Journal of the Meteorological Society of Japan. Ser. II
Search
OR
Browse
Search
Volume 35A
Showing 1-50 articles out of 58 articles from the selected issue
  • Giichi Yamamoto
    Volume 35A (1957) Pages 1-4
    Released: February 18, 2015
    JOURNALS FREE ACCESS
    Download PDF (6795K)
  • Minora Kawano
    Volume 35A (1957) Pages 5-10
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     The vertical distribution of the air-resistivity in the exchange layer is calculated by discussing the ionization equilibrium considering the influence of the eddy diffusion. This result shows that the vertical distribution of the air resistivity in the exchange layer is controlled by the nuclei content, radioactive substance content and the coefficient of eddy diffusivity. The height of the exchange layer estimated by the vertical distribution of the air resistivity and columnar resistance is about 900∼1400m. This calculated value coincides with that obtained by several direct observations.
    View full abstract
    Download PDF (7543K)
  • H. Hatakeyama, M. Kawano
    Volume 35A (1957) Pages 11-14
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     Several authors observed an abnormal increase of the electrical conductivity of the atmosphere near the ground during a thunderstorm.
     It is considered that the abnormal increase of conductivity is due to the natural radio activity (RaB and RaC) captured by rain drops. The β-ray irradiation of RaB and RaC produces small ions in the atmosphere near the ground. They contribute to the abnormal increase of the electrical conductivity of the atmosphere near the ground. We estimated the production of small ions by using the observed value of the electrical conductivity of the atmosphere. Then by radiological treatment we estimated the quantity of RaB and RaC brought down by the thunderstorm rain.
     For the thunderstorm rain of August 3, 1941, it was estimated at several hundred times of 10-13 curie per cm2 of the earth’s surface. An observed value of the intensity of radioactivity of thunderstorm rain is 50∼300×10-13 curie/cc. The value estimated by us is in good coincidence with the observed value.
    View full abstract
    Download PDF (5682K)
  • Par L. Facy
    Volume 35A (1957) Pages 15-24
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     Dans une première partie, l’auteur expose comment les transferts de vapeur par diffusion moléculaire peuvent être décelés visuellement au moyen de particules submicroscopiques jouant le rôle d’indicateurs. Les équations du mouvement de ces particules sont semblables à celles déjà indiquées par EINSTEIN et d’autres chercheurs pour l’effet radiométrique et la photophorèse. Le gradient de tension de vapeur remplace ici le gradient thermique et, en première approximation, les vitesses ne dependent pas des dimensions des particules.
     Dans la seconde partie l’auteur traite des conséquences qui découlent de ces mécanismes de cinétique moleculaire. Certains processus de microphysique des nuages se trouvent ainsi facilement expliqués, en particulier le déclenchement naturel ou artificiel des précipitations ainsi que l’application possible de ces mécanismes de capture à une nouvelle technique de dépoussierage des atmosphères contaminées.
    View full abstract
    Download PDF (18435K)
  • M. Komabayasi
    Volume 35A (1957) Pages 25-30
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     It has been found statistically that the occurrence of thunder clouds in the neighbouring area of the volcano Asama was significantly less frequent in summers when the volcano had frequent eruptions than in summers when the volcano was less active. The average occurrence frequency of thunder clouds in the former case has been about a half of that in the latter case.
     Results of analysis on this fact suggest that frequent eruptions of the volcano have modified the nature of cumulonimbus and suppressed the occurrence of thunder and lightning through the effect of some cloud-physical mechanism induced by seeding of the volcanic dust particles.
    View full abstract
    Download PDF (10797K)
  • K. Isono
    Volume 35A (1957) Pages 31-37
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     The processes of the ice-crystal formation on nuclei have been studied experimentally. Replicas of ice-crystals formed by seedings of AgNO3 MgO, AgI, etc. were examined under optical and electron microscopes. The mode of the growth of ice-crystal by sublimation depends not only on temperature and water vapour excess, but also on condition of diffusion field of water vapor surrounding the crystal and impurities in air. The mode of ice-crystal growth is briefly discussed.
