All issues
Volume 33 (1982)
- Issue 4 Pages 187-
- Issue 3 Pages 117-
- Issue 2 Pages 55-
- Issue 1 Pages 1-
Volume 33, Issue 2
Displaying 1-5 of 5 articles from this issue
- |<
- <
- 1
- >
- >|
Full Papers
-
Takayo Matsuo, Yoshio Sasyo1982 Volume 33 Issue 2 Pages 55-64
Published: 1982
Released on J-STAGE: March 09, 2007
JOURNAL FREE ACCESSThe air temperatures for the onset of melting and for the completion of melting of snow pellets below freezing level were obtained by an analysis of the routine observational data and were compared with those from theory. The theory, which allows for melt water to percolate into the porous core of a snow pellet, agreed well with the analysis. It was demonstrated both analytically and theoretically that the fall distance below freezing level for the onset of melting increased with decreasing relative humidity and that the fall distance for the completion of melting increased with decreasing relative humidity and with increasing snow pellet size and density. These results show that the melting process of snow pellets in the atmosphere is essentially the same as that of snowflakes revealed through the study of Matsuo and Sasyo (1981a, b, c) and Matsuo et al. (1981d).View full abstractDownload PDF (762K) -
Tsutomu Takashima, Yozo Takayama, Kazuo Matsuura, Keikichi Naito1982 Volume 33 Issue 2 Pages 65-78
Published: 1982
Released on J-STAGE: March 09, 2007
JOURNAL FREE ACCESSA feasibility study of deriving cloud height was conducted by the use of two geosynchronous meteorological satellites (GMS-1 and GMS-2). The GMS-1 was located at about 140°E on the equator and the GMS-2 was at about 160°E on the equator. The cloud height was observed by the GMS-1 through the visible and IR channels at 23:32 GMT on Sept. 17, '81 (23:36 GMT for the GMS-2), but at equator the time difference between the data acquisitions by these two satellites is less than a minute due to their spin rate and attitude difference. These observations were made by the Meteorological Satellite Center, JMA.
To obtain the good quality of anaglyphic photographs, apparent image distortions were reduced through the mapping process by which all the pixels in the observational coordinates were converted to those in the longitude-latitude coordinates. Upon deriving the cloud height, the earth was assumed to be spheroid. It was found from the analysis that it is possible to obtain the fine structure of cloud in a relative accuracy of 200 m, but a large number of dependable reference points around the target cloud are required as well as the precise orbit parameters, to obtain a high accuracy of absolute cloud height. This analysis was practically impossible by the use of infrared technique due to the unknown emissivity of cloud and the vertical temperature profiles.View full abstractDownload PDF (8062K) -
Yozo Takayama, Tsutomu Takashima1982 Volume 33 Issue 2 Pages 79-83
Published: 1982
Released on J-STAGE: March 09, 2007
JOURNAL FREE ACCESSMeasurements of temperature at points ranging from 10 cm above the water surface to 6 cm below it were undertaken by the use of thermocouples at the water pool installed outside the Meteorological Research Institute. At the same time, the water surface temperature was measured by the radiometer (7.5-11.5 μm) to compare it with the water temperature measured by the thermo-couples. Then the radiometer was scanned along the nadir angle of observations ranging from 30° to 80° under various weather conditions. A comparison of water surface temperature thus measured with that derived theoretically tells that at large nadir angles of observations, the temperature deviation from the calculated ones is large. This may be due to the surrounding conditions, particularly the existence of cloud. Furthermore, the temperature below the water surface is different from that measured by the radiometer. Hence to discuss the accuracy of the sea surface temperature measured by satellites, it is essential to obtain radiometric sea surface temperature by ships.View full abstractDownload PDF (489K) -
Yukio Katsuragi, Katsumi Hirose, Yukio Sugimura1982 Volume 33 Issue 2 Pages 85-93
Published: 1982
Released on J-STAGE: March 09, 2007
JOURNAL FREE ACCESSThe monthly fall rate of 239+240Pu in Tokyo and Tsukuba Science City during January 1974 through December 1980 is given. The cumulative amount of plutonium fallout in Tokyo from the beginning of nuclear detonations to the end of 1980 is estimated to be about 1.2 mCi/km2. The ratio of 239+240Pu to 90Sr deposition during the same period was about 1.6%. Samples collected at Akita, the Japan Sea side of Honshu Island, Japan, during 1963 to 1964 indicate that the fall rate of plutonium isotopes is about 2 times higher than that in Tokyo. After the removal of our Institution to Tsukuba Science City, about 60 km north of Tokyo, the sampling and analysis of plutonium isotopes were continued and it was confirmed that the amount of plutonium deposition in both cities are in good agreement with each other.View full abstractDownload PDF (593K) -
Hideo Akamatsu1982 Volume 33 Issue 2 Pages 95-115
Published: 1982
Released on J-STAGE: March 09, 2007
JOURNAL FREE ACCESSThe seiche in Nagasaki-Bay, i.e. ABIKI in Japanese, is discussed from three standpoints. Firstly, the statistical aspects of the seiche in Nagasaki-Bay are studied by use of the observed data from 1961 to 1979. Secondly, the seiche which occurred on March 31, 1979, the largest one in the history of tidal observation in Nagasaki-Bay, is studied. The maximum amplitude of the seiche observed at Matsugae-quay, located at the middle part of the bay, was 278 cm and the period was about 35 minutes, while it was 478 cm at the mouth of the Urakami-river located at the northern end of the bay. This seiche may be due to the severe barometric pressure jump associated with the apparent cold air front which advanced over the sea west of Kyushu. Thirdly, the response of Nagasaki-Bay to the forcing at the mouth of the bay is examined by means of a two-dimensional numerical model. Results show that the bay has an eigen period of 35 minutes, 20 minutes and 10 minutes as the uni-, bi-, tri-nodal oscillations of the bay, respectively. These periods agree with the predominant periods observed. According to the report of Hibiya and Kajiura (1981), the dominant periods of long waves that reached the Goto-Nada sea area are 64, 36 and 24 minutes. Since the latter two periods are very close to the eigen periods of Nagasaki-Bay, it is reasonable to consider that the seiches of Nagasaki-Bay are caused by the resonance to the long waves due to the barometric pressure jump.View full abstractDownload PDF (1520K)
- |<
- <
- 1
- >
- >|