatively stable in accordance with the peaks of the water need of crops; heat resources are very plenty with high guaranteed accumulated temperature during the periods of crop growth and development except in the eastern mountain areas; and the solar and wind resources are also abundant in Liaoning Province.
2004, 32(1):44-47.
Abstract:
Usual radiosonde data (1988 to 1997,07:00,19:00) and surface precipitation data (1988 to 1997) are used, and the natural precipitation efficiency in summer in Jiangxi is calculated and analyzed. The results indicate that the average precipitation efficiency in summer is 7.65% in the period of 1988 to 1997, 7.04%, 9.90%, 6.02% in July, August, September in Jiangxi Province, respectively. The maximum precipitation efficiency is 13.77%. The minimum precipitation efficiency is 3.55%. Under the influence of the weather of low-pressure convergent systems, the precipitation efficiency is the greatest (20.48%) and under the influence of the weather of typhoon low systems, the precipitation efficiency is the least (3.33%). The precipitation efficiencies are 11.90%, 8.56%, 7.05%, 7.04% under the weather systems of low-though, typhoon low pressure, continental high pressure, easterly wave, respectively.
Usual radiosonde data (1988 to 1997,07:00,19:00) and surface precipitation data (1988 to 1997) are used, and the natural precipitation efficiency in summer in Jiangxi is calculated and analyzed. The results indicate that the average precipitation efficiency in summer is 7.65% in the period of 1988 to 1997, 7.04%, 9.90%, 6.02% in July, August, September in Jiangxi Province, respectively. The maximum precipitation efficiency is 13.77%. The minimum precipitation efficiency is 3.55%. Under the influence of the weather of low-pressure convergent systems, the precipitation efficiency is the greatest (20.48%) and under the influence of the weather of typhoon low systems, the precipitation efficiency is the least (3.33%). The precipitation efficiencies are 11.90%, 8.56%, 7.05%, 7.04% under the weather systems of low-though, typhoon low pressure, continental high pressure, easterly wave, respectively.
2004, 32(1):48-51.
Abstract:
In accordance with the characteristics of several types of weather radar images used in the aeronautical meteorology support, a suitable scheme for radar image compression software is presented on the basis of the bi-orthogonal wavelet transformation, embedded zero tree coding and adaptive arithmetic coding technologies. Tests indicate that this scheme is one of the effective ways to solve the problems of storage and long-distance transmission of weather radar echo images.
In accordance with the characteristics of several types of weather radar images used in the aeronautical meteorology support, a suitable scheme for radar image compression software is presented on the basis of the bi-orthogonal wavelet transformation, embedded zero tree coding and adaptive arithmetic coding technologies. Tests indicate that this scheme is one of the effective ways to solve the problems of storage and long-distance transmission of weather radar echo images.
2004, 32(1):52-56.
Abstract:
Due to the differences in locations, types, emissive power, elevation and boot-strap time, etc, of weather radars, a method for normalizing echo image data for weather radar is put forward. The normalization was carried on the power, time, and location of echo data from different weather radar. It provides a reliable data foundation for the concatenation of the regional weather radar echo images. It can use the echo technology over overlapped regions to form the networking radar echo images, thus adopting the sphere projection to get better weather radar echo images.
Due to the differences in locations, types, emissive power, elevation and boot-strap time, etc, of weather radars, a method for normalizing echo image data for weather radar is put forward. The normalization was carried on the power, time, and location of echo data from different weather radar. It provides a reliable data foundation for the concatenation of the regional weather radar echo images. It can use the echo technology over overlapped regions to form the networking radar echo images, thus adopting the sphere projection to get better weather radar echo images.
2004, 32(1):57-59.
Abstract:
Based on the remote sensing data of NOAA/AVHRR from 1991 to 2000 and the winter wheat yield data at the same period, the correlation equation between winter wheat yields and vegetable index of every pixel was established and hereby the winter wheat yield of every pixel was computed. According to the threshold values of the high, middle and low yield farmlands, the yield type of every pixel was determined. The distribution diagram of winter wheat yield types in Shandong was given by means of GIS. The formation causes of the middle and low farmlands were analyzed.
Based on the remote sensing data of NOAA/AVHRR from 1991 to 2000 and the winter wheat yield data at the same period, the correlation equation between winter wheat yields and vegetable index of every pixel was established and hereby the winter wheat yield of every pixel was computed. According to the threshold values of the high, middle and low yield farmlands, the yield type of every pixel was determined. The distribution diagram of winter wheat yield types in Shandong was given by means of GIS. The formation causes of the middle and low farmlands were analyzed.
2004, 32(1):60-62.
Abstract:
The optical principles of NOAA and TM satellite monitoring flood are explained, and taking Heishan and Taian counties (Liaoning Province) as examples, the NOAA/AVHRR data in flood monitoring are corrected and analyzed in precision by means of the high spatial resolution of Landsat TM data. The average relative error is 4.4%. The results indicate that it is an effective and feasible method in improving the precision of NOAA/AVHRR flood monitoring using TM data.
The optical principles of NOAA and TM satellite monitoring flood are explained, and taking Heishan and Taian counties (Liaoning Province) as examples, the NOAA/AVHRR data in flood monitoring are corrected and analyzed in precision by means of the high spatial resolution of Landsat TM data. The average relative error is 4.4%. The results indicate that it is an effective and feasible method in improving the precision of NOAA/AVHRR flood monitoring using TM data.
2004, 32(1):63-64.
Abstract:
由于地物杂波不可避免地出现在雷达回波资料中，因此剔除地物杂波对于提高雷达观测资料质量的控制，充分发挥其在实际业务中的作用及其潜力具有重要意义。笔者利用区域膨胀法设计了一种新的剔除地物杂波方法。该方法首先利用区域膨胀法将雷达速度回波分成具有不同性质的几个区域，然后对每一个区域进行统计分析，设定阀值并识别出地物，同时将地物剔除。区域膨胀法的目标是将输
由于地物杂波不可避免地出现在雷达回波资料中，因此剔除地物杂波对于提高雷达观测资料质量的控制，充分发挥其在实际业务中的作用及其潜力具有重要意义。笔者利用区域膨胀法设计了一种新的剔除地物杂波方法。该方法首先利用区域膨胀法将雷达速度回波分成具有不同性质的几个区域，然后对每一个区域进行统计分析，设定阀值并识别出地物，同时将地物剔除。区域膨胀法的目标是将输
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Supported by:Beijing E-Tiller Technology Development Co., Ltd.