“…Deep waters of North Atlantic (NADW), North Pacific (NPDW), and Indian Ocean (Indian Ocean Deep Water (IDW)) origin enter the Southern Ocean and mix to form the main body of the CDW (Talley et al, 2011). It can be subdivided into the oxygen-depleted and nutrient-rich Upper CDW (UCDW) and the more saline Lower CDW (LCDW) (Reid and Lynn, 1971;Orsi et al, 1995;Talley et al, 2011). The UCDW, which acquires its oxygen minimum from IDW and NPDW, is defined by a density range of 27.55 kg/m 3 < γ n < 28 kg/m 3 .…”