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1985 Vol. 2, No. 4

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TEN YEARS' ADVANCES OF RESEARCH ON KNOTTY TYPHOONS IN CHINA
Wang Zhilie
1985, 2(4): 415-425. doi: 10.1007/BF02678741
Abstract:
The forecast and research skill of knotty typhoon tracks of various kinds is presented. It is a practical approach to raise the diagnosing ability of the forecasters and to improve the forecast of knotty typhoon tracks at the present stage by revealing and studying the causes of the erratic tracks, obtaining their characteristics and gradually perfecting the prediction models.
THE HEATING FIELD IN AN ASYMMETRIC HURRICANE PART II:RESULTS OF COMPUTATIONS
T.N.Krishnamurti, Sheng Jian
1985, 2(4): 426-445. doi: 10.1007/BF02678742
Abstract:
This is the second part of a paper on the distribution of heating fields in a hurricane. The first part dealt with the mathematical framework. The second part, i. e. the present paper deals with numerical calculations for an actual hurricane.The following sequence of calculations has been performed after the analysis and tabulation of an initial field of the tangential velocity V (r, θ, p): (1) the radial equation of motion is used to determine the geopotential heights; (2) the hydrostatic equation is used to determine the temperature field; (3) the tangential equation and the mass continuity equation are combined to obtain an omega equation whose solution determines the vertical velocity; (4) the radial velocity is next determined from the mass continuity equation; and (5) the heating function is finally determined from the first law of thermodynamics.The results of this study show an asymmetric banded structure (eye wall and rainband) of the vertical motion field as well as the heating field; these show close resemblence to observations. An analysis of the non-linearities of the asymmetric momentum distribution is shown to be crucial in the analysis of the hurricane heat sources.
CALCULATION ON THE LIGHT SCATTERING FUNCTION OF HEXAGONAL ICE CRYSTALS
Cai Qiming, Kuo-Nan Liou
1985, 2(4): 446-454. doi: 10.1007/BF02678743
Abstract:
Hexagonal ice crystal is a basic form of the particles in cirrus. The emphasis in this paper is on discussing the computational results of scattering phase matrices for infrared absorptive band by making use of the model developed by the authors. Comparisons have been made between infrared and visible light as well as between hexagonal columns and plates and equivalent spheriods and spheres. It is found that the effects of light absorption on phase function may cause the decreases of scattering energy in side direction and the directions near backscattering, and weaken halo and rainbow peaks which are induced by the refractions and internal reflections. There is a general agreement in the phase functions for ice crystals with different shapes. However, the scattering intensity in side direction for spheres and in backward and backside directions for spheroids is weaker as compared with hexagons. It is believed that these features would, doubtless, have influences on the detection of cirrus by laser and radiation transfer in the atmosphere.
THE ATMOSPHERIC HEAT BUDGET OVER THE WESTERN PART OF THE TIBETAN PLATEAU DURING MONEX, 1979
Feng Zhiqiang, Elmar R.Reiter, Chen Longxun
1985, 2(4): 455-468. doi: 10.1007/BF02678744
Abstract:
The atmospheric heat source strength over western Tibet has been computed for the period beginning with the last ten days in May, 1979 and extending through August, 1979. Our results show a significantly smaller heat source than that obtained by other authors. The discrepancy is mainly due to adjustments in the dray, coefficient suggested by observations and numerical modeling experiments. We subdivided western Tibet into northern and southern parts. In the north sensible heating, SH, provides the dominant input into the atmospheric heat source, whereas in the southern part latent heat, LP, offers a significant contribution after the start of the rainy season.Detailed heat budget calculations were also carried out over limited regions of southwestern Tibet which hau good station coverage. During periods with area-averaged rainfall ≤1 mm/day an atmospheric heat source maximum was located over southwestern Tibet near the 500 hPa level, while a heat sink dominated the upper troposphere in a layer of subsidence. When rainfall exceeded 4 mm/day, ascending motions and heal sources prevailed throughout the troposphere with maxima near 400 hPa. Time series analyses of the heat sourcs components show that the total atmospheric heat source is strongly modulated by the release of latent heat. Atmospheric radiational cooling reveals a phase shift in its relation with precipitation. During the first part of the observation period a correlation of that cooling exists mainly with the net radiation at the top of the atmosphere, during the last part with the net radiation at the ground.
