应用气象学报

Numerical Experiments for the Influence of the Surface Drag Effect of the Qinghai Xizang Plateau on the General Circulation in Spring

Zheng Qinglin Song Qingli

1997, 8(3): 335-341.

[FullText](2957) [PDF 280KB](1162)

Abstract:
This long-range numerical experiments for the influence of the surface drag effect of the Qinghai-Xizang Plateau on the general circulation in spring by using a CCM1 (R15L7) –LNWP model based on CCM1 (R15L12) are carried out. The results show that the prediction results can be improved when difference of the mean monthly drag coefficient between Qinghai Xizang Plateau and other land areas increases from 0.0008 to 0.004. The surface drag effect of the Plateau is advantageous to the increasing of the temperature over the Plateau and the decreasing at the north of the Plateau, which induce to the enhancing of the westerly wind in the upper levels over the Plateau and its north side, and the weakening centers of the westerly appear on the south side of the Plateau, which are favorable to the northward shift of the southern subtropical westerly jet in East Asia. It is also beneficial to the enhancement of the Northern Hemispheric three-circle and global meridional circulation.

Numerical Simulation of the Earliest Torrential Rain Event over South China in 1996

Wang Jianjie Guo Xiaorong

1997, 8(3): 257-268.

[FullText](4521) [PDF 589KB](1314)

Abstract:
The earliest torrential rain event over South China in 1996 is simulated, and a series of sensitivity experiments are carried out using a nested grid version of PSU/NCAR’s mesoscale model (MM5) with a fine mesh grid size of 20 km. It is shown that the MM5 model reproduces successfully the development of the torrential rain and mesoscale system; latent heat release acts a vital role in the development of the torrential rain event by a mechanism similar to CISK; the low-level southwest jet transports potential unstable energy to the torrential rain region, and interacts with torrential rain to maintain and strengthen itself; the store of the low-level potential unstable energy over the South China Sea and the South China region at initial time (12 h before the occurrence of the torrential rain) is a crucial condition for the formation of the torrential rain

Strong Convective Cloud Characteristics Derived from Satellite Cloud Picture

Lu Naimeng Wu Rongzhang

1997, 8(3): 269-275.

[FullText](4787) [PDF 318KB](1707)

Abstract:
In order to get the strong convective cloud characteristics exhibiting in satellite images, about 20000 hourly gauge data of 333 surface rainfall stations and corresponding 4000 IR digital cloud images of GMS-4 during the period of 1992~1994 in Henan, Hubei and Sichuan Provincess were analyzed. The results show that the cloud top temperature, the temperature gradients, the expansion of a convective cloud cluster, the occurrence of overshooting tops and the normalized distance from a cloud-covered area to the cluster center have correspondent relations to the cloud precipitation. These relations could vary with different geographical regions.

A Study of Composite Evaluation Method of Real-time Agricultural Climate for Rice in Guizhou Province

Gu Xiaoping, Liu Xuemei, Wu Wenhui

1997, 8(3): 276-282.

[FullText](4554) [PDF 521KB](1429)

Abstract:
On the basis of mathematical statistics principle, the composite evaluation method of real-time agroclimale for rice is studied in Guizhou Province by using the meteorological and phonological observation data from 1979 to 1991. And, by using the method, the rice yield prospects of Guizhou Province are verified, the results show that there is high practical value for rice production

Parameterization of Shortwave Radiation Properties of Ice Cloud

Zhang Guodong

1997, 8(3): 283-291.

[FullText](2891) [PDF 1103KB](1330)

Abstract:
The 15 kinds of ice crystal size distributions, 3 kinds of cloud heights and thickness, 30 kinds of ice water contents and 90 kinds of ice water path models for cirrus (Ci) and altostratus (As) are constructed, respectively. The single scattering properties of ice crystal particles, with sizes larger or smaller than 30 μm, are derived based on Mie theory and ray optical theory. The multiple scattering radiation transmission properties of the ice clouds for 4 kinds of ground surface albedos are calculated by using delta-Eddington method, and the new parameterization of ice cloud radiation characteristics is formulated. The formula can be used in climate model or atmospheric circulation model.