    View full abstract
    Download PDF (13617K)
  • T. Kobayashi
    Volume 35A (1957) Pages 38-47
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     With the object of examining whether or not Marshall and Langleben’s theory on the snow-crystal habit is in agreement with experimental fact, we carried out a series of experiments on artificial snow crystals by means of a diffusion cloud chamber where the cloud droplets had teen previously removed. The ambient vapour density was measured by a “drop hygrometer” method.
     It was found (1) that the snow-crystal habit is primarily determined not by the excess of the ambient vapour density tut by the ambient temperature; (2) that snow crystals produced in aerosol-free air show tendencies to grow either in sheath form or in dendritic form with sector-like structure; (3) that the trace of foreign vapours e. g. silicone or acetone remarkably affects the snow crystal habit.
    View full abstract
    Download PDF (17629K)
  • Ukichiro Nakaya, Motoi Kumai
    Volume 35A (1957) Pages 49-55
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     Experimental work was carried out in an igloo, half way up Mt. Tokachi, 1030 m above sea level, in the central part of Hokkaido. One solid nucleus (center nucleus) was observed at the center of snow crystals in 190 cases among 202 samples tested. Combining with the former result obtained by M. Kumai, it was confirmed that almost all snow crystals have detectable nuclei at the center. Electron-microdiffraction patterns were taken with respect to same of the samples. From these patterns and the shape of the nuclei, the material of the nuclei was estimated. Roughly speaking, soil particles occupy 60 % of observed nuclei, sea salt particles 20 %, combustion product or carbon particles 10 %, and 10 % cannot be estimated.
    View full abstract
    Download PDF (12632K)
  • M. Fujiwara
    Volume 35A (1957) Pages 57-64
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     Collision frequency of snow aggregates is discussed from some simple estimations. Estimation shows that, if cohesion condition exists, a rapid growth by aggregation may occur, throughout crystal and aggregation stages.
    View full abstract
    Download PDF (13365K)
  • Ichiro Imai
    Volume 35A (1957) Pages 65-71
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     The attenuation of microwaves by rain at 3.2, 5- 7 and 10 cm wavelengths are computed. By using Laws and Parsons’ drop-size distributions, respective formulae for the three wavelengths, 0. 007R1.3, 0.0013R1.1 and 0.0003R, are obtained. Calculations based on drop-size data obtained by the M. R. I. group show that the attenuation at 3.2 cm for a given rainfall rate R is largely dependent on radar reflectivity Z for R>1 mm/hr. On the contrary, the attenuation at 5.7 cm depends only upon R approximately. For radar rainfall measurements, 5.7 cm wavelength is considered to be more appropriate than 3.2 cm.
    View full abstract
    Download PDF (9109K)
  • Par Roger Lhermitte
    Volume 35A (1957) Pages 72-82
    Released: February 18, 2015
    JOURNALS FREE ACCESS
    Download PDF (19600K)
  • K. Koenuma
    Volume 35A (1957) Pages 83-86
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     Classificationof fogs are usually made by the processesof theirformation. However, as regards land fogs,they are produced by interwoven processesand are closelyconnected with topographic features,and so we may rather classifythem according to topography.
    View full abstract
    Download PDF (6279K)
  • N. Rao.
    Volume 35A (1957) Pages 87-91
    Released: February 18, 2015
    JOURNALS FREE ACCESS
    Download PDF (7509K)
  • Y. Ogura
    Volume 35A (1957) Pages 92-94
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     The distribution of energy transfer between eddies of different sizes is examined, on the basis of Burgers’ model of turbulence, for a special form of the energy spectrum of turbulence. Uses are made of the statisticalhypotheses that fourth-order mean values are related to second-order mean values as they would be for a normal probability distribution. In particular, the exact solution of the inviscid eqution for the velocity gradient is obtained and it is shown that the mean-square value of the velocity gradient increases to infinity within a finite time.
    View full abstract
    Download PDF (4484K)
  • Y. Masuda
    Volume 35A (1957) Pages 95-102
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     In order to filter out small scale disturbances in the contour field, a tentative method of smoothing is proposed. This method is specified by the finite-difference smoothing operators combined with two sorts of single smoothing operators. Only by one or two times iterations of this combined finite-difference operator, the small scale disturbances are filtered out almost completely, and at the same time, the large scale ones are retained essentially unchanged.
