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Volume 37, Issue 1
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Toshihiko MAITANI, Keiji TAKEUCHI1981 Volume 37 Issue 1 Pages 1-7
Published: June 10, 1981
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSObservations were made on the characteristics of vertical transport of momentum, heat and water vapor in the surface layer over a paddy field in September, 1977. The height of the canopy was about 90cm. Vertical fluxes were determined from fluctuation data measured by sonic anemometers, thermocouple thermometer and infrared hygrometer at 110cm. The stability was in the neutral condition. The acquisition and analysis of data were performed by an off-line data acquisition system for micrometeorological observations. The results are summarized as follows:
1) Intermittent transports of momentum and water vapor are closely related to high winds which are associated with downdrafts.
2) The ratio of fluxes transported by downdrafts to flux by updrafts was about 1.5 for momentum, water vapor and sensible heat, respectively.
3) Nondimensional cospectra nCowu(n), nCoWT(n), nCowq(n) and spectral correlation coefficients Rwu(n), RwT(n), Rwq(n) have similar shapes over the analyzed range of frequency.
4) In the inertial subrange, cospectra Cowu(n), CowT(n), Cowq(n) rapidly fall off with slopes from -7/3 to -8/3. These slopes are close to -7/3 predicted by Wyngaard and Coté (1972).
5) Power spectra Swu(n), SwT(n), Swq(n) and cospectra Cow.wu(n), COw.wT(n), Cow.wq(n) had a slope of -5/3 in the inertial subrange. The slope of power spectra is different from -7/3 law predicted by dimensional analysis. The disagreement probably seems to be due to high correlation between vertical velocity w and instantaneous fluxes wu, wT, wq in high frequency range.
6) Contributions by downdrafts to wu, wT and wq are more than those by updrafts throughout the analyzed frequency range.View full abstractDownload PDF (897K) -
1981 Volume 37 Issue 1 Pages 8-8,38
Published: June 10, 1981
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (535K) -
Tetsuo SAKURATANI1981 Volume 37 Issue 1 Pages 9-17
Published: June 10, 1981
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThis paper describes the method and apparatus for measuring the flow rate of water in intact plant stems, on the basis of heat balance of a stem segment. Under stationary conditions, the heat energy supplied continuously to a segment of plant stem is partitioned into three components such as conduction, mass flow and convection [see Eq. (1)]. By predetermining both heat losses due to conduction in the stem and convection from the segment surface into ambient air, it is possible to evaluate the heat loss due to mass flow of water in the stem, that is, the water flow rate equivalent to the transpiration stream. The water flow rate evaluated by this method is compared with the transpiration loss of water determined directly by weighing potted soybean and sunflower plants and measured by using a chamber method. The comparison shows there is a good agreement between them. This indicates that the newly developed method can be applied for determining transpiration rates of intact plants under laboratory and field conditions.View full abstractDownload PDF (1096K) -
Equations on Heat Flux-Temperature and their Applications (1)Kazuo TACHIBANA1981 Volume 37 Issue 1 Pages 19-27
Published: June 10, 1981
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe stiffness matrix of the finite element method is applicated to the heat transfer of the greenhouse and the equations of heatflux-temperature are extended and improved. It is shown by the equation (5). [K], Eq. (6) and [Kαα]-1, Eq, (8) are the heat transfer matrix of the greenhouse and the heat flux-temperature matrix, respectively. The elements of the matrix [Kαα]-1, which are calculated from Eqs. (10)-(15), are heat transfer coefficients of the greenhouse. These coefficients are different from each other, by the heating position and the measuring point.
From these equations, the equivalent temperatures of the solar radiation and the atmospheric one are found [Eqs. (23) and (25)]. The overall heat transfer and heating load coefficients are also found by Eqs. (32) and (33).
Fig. 6 shows the relation between these values of the hot-air-heated glasshouse, PVC and PE houses and the temperature difference of outside and inside air. Fig. 7 also shows that on the pipe-heated glasshouse.
Required air flow rate on the ventilation is shown in Fig. 8 calculated from Eq. (41).View full abstractDownload PDF (972K) -
Part 3. Land and Lake Breeze of Lake Toya, Hokkaido, in SummerHisashi KATO, Hidenori TAKAHASHI1981 Volume 37 Issue 1 Pages 29-37
Published: June 10, 1981
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSAs part of a series of observational studies, the local climate near a small lake (not exceeding 200km2) in summer was investigated. The observations of land and lake breeze were carried out on and around Lake Toya, and some features and the structures of these wind systems were noted.
1) Land and lake breeze was observed in the entire lake shore, and the mean speeds of these winds were found to be approximately 1-2m/sec at lake shore. But the transition from land breeze into lake breeze was different at each site in mode and in time.
2) The maximum depth of the land breeze was about 100m, and the lake breeze was approximately 150m. The structures of these wind circulations were considered to be slightly twisted.
3) It is found that the lake breeze set in when the air was still cooler than water surface. This unique feature is explained in relation to the topography around the lake.View full abstractDownload PDF (2525K) -
(3) Effects of Meteorological Factors on Number of Fruits SetsShoichi IKEDA, Akitoshi TAOKA, Sadayoshi ONO, Yuuhei IIYA1981 Volume 37 Issue 1 Pages 39-46
Published: June 10, 1981
Released on J-STAGE: February 25, 2010
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1. An Analysis of Cold Air Currents for Cool Summer Days in Aomori Prefecture in 1979Takeharu BOKURA, Hiroshi YAMASHITA, Tetsuo SUZUKI1981 Volume 37 Issue 1 Pages 47-52
Published: June 10, 1981
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (2462K)
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