Vol.7, NO.4, 1996

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Vorticity Source Energy Source and Energy Propagation of the Teleconnection Patterns in the Upper Troposphere of Northern Hemisphere
Geng Quanzhen
1996, 7(4): 414-420.
[FullText](3895) [PDF 354KB](1138)
Abstract:
The vorticity source, energy source and energy propagations of the two major teleconnection patterns (the Atlantic/Eurasian pattern and Pacific/North American pattern) are studied with ECMWF data of 1980~1988, respectively. It is found that the vorticity source and energy source of these two teleconnection patterns were mainly concentrated in the North Atlantic and North Pacific regions, respectively. They obtained energy from climatologically mean flow through barotropic energy conversions in the North Atlantic and North Pacific regions, respectively, and propagate the energy outside from these two regions, so as to maintain their horizontal teleconnection structures.
The Multi-tasking Concurrent Computing of Medium-range Numerical Weather Prediction Model T63L16 on Galaxy-2 Supercomputer
Yang Xuesheng, Song Junqiang, Huangfu Xueguan
1996, 7(4): 431-436.
[FullText](2740) [PDF 281KB](1279)
Abstract:
The multi-tasking medium-range numerical weather prediction model T63L16 introduced from ECMWE’s operational model was developed successfully on the Chinese Galaxy-2 supercomputer which provided a multi-tasking concurrent computer environment, and it was performed efficiently over 2 or 4 processors.
The Spatial Patterns and Teleconnection Analysis of Low Frequency Oscillation over West Pacific and Indian Ocean in Low-latitude form 1980 to1983
Wen Zhiping, Liang Biqi
1996, 7(4): 460-465.
[FullText](2759) [PDF 287KB](1083)
Abstract:
Using the filtered OLR data from 1980 to 1983, the features of low frequency oscillation over the West Pacific and the Indian Ocean in lower latitude are studied by means of the EOF method. The results show that there exist great differences to the intensities, spatial patterns and the variations of time coefficient of low frequency oscillation in these regions between normal years (1980~1981) and abnormal years (1982~1983). Furthermore, it is found that there exist three species of low frequency teleconnections for normal years, i.e. the equatorial West Pacific, the northern tropical West Pacific and the equatorial Indian Ocean patterns, while there only exist two species of those for abnormal years, i. e. the equatorial West Pacific and the southern tropical West Pacific patterns. Because of the influences of E1 Nino, there exist great variations both for the locations and intensities of low frequency oscillation centers of west-east bipolar circulation pattern.
A Comparison of Different Schemes for Solving Nonlinear Chemical Kinetic Equations
Wang Tijian, Li Zongkai
1996, 7(4): 466-472.
[FullText](3518) [PDF 307KB](1136)
Abstract:
Based on a simplified gaseous chemical, the Hybrid, QSSA and Sklarew schemes are used to solve nonlinear chemical kinetic equations, and the results of different methods are compared. Also, the mass conservation techniques, such as error distribution and linear combination are applied to study their influence on the modeling results. It is found that three schemes make no difference to the calculations of the concentration of hydrocarbon, but some difference to those of other gaseous species. The result predicted from QSSA is similar to that from Sklarew, and the balance time of concentration of gaseous species is shorter for Hybrid than that for other two schemes. As a result, the mass conservation techniques can further improve the results. The error distribution technique is suitable for Hybrid and QSSA, and the linear combination is more suitable for QSSA
The Developing Structure of a Black Storm and Its Numerical Experiment of Different Model Resolution
Cheng Linsheng, Ma Yan
1996, 7(4): 385-395.
[FullText](3652) [PDF 562KB](1376)
Abstract:
The developing structure and evolution of a black storm occurred in the northwest region of China from 4 to 6 May 1993 (“93.5”) can be basically simulated by using a control experiment of the improved MM4 model with high resolution PBL parameterization and 40 km fine-mesh. The simulated results show that the black storm was associated with both a mesoscale cyclonic strong vortex in the PBL and a vertical vortex column in the troposphere during the developing stage. The lower (upper) part of this vortex column, stretching to the tropopause was cyclonic (anticyclonic) vortex column associated with intensive converence (divergence) inflow (outflow). According to the cross section of the equivatlent potential temperature, the major differences of the structure of the black storm from that of black storm from of general front are: the steep slope of the boundary surfaces, the large horizontal gradient of θe, the quite intensive baroclinity, the obvious warm-core in the PBL. The warm-cored structure in the lower part of the black storm was related to intensive thermal over underlying surface. The comparison experiments of the different PBL parameterization and model spatial resolutions show that it would be necessary to enhance the spatial resolution of the mesoscale numerical model and to adopt a better PBL parameterized scheme in order to improve the simulation of the developing structure and evolution of black storm.