    View full abstract
    Download PDF (11417K)
  • S. Syono
    Volume 35A (1957) Pages 103-107
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     The Jacobian term in the barotorpic vorticity equation vanishes, if one of following conditions is satisfied; (1) Δ2ψ = F(ψ) (2) Δ2ψ = F(t) (3) Δ2ψ and ψ are functions of one same space variable. All simple solutions ever obtained satisfy one of these conditions. We discussed these solutions from unified standpoint and remarked existence of certain solutions which escaped the attention of meteorogists.
    View full abstract
    Download PDF (6376K)
  • K. Gambo
    Volume 35A (1957) Pages 108-115
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     In this paper, the author attempts to make clear the physical meanings of the internal and gravitational waves by using the dimensionless equations of motion. The small scale disturbances in the typhoon or near the frontal surface are also dicussed in connection with the Rossby number. Since the effect of horizontal divergence or convergence is large compared with the vorticity in such cases, the internal gravitational wave whose character changes when the condensation occurs predominates. As a numerical example, we discuss how the initial small scale disturbances develop with increasing time in the case where the divergence of horizontal velocity is considerably larger than the vorticity.
    View full abstract
    Download PDF (10163K)
  • J. van Mieghem
    Volume 35A (1957) Pages 116-118
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     Critical remarks on some results deduced from the classical expressions of the potential and internal energy of vertical air columns of infinite extent.
    View full abstract
    Download PDF (4152K)
  • Masamichi Oi
    Volume 35A (1957) Pages 119-125
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     It is shown that middle-scale quasi-stationary disturbances of the middle-latitude zonal current are produced by the forced ascent of the zonal current, not only over the mountain range (continental land masses, submarine topographies or aero-topographical barriers etc.) but also both upstream and downstream. In other words, the remote effect of the forced ascent of a zonal current is studied in synoptic scale.
    View full abstract
    Download PDF (9545K)
  • S. Kubota
    Volume 35A (1957) Pages 126-129
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     In this paper the author investigated the vertical distribution of vertical velocity, by applying the double-Fourier series to the c-equation. And we can derive the conclusion that the parabolic distribution usually assumed in the parametric representation does hold generally in the large scale disturbances, but its validity is questionable for the small scale disturbances. It may be said that the level of the maximum vertical velocity locates at the 500 mb level for the large scale and at the 700 mb level for the small scale disturbances, and such displacement depends upon the stability of the atmosphere.
    View full abstract
    Download PDF (5226K)
  • T. C. Yeh
    Volume 35A (1957) Pages 130-134
    Released: February 18, 2015
    JOURNALS FREE ACCESS
    Download PDF (7801K)
  • P. R. Pisharoty
    Volume 35A (1957) Pages 135-139
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     When height contours on a high level constant pressure (say the 300 mb.) chart exhibit a strongly curved anticyclonic ridge, air parcels moving even with the maximum possible gradient wind, namely twice the geostrophic wind, cannot follow the contours and instead will be forced to move from higher to lower contours and thereby acquire appreciable amounts of kinetic energy. Studies with the machine processed daily wind data of the northern hemisphere for January and February, 1949, has enabled the author to compute the day-to-day net production of large-scale-eddy kinetic energy in complete zonal belts around the globe, allowing for (a) the convergence of the flux of the eddy kinetic energy across the latitudinal walls and (b) the conversion of the eddy kinetic energy into the mean zonal kinetic energy by the action of the eddy stresses. On a few instances of very large net production of largescale-eddy kinetic energy at the 300 mb level, at latitude 45°N, it was found that nearly a third of it was accountable by the cross-contour flow necessitated by a well marked anticyclonic ridge near the Canadian-Pacific coast. It is likely that such unstable ridges play a role in the generation of ‘velocity maxima’along the meandering axis of a well-developed ‘stream’ of the middle latitudes.
    View full abstract
    Download PDF (7492K)
  • Guy A. Franceschini
    Volume 35A (1957) Pages 140-143
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     The effect of wind stress on the surface of the ocean in the region southeast of Japan is considered. Divergence of the mass transport due to the mean annual stress in this region is such that it favors alternating areas of upwelling and sinking. This may in part explain the existence of the semi-permanent cold and warm water areas around which the Kuroshio current flows.
