Volume 31,Issue 4,2003 Table of Contents
2003, 31(4):193-200.
Abstract:
A review is made of the research on atmospheric low frequency oscillation (LFO), including the evolution of LFO, relationship between monsoon and LFO, origin and maintaining mechanisms of LFO in the tropic and the middle high latitude regions.
A review is made of the research on atmospheric low frequency oscillation (LFO), including the evolution of LFO, relationship between monsoon and LFO, origin and maintaining mechanisms of LFO in the tropic and the middle high latitude regions.
2003, 31(4):201-205.
Abstract:
The advanced sounding capability of high spectral resolution infrared satellite measurement is briefly described. The retrieval methods for thermodynamic parameters are reviewed with the current satellite and aircraft data. The highlight is given to the eigenvector regression method and the physical retrieval method for the AIRS (Atmospheric InfraRed Sounder) onboard the second Earth Observing System of NASA.
The advanced sounding capability of high spectral resolution infrared satellite measurement is briefly described. The retrieval methods for thermodynamic parameters are reviewed with the current satellite and aircraft data. The highlight is given to the eigenvector regression method and the physical retrieval method for the AIRS (Atmospheric InfraRed Sounder) onboard the second Earth Observing System of NASA.
3 Using Dynamically Combined Nonlinear Multi-Factor Equation to Forecast Probability of Precititation
2003, 31(4):206-210.
Abstract:
将逐时段定点降水预报这个以往一般作为非连续量处理的预报问题转化为对一个连续的降水可能函数的预报问题。降水可能函数为一由实况值确定的函数。因为现在模式变化较快，且许多因子和降水可能函数为非线性关系，文章采用一种新的非线性多因子动态组合方法，通过对降水可能函数的预报，作客观分站降水概率预报。
将逐时段定点降水预报这个以往一般作为非连续量处理的预报问题转化为对一个连续的降水可能函数的预报问题。降水可能函数为一由实况值确定的函数。因为现在模式变化较快，且许多因子和降水可能函数为非线性关系，文章采用一种新的非线性多因子动态组合方法，通过对降水可能函数的预报，作客观分站降水概率预报。
2003, 31(4):211-215.
Abstract:
Several similarity criterions most frequently used are tested and discussed objectively. A composite similar coefficient is introduced. The field experiments indicate that the coefficient is highly applicable in the analogue forecasting of precipitation.
Several similarity criterions most frequently used are tested and discussed objectively. A composite similar coefficient is introduced. The field experiments indicate that the coefficient is highly applicable in the analogue forecasting of precipitation.
2003, 31(4):216-219.
Abstract:
By using different mesh densities to eliminate different frequency components of errors, the multigrid method can accelerate the convergence of iteration. It has advantages of high convergent speed and high accuracy. The multigrid method is compared with the super relaxation iteration method. Experiments show that the multigrid method performs better in improving the validity in the iteration.
By using different mesh densities to eliminate different frequency components of errors, the multigrid method can accelerate the convergence of iteration. It has advantages of high convergent speed and high accuracy. The multigrid method is compared with the super relaxation iteration method. Experiments show that the multigrid method performs better in improving the validity in the iteration.
2003, 31(4):220-222.
Abstract:
The spatial and temporal characteristics of 16 hail events are analyzed by means of radiosonde data from three nearby stations and conventional data of Rizhao Station from 1960 to 2000. Based on the synoptic weather classification, hailing factors are calculated by using the numerical cumulus model. The historical hailing factor case database is established by using the hailing factors and single station data, and a actual case database by using historical observation data. A method for forecasting the amount, time and location of hails in Rizhao, Shangdong Province is developed by means of the distance analog method.
The spatial and temporal characteristics of 16 hail events are analyzed by means of radiosonde data from three nearby stations and conventional data of Rizhao Station from 1960 to 2000. Based on the synoptic weather classification, hailing factors are calculated by using the numerical cumulus model. The historical hailing factor case database is established by using the hailing factors and single station data, and a actual case database by using historical observation data. A method for forecasting the amount, time and location of hails in Rizhao, Shangdong Province is developed by means of the distance analog method.
