| Summary: | 碩士 === 國立交通大學 === 土木工程系 === 89 === Altimeter data from TOPEX/POSEIDON (T/P), ERS-1 and ERS-2 are used to study the Kuroshio Current east of Taiwan and eddies in the Kuroshio Upstream Dynamics EXperiment (KUDEX) area. A geoid model derived altimeter and ship data, and 8 years of 10-day repeat T/P data were used to compute time series of Kuroshio’s volume transport, width, axis velocity and axis location. These Kuroshio time series show semi-annual, annual and inter-annual variations, which are probably caused by eddy disturbance, moonsoonal winds, solar activity and ENSO. The averaged volume transport of the Kuroshio east of Taiwan is 19 Sv and is consistent with the in situ measurement at the WOCE PCM-1 line. East of Taiwan the axis of the Kuroshio varies with seasons, and in general in autumn the axis moves closer to the East China Sea while in summer the axis is away from East China and near the Rykyu Islands. Sea level anomaly (SLA) over KUDEX also has annual and inter-annual variations, and the later is closely linked to ENSO. During an El Niño event, easterly wind weakens, SLA is unusually high and cold eddies almost disappear. Ocean circulations over KUDEX at a 10-day interval are computed and the patterns of circulations are examined with respect to sea surface temperature, wind stress curl and eddy kinetic energy. Cold-cored and warm-cored eddies over KUDEX during 1993-2000 are identified by a combination of human judgment and a least-squares method. The kinematic properties of these eddies are also computed and analyzed in relation to time, location and eddy radius. Due to the well-known ocean physics, a warm-cored or cold-cored eddy created over KUDEX will move westwards to the Asia continent. Detailed traveling paths, moving velocities of two selected eddies are studied to understand the dynamics and the evolution of an eddy over KUDEX and how it interacts with the Kuroshio Current east of Taiwan.
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