Volume and heat transports and material fluxes in the East China Sea during April 1994

A modified inverse method is used to compute the volume transport(VT),the heat transport (HT) and the horizontal material fluxes in the East China Sea with data of CTD,T_CO2,DOC,POC,etc.obtained in April 1994.In April 1994 VT and HTthrough Section PN in the East China Sea are 30.6×10⁶ m³/s and 2.42×10¹⁵ W respectively,and the horizontal fluxes of T_CO2,DOC and POC through Section PN are 65×10⁶,2.2×10⁶ and 0.17×10⁶ mol/s respectively.This means that the percentages of fluxes of T_CO2,DOC and POC in total C flux are about 96.5%,3.3% and 0.2% respectively.VT and HT through Section S₅(near the Tokara Strait) are 26.7×10⁶m³/s and 2.14×10¹⁵W respectively,which are about 87% and 88% of VT and HT through Section PN respectively.The horizontal flux of T_CO2 through Section S₅is 61×10⁶ rnol/s,which is about 93.8% of the flux of T_CO2 through Section PN,i.e.,its percentage is close to that of VT and HT of Sections S5 and PN.The horizontal fluxes of DOC and POC through Section S5 are 2.5×10⁶ and 0.08×10⁶ mol/s respectively.The sum of the horizontal influx and outflux of T_CO2 through the boundaries of Box-2 is about -2×10⁶ mol/s (outflux),which is about 3% of the flux of T_CO2 through Section PN.This value is the same order of magnitude of the vertical flux caused by the downwelling or the upwelling.This means that the horizontal flux of T_CO2 must be considered,when the vertical flux of T_CO2 is computed,and so are the other material vertical fluxes (DOC,etc.).Finally,the vertical velocity component is computed with a diagnostic model.