SOURCE IDENTIFICATION AND APPORTIONMENT FOR ATMOSPHERIC AEROSOL BY FACTOR ANALYSIS
Wang Mingxing
1985, 2(4): 469-477. doi: 10.1007/BF02678745
Abstract:
The statistical basis for factor analysis is briefly discussed. A method combining common factor analysis with orthogonal transformation has been proposed and discussed in detail. The method has been tested with a data set consisting of 16 elemental concentrations in 40 samples collected at the Beijing meteorological tower, March 1980. Seven sources-soil+coal fly ash, sulfate, cement and lime dust, oil, plant burning, motor, and marine aerosol-corresponding to the first seven factors have been identified. The source profiles and their contributions have been obtained.
A STUDY OF THE RELATIONSHIP OF ZONAL WIND OSCILLATION BETWEEN EAST AUSTRALIA AND NORTHWESTERN PACIFIC TROPICAL AREA
He Shixiu
1985, 2(4): 478-486. doi: 10.1007/BF02678746
Abstract:
The spectral analysis of zonal wind at two stations in East Australia has been studied. It is confirmed that the oscillation with period between 40-50 days and 21-25 days do exist at both high and low levels. These oscillations are closely related with that of zonal wind with the same period over the Truk Island of the northwestern Pacific. The oscillation with a 40-50 day period over East Australia is 8-11 days earlier than that over the NW Pacific. But the oscillation with a 21-25 day period over the NW Pacific is about 3 days earlier than that over East Australia.
THE ATMOSPHERIC HEAT BUDGET IN SUMMER OVER ASIA MONSOON AREA
Chen Longxun, Li Weiliang
1985, 2(4): 487-497. doi: 10.1007/BF02678747
Abstract:
For better understanding the mechanism of monsoon formation and designing the numerical simulation of the general atmospheric circulation, a new approach of calculating atmospheric radiation is proposed to investigate the distribution of the atmospheric heat source, and the budget of heat component is recalculated. The results show that there is a tremendous atmospheric heat source region over central India, northeast of the Bay of Bengal, east of the South China Sea and about 10 °N at the west Pacific, among which the heating center with a maximum heating rate of 8 ℃/day is located over the Bay of Bengal and the average rate in the Plateau is about 1 ℃/day.
SOME CATASTROPHE PROPERTIES OF TWO-LAYER SHEAR FLOW
Yang Peicai
1985, 2(4): 498-507. doi: 10.1007/BF02678748
Abstract:
In this paper a simple current system which consists of two stratified incompressible layers is examined. For the basic equations of the motion of fluid a lower order spectrum model is established by means of Galerkin method. Adopting the difference of wind velocity between the upper and lower layers, As =as a control parameter, the bifurcation and stability of the solution of the dynamical systemare discussed. It is found that the flow states in the lower layer will have a catastrophe, when where Cg is the phase velocity of the internal inertio-gravitational wave in a geostrophic current.These results may give a reasonable explanation for the mechanism of the catastrophe phenomena, including the "pressure-jump" in the atmosphere.
