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Volume 55, Issue 4
Displaying 1-9 of 9 articles from this issue
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Mitsuo MIZUMA1999 Volume 55 Issue 4 Pages 307-314
Published: December 10, 1999
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe meteorological data obtained in the Sino-Japan joint research project (HEIFE) are utilized for the analysis of the local wind system in the project area in northwestern China. The local winds appearing at the respective observational sites in the summer days with fine weather and weak synoptic-scale forcing are made clear. The katabatic wind is predominant in the foot of the Qilian Mountains. When the katabatic wind is prevailing, the ground surface temperature seems somewhat lower than the air temperature in the lowest layer of the atmosphere. The air temperature in the location where there is a noticeable katabatic wind is considerably higher than that in the location where the air tends to be stagnant on clear nights. Harmonic analysis of the temporal variation of wind speed and temperature shows no significant periodicity of the cold air drainage. The periodic components shorter than 100 minutes, if they exist, have the amplitudes of, at most, 0.6m/s and 0.25°C for wind speed and temperature, respectively, in the drainage.View full abstractDownload PDF (1085K) -
Yoshitaka KUROSE, Kenji NAGATA, Kazuhiko OHBA, Atsushi MARUYAMA1999 Volume 55 Issue 4 Pages 315-322
Published: December 10, 1999
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSTo clarify the spatial distribution of solar radiation, a model to estimate the potential incoming solar radiation with 50m grid size was developed. The model is based on individual calculation of direct and diffuse solar radiation accounting for the effect of topographic shading. Using the elevation data in the area with radius 25km, which was offered by the Digital Map 50m Grid, the effect of topographic shading is estimated as angle of elevation for surrounding configuration to 72 directions.
The estimated sunshine duration under clear sky conditions agreed well with observed values at AMeDAS points of Kyushu and Shikoku region. Similarly, there is a significant agreement between estimated and observed variation of solar radiation for monthly mean conditions over complex terrain. These suggest that the potential incoming solar radiation can be estimated well over complex terrain using the model.
Locations of large fields over complex terrain agreed well with the area of the abundant insolation condition, which is defined by the model. The model is available for the investigation of agrometeorological resources over complex terrain.View full abstractDownload PDF (3237K) -
Koichi MIYASHITA, Toshihiko MAITANI, Kazuyoshi TAKEDA1999 Volume 55 Issue 4 Pages 323-328
Published: December 10, 1999
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSRegional specialities of world wide barley cultivars under high temperature conditions were studied, using surface temperatures of plant canopy measured by an infrared thermometer. A total of 274 barley cultivars consisting of 5 north American cvs, 11 north African cvs, 19 Chinese cvs, 37 Ethiopian cvs, 35 south west Asiatic cvs, 30 Japanese cvs, 30 Korean cvs, 21 Nepalese cvs, 18 Turkish cvs, and 68 European cvs were randomly taken from the stocks preserved in the Barley Germplasm Center of Okayama University.
Under nearly zero stress conditions on cloudy days, differences (Ts-Ta) between canopy surface temperatures (Ts) of barley cultivars and ambient air temperatures (Ta) decrease with increasing air temperatures and water vapor pressure deficits, having very high correlation coefficients. On the other hand, under higher air temperature and dry conditions on clear afternoons, Japanese cvs, south west Asiatic cvs, and Nepalese cvs maintained low surface temperatures, but barley cultivars from higher latitudes such as European cvs had the tendency to increase surface temperatures. These imply that the former cvs have the ability to change energy dissipation rates in response to changes in energy absorption but the latter cvs have a limited ability to change the rates of some energy loss mechanisms such as transpiration. Barley cultivars in the habitats with higher annual air temperature and more annual precipitation generally tended to have greater ability to moderate leaf temperatures.View full abstractDownload PDF (692K) -
Munekiyo HORIMOTO, Hitoshi ARAKI1999 Volume 55 Issue 4 Pages 329-336
Published: December 10, 1999
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSIn order to develop effective control methods against freezing injury in Japanese chestnut trees, the effects of treatments intended to restrict water uptake by roots during winter were examined. Three kinds of treatments were tested: root pruning, root loosening and soil application of molasses. Although intensive root pruning (38% of the whole root was eliminated) in January effectively suppressed the occurrence of freezing injury, the treatment may cause undesirable effects on tree growth. The other two kinds of water stressed treatments, root loosening (making a number of cracks throughout the root zone soil with an excavator) and molasses application into root zone soil, successfully avoided this problem.
Both treatments delayed the spring-time increase in twig water content and effectively protected chestnut trees from freezing injury without causing any harmful effects on their growth.
For molasses application (Brix 77.2, total sugar content 50.2%, specific gravity 1.4), half strength solution (diluted with same weight of water) was more effective than quarter strength solution. For 2 or 3-year-old trees, 5kg molasses/tree (sprinkle half strength solution and let the solution permeate into root zone soil) was enough to avoid freezing injury. For 4-year-old trees, 10kg/tree was enough, but the solution should be injected with pressure (20kgf/cm2) into the root zone soil.View full abstractDownload PDF (3066K) -
Hiromitsu KANNO, Kiyoshi OZAWA1999 Volume 55 Issue 4 Pages 337-344
Published: December 10, 1999
Released on J-STAGE: February 25, 2010
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Yoshinobu HARAZONO, Yousay HAYASHI1999 Volume 55 Issue 4 Pages 345-346
Published: December 10, 1999
Released on J-STAGE: February 25, 2010
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Tomoyoshi HIROTA1999 Volume 55 Issue 4 Pages 347-350
Published: December 10, 1999
Released on J-STAGE: February 25, 2010
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[in Japanese], [in Japanese], [in Japanese]1999 Volume 55 Issue 4 Pages 351-353
Published: December 10, 1999
Released on J-STAGE: February 25, 2010
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Local-Climatological Information with 50m Mesh Size and Its Relation to Agricultural ProductionThe Executive Committee of Section Meeting on Loca1999 Volume 55 Issue 4 Pages 355-357
Published: December 10, 1999
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (389K)
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