HR: 0800h
AN: OS41B-0480    [Abstracts]
TI: Coastal-Trapped Waves caused by typhoon along the southeast coast of Japan
AU: * Igeta, Y
EM: od02103a@edu.s.kaiyodai.ac.jp
AF: Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo, 108-8477 Japan
AU: Kitade, Y
AF: Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo, 108-8477 Japan
AU: Matsuyama, M
AF: Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo, 108-8477 Japan
AB: To clarify the vertical structure of a coastal-trapped wave (CTW) in Sagami Bay located at the southeast coast of Japan, where the CTW was frequently observed, mooring observation using ADCP and memorable temperature was performed at shelf edge (water depth of 95m) and shelf slope (water depth of 250m) from July 28 to October 6 in 2003. Two Typhoons had passed nearby Japanese Island during the observation period. One is Typhoon 0310 (T10) passed through the western side of study area and the other is Typhoon 0315 (T15) passed through the eastern side. The CTWs were caused along the southeast coast of Japan by strong wind associated with T10 and T15, hereafter we call CTW10 and CTW15, respectively. The characteristics of the CTWs observed at the eastern coast of Sagami Bay were as follows; (1) Significant temperature rise and strong inflow in the upper layer were found in the case of CTW15, while strong outflow with little temperature variation were found in CTW10; (2) The current direction in the case of CTW15 changed at 100m depth, whereas the outflow associated with CTW10 was almost homogeneous throughout the water column; (3) The current maxima associated with CTW were appeared at 22 hours for theCTW10 and at 18 hours for the CTW15 after the peaks of the wind at Choshi. The first characteristic was explained by the wind direction associated with each Typhoon. However, the reasons for the second and third characteristics were not clear. To clarify these characteristics, we carried out numerical experiment using a three-dimensional level model with realistic bottom topography. The model result well represented the current structure and propagation speed of the observed CTWs. The CTW15 was the down-welling caused by the southward wind and it propagated as the CTW in the strong stratification. On the other hand, the CTW10 was explained to propagate as the CTW in the weak stratification, because the thermocline outcropped in the surface layer by the significant upwelling.
DE: 4528 Fronts and jets
DE: 4544 Internal and inertial waves
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting