Residual currents in a semi‐enclosed bay of the Seto Inland Sea, Japan

Abstract

[1] On the basis of the Princeton Ocean Model, a robust diagnostic model is developed to calculate the residual currents in the Hiuchi-Nada, a semi-enclosed bay of the Seto Inland Sea. The input water temperature and salinity data are from six hydrographic surveys in 2002, and the model results in the summer show a clockwise eddy in the western part of the bay and an anticlockwise eddy in the eastern part. The magnitude of two eddies is $10 cm/s. The modeled flow pattern is consistent with early observations derived from moored arrays. The two eddies are persistent throughout the summer because winds are usually weak and cannot influence their existence. The tide-induced residual currents are appreciable only in the close vicinity of the Kurushima Strait and Bisan Strait, the two straits connecting the bay to the other bays, and have little affect on the two eddies that are inside the bay. Thus the two density-driven eddies in the Hiuchi-Nada are the basic pattern of circulation in the summer. Using the calculated residual currents, we examined the intrusion route of waters from the Kurushima Strait and Bisan Strait with passive tracer experiments. The results show that the water in the Kurushima Strait intrudes into the bay mainly through the middle and bottom layers while the water in the Bisan Strait intrudes mainly through the surface layer. Furthermore, the tracer cannot reach the center of the anticlockwise eddy in the eastern part of the bay. This indicates that the eddy prevents water exchange between its center and outer edges and provides favorable conditions for the formation of oxygen-deficient waters in the central part of the eddy.

Effects of temperature, food availability, and body size on daily growth rate of Japanese anchovy Engraulis japonicus larvae in Hiuchi-nada

“…At the end of May, the lowest temperature in the surface layer was in Kurushima strait, the highest temperature in the eastern part of Hiuchi-nada, and an intermediate temperature in the Bisan strait and northern part of Hiuchi-nada. This distribution pattern was unchanged in June and July [8]. Data variation in temperature at 10 m depth layer was small in each cruise in our study; the coefficient of variation was 0.02-0.05 (Table 1).…”

“…Water in Hiuchi-nada enters the Kurushima strait through the surface layer and moves into the Bisan strait through the bottom layer, which can be considered as a compensatory effect for the intrusion of water from the two straits [8]. There is a clockwise circular residual current in the western part of Hiuchi-nada, whereas a counterclockwise circular residual current occurs in the eastern part of Hiuchi-nada [9].…”

Photosynthetic property and primary production of phytoplankton in sublittoral sand bank area in the Seto Inland Sea, Japan

“…2) due to fast current of water in the region (Guo et al 2004). Data on water temperature and chlorophyll a concentration from Seto Inland Sea Water Quality (2000)(2001)(2002)(2003)(2004)(2005) were also vertically uniform regardless of season or year.…”

Nonlinear effects of particle shape angularity in sheared granular media

“…These shape characteristics strongly affect the rheology and texture of granular materials. This has been recently evidenced by a number of numerical and experimental studies carried out using angular particles [1][2][3][4][5][6][7][8][9][10][11][12] and by a number of investigations that have focused on other important characteristics such as elongation [13][14][15][16][17][18][19][20] or non-convexity [21,22]. The existing research results suggest that the effect of shape parameters is often nonlinear and counterintuitive as in the case of the unmonotonic relation between the elongation of the particles and the packing fraction [13,14,18].…”