应用气象学报

High Resolution Limited Area Operational Numerical Prediction Model and Precipitation Forecast Experiment

Yan Zhihui Zhao Junying Zhu Qi Guo Xiaorong

1997, 8(4): 393-401.

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Abstract:
Based on the original operational limited area model, a new high resolution limited area model was developed and started operational run on May 15, 1996. Besides the increasements of horizontal resolution, the main improvements in the model are: (1) introduction of more reasonable physical processes, such as soil process, the budget of radiation on surface, surface friction and vertical diffusion in PBL; (2) Kuo scheme is replaced by mass flux scheme in the cumulus convection parameterization. The results of quasi-operational run are reviewed completely

Atmospheric Circulation Anomaly Prior To Drought/flood of Summer in North China and Its Relations to North Pacific SST

Zhu Pingsheng Zhang Suping

1997, 8(4): 437-444.

[FullText](3079) [PDF 1117KB](1073)

Abstract:
The atmospheric circulation anomaly and North Pacific SSTA in spring prior to drought/flood of summer in North China are analysed and the relationships between SSTA and atmospheric circulation anomaly are discussed. Then numerical simulation forced by heat source anomaly in Kuroshio current area is made by using OSU-AGCM. The results show that rainy summers in North China would occur if arctic low vortices weaken significantly and zonal circulations strengthen in middle-high latitudes in Eurasian continent and West Pacific subtropical high lies northerly and westerly, and remarkable negative PNA-pattern exists in springs. Otherwise, there would be dry summer in North China. At the same period positive and negtive SST departures exist in the Western North Pacific and in equatorial East Pacific, respectively, which is closely related to atmospheric circulation anomaly in springs. SSTA in Kuroshio current area has great influence upon subtropical atmospheric circulations as well as those of its northside in the Northern Hemisphere. Positive SSTA in Kuroshio current area is an important factor for the anomalous atmospheric circulation pattern prior to flood of summer in North China

Short-term Climate Forecast Experiment of Winter Temperature in China Using Canonical Correlation Analysis

Mao Hengqing Li Xiaoquan

1997, 8(4): 385-392.

[FullText](4309) [PDF 931KB](3101)

Abstract:
By using the mulativariate linear statistical climate forecast model developed from canonical correlation analysis (CCA), a forecast experiment for winter temperature in China is carried out. Forecast skill is assessed using the test method of historical data independent samples. The results show that there is specified statistical predictive skill for short-term climatic prediction of winter temperature in China using CCA method. In most areas the best correlation coefficient between forecasts and observed values at lead times of 0~2 seasons is more than 0.5. The mean seasonal prediction is more effective than mean monthly one in general. The sea surface temperature is the most effective predictor field. The SST as predictor field can get higher skill score than other single one, and SST combined with other predictors would get much higher skill score

Short-term Climatic Change of Antarctic Ozone

Lu Longhua, Bian Lingen, Jia Pengqun

1997, 8(4): 402-412.

[FullText](3397) [PDF 1292KB](1651)

Abstract:
The spatial-temporal variations of Antarctic ozone are studied by using the surface-observed data of Antarctic ozone from 1957 to 1992. The results show that during the last 35 years the mean total ozone in Antarctic has an obvious decreasing trend, but in different regions, periods and seasons, there are great differences for the ozone variable trend. In recent years the ozone discrepancy in Antarctic is caused by the formation and development of Antarctic ozone hole. There exist obvious annual oscillation periods, quasi-20 and quasi-30 months for Antarctic ozone. The ozone variations are in close relationship with astronomical sunshine, stratospherical temperature field, polar stratospherical ice crystal clouds and presence of man-made CFCs and halons, etc

Estimation of Humidity Field Using GMS Dual Spectrum Data and Application in Numerical Prediction

Wang Dengyan

1997, 8(4): 413-420.

[FullText](2444) [PDF 1078KB](1387)

Abstract:
GMS infrared and visible channel data were processed, and by which 700 hPa and 850 hPa humidity fields were estimated. By using satellite-derived humidity field to take the place of conventional humidity field in numerical model, the control tests were made. The operational tests show that the forecast results were greatly improved

The Effects of Basic Flow on the Equatorial Rossby Waves and Gravity Waves

Zhou Xiaogang

1997, 8(4): 421-427.