The Solar Heating Effect of the Winter Aerosol in Lanzhou and Its Influence on Evolution of the Mixed Layer

Tian Wenshou Chen Changhe Huang Jianguo Zhang Lei, Huang Jianguo, Zhang Lei

1997, 8(3): 292-301.

[FullText](2848) [PDF 404KB](1408)

Abstract:
A shortwave heating rate model of the aerosol atmosphere is established in consideration of the effects of atmospheric aerosol and absorbing gases on the solar radiation under conditions of cloudlessness. The shortwave heating effect of the winter aerosol in Lanzhou is studied by using this model. The results show that the effects of the atmospheric aerosol on the solar heating of the atmosphere are significant. Based on the above work, a perfect closed mixed layer model is established and the radiative effects of aereosol on the evolution of the mixed layer are studied by using the numerical method. The results indicate that increasing of atmospheric aerosol would restrain the evolution of the mixed layer and decrease the mean potential temperature in the mixed layer.

Construction of PBL Wind Fields by Fitting Numerical Simulation Output with Observations

Yu Jinxiang Qiu Chongjian

1997, 8(3): 302-309.

[FullText](3136) [PDF 309KB](1461)

Abstract:
The optimization method is used to modify some external forcing terms in the PBL model. By this way the output of the model is fitted with the observations, and wind fields in the PBL are produced. The gradients of the objective function with respect to the parameters are obtained through perturbation method. Furthermore, the reasonableness of this method is tested by using the model data and the observation in Lanzhou city.

Estimation of Aerodynamic Parameters on Non-single Horizontal Homogeneous Underlying Surface

Zhang Hongsheng, Chen Jiayi

1997, 8(3): 310-315.

[FullText](4340) [PDF 273KB](1961)

Abstract:
The method to estimate aerodynamic parameters with only velocity and temperature fluctuation data is applied to non-homogeneous surfaces and non-neutral stratification. The turbulence data measured in Beijing Meteorological Tower which is 325 m high are used to determine the zero plane displacement d and surface roughness z0. It is shown that the d and z0 are considerable dependent on wind direction

Analysis of Summer Monsoon Activityduring the 1991 Excessively Torrential Rain over Changjiang-Huaihe River Valley

Lu Er Ding Yihui

1997, 8(3): 316-324.

[FullText](2977) [PDF 1007KB](1233)

Abstract:
The features of monsoon activity and its role (Jianghuai) during the 1991 excessively torrential rain over Changjian-Huaihe River valley are analyzed. The results show that the first episodes of torrential rain occurs before the onset of summer monsoon and is mainly induced by synoptic systems in subtropical westerlies; while the activity of southwest monsoon becomes most important during the second and third episodes of torrential rain when subtropical high in West Pacific and southeast monsoon stay stably. The maintenance and break of Meiyu are as a result of the activity of southwest monsoon. A significant effect of southwest monsoon is to transport convective air from tropical area (Arabian Sea and the Bay of Bangal) to Jianghuai valley, thus the convective rain formed in the middle and late stages of the Meiyu is much stronger than that in the normal year, especially in the third episode. The distribution and propagation of strong wind core along southwest airflow are also studied

Simulation of Severe Storm Rainfall Event in 1991 over Changjiang-Huaihe River Valley with a Chinese Regional Climate Model

Gong Wei Li Weiliang

1997, 8(3): 325-334.

[FullText](3647) [PDF 727KB](1741)

Abstract:
The development of a Chinese Regional Climate model based on an introduced NCAR Regional Climate Model (RegCM1) is described. Using the newly developed model, the summer severe storm occurring in Yangtze and Huaihe River valley in summer of 1991 are simulated. It is shown that the model has the ability to reproduce the atmospheric circulation pattern and its seasonal change as well as the main rain-belts

A Study of Climate Changes of Atmospheric Water Vapor in China

Zhai Panmao Zhou Qinfang

1997, 8(3): 342-351.