LARGE SCALE ENVIRONMENTAL CONDITIONS FOR THUNDERSTORM DEVELOPMENT
Yang guoxiang, Shu Cixun
1985, 2(4): 508-521. doi: 10.1007/BF02678749
Abstract:
The large-scale environmental conditions for thunderstorm development have been studied with 40 selected synoptic processes during 1972-1983. It is shown that the thunderstorms in eastern China can be divided into two types: pre-trough and post-trough. The convective instability before the pre-trough thunderstorms is established primarily by the dry and moist differential advection and that before the post-trough thunderstorms by the cold and warm differential advection. The subsynoptic scale circulation has direct effects on the establishment and release of instability. The pre-trough thunderstorms occur in the overlapping region of the ascending motion in the upper baroclinic waves and the ascending branch of the low-level jet strong wind core circulation and the post-trough thunderstorms occur in the lower convergent region below the ascending branch of the jet-front circulation. The effect of the lower dry and warm lids, the coupling of the low-and upper-level jets and the dry advection in the middle-level jet are the favorable factors for the severe storm formation.
A NUMERICAL INVESTIGATION ON THE INTERACTION OF TURBULENT AND LONG-WAVE RADIATIVE FLUXES IN THE SURFACE LAYER
Li Xingsheng, Bian Xindi, Zhong Shiyuan
1985, 2(4): 522-530. doi: 10.1007/BF02678750
Abstract:
The interaction of turbulent and radiative transfer applied to a number of plausible atmospheric situations in the surface layer under the stably stratified condition is discussed.The calculated results show that the long-wave radiative flux has a great influence upon the thermal structure of the surface layer, and that it usually acts in such a way as to weaken the thickness of the constant turbulent heat flux layer. In the case of low wind velocities and strongly stable stratifications, the thickness of the turbulent heat flux layer will become very thin and/or inexistent.
AN EXACT CALCULATION OF INFRARED COOLING RATE DUE TO WATER VAPOR
Xu Li, Shi Guangyu
1985, 2(4): 531-541. doi: 10.1007/BF02678751
Abstract:
The longwave (0-2380 cm-1) cooling rate due to water vapor in the troposphere and the stratosphere has been calculated by a new infrared transmission model in this paper. An exact scheme is used for treating the integration over wavenumber and the inhomogeneous path in the atmosphere. It is shown that the atmospheric window region (730-1200 cm-1) (mainly water vapor continuum) plays an important role in the total cooling near the surface, about 72% of the total cooling lying in this region at the height of 1 km; the CG approximation used for an inhomogeneous path is fairly applicable for calculating the cooling rate due to water vapor, with a maximum error of 0.16 K/day throughout the troposhere and the stratosphere; on the other hand, the error due to the diffusivity factor of 1.66 appears to be slightly larger near the surface. In this study, the influences on the calculation of above infrared cooling rate, of the temperature-dependence of the absorption coefficients of water vapor, the upper level cutoff and the integration step for altitude, and the substitution of the quasi-grey approximation for the exact integration over wavenumber, are also examined.
THE SOUTHERN OSCILLATION AND ITS ASSOCIATEDSUMMER RAINFALLS IN CHINA-CONCURRENTDISCUSSION OF THE RELATIONSHIP BETWEEN THE SOURTHERN OSCILLATION AND WALKER CIRCULATION
Chen Lieting
1985, 2(4): 542-548. doi: 10.1007/BF02678752
Abstract:
The relationship between Southern Oscillation (SO) and summer rainfalls in China is further studied by using empirical analyses. Two possible channels for the effects of SO on such rainfalls are proposed. One is mainly brought about by the subtropical anticyclone over the South Pacific through the air-sea interactions ; the other is related to the Australia-Indonesia low pressure trough through the Southern-Northern Hemisphere interaction.
RESEARCH ON THE PHOTO-TEMPERATURE MODEL FOR THE DEVELOPMENTAL RATE OF RICE
Lan Hongdi, Jiang Maoji
1985, 2(4): 549-552. doi: 10.1007/BF02678753
Abstract:
Rice is one kind of crops with short length of light, its developmental rate in the photophase depends on the light-length and temperature. Since uncultivated rice was discovered in China, about 40,000 species of rice, including photo-sensitive and temperature-sensitive types, have been growing. A number of researches have been carried out by agrometeorologists in this field. The purpose of this paper is to develop a photo-temperature model based on a considerable amount of experimental data.