Physical oceanography of Rangaunu Harbour,Northland, New Zealand

Current meter, current drogue, salinity, temperature, and tidal elevation observations from Rangaunu Harbour are presented. The flow is dominated by the tides, the ebb tide in general being stronger than the flood. The time of high tide is increasingly delayed with distance from the open ocean. High tide at the head of the harbour lags about an hour behind that at the mouth. The phase of the flow relative to that of the elevation is less than that for a frictionless system. This difference from a quarter of a tidal period results from tidal energy dissipation and probably varies through the spring‐neap tidal cycle. The outer harbour has essentially coastal water which is exchanged each tide. Residence time of the inner harbour waters and the inner harbour shallows (where evaporation is sufficient to raise the salinity) is several days.     

Short-wave radiolocation in oceanography

This paper reports on the application of coastal radar systems operating in the short-wave frequency band (wavelengths from 10 to 100 m), designed to determine the parameters of wind fields over the sea surface, as well as those of waves and currents. The regularities of radar signal generation by the sea surface and the propagation of short-frequency radiowaves are discussed. The possibility of employing radars in oceanography (including CODAR systems), using ionospheric and ground beams, is considered.Translated by Vladimir A. Puchkin.     

Pseudo-nitzschia blooms and physical oceanography off Washington State,USA

Blooms of harmful algal species occur along the Washington coast, usually as a fraction of the total phytoplankton population. Although more than 20 potentially harmful species have been identified along that coast, the most deleterious effects on public health and the economy are from Pseudo-nirzschia spp. and Alexandrium carenella. During three surveys conducted in early summer 1996, 1997 and 1998, high concentrations of Pseudo-nirzschill spp. (values of up to 10⁶ cells·? ^?1, but generally <10⁵ cells·? ^?1) were present. P. pungens was dominant in 1996, whereas P. pseudodelicatissima was most abundant in 1997 and 1998. A. carenella was rare and in low concentrations (usually <10⁴ cells·? ^?1). Patterns of phytoplankton distributions during each survey appear to be closely related to upwelling and downwelling conditions prior to the survey.