2003, 31(4):223-225230.
Abstract:
Based on the numerical forecast products, the reliability of numerical rainfall forecast products is analyzed by using the grey relational grade and the area rainfall prediction models are established with the grey forecasting methods for five areas in upstream of the Changjiang River. In 2001 and 2002, the grey forecasting method performed well in the operational forecasting practice in summer.
Based on the numerical forecast products, the reliability of numerical rainfall forecast products is analyzed by using the grey relational grade and the area rainfall prediction models are established with the grey forecasting methods for five areas in upstream of the Changjiang River. In 2001 and 2002, the grey forecasting method performed well in the operational forecasting practice in summer.
2003, 31(4):226-230.
Abstract:
Preliminary study is undertaken of the spring soil moisture variation in the eastern part of Northwest China based on the dekad soil moisture data of target agricultural meteorological stations from 1981 to 2001. The results show that the variation of soil moisture with a period of 3 years is related to changes of rainfall and air temperature, and the moisture took on a decline tendency in the 1990s. Meanwhile, the variation contributes to the break outs of sandstorms in this region.
Preliminary study is undertaken of the spring soil moisture variation in the eastern part of Northwest China based on the dekad soil moisture data of target agricultural meteorological stations from 1981 to 2001. The results show that the variation of soil moisture with a period of 3 years is related to changes of rainfall and air temperature, and the moisture took on a decline tendency in the 1990s. Meanwhile, the variation contributes to the break outs of sandstorms in this region.
2003, 31(4):231-236.
Abstract:
Expansion of Chebyshev Fourier mixed polynomial is conducted by means of the NECP 500 hPa geopotential height data from 1981 to 1990 without rain enhancement operation and the same data in 1996 and 1997 with rain enhancement operation in Jilin Province to determine the minimum correlation between the two element fields. Hereby, case studies of different weather patterns in the two years are made and the percentages of rain enhancement effectiveness of 23 seeding flights are given. The results indicate that when the correlation between the two element fields reaches the minimum, the patterns of the two element fields are highly similar and the rainfall over the seeding area is mostly higher obviously; generally speaking, the rain enhancement operations have positive effect on rainfall.
Expansion of Chebyshev Fourier mixed polynomial is conducted by means of the NECP 500 hPa geopotential height data from 1981 to 1990 without rain enhancement operation and the same data in 1996 and 1997 with rain enhancement operation in Jilin Province to determine the minimum correlation between the two element fields. Hereby, case studies of different weather patterns in the two years are made and the percentages of rain enhancement effectiveness of 23 seeding flights are given. The results indicate that when the correlation between the two element fields reaches the minimum, the patterns of the two element fields are highly similar and the rainfall over the seeding area is mostly higher obviously; generally speaking, the rain enhancement operations have positive effect on rainfall.
2003, 31(4):237-242.
Abstract:
Taking Wulanchabumeng as an example, on the basis of the relative variation of per unit area potato yields from 1961 to 2000, using such indexes as the yield reduction rate, the yield reduction rate variation coefficient, the yield reduction rate probability and synoptic risk as evaluation stands, the risk distribution regularity of per unit area potato yields in Wulanchabumeng is analyzed by means of the small grid resource deduction method. According to the climate similarity theory, using the optimal dynamic cluster method, the risk compartment of potato plating is given. At the same time, factors that affect the potato yields are also analyzed. Results show that droughts either in spring, summer or all the year round, as well as big precipitation variations, are main reasons that cause potato yield fluctuation in the area.
