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Volume 46 (1984)
- Issue 4 Pages 153-
- Issue 3 Pages 101-
- Issue 2 Pages 45-
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Volume 46, Issue 1
Displaying 1-4 of 4 articles from this issue
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Katsuhiro YAMAMOTO, Shinji KUSU, Keiji HIGUCHI1984 Volume 46 Issue 1 Pages 1-9
Published: March 30, 1984
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSThe formula for calculation of the complex dielectric constant of wet snow is determined on the basis of the following assumptions : 1) Wet snow is a mixture of ice spheres and water meniscuses packed in air. 2) The depolarization factor of a spheroid, (δ, δ, 1-2δ); 0≤δ≤1/2, is assumed to be that of a water meniscus, as an approximation. 3) Polder and van Santen's mixing formula (1946) is applicable. 4) The depolarization factor depends on the volume fraction of water, Vw', in the sample. There is an adjusting parameter in the formula yielded from assumption 1-3). To determine the parameter, the dielectric constants of mixtures of glass beads and water, which were substitutes for wet snow samples, were measured at 8.83 GHz. Glass bead samples are suitable for many accurate measurements. The relation, δ=0.06+0.25Vw is determined using the present data and the same data at 6 GHz measured by Sweeny and Colbeck (1974). This relation shows that the equivalent spheroid is flattened oblate (the axis ratio is 0.08-0.15 when Vw≤0.15). The calculated dielectric constants agree well with the measured values.
The dielectric constants of natural snow samples were also measured at 8.83 GHz. Half of the measured values agree with the calculated values. Many of the remainder suggest water droplets in these samples to be spherical, and the rest suggest more flattened droplets than those in glass bead samples.
The frequency dependence of the calculated value is examined. Below 100 MHz, the present values are slightly less than those determined by Denoth and Schittelkoph (1978) at 18.5 MHz. Numerical analyses show that this difference is caused by the difference between the dielectric constants of ice calculated from dry snow data at 20 MHz and 9 GHz, and suggest the applicability of the present theoretical model in a wide frequency range.View full abstractDownload PDF (1488K) -
Heat budget during ablation seasonShigeo MORIBAYASHI, Keiji HIGUCHI, Tetsuo OHATA1984 Volume 46 Issue 1 Pages 11-18
Published: March 30, 1984
Released on J-STAGE: July 23, 2009
JOURNAL FREE ACCESSHeat budget studies of a perennial snow patch at Tsurugizawa, Mt. Tsurugi region (36°36'N, 137°37'E) in central Japan were carried out to clarify the role of heat source components in the ablation of the snow patch. Analyses are based on the data obtained in June-September 1968, June-July 1969, and September 1977. The percentage of each component in the heat balance during the whole ablation period (June-September) in 1968 was 59% for net short wave radiation, 23% for sensible heat, 15% for latent heat, and 2% for heat transported by rain in the heat gain, while 97% of the heat loss was due to melting. The value of 15% for latent heat is almost the same as the values for maritime glaciers, and relatively high when all types of ice and snow areas are considered. In the heat balance components, the latent heat increases mostly from early summer to midsummer and the sensible heat also increases greatly during the same period while the net short wave radiation shows less variation, and the change of the ablation amount strongly depends on the changes of latent heat and sensible heat.View full abstractDownload PDF (1337K) -
Norikazu MATSUOKA1984 Volume 46 Issue 1 Pages 19-25
Published: March 30, 1984
Released on J-STAGE: July 23, 2009
JOURNAL FREE ACCESSThe intensity of frost shattering which acts on the bedrocks in the periglacial regions of the Nepal Himalaya was estimated from the meteorological records at Lhajung (4420 m in altitude), Khumbu region, eastern Nepal. Air temperature records showed that more than 150 cycles of freeze-thaw within a year occurred in the periglacial zone above 4000 m in altitude. As these freeze-thaw cycles mainly occur in the monsoon season, bedrockes exposed at around 5000-5500 m in altitude maintain the high water-content required for frost shattering. Intensive frost shattering was due to high frequency of freeze-thaw cycles and abundant moisture, thus depositing a large quantity of debris onto the surfaces of debris-covered glaciers in the Nepal Himalaya.View full abstractDownload PDF (1139K) -
Yoshio OOZEKI, Shigeo WATANABE, Shoji NIWANO1984 Volume 46 Issue 1 Pages 27-29
Published: March 30, 1984
Released on J-STAGE: July 23, 2009
JOURNAL FREE ACCESSDownload PDF (3293K)
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