Journal of the Meteorological Society of Japan. Ser. II
Online ISSN : 2186-9057
Print ISSN : 0026-1165
ISSN-L : 0026-1165
Volume 46 , Issue 1
Showing 1-6 articles out of 6 articles from the selected issue
  • M. Iida
    1968 Volume 46 Issue 1 Pages 1-13
    Published: 1968
    Released: May 27, 2008
    JOURNALS FREE ACCESS
    The momentum, sensible heat and latent heat transports for the years 1958 and 1959 were measured by using the observations of wind, temperature and humidity in the troposphere at 14 stations in the Equatorial zone.
    The vertically integrated momentum transport shows a flow of momentum towards the Northern Hemisphere in all seasons. The northward transfer due to the mean cell in winter is especially large. The vertically integrated transport of sensible heat and latent heat shows respectively a flow of the heat towards the summer hemisphere mainly by the mean cell. The eddy transports of heat across the equator are found to be very small. The annual sum of the vertically integrated flux of sensible heat and latent heat results in a net transfer of heat toward the Southern Hemisphere from the Northern Hemisphere.
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  • Freezing of a Supercooled Water Drop due the Collision of Ice Crystals
    Takao Takeda
    1968 Volume 46 Issue 1 Pages 14-28
    Published: 1968
    Released: May 27, 2008
    JOURNALS FREE ACCESS
    The freezing-probability of a supercooled water drop, which grows by the capture of cloud droplets, due to the collision of ice crystals formed on ice nuclei was numerically studied in clouds with various conditions. In all cases, the probability increases about 100 times during staying of the drop at cloud top and most of collisions with ice crystals take place when the drop stays near cloud top. The accumulated number of ice crystals colliding with the drop increases with the vertical velocity of air-current and the height of cloud top. The accumulated number of colliding ice crystals is larger in clouds of small water content of cloud droplets than in clouds of large water content after a sufficiently long time, although it tends to increase with the water content in early stage of the growth of the drop. Most favourable water content for the collision is dependent upon the velocity of updraft and the time length. In clouds which are lower than 3000m in the height of cloud top and which are a few m/s in the velocity of updraft, at most one drop of 10 to 100 supercooled water drops can collide with one ice crystal in 1.0 to 1.5 hour.
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  • Yasushi Mitsuta
    1968 Volume 46 Issue 1 Pages 29-35
    Published: 1968
    Released: May 27, 2008
    JOURNALS FREE ACCESS
    The results of direct measurement of vertical eddy transport of momentum near the ground by the use of sonic anemometers are discussed. Measurements were made at the heights from 1.5 to 3.0m above the ground together with surface drag force measurements by a specially designed drag-meter. The magnitude of directly measured momentum flux varies with height and is larger than that expected from the surface drag force. The existence of abrupt momentum release of short duration in the airflow with large shear was also found.
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  • Tadashi Takakura
    1968 Volume 46 Issue 1 Pages 36-44
    Published: 1968
    Released: May 27, 2008
    JOURNALS FREE ACCESS
    This paper provides a weighting function for solar radiation and prediction of air temperatures in the glasshouse by superposition of responses to outside air temperature, effective radiation, and solar radiation.
    It is found that computed values and experimental results are in tolerably good agreement with each other in spite of several assumptions. Temperature rise due to solar radiation changes according to the change of absorption coefficient of glass (∉4) and heat transfer coefficient of outside glass surface (1/R0g) . A large amount of temperature rise in the daytime occurs when ∉4 is large, while a slight dip exists in the nighttime at R0g=0.111 (m2hr•deg C•kcal-1) . So-called heat-absorbing effect of a specified glass appears when R0g is small.
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  • R.F. Mackinnon
    1968 Volume 46 Issue 1 Pages 45-59
    Published: 1968
    Released: May 27, 2008
    JOURNALS FREE ACCESS
    Numerical evaluations of theoretical expressions for ground pressure waves due to explosions in the atmosphere are presented for a model atmosphere containing winds. Various wind conditions are studied and distinction is made between winds of the upper and lower atmosphere. It is found that wave speed and amplitude depend on wind conditions, so that any analysis of microbarograms must take into account prevailing wind conditions. Previously published records are studied in the light of the new results presented.
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  • Katsuhiro Kikuchi, Toshiyuki Kasai
    1968 Volume 46 Issue 1 Pages 60-67
    Published: 1968
    Released: May 27, 2008
    JOURNALS FREE ACCESS
    Several photographs taken by NIMBUS II APT system were analyzed stereoscopically by a “Stereotop”. It was possible to distinguish the areas of sea ice from the areas of cloud, and furthermore it was possible to classify clouds into three grades, using the relative height of the clouds. According to the result of analysis, it is considered that the stereoscopic analysis of NIMBUS II APT photographs is a useful technique for the observation of clouds, at least for the judgement whether a white area is a cloud area or a sea ice area.
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