No abstract

Hydrological observations made in January 1984 in the region near Cape Farewell, New Zealand, are described and previously published observations reviewed. It is shown that upwelling depends on the existence of the intermittent Westland Current, and is intensified by an onshore wind. Such a wind induces a fall in sea level near Cape Farewell, and the resulting favourable sea surface slope accelerates deep water over the bathymetric rise inshore of Kahurangi Shoals. The hydraulic response of the thermocline, coupled with a coastal convergence of the bottom Ekman flow, produce a strong upwelling source near Kahurangi Point. M90020

Hydrographic data from the region of the Subtropical Convergence east of New Zealand between 177°E and 179°E show that in spring the convergence occurs near the Chatham Rise. North of the Chatham Rise the structure is fairly regular with isolines of temperature and salinity sloping upwards towards the south. To the south of the Chatham Rise the structure is more complex with an apparent intrusion of Subtropical Water into the Subantarctic Water below depths of about 150 m.