[FullText](4962) [PDF 732KB](2202)

Abstract:
An equatorial β-plane linear model with basic flow was used to study the effects of basic flow on the equatorial waves. The results show that the equatorial Rossby wave and the gravity wave are still mixed in westerlies for n=0, but they are separated completely in easterlies, and the instable growth of the equatorial Rossby wave may occur in westerkies under some conditions

Modelling of the Relationship Between Water Circulation in the Soil-plant-atmosphere Continuum System and Crop Production

Zhao Yanxia Wang Futang

1997, 8(4): 428-436.

[FullText](3035) [PDF 868KB](1385)

Abstract:
A dynamic-statistical model which shows interactions between crop water consumption, biomass production and yield formation has been established based on the simulation of soil water dynamic evolution and some processes of winter wheat growth and development. Through the verification in three years by using the field data, the mean simulated errors for the total weight of dry matter, grain yield and soil water content are 6.39%, 5.60% and 5.45%, respectively. In addition, the simulations about developmental stages, the leaf area index, the process of dry matter accumulation etc. are close to the observed data

Impact of Climate over North Indian Ocean on the Route Choice in Winter and Summer

Zhuang Li

1997, 8(4): 445-451.

[FullText](2939) [PDF 949KB](2738)

Abstract:
Necessity for developing of ocean-meteorological navigation, and its principle and impact factors of the route choice are described. With the operation of route choice in recent 10 years at the Center of Ocean-Meteorological Route in the Central Meteorological Observatory, the impact factors of climate over North Indian Ocean on route choice in winter and summer are summarized. It is shown that different meteorological routes should be chosen in combining with winter and summer climate variation over North Indian Ocean and characteristics of ocean orography. This work supplies a valuable basis in the operation for choosing different favorable routes avoiding high frequency regions with strong wind and huge wave according to the conditions of different seasons and ships

Analysis and Forecast of Precipitation Distribution Trend Prior to Flood Season in Guangdong Province

Xie Jiongguang

1997, 8(4): 452-459.

[FullText](2861) [PDF 772KB](1260)

Abstract:
Classification of precipitation distribution trends prior to flood-season in Guangdong Province was carried out by using fuzzy cluster analysis technique. Corresponging analysis was also made for the sampled representative stations. The distribution trends of flood-season precipitation were classified by taking the first two common factors to analyse mean height fields at 500 hPa and investigate their differences. Meanwhile, evolution characteristics of 500hPa circulation situation in the previous winter seasons (Jan. ~ Feb.) and SST distribution (Dec. ~ Feb.) were studied. Finally, Precipitation distribution trend in floodseason was predicted by using forecast values of the first two loading variables

Carbon Dioxide Enrichment Technique in Greenhouse Vegetable Culture

Wang Yongqin, Liu Ronghua, Wang Liangqi

1997, 8(4): 460-468.

[FullText](3045) [PDF 1149KB](1407)

Abstract:
Based on the experiment data at home and abroad and the experimental results of CO2 enrichment in the greenhouse vegetable culture in Henan Province, the increasing yield mechanism of CO2, ideal CO2 source, optimum CO2 enrichment concentration and daily enrichment time, calculating method of daily optimum CO2 enrichment quantity and reasonable enrichment model are analysed in order to increase CO2 exploitation and utilization efficiency in agriculture and raise vegetable productivity in greenhouse

QBO Analyses of Precipitation in China from 1986 to 1995

Chen Xingfang Song Wenling

1997, 8(4): 469-476.

[FullText](4537) [PDF 1085KB](2323)

Abstract:
During the last ten years, the interannual changes of the precipitation distribution tendency in eastern China are characteristic of QBO. The precipitation in even numbered years is more than normal in central China, and less in northern and southern areas whereas the precipitation in odd numbered years is contrary, more precipitation in the central area, and less in northern and southern parts. The feature of precipitation change in Changjiang-Huaihe River basin is the most obvious. The analyses show that QBO feature of precipitation has relations with West Pacific subtropical high and cold air actions. Generally in the even numbered years, subtropical high is to the north of its normal position, the zonal circulation of Asia develops, and corresponding rain belt maves northward. The condition for odd numbered years is contrary, the subtropical high is southward, meridional circulation of Asia develops, and the rain belt moves southward, the precipitation in Changjiang-Huaihe River basin is more than normal

Retrieval of Turbulent Structure Coefficients from Sodar Echo

Pan Naixian

1997, 8(4): 477-484.