A Study of Aerosol at Regional Background Stations and Baseline Station
Yang Dongzhen, Yu Xiaolan, Fang Xiumei, Wu Fan, Li Xingsheng
1996, 7(4): 396-405.
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Abstract:
The spatial and temporal distribution characteristics and variation regularity of mass concentration of aerosol and water soluble ionic concentration for the samples collected at Waliguanshan Mt. baseline station (36°17′N, 100°54′E, 3816 m SLE); Longfengshan Mt. (44°44′N, 127°36′E, 331 m SLE) and Lin’an (38°18′N, 119°44′E, 131 m SLE) regional background stations in autumn (October 1994) and winter (January 1995) were analyzed. The preliminary conclusion was drawn as follows: the highest values of mass concentration of aerosol and water soluble ionic concentration were observed at Lin’an, the middle at Longfengshan Mt. and the lowest at Waliguanshan Mt.; the mass concentrations of aerosol were higher in autumn than in winter at all the three stations. In addition, the impacts of winds and some trace gases on the concentration distribution characteristics of aerosol were also discussed.
Design and Study of Forecasting and Service System for Typhoon and Torrential Rain in National Meteorological Center (NMC)
Xu Xianan, Li Zechun
1996, 7(4): 406-413.
[FullText](2827) [PDF 428KB](1489)
Abstract:
A real-time forecasting and service system for typhoon and torrential rain in NMC was established based on the modern conditions of meteorological operation and scientific achievements. The structure and major functions of the system are brief introduced in this paper. Many monitoring information, forecasting and warning products for typhoon and torrential rain can obtained by using this system. The system was put into the operation in the summer of 1995.
An Improvement on the Simple Conjugate Method for Retrieving the Wind Fields from Single-Doppler Data
Qiu Chongjian
1996, 7(4): 421-430.
[FullText](2828) [PDF 451KB](1272)
Abstract:
The simple conjugate method for retrieving the wind fields from single-Doppler data proposed by Qiu and Xu (1992) is improved and tested using the Denver airport microburst data of summer 1998. In the upgraded method the temporal departures of radar velocity or reflectivity are used instead of the state variables and a retrieved error term is added into the model equation. The test results show that the upgraded method improves the wind retrieval significantly.
Retrieval of Total Ozone from TOVS Data and Its Comparison with Brewer Observations in Antarctic Spring
Hu Xiaoxin, Lu Longhua, Zhang Fengying, Zhou Xiuji
1996, 7(4): 437-442.
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Abstract:
Total ozone during the period of Antarctic ozone hole of 1993 at Zhongzhan station in Antarctica is extracted from TOVS data of NOAA-12 by using an improved statistical regression scheme. The present results, NOAA’s ozone retrievals and surface Brewer observations were compared with each other, it is found that although the three kinds of data are in good agreement for the remarkable decrease of ozone amounts, corresponding to Brewer observations, both the present results and NOAA’s retrieval products have larger errors with 29 and 34 Dobsons of RMS, respectively. Obviously, the former is superior to the latter. Additionally, the characteristics of the two retrieval error were discussed.
Multi-variable State-space Method and its Application in Dekad Rainfall Forecast
Yan Zhongwei
1996, 7(4): 443-451.
[FullText](2448) [PDF 472KB](1417)
Abstract:
Combining the two streams of thoughts, i. e. the state-space reconstructed from single variable time series and traditional multi-variable analysis, a multi-variable state-space forecasting method was developed and applied to dekad rainfall prediction for two regions in eastern China. The new method, by considering temperature and seasonality in rainfall-state-space, improved the prediction correlation by 5% (for 437 pairs of data). The improvement remarkably deals with large rainfall deviations, thus having particular significance to meteorological prediction. Great potential of further improvement through combining more reasonable variables in state-space could be expected
The Importance of Mixed-phase Clouds in GCM Climate Simulation
Sun Zhian, Keith P. Shine
1996, 7(4): 452-459.
[FullText](3390) [PDF 371KB](1806)
Abstract:
A Scheme of simple radiative parameterization of ice clouds suitable for use in GCM model is presented. The importance of mixed-phase clouds in GCM climate simulations is investigated using this scheme together with UGAMP general circulation model. It is found that the change in cloud phase state and the effect of its feedback have a significant impact on the model climate. In the high latitude regions, the net radiation in the earth-atmosphere system could be increased due to the changes in cloud phase state, whereas the net radiation could be deceased in the tropics.