Taking Wulanchabumeng as an example, on the basis of the relative variation of per unit area potato yields from 1961 to 2000, using such indexes as the yield reduction rate, the yield reduction rate variation coefficient, the yield reduction rate probability and synoptic risk as evaluation stands, the risk distribution regularity of per unit area potato yields in Wulanchabumeng is analyzed by means of the small grid resource deduction method. According to the climate similarity theory, using the optimal dynamic cluster method, the risk compartment of potato plating is given. At the same time, factors that affect the potato yields are also analyzed. Results show that droughts either in spring, summer or all the year round, as well as big precipitation variations, are main reasons that cause potato yield fluctuation in the area.
11 Analysis of Cumulus Precipitation Frequency and Potential of Rain Enhancement in Summer in Liaoning
2003, 31(4):243-247.
Abstract:
Based on the observations from 14 stations in Liaoning Province and the radiosonde data from Shenyang Station, analysis is conducted on the occurrence frequency of various cumulus and its precipitation characteristics from June to August, as well as the precipitation probabilities of various cumulus and their potential affected by artificial. The results indicates that: (1) The probability of the cumulus emergence is very high in summer in Liaoning, the annual average rate is 41.5 days and it is over 50% of the total cloud days in summer. (2) There is more than 11 rainy days caused by cumulus on average, and it is 36.9% of the total rainy days in summer. (3) The area averaged cumulus precipitation is 33.5% of the total precipitation, in which the rainfall produced by cumulus heavy rains is 43.1% of the total. (4) The probability of cumulus along with stratiform clouds is quite high, but the precipitation efficiency is not very high in most of situations. There is quite high potential and a great deal of operation opportunities for rain enhancement in Liaoning Province
Based on the observations from 14 stations in Liaoning Province and the radiosonde data from Shenyang Station, analysis is conducted on the occurrence frequency of various cumulus and its precipitation characteristics from June to August, as well as the precipitation probabilities of various cumulus and their potential affected by artificial. The results indicates that: (1) The probability of the cumulus emergence is very high in summer in Liaoning, the annual average rate is 41.5 days and it is over 50% of the total cloud days in summer. (2) There is more than 11 rainy days caused by cumulus on average, and it is 36.9% of the total rainy days in summer. (3) The area averaged cumulus precipitation is 33.5% of the total precipitation, in which the rainfall produced by cumulus heavy rains is 43.1% of the total. (4) The probability of cumulus along with stratiform clouds is quite high, but the precipitation efficiency is not very high in most of situations. There is quite high potential and a great deal of operation opportunities for rain enhancement in Liaoning Province
2003, 31(4):248-252.
Abstract:
Based on the ecoclimatic indexes of several high quality fruits and melon, the climatic adaptiveness and the climatically optimum regions of these fruits and melon in Gansu Province are analyzed. The research results provide a scientific basis for developing the production of famed high quality fruits and melon in Gansu Province.
Based on the ecoclimatic indexes of several high quality fruits and melon, the climatic adaptiveness and the climatically optimum regions of these fruits and melon in Gansu Province are analyzed. The research results provide a scientific basis for developing the production of famed high quality fruits and melon in Gansu Province.
2003, 31(4):253-256.
Abstract:
The analysis of temperature on different underlying surfaces indicates that underlying surface temperature is obviously higher than thermometer shelter temperature, especially in daily maximum temperature. The variations of temperature on different underlying surfaces are greatly different; there is close relationship between underlying surface temperature and meteorological elements. Hereby, the prediction equation of temperature on different underlying surfaces is obtained by the statistic method.
The analysis of temperature on different underlying surfaces indicates that underlying surface temperature is obviously higher than thermometer shelter temperature, especially in daily maximum temperature. The variations of temperature on different underlying surfaces are greatly different; there is close relationship between underlying surface temperature and meteorological elements. Hereby, the prediction equation of temperature on different underlying surfaces is obtained by the statistic method.
External LinksChina Meteorological AdministrationCMA Meteorological Observation CentreChinese Academy of Meteorological SciencesBeijing Meteorological ServiceNational Satellite Meteorological Center
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Supported by:Beijing E-Tiller Technology Development Co., Ltd.
Supported by:Beijing E-Tiller Technology Development Co., Ltd.