Abstract:

The Antarctic circumpolar wave (ACW) has become a focus of the air-sea coupled Southern Ocean study since 1996, when it was discovered as an air-sea coupled interannual signal propagating eastward in the region of the Antarctic Circumpolar Current (ACC). In order to analyze the mechanism of discontinuity alon g the latitudinal propagation, a new idea that ACW is a system with a traveling wave in the Southern Pacific and Atlantic Ocean and with a concurrent standing wave in the southern Indian Ocean is proposed in this paper. Based on the ideal w ave principle, the average wave parameters of ACW is achieved using a non-linea rapproximation method, by which we find that the standing part and the traveling part possess similar radius frequency, proving their belonging to an integral system. We also give the latitudinal distribution of wave speed with which we could tell the reason for steady propagation during the same period. The spatial di stribution of the propagation reveals complex process with variant spatial and temporal scales—The ENSO scale oscillation greatly impacts on the traveling process, while the result at the south of Australia indicates little connection betw een the Indian Ocean and the Pacific, which may be blocked by the vibration at t he west of the Pacific. The advective effect of ACC on the propagation process s hould be examined clearly through dynamical method.

Key words: The Antarctic circumpolarwave, Sea level pressure, Wave propagation system, Travelling wave, Standing wave, Oscillation