    View full abstract
    Download PDF (5624K)
  • Par J. Saissac
    Volume 35A (1957) Pages 144-148
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     Des études sur la diffusion de particules sont effectuées en France depuis 1953 à l’Etablissement d’Etudes et Recherches Météorologiques du Service de la Météologie Nationale.
     Elles portent sur deux problemes particuliers, celui d’une quantité finie de particules instantanément libérée en un point (cas des flocons de fumée) et celui d’une émission continue de particules, à débit constant, à partir d’un point situé au-dessus du niveau du sol (cas du panache de fumée).
     Nous nous proDQSons dans cet article d’exposer l’état actuel de ces études.
    View full abstract
    Download PDF (8219K)
  • B. Haurwitz, Gloria M. Sepúlveda
    Volume 35A (1957) Pages 149-155
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     From the investigations by Hann and Schou the amplitudes and phases of the 12-hourly pressure oscillation (S2) were obtained for 136 stations for four months (January, March, July, and September). These data were grouped into latitude zones. It was then assumed that the observed oscillation is due to two component oscillations of the atmosphere: one (W2) having the same phase in local time on each circle of latitude and the other (Z2) having the same phase in Greenwich time on each circle of latitude. Because of lack of data from high latitudes only the amplitudes and the phase angles of W2 could be determined with reasonable reliability. A strong asymmetry in the latitudinal distribution of the amplitudes of W2 was found for January, resulting in larger amplitudes in the northern hemisphere than in the southern hemisphere. In March W2 has likewise larger amplitudes in the northern hemisphere, while in July and September it has smaller amplitudes in the northern hemisphere. It is surmised that this asymmetry is due to the meridional temperature distribution of the atmosphere.
     The amplitude of W2 shows at all latitudes a minimum in the summer, in agreement with earlier to season is small, and it is impossible to decide seasonal variation or is due to residual errors in the data.
    View full abstract
    Download PDF (12734K)
  • I. Huzimura
    Volume 35A (1957) Pages 156-159
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     As the cause of the diurnal change in barometric pressure, the author proposes two elementary changes: the thermal effect Δp and the dynamical effect Δπ, i.e. dp(τ) = Δp(τ) + Δπ(τ). Here, dp(τ) is the diurnal variation in barometric pressure and

    Δp=c·2θ(τ)/∂τ2=2cβθ02{β(τ-13)2-1}e-β(τ-13)2
    Δπ=c·ΔPh=-c·(ρu{u0e-r(τ-3)2+u-u)h}

    where c, β, γ and c, u are all constants, θ0 and u0 the diurnal ranges of air temperature and upper wind speed respectively, ρ and u the mean density and mean wind speed in upper air layer respectively, e the Napier's constant and τ the local time.
    View full abstract
    Download PDF (2740K)
  • Von P. Raethjen
    Volume 35A (1957) Pages 160-164
    Released: February 18, 2015
    JOURNALS FREE ACCESS
    Download PDF (8860K)
  • N. W. Cunningham
    Volume 35A (1957) Pages 165-172
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     Wind and temperature data from a specially instrumented B-29 aircraft, operating near 400 and 300 mb, are used to test the thermal wind equation in the vicinity of a middle-latitude jet stream. Analyses of the data at the two levels are presented with respect to both the small and large-scale distribution of wind and temperature. The geostrophic wind shear between the two levels is calculated for horizonal temperature gradient computed over varying distances, and these are compared with the vertical shear obtained from aircraft-measured winds at the mid-point of each interval over which the temperature gradient is measured. The flow patterns at the two levels are considered in determining the ageostrophic components of the wind due to curved flow, and these corrections are applied in the final comparisons of calculated and aircraft-measured shear. A method using averaged winds at the lower level of the layer suggests that this may be a more representative reference than “spot winds” for approximating the wind above when using the thermal wind relation.
    View full abstract
    Download PDF (13615K)
  • Keitaro Mohri
    Volume 35A (1957) Pages 173-175
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     A cross section which shows an extremely strong jet stream with maximum observed speed of 192 m sec-1 is presented. Baroclinic field associated with the jet is remarkable, suggesting that the strong cold outbreak is related to the strong jet.
