2 Physical Oceanography Department,Woods Hole

The abyssal ocean is filled with cold, dense water that obtains it characteristics on the Antarctic continen-tal shelf and by mixing while sinking along the slope. Recent estimates of water mass formation rates using CFC inventories suggest that a total of 8 Sv of Antarctic Bottom Water (AABW) are formed (Orsi et al., 1999). The Weddell Sea Gyre transports about 5 Sv of Deep and Bottom water and thus contributes as much as 50 % to the formation of AABW (e.g. Gordon et al., 2001, Fahrbach et al., 1994; 1995; Meredith et al., 2001). Global steady state tracer budgets have yielded much larger southern hemispheric abyssal ventilation rates for wa-ters below 1500m (Broecker et al., 1998; Peacock et al., 1999). However, Orsi et al. (2001) point out that part of the controversy can be explained by separately consid