[FullText](3342) [PDF 796KB](1561)

Abstract:
Temperature structure coefficient (C) and velocity structure coefficient (C) can be deduced from the sodar return intensity. The past researches are reviewed briefly. The impacts of these physical factors, such as excess attenuation, wind and turbulence etc on the echo measurements are discussed. The results show that the excess attenuation of acoustic wave is mainly caused by the velocity fluctuation. On the other hand, the wind also causes some echo attenuation. When wind speed reaches 10 m/s, the received energy at antenna will reduce about half. At the end, a modified sodar equation and the retrieval method of C and C are given. The primary tests indicate a qualitative agreement with the theory presented here.

Experiment on Aviation Meteorological Factor Forecasting Based on a Limited Area Model

Li Yaodong, Jin Weiming, Wang Bingren, Wang Hongfang, Liu Jianwen

1997, 8(4): 485-491.

[FullText](3287) [PDF 989KB](2188)

Abstract:
The aviation meteorological factors (turbulence, icing, cloud, etc.) forecasting techniques based on limited area model system are introduced. The clear-air-turbulence index for bump, severity index for icieng and distribution specification for cloud are given. And, by using this forecast model the model cloud formation forecast and cloud field diagnostic analysis are made, some simulated and forecasting results are obtained

A Tornado Type Severe Storm — Report of Detailed Analysis on Hongqili Tornado 19 April 1995

Jiang Rugeng

1997, 8(4): 492-497.

[FullText](4153) [PDF 748KB](1316)

Abstract:
A strong convective process involved an extensive area covering Zhaoqing, Foshan, Shunde, Nanhai, Panyu, Zhongshan and many other cities form 13 : 00 to 21 : 00 on 19 April 1995. The whole process was observed and complete radar data were obtained in Guangzhou Radar Observatory. The detailed analysis was made for the tornadic storm over Wanqingsha area. The results show that: (1) it is a rare anticyclonic tornado, (2) its scale belongs to the range of micro-small scale (1200 ~ 4000 m), (3) the life time of the accompanied storm cell is as long as 4~5 h, and (4) the calculated parameters such as tornado strength and tornado circulation are in the same order as those of Dellas, Fargo, et al

Application of the Hirlam System in China — Torrential Rain Forecasting Experiments in Yangtze River Valley

Yu Xiaoding, Huang Xiangyu, L.Laursen, E.Rasmussen

1997, 8(4): 498-502.

[FullText](3060) [PDF 592KB](2140)

Abstract:
The HIRLAM system was used in China to test its ability in forecasting the summer torrential rain in Yangtze River valley. The experiments of three selected torrential rain cases show 0 ~ 24 h accumulated rainfall forecasts are quite successful, being able to reproduce most of the observed torrential rain areas (daily rainfall≥50 mm) in the Yangtze River valley. The 24 ~ 48 h accumulated rainfall forecasts vary with different cases. Some cases are successful, some are failure. On the whole 24 ~ 48 h rainfall forecasts are worse than 0 ~ 24 h forecasts, especially for the forecast of daily rainfall≥50 mm.

Estimation of Farm Water Budget for Major Variety of Crops in Jiangsu Province

Tang Zhicheng Zhang Xuhui

1997, 8(4): 503-508.

[FullText](3100) [PDF 595KB](1668)

Abstract:
Based on the soil moisture data from 1980 to 1992, according to the principle of soil water balance and the optimization technique in operational research, and considering the special natural conditions and actual state of crop growth in Jiangsu Province, the calculating methods of effective rainfall and the amount of complement water of low level soil are given, and the calculating models of water budget of dry farmland and rice field are proposed. By using these models and real-time rainfall and soil moisture data, the amount of farm water budget can be calculated accurately, so that the effective service to agrometeorological information would be provided.

A Method of the Remote Sensing Techniques of Rice Yield Estimation

Ji Shuqin, Chen Pengshi, Zhang Yushu

1997, 8(4): 509-512.

[FullText](5077) [PDF 434KB](1386)

Abstract:
Based on NOAA/AVHRR characteristics of wide-ranging space coverage and frequent data reception, the best estimation time of forecasting rice yield in North China is explored, the forecasting model about per unit area yield is set up by using vegetable index, and rice planting area is estimated by remote sensing. The studying results for two years show that by means of satellite remote sensing to estimate rice yield, the forecasting accuracy is higher than that for the normal agrometeorological model forecasting, and the period of validity is improved.

Vol.8, NO.4, 1997