    View full abstract
    Download PDF (4144K)
  • Par R. Genève, G. Jacquemard
    Volume 35A (1957) Pages 176-179
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     A partir de deux series de coupes méridienn es en 1955 et en 1956, les mois correspondants sont compares en vue de mettre en évidence des decalages relatifs en latitude des maxima de vent et de les relier aux déplacements du front intertropical.
    View full abstract
    Download PDF (5328K)
  • H. Flohn
    Volume 35A (1957) Pages 180-186
    Released: February 18, 2015
    JOURNALS FREE ACCESS
    Download PDF (13350K)
  • H. Arakawa
    Volume 35A (1957) Pages 187-191
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     During the first half of February, 1956, two well-developed cyclones showed pronounced abnormal trajectories in the NW-Pacific. In this case, the upper-air circulation suggested by 300-mb charts and the trajectory of transosonde flights at 300-mb made by U. S. Navy TRANSOSONDE PROJECT show a fine harmony with the said trajectories of two cyclones.
    View full abstract
    Download PDF (7860K)
  • Ken Suda
    Volume 35A (1957) Pages 192-198
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     The pressure patterns characteristic to extreme warmth and coldness in north Japan are compared with each other on various composite maps and 500 mb correlation field. It is found that the eastward shift of the Far Eastern permanent trough due to the combined effect of the geographical condition of the Far East and the decrease of zonal index is responsible to the large scale cold waves in north Japan.
    View full abstract
    Download PDF (11903K)
  • S. M. Serebreny, E. J. Wiegman
    Volume 35A (1957) Pages 199-214
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     The Jet Stream complex over the Pacific is comprised of multiple Jet Streams which form, intensify and weaken in differing manner depending upon the synoptic situation and area. Regional differences within the Pacific are discussed. The axis of seasonal “strong” winds is determined and compared to the mean position of the principal baroclinic zone. Multiple Jet Stream systems are related to multiple baroclinic zones and characteristic temperature ranges of these zones are delineated and compared to values given for North America. Specific thermal and contour height ranges at the 500 mb level can be identified with each of the multiple Jet Stream systems. The distribution and incidence of “strong” wind velocities at the 500 mb level with certain 500 mb contour heights and temperatures is demonstrated for selected stations in the Pacific. Use of these thermal-contour height ranges as an aid in identification,location and forecasting of the Jet Stream complex is emphasized.
    View full abstract
    Download PDF (26837K)
  • Dao Shih-Yen, Chen Lung-Shun
    Volume 35A (1957) Pages 215-229
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     In this article, an analysis is made on the structure of the mean flow field at 5000, 10000 im one 20000 ft level in July over the continent of Asia during the year 1950-1955 and the mean wind contours at 200 mb over Asia for July and August, 1956. The vertical cross-sections of the mean flow and temperature fields along 75°E, 90°E, 105°E and 120°E for July and August, 1956 have been constructed. The three-dimensional structure of flow over continent of Asia is constituted of the following three basic currents: (1) the westerlies of middle latitudes,(2) the upper level tropical and subtropical easterlies, and (3) the south-westerly monsoon under the upper level tropical and subtropical easterlies.
     Moreover, the changes of the general circulation over Asia in the transitional period between that a leaping change of the general circulation over Asia occurs during this period. The upper level subtropical westerly jet-stream to the south of Himalaya retreated northward and a subtropical ridge was established over the latitude of Tibet, and over south Asia (to the south of 12°N) an high level easterly jet-stream India and the “Meiyu” (plum rain) season of the Yangtze Valley set in. The authors also found that the northward displacement of the rain belt is closely related to the northward retreat and the accompanying weakening in intensity of the westerlies over China main land.
    View full abstract
    Download PDF (22197K)
  • Akio Arakawa
    Volume 35A (1957) Pages 230-236
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     The longitude-mean meridional circulation,which is determined through the balance requirement of angular momentum, is discussed and computed in the case of winter and summer, 1949. Main occur in the estimation of frictional dissipation and vertical eddy transport of angular momentum. Theoretical treatments for the adiabatic, frictionless disturbance are developed assuming the phase angle of each wave component of disturbance to be random, and, a rlation between the accumulation of angular momentum by three-dimensional eddy process and the horizontal eddy transport of sensible heat is found. This relation makes it possible to estimate the direction and the strength of meridional circulation if the horizontal eddy transport of sensible heat and frictional dissipation are known.
