Figure 7. Total organic carbon (TOC) as a function of from Survey I and II [Peltzer and Hayward, 1996; Archer et al., in press]. Survey II data (squares) with 22.5 < < 24 is elevated by ~10 umol kg^-1 relative to Survey I (circles). As noted in the lower panels, water of this density was between 60 and 120 m during Survey I, but reached the surface from the equator to 2 N, where it was subducted. It is likely that exposure to the euphotic zone during Survey II results in the elevated TOC levels.The short exposure time of this water to the sea surface (10-20 days: