Local and remote wind forcing of New South Wales inner shelf currents and sea level

Linear multiple regression analysis is used to identify the locally and remotely wind-driven components of the nearshore current and adjusted sea level (ASL) variability at Sydney, New South Wales. The data analyzed comprise a one year time series of current meter records acquired 3 km offshore in 60-80 m of water together with coastal sea level and wind data from one local and 12 remote stations in NSW, Bass Strait and the Great Australian Bight. Approximately 60% to 70% of the "weather band" (40 h to 2 d period) current and ASL variance at Sydney appears to be wind-driven, with the major contributors to the variance being the southern New South Wales and Bass Strait winds, both lagged by intervals corresponding to the propagation speed of the first coastal trapped wave (CTW) mode. The "multipath" nature of wind energy transmission by at least two CTW modes is evident but the energy flux at Sydney of the freely propagating second mode from Bass Strait appears to be only one-fifth to one-third of the flux of the first mode, instead of exceeding it as was the conclusion of the Australian Coastal Experiment.