All issues
Volume 36 (1980 - 198･･･
- Issue 6 Pages 275-
- Issue 5 Pages 231-
- Issue 4 Pages 177-
- Issue 3 Pages 141-
- Issue 2 Pages 97-
- Issue 1 Pages 1-
Volume 36, Issue 3
Displaying 1-4 of 4 articles from this issue
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Masao FUKASAWA, Yutaka NAGATA1980 Volume 36 Issue 3 Pages 141-150
Published: August 30, 1980
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSBy using data obtained at about 120 XBT stations, cold water regions in the vicinity of the shoal, Kokush3-sone (30°00'N, 128°30'E), which is located in the current zone of the Kuroshio in the East China Sea, were investigated.
The temperature cross-sections obtained were compared with corresponding cross-sectionsobtained from the four former cruises which were already reported. On the present cruise
forced upwelling area was found along the south slope of the shoal, instead of the north slope as was found on the former cruises. The area of the cold water region found along the south slope tends to decrease with decrease in depth, and at depths shallower than 250 m the cold water region extends northward passing the shoal. The area at a depth of 400 m is comparable to that of the shoal itself, and is about 35 km2.
Physical parameters and their scales which seem to be related to the dynamics near the shoal are given in the Appendix.View full abstractDownload PDF (1567K) -
Norihisa IMASATO, Toshiyuki AWAJI, Hideaki KUNISHI1980 Volume 36 Issue 3 Pages 151-162
Published: August 30, 1980
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSIn order to re-evaluate the water volume exchange through Naruto Strait, we have performed a numerical experiment (nonlinear barotropic model including the actual depth. of water and the details of shoreline) where trajectories of a number of labeled particles are calculated during a full cycle of the M2 tidal current. The ratio of water volume exchanged. through Naruto Strait to that through Akashi Strait is found to be twice as large as the previously estimated value. The calculated water exchange rate is 104% for Naruto Strait, 52% for Akashi Strait and 28 % for Kitan Strait. In the case where the tide-induced residual. current is excluded from the calculated velocity field (i.e. considering only the M2 current), the calculated exchange rate maintains the level of 68% for Naruto Strait, 18% for Akashi Strait and 11% for Kitan Strait, respectively. The mechanism of tidal exchange through these three straits is discussed, and it is shown that a suitable exchange rate is obtained by starting the calculation of trajectories of labeled particles at the time of either a maximum ebb- or flood-current.View full abstractDownload PDF (7663K) -
Studies on Storm Surges and TidesMasamori MIYAZAKI1980 Volume 36 Issue 3 Pages 163-166
Published: August 30, 1980
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSStudies on storm surges and tides by the author can be classified into following four categories of works;(1) observational results on storm surges;(2) dynamics of storm surges including their numerical simulations;(3) methods of tidal analysis; and (4) longperiod variations of sea level.
As for the first subject, distributions of tidal deviations were investigated for some representative typhoons. Peak surges exceeding a definite value were also extracted, from tidal records of Kôbe, Ôsaka and other ports. They were used to estimate return periods of storm surges, and to clarify the relations between storm surges and meteorological conditions.
Dynamic studies on storm surges were concentrated especially to those produced by progressive meteorological disturbances. Numerical simulations by the “primitive method” started soon after the damage of Ise Bay Typhoon in 1959. Computations were made also for Ise Bay, Tôkyô Bay, Ôsaka Bay and other basins along the Japanese coast. Numerical simulations were also made for storm surges produced by Hurricane Carla striking the Coast of the Gulf of Mexico in 1961.
Tidal analysis were also made by the author, and they included a new method based on the harmonic analysis of consecutive data for 355 days.
Seasonal and long-term variations of sea level were also studied.View full abstractDownload PDF (812K) -
Microbial Ecology concerning to the Degradation of Nucleic Acid in the Marine EnvironmentMasachika MAEDA1980 Volume 36 Issue 3 Pages 167-176
Published: August 30, 1980
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSThis article summarizes the author's current work on microbial degradation of nucleic acid. The aim of this work is to elucidate parts of the saprogenic process in the marine ecosystem through the study of the behavior of nucleic acid-hydrolyzing bacteria inhabiting seawater and sediments.
Considerably large population of nucleic acid-hydrolyzing bacteria was found to occur in seawater and sediments. The main genera of these microbes are Vibrio spp. in coastal seas, and Pseudomonas spp. in the oceanic waters. As a result of microbial attack, nucleic acid components are released into seawater. The properties of extracellular nuclease produced by a marine Vibrio sp. are well adapted to the seawater environment; consequently this enzyme has high activity and stability in seawater. By determining nuclease activity in seawater and sediments, the intensities of nucleic acid-hydrolysis in situ were evaluated.
Distribution patterns of marine bacteria are also discussed in reference to the occurrence of phytoplankton in seawater.View full abstractDownload PDF (1393K)
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