The tropical marine boundary layer is of fundamental importance to the whole of the atmospheric motion system by providing a large amount of water vapor into the free atmosphere. It is one of the important subjects for GARP to investigate the turbulent transport mechanism in this layer. In this paper a description is given of a stable platform system that was aimed for turbulent transport measurements on board. The system is designed primarily for turbulent flux measurements by the eddy correlation method on a ship. Various components of the system are briefly described and evaluation data obtained during the summer MONEX field program are also presented. It was found that this system is applicable to the turbulent flux measurement by the eddy correlation method on a ship during MONEX. By further estimation of total errors, it was also found that this system is applicable to the measurements under rougher sea surface conditions.
The Q-structure of Izu-Oshima Volcano Island has been studied based on the propagation characteristics of the isolated-type eruption tremor originated from the central crater, Mihara-crater. This kind of tremor has been known to occur at the time of a small Strombolian eruption at the crater. Temporary observation was carried out at thirty-nine points, using one portable seismometer. The frequency detected of the tremor is within the range lower than 30 Hz, and its maximum amplitude exists roughly at 3 Hz wave component. The propagation mode of higher than 5 Hz seismic wave of the tremor looks like that of the body wave. The high frequency body wave generated is considered to have been by the explosion sound at the crater or by high frequency vibration of the materials at the crater due to the volcanic explosion. Large attenuation of certain wave components has been observed on the eastern flank of the volcano. On the other hand, notable large power of 10 to 12 Hz wave component is observed to the WNW and ESE just outside of Mihara-crater. The former phenomenon seems to be by the influence of the coarse materials which form the eastern area of the volcano, which is the low Q-structure region. The latter phenomenon seems to be by the influence of new pyroclastic materials stratified in the atrio of Mihara-crater.
A new method of determination of metal-organic complexes and compounds in sea water is developed using Amberlite XAD-2 resin. Neutral or basic metal-organic species are adsorbed on the resin at pH 8 and acidic ones are adsorbed at pH 3. Elution of each metal-organic compound is done by methyl alcohol and dilute NH4OH. After decomposition of organic matters in the eluate, the determination of metallic elements is done by spectrophotometric, fluorometric or atomic absorption spectrophotometric methods. Although the ratio of organic species to the total varied from element to element, the reproducibility of the analytical result is excellent. The result of comparison with gel-exclusion method shows good agreement with that of the present method. The molecular size distribution of metal-organic species shows that the major fraction is involved in high polymer organic matters with molecular weight ranging from 1×103 to 2×104 daltons. The concentration of metal-organic species shows an intimate correlation with that of combined amino acids or proteins adsorbed on the resin, and composition of individual amino acids is specific for each molecular size group. Every result indicates the presence of stable metal-organic species in sea water and that the present method is one of the useful tools for chemical speciation of metallic elements dissolved in sea water.
Characteristics of secular variation, response to precipitation, and change of atmospheric pressure coefficient for strain observed by borehole volume strainmeter at Omaezaki are investigated. Generally, strain contracts by precipitation and the more rain falls, the more it contracts, but there seems to be a ceiling to this effect. Atmospheric pressure coefficients show seasonal variation which is considered to be related to change of groundwater level. Sudden contraction of strain that has been observed several times are not a net increase of contraction but seems to exhibit a recovery to a stationary state. By carrying out similar investigations for strain data of other observation sites and comparing them, we will be able to discriminate phenomena due to regional stress change from various noises of local origin such as caused by change of the coupling state of the very site and change of ground water level, etc., which is the most important for catching significant signals related to the focal processes before earthquake occurrence.