Ocean currents produced by sources and sinks on a β-plane are treated. In presence of an eastern coast an isolated sink (or source) yields zonal flows only to the west of the sink (or source). The total zonal transport due to the sink (or source) is eastwards (or westwards). The pressure and velocity distributions induced by a point source are determined for the flow with frictional forces.

View full abstract

The tidal records of Alligator Harbor of two months in summer of 1952 are analyzed. The frequency of occurrence of seiches and their amplitudes and energy distributions against periods are determined. Several methods of computing periods of seiches are applied to the bay. A dynamical explanation for initiation of oscillations of different modes in a bay is proposed. Correlograms and power spectra of sea level deviations from tides are determined in several parts of the records with conspicuous amplitudes. Relationships between seiches and meteorological conditions are discussed.

View full abstract

It is important to know the relation between the oceanographical condition and the meteorological one. Many investigators have solved it on an averaged value in a long term or on a climatic condition.
Some large variations in a few days were found at the sea surface: typhoon 5906 gave us the appropriate data to consider the relation; the water temperature at the sea surface was decreased about 2°C during only a week in the region of south of Shikoku. This typhoon passed very slowly by West Japan, and the area was under its influence during more than 3 days.
In this paper, we considered the variations of the water temperature and chlorinity from the viewpoint of the evaporation and the precipitation.
On the evaporation we used the following equation,
E=k (e_w-e_a) W, where
k: evaporation cfactor
e_w: vapor pressure at the sea surface,
e_a: vapor pressure in the air, altitude of a m,
W: wind velocity.
We assumed that the water temperature decreased linearly with the depth from the surface and that on cooling the water by the evaporation there was no inversion layer, but homogeneous temperature layer was created; the following equation showed the vertical distribution of the temperature,
θ=θ₀-bz where
θ: the water temperature of the depth of z cm, or of the surface after cooling during t days,
θ₀: initial surface temperature
b: temperature gradient.
And we assumed that the saturated vapor pressure at the sea surface was proportional to the surface temperature, i, e.,
eW=eW₀-c (θ₀-θ) where
eW₀: the saturated vapor pressure at the sea surface when the surface water temperature was θ₀°C,
θ_W: the saturated vapor pressure at the sea surface when the surface water temperature was θ°C,
c: const..
And the precipitation was computed from the decrease of the water temperature and chlorinity.

View full abstract

As a step to investigate the chemical characteristics of “Shiome” in Urado Bay, the author has studied the distribution of iron and manganese in sediments collected from the Bay of Urado, Kochi Pref., Shikoku. On the basis of the results obtained by a number of chemical analyses on them, the following conclusions have been deduced.
1. The concentration of total iron in dry sediments was 30.90-58.72 mg/g and of, total manganese was 0.524-0.911 mg/g. The ratio of total manganese to total iron tends to be higher around the current rips; the greater the distance from “Shiome”, the smaller the ratio.
2. The fraction of ferrous iron in total iron extracted from wet sediments by using buffer solutions of sodium acetate-acetic acid (at pH 4.0), was 20-89%, and the ratio of total manganese to total iron was 0.026-0.274.
3. The fraction of ferrous iron in the total iron decreases as the location of the sampling shifts from the inner end of the bay towards the mouth. This shows the tendency of oxidation of ferrous iron into ferric state towards the mouth of the bay. Manganese tends to decrease as ferrous iron increases.

View full abstract

The primary production in the northwestern Pacific waters was measured during the cruises in August 1957 and in May, July-August 1958. The standing crop of phytoplankton was measured on the basis of its chlorophyll content, and the photosynthetic rate of phytoplankton was determined by the ¹⁴C method.
The average chlorophyll value in euphotic layers was found within the range from 0.4 to 0.7 mg. /cu. m. for the Oyashio area and from 0.1 to 0.2 mg. /cu. m. for the Kuroshio, except for the coastal water. Furthermore, it was observed in euphotic layers that a linear relationship exists between transparency of water and average chlorophyll content. The photosynthetic capacity of water taken from various depth of the sea was measured under an optimal light condition and at temperature of water in situ. On evaluation of photosynthetic capa-city, the Oyashio area gave values 1-4 mg. C/cu. m. /hr., and the Kuroshio area from 0.1-0.7 mg. C/cu. m. /hr., respectively. The production was estimated by means of the tank and chlorophyll methods. The calculated value of the daily production rate was 0.2-0.4g. C/sq. m. /day for the Oyashio area as well as the littoral region of the Kuroshio, and 0.05-0.1g. C/ sq. m. /day for the pelagic area of the latter.

View full abstract

Tow flow-meters attached to a plankton net were hauled simultaneously, one being set up at the center of the mouth ring of the net, and the other 50 cm above. Examination was made on the relations of the ratio of the two readings of flow-meter to the settling volume and to the phytoplankton cell numbers.
Obtained results show that, when the values of settling volume and cell numbers exceed certain values, the filtering efficiency of the net is varied. Furthermore, the relation between wire angle and hauling distance is stationary when the angle is 50°.

View full abstract