The Spatial and Temporal Distributions of Severe Mesoscale Convective Systems over Tibetan Plateau in Summer
Jiang Jixi, Xiang Xukang, Fan Meizhu
1996, 7(4): 473-478.
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Abstract:
By using GMS-4 hourly IR stretched digital data from June through August 1991, all 293 severe Mesoscale Convective Systems (s-MCSs) Over Tibetan Plateau were investigated and analysed. The results show that those s-MCSs had larger frequency and more typical features of Meso-β scale system in its life cycle, size and intensity; their initiation and development was mainly derived from the thermotopographic effect; their movement basically consorted with the mean flow between 300 and 200 hPa, and few of them moved away from Tibetan Plateau.
Features of Spatial and Temporal Distributions of the Dust Storms in Northwest China
Xu Qiyun, Hu Jingsong
1996, 7(4): 479-482.
[FullText](5122) [PDF 173KB](1577)
Abstract:
By analyzing the meteorological observational data of dust storms from 1952 to 1994, the intensity division standards are put forward, the features of spatial and temporal distribution are studied. The results show the regions easy for the occurrences of dust storms, and high frequency regions and high frequency periods of dust storm genesis in Northwest China. All of these would provide the basis for establishing the integrated monitoring system of dust storms and the systematic engineering of disasters prevention and disasters reduction.
An Analysis of the Explosive Cyclone over Yellow Sea and Bohai Sea
Yi Qingju
1996, 7(4): 483-490.
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Abstract:
A case of explosive cyclone with a obvious “eye area” occurred over the Yellow Sea and the Bohai Sea in early June, 1993 is studied. The results show that the dynamic functions of thermal advection, vorticity advection, coastal frontogenesis and air jet stream made great contribution to the explosive development of the cyclone.
Analysis and Study of the Dry Layer in Torrential Rain
Lin Biyuan
1996, 7(4): 491-495.
[FullText](2768) [PDF 209KB](1479)
Abstract:
The vertical distribution of the humidity field in the torrential rain process is analyzed using the sounding data of three weather stations in Hunan Province during the period of June, 1974~1987. It is found that there was a layer in the middle of troposphere (600~400 hPa) before beginning of heavy rainfall. Furthermore, the feature, evolution and cause of dry layer, and their mechanism which led to heavy rainfall, are investigated. The results show that the humidity change in vertical direction was very quickly, the dry layer was formed before the heavy rainfall and would distort gradually after the heavy rainfall. Additionally, the dry layer formed in heavy rainfall was clearly different from that of the other severe convection weathers (such as severe storm and hail). There was an instable convection layer below the dry layer and a convective stability layer over the dry layer.
A Preliminary Analysis on Agroclimatic Resource Utilization and Its Economic Benefit in Market Economic System
Tan Jianguo
1996, 7(4): 496-499.
[FullText](2914) [PDF 230KB](1589)
Abstract:
The relationship between agroclimatical resource utilization and its economic benefit in market economic system is analysed theoretically. Cite the city of Jiaxing (Zhejiang Province) as an instance, both the potential climatic risk and the potential market risk of main crops are analysed and the climatic countermeasures for High output, Good quality and High effect (HGH) agriculture are proposed. It points out that the reasonable utilization and effective disposition of agroclimatic resources must be paid attention for the development of China’s agriculture in the market economic system
An Approach to Parameters Correcting Methods for Calculating the Climatic Productive Potenti-Alities of Crops in Mounain Areas
Wang Xiaorui, Tian Hong
1996, 7(4): 450-506.
[FullText](3027) [PDF 330KB](1690)
Abstract:
On the basis of the normal and temporary meteorological data (1957~1993) in Yuexi County of Dabie Mountain areas in west Anhui Province and with the help of recent research achievements, the three parameters of light, temperature and water corrected by topographic factors (sea level elevation, slope, slope direction) are obtained. As a result, a corrected scheme of calculating climatic productive potentialities of crops, which is suitable for Dabie Mountain areas concerning various altitudes, slopes and directions, is established.
A Method of Monitoring Grassland Resource in Qinghai Province Using Satellite Data
Zhou Yongmei, Wang Jiangshan
1996, 7(4): 507-510.
[FullText](2936) [PDF 196KB](1447)
Abstract:
A method of monitoring the grassland resource of Qinghai Province was introduced. Using timely AVHRR data and ground data, the model of monitoring output of green grass was set up, so as to evaluate the regime of grassland resource in Qinghai. The method was put into operation application around the Qinghai Lake and the southeastern Qinghai areas. The results show the method is effectiveness.
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