MASS, HEAT, SALT, AND OXYGEN BUDGETS IN THE TASMAN-SEA, MAY JUNE 1993

In May and June 1993, as part of New Zealand's contribution to the Wor ld Ocean Circulation Experiment (WOCE), three hydrographic sections we re made to enclose the Tasman Sea. Two of these sections followed WOCE repeat hydrography lines: PR13N, between New Zealand and Tasmania alo ng 43 degrees 15'S, and PR11 from north of New Zealand to Australia al ong 30 degrees 05'S. The third section was made along 173 degrees E fr om north of New Zealand to close the box, thus enabling mass, heat, sa lt and oxygen balances for the Tasman Sea to be estimated. The geostro phic transport along 30 degrees 05'S was 11.9 Sv into the Tasman Sea, the transports out through 43 degrees 15'S and 173 degrees W were 6.6 and 6.7 Sv, respectively, leading to a net outflow of approximately 1. 4 Sv. To some extent this is balanced by a total Ekman transport into the Tasman Sea of 0.6 Sv, leaving a total volume deficit of 0.8 Sv. In tegrating the heat fluxes into the Tasman Sea indicates a net heat inf low of 1.2 x 10(14) W into the sea during the cruise. Balancing this b y heat flow into the atmosphere, would require an average heat flux of about 48 W m(-2). The salt budget is approximately balanced with 4.3 x 10(8) kg s(-1) entering through the northern section, which is appro ximately evenly split through the southern and eastern boundaries. A n et oxygen outflow of 500 mol s(-1) from the Tasman Sea indicates eithe r a net inflow through the surface, or a net increase through biologic al production.