     Under the conditions which exist in the atmosphere, it is concluded that there is a three-cell meridional circulation in the troposphere with an indirect cell (Ferrel type) in middle latitudes and direct cells (Hadley type) in low and, perhaps, high latitudes.
    View full abstract
    Download PDF (11096K)
  • N. Arizumi, S. Nakamura
    Volume 35A (1957) Pages 237-242
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     June 8-June 18, 1949 were International Meteorological Days and a warm high was observed over the sea of Okhotsk in this period. In this paper, this warm high is analysed, and it is suggested that the turning term in the equation of vorticity would play an important role in the formation of the warm high.
    View full abstract
    Download PDF (8006K)
  • C. W. Newton
    Volume 35A (1957) Pages 243-255
    Released: February 18, 2015
    JOURNALS FREE ACCESS
      The general processes leading to the development of convective precipitation ahead of a major cyclone are discussed, including the effects of horizontal advection and vertical motions on the creation and triggering of potential instability.
      By use of hourly rainfall charts, the history of development of a relatively narrow streak of heavy rainfall is illustrated. Heaviest rain occurred where several individual large rainstorms moved successively over nearly the same path. These rainstorms formed in a rather small area over a period of 16 hours. While the earliest formation took place in the region of greatest instability and general upward motions, no reason could be found for the successive formation of rainstorms in one locality. The analysis suggests quite definitely that the answer does not lie in any stationary feature of the general large-scale flow field.
    View full abstract
    Download PDF (21706K)
  • Tetsuya Fujita
    Volume 35A (1957) Pages 256-261
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     The introduction in this paper is a discussion of mesoscale, 10 to 100 miles in horizontal dimension, followed by a report of the recent work done by the Severe Local Storm Research Project at The University of Chicago. A study of radar echoes revealed the fact that the movement of individual echoes and that of the squall-line are quite different. Analysis shows that a mesosystem seen in Japan had features similar to those usually seen in the United States. It is concluded that international attention and cooperation to the study of this scale is important.
    View full abstract
    Download PDF (9729K)
  • N. A. Phillips
    Volume 35A (1957) Pages 262-267
    Released: February 18, 2015
    JOURNALS FREE ACCESS
    Download PDF (10264K)
  • Guy A. Franceschini
    Volume 35A (1957) Pages 268-270
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     Recent investigations conducted at the Agricultural and Mechanical College of Texas indicate the constant pressure balloon may play an increasing role as a means of observing the atmosphere. Observed trajectories and those predicted may well form the basis of new methods of meteorological analyses and forecasting.The status of the problem, present and future, is considered from a general standpoint.
    View full abstract
    Download PDF (5284K)
  • Eiichi Suzuki
    Volume 35A (1957) Pages 271-274
    Released: February 18, 2015
    JOURNALS FREE ACCESS
    Download PDF (6016K)
  • P. K. Das
    Volume 35A (1957) Pages 275-279
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     Charney’s equation for a non-divergent barotropic model has been applied to a depression in the Bay of Benegal. The equations were solved by relaxation method, and the predicted height changes were compared with those observed. The agreement was not discouraging, although there was considerable room for improvement.
     The limitations of the above model, specially in low latitudes, is discussed with special reference to the non-barotropic nature of the atmosphere and the quasi-geostrophic approximation.
    View full abstract
    Download PDF (7335K)
  • Y. Nabeshima
    Volume 35A (1957) Pages 280-288
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     Some attempts are made to produce prognostic charts at the 300 or 400 mb level, using the same method as we used in the previous paper (1). In this method the divergence term is included in the vorticity equation, in order to take into account the baroclinity.
     The result shows that the divergence term and the height of the tropopause are important because the divergence which is derived from vertical distribution of vertical velocity is affected by abrupt change of stability near the tropopause.
     In the stratosphere, the atmosphere becomes fairly barotropic, but near the tropopause level divergence term must be considered. The correlation between the observed and calculated height changes including the divergence term is fairly better than in the case of barotropic model.
    View full abstract
    Download PDF (11565K)
  • Eiichi Terauchi
    Volume 35A (1957) Pages 289-295
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     Some assumptions used in the graphical method for numerical prediction of surface presure patterns are examined.
