Sea surface temperature (SST) observations from 16 coastal sites around New Zealand are analysed along with some corresponding air temperatures. Day-to-day variations in SST show weak periodicity over an 8-16 day range. Air temperatures are generally cooler and short-term fluctuations have 3-4 times the standard deviation of the SSTs. Seasonal SST variations are described and coastal SSTs are compared with offshore SST data. At Farewell Spit the coastal SSTs were always cooler than offshore SSTs which supports the view that upwelling is persistent in the Cape Farewell region. Inter-annual variations in SST are found to be correlated with Southern Oscillation atmospheric pressure anomalies. In particular we find that the El Nino phenomenon which is accompanied by warm SSTs in the central and eastern tropical Pacific is also accompanied by lowered SSTs throughout New Zealand's coastal waters.

The temperature and salinity of the water at the ocean floor has been estimated by extrapolation of selected serial station data. Plots of extrapolated bottom water temperatures and salinities against bottom depth are presented, together with a chart showing the regional distribution of bottom water temperature. Discussion of the results in terms of water masses is offered.

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A survey of the Subtropical Convergence (STC) in the Tasman Sea during October/November 1977 revealed two frontal zones. The southern front, centred on surface salinity 34.9, was interpreted as the main STC front because all nearsurface water north of this front was of subtropical origin. The front was found near 44° S in the western Tasman Sea but east of 160° E it swung southwards, passing to the south of New Zealand. The shallower northern front was centred on the 35.2 isohaline and exhibited larger meanders. This front was not part of the STC if this is defined as a water mass boundary. It appeared strongest in the mid Tasman Sea and was possibly associated with East Australian Current (EAC) Eddy A, although it had been suggested previously that the position of this front is strongly influenced by the latitudinal position of the atmospheric high-pressure belt. There was no particular enhancement of geostrophic flows in the STC zone. This was because of the counteracting effects of the temperature and salinity changes which lead to relatively small density contrasts across the front. Some observations made in EAC Eddy B showed that the summer capping of this eddy had started at this time.

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