[FullText](3238) [PDF 346KB](1331)

Abstract:
The climate distribution features of atmospheric water vapor and the climatic change trend for recent 20 years are analyzed by using the sounding data twice daily which are made through the quality control of CHQC and the check of sequence homogeneity. The linkages between the change trend of atmospheric water vapor and surface air temperature, and between summer water vapor content and precipitation anomaly of eastern China are discussed.

The General Frame of Distributed Climatological Database

Hua Canhua

1997, 8(3): 352-357.

[FullText](2736) [PDF 275KB](1577)

Abstract:
The system goal, which is required to have unified standard in the respects of data format, data structure, use interface and user interface, is introduced in order to ensure data consistency and interchangeability. Thus the correlated systems of meteorological and non-meteorological departments can be received into a general frame which are connected and transferred with each other. And, the system structure is also described. It is a multiple data structure system with the geographically state-regional-provincial-prefectural levels climate database, but under the control of distributed database managing system. Logically, it is an entire database

The New Operational Numerical Prediction System of Shanghai Regional Meteorological Center and Preliminary Analysis of Operational Results

Yin Hebao, Gu Jianfeng, Lei Xiaotu

1997, 8(3): 358-367.

[FullText](3334) [PDF 357KB](1396)

Abstract:
According to computer resources disposition in Shanghai Meteorological Bureau and numerical forecast products of National Meteorological Center, a new operational numerical prediction system of Shanghai regional Meteorological Center is set up with the model frame of NCAR-PSU/MM4, and the former operational system of five level nested model is renewed. According to whether there is tropical cycle or not getting to the domain, the typhoon model or limited-area model is carried out, respectively. Through one year operation, it is shown that the computation of new operational system is of stability and there is a good prediction effect. In the meantime the forecast products, including the surface element predictions every 6 h for 25 cities in East China, can be provided for provincial meteorological Burean in the regional center.

A Study of Objective Synoptic Model and Physical Diagnostic Model of Torrential Rain Forecast in Jiangxi Province

Cao Xiaogang, Wang Tianmin, Dai Ximin, Zhang Mingxi

1997, 8(3): 368-373.

[FullText](2699) [PDF 234KB](1430)

Abstract:
The objective synoptic model, diagnostic model of torrential rain forecast and prediction flow in Jiangxi Province are introduced, and the short-range tracking forecast technique of torrential rain location by using the digitized cloud images is presented. The experimental forecasts of flood season model from 1992 to 1995 are given

An Appraisal of the High Yield Property for Rice Varieties by Numerical Simulation

Li Jun Wu Yuanzhong

1997, 8(3): 374-378.

[FullText](4209) [PDF 199KB](1258)

Abstract:
A nonlinear hyperbolic photoresponse model of single leaf photosynthesis is introduced and applied in the appraisal of the high yield property for three rice varieties in the paddy field. The result shows that the kind of breed called “Hanyou Xiangqing” is the best one in the selected three rice varieties for its high yield property in Shanghai suburbs.

The Potential Influence of Temperature on Cotton Yield Structure and Development Rate

Zhang Jianhua Yu Xingjie Li Yinchun, Li Yingchun

1997, 8(3): 379-384.

[FullText](3058) [PDF 234KB](1471)

Abstract:
On the basis of variety maturity index of cotton, a model of the influence of temperature on yield structure and development rate for different cotton varieties is set up. By using agro meteorological observational data from Xingjiang, agrometeorological statigns during 1980~1993. The potential influences of temperature change on ball number of single plant, single ball weight, the perecentage of flower before frosting and development rate of different cotton varieties are analyzed. This work is significant in the agrometeorological monitoring, prediction and assessment of cotton production

Vol.8, NO.3, 1997