     The mesh-size, the height of the level of non-divergence, and the vertical distribution of height with pressure, suitable for any graphical methods are obtained theoretically.
    View full abstract
    Download PDF (7061K)
  • Y. Masuda, H. Itoo
    Volume 35A (1957) Pages 296-303
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     As an attempt to improve the barotropic forecast of typhoon movement, a stream function is used in this paper in place of the geopotential. The stream function in the typhoon region is obtained by solving the balance equation by the Masuda's method. Using the stream function, the 24 hr and 36 hr forecasts of typhoon movement for 700 mb level and the 48 hr forecast for 500 mb level are performed based on the barotropic model. The machine used for computations is the electronic computer " Fujic." In spite of insufficient boundary condition, the results of the prediction are remarkably improved. From the results we obtained, we find that our method might be useful for the practical forecast.
    View full abstract
    Download PDF (11718K)
  • S. Fujiwara, A. Fukui, K. Hata, K. Ishihara, T. Noguchi, S. Sugiura, K ...
    Volume 35A (1957) Pages 304-308
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     As a first attempt to establish a quantitative method of predicting the rainfall pattern of small scale, the effect of topography is investigated in detail based on the numerical prediction method. The calculation is carried out by dividing the atmosphere into two layers; one above 850 mb, the other below it. The vertical velocity for the upper layer is computed by the ω-equation under the assumption that the vertical distribution of ω is parabolic. For the lower layer, only the vertical motion due to the orographic effect is considered. By multiplying the water vapor condensation function to these vertical velocities and summing up the results, the amount of rainfall at the ground surface is calculated.
     Grid distances used for the calculation are 300 km for the upper layer and 10 km for the lower layer respectively.
     The method is tested for the case of typhoon Kitty which passedover Kanto District from Aug. 31 to Sept. 1, 1949. The result is satisfactory as far as the general feature of the distribution of rainfall is concerned. But the correlation coefficient between 24-hr. forecast and the observed amount of rainfall is 0.63 and indicating that the result is not satisfactory yet. To get better result, the effects of surface friction and of isallobaric wind should be considered.
    View full abstract
    Download PDF (7528K)
  • P. Koteswaram, C. A. George
    Volume 35A (1957) Pages 309-322
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     The conditions in the upper troposphere leading to the formation of severe tropical cyclones in the Bay of Bengal have been examined. It is noticed that the westward movement of anticyclonic vortices over pre-existing sea level troughs is favourable for the formation of these cyclones. The formation, structure and dissipation of two cyclones in the Bay are discussed. The initial intensification of the sea level trough took place with the by-passing of the upper anticyclonic vortex, while the rapid ‘winding up’ of the cyclone occurred with an in-phase superposition of troughs in the easterlies and westerlies as suggested by Riehl. While the trough in the broad westerlies interlocked with the cyclonic trough in the easterlies south of the sub-tropical ridgeline in the case of the post-monsoon cyclone, a trough in the broad easterlies got interlocked with a cyclonic trough in the westerlies north of the subtropical ridgeline in the case of the pre-monsoon cyclone.
     The disturbances start with cold air in the centre and develop a warm core during the stage of their intensification. Their dissipation occurs with the inflow of cold air from neighbouring jet streams or wave troughs in the high troposphere.
     In all these respects the Indian cyclones bear a close similarity with the Typhoons of the Pacific and Hurricanes of the Atlantic oceans.
    View full abstract
    Download PDF (23629K)
  • T. Masui
    Volume 35A (1957) Pages 323-329
    Released: February 18, 2015
    JOURNALS FREE ACCESS
     As the result of the investigation of the distributions of potential temperature field in the typhoon which passed over Japan in recent years, the diagrams of horizontal distribution of the vertical motion on 150 mb surface were constructed.
    View full abstract
    Download PDF (9900K)
  • Horace R. Byers
    Volume 35A (1957) Pages 330-335
    Released: February 18, 2015
    JOURNALS FREE ACCESS
      The vertical distribution of water vapor can be expressed by an index coefficient which provides information about eddy and advective transports in a region or in an air mass. The relationship between evapotranspiration and eddy diffusivity of water vapor can be studied in this way. Striking differences in conditions between the arid Southwest and the remainder of the country are shown.
    View full abstract
    Download PDF (10110K)
feedback
Top