@article{oai:ir.kagoshima-u.ac.jp:00002295,
 author = {YUWAKI, Yasutaka and HENMI, Tomio},
 journal = {鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University},
 month = {2016-10-27},
 note = {The oceanographical observations and biological researches in the southern region of the
Hawaiian Islands were carried out on board the training ship the Keiten Maru of Kagoshima
University during the summers of the successive three years, 1977-1979. As summarized in
the following, some informations were gained on the oceanic characteristics and on the
distribution of zooplankton from the synthetic discussions on the results obtained throughout the
three years.
1) South of 09°N, the surface temperature in the three years were almost equal, decreasing
gradually towards the north from 09°N. In 1979, a discontinuous distribution of the surface
temperature was supposed to exist near 10°N.
2) The depth of the thermocline, centered at 19°C to 20°C, was in a layer at a depth of about
125 m near 15°N and about 90 m near 08°N, becoming gradually shallower towards the equator
from the north. The thermocline, the center of which was shallowest, was situated near 11°N
in 1977 and near 09°-30'N in 1978 and 1979. The vertical gradient of temperature in the
thermocline was largest at the section where the depth of the thermocline was shallower, its
numerical value being ca. 0.20°C/m.
3) Below the thermocline, the upwelling was suspected to have taken place near 12°N and
13°N.
4) South of 09°N, the surface salinity were almost equal throughout the three years,
decreasing north of 10°N. The variation in the value of maximum and minimum surface
salinity was largest in 1979, its numerical value being ca. 0.40%.
5) A tonguelike protuberance with salinity higher than 35.00% extending from the north
was found in a layer at a depth of about 150 m. The location of the high salinity was variable
due to the shifting over the years.
6) The salinity water lower than 34.50% extending from the north was found near 15°N
in a layer at a depth of about 250 m, the depth of the low salinity water becoming shallower
gradually toward the south. The water with a salinity of 34.70% extending from the south,
was found near 08°N, in a layer at a depth of about 250 m, the location of the water shifting
somewhat southward from year to year.
7) The main axis of the eastward flow was situated 10°-30'N in 1977, near 08°-45'N in 1978,
and 07°-15'N in 1979. The main axis of the westward flow was situated near 09°-30'N, and
11°-45'N in 1977, and near 09°-30'N in 1978 and 1979.
8) The maximum velocities of the eastward flow and of the westward flow were 23 cm/sec
and 33 cm/sec, respectively. It was larger in 1978 than those in 1977 and 1979.
9) It was estimated that the boundary between the North Equatorial Current and the Equatorial Countercurrent was situated south of 07°N in 1977, and near 09°N in 1978 and 1979.
10) The zooplankton-communities were represented by the species of Copepoda, Radiolaria,
Appendicularia, Ceratium and Foraminifera. Copepoda occupies the greater part of the zooplankton. The numerical value of the zooplankton appearance per cubic meter throughout the three
years was 545 individuals as maximum, and 37 individuals as minimum. The average of
the individuals in 1977, 1978 and 1979 were 252, 270 and 229, respectively.},
 pages = {179--192},
 title = {The Oceanographical Research in the Southern Region of the Hawaiian Islands III},
 volume = {29},
 year = {}
}