|(a)Oceanographic Conditions near the Spawning Ground of Southern Bluefin Tuna; Northeastern Indian OceaniJournal of Oceanography, 1997j
(b)One analytical solution of a diffusion equation when diffusivity is a function of time and spaceiJamstec report, 1997j
Hydrographic surveys and surface current observations using satellite tracked buoys were conducted from December 1992 to February 1993 near the spawning ground of Southern bluefin tuna to study the oceanographic conditions. Surface of the Timor sea during this period was covered by warm tropical water. Warm water was also observed along the west coast of Australia extending from the North West Cape. Below the surface, there appears that tropical east Indian Ocean water was spreading in the northern part of observation area(north of 19 degree S) while subtropical east Indian ocean water was spreading in the southern part of observation area. The thickness of the surface mixed layer was about 20 to 50m and chlorophyll was very low. Chlorophyll started increasing rapidly from slightly below the bottom of the surface mixed layer and reached maximum at about 75m. Below this depth, it decreased rapidly. Surface geoptential anomalies along the observation line west of Australia showed eastward geostrophic flow. In general, these results qualitatively agree with past research in the region.