Changes in meridional fluxes and water properties in the Southern Hemisphere subtropical oceans between 1992/1995 and 2003/2004

The substantial seasonal or higher-frequency variations are filtered out by comparing the water properties on neutral density surfaces. Along the South Pacific P06 line, Subantarctic Mode Water on γ = 26.8 (the neutral density surface of 1026.8 kg m−3) becomes cooler and fresher by up to 0.2 °C and 0.04 psu (practical salinity unit). The property changes are largest in the Chile Basin and smallest in the Tasman Sea. In the deep Southwest Pacific Basin, a small but statistically significant freshening of 0.002 psu was found in the Circumpolar Deep Water (γ = 28.11). Along the South Atlantic A10 line, Subantarctic Mode Water and Antarctic Intermediate Water were found warmer and saltier to the east of the Mid-Atlantic Ridge (e.g. by 0.2 °C and 0.05 psu on γ = 26.8; 0.1 °C and 0.02 psu on γ = 27.4). North Atlantic Deep Water and Antarctic Bottom Water were found warmer and saltier particularly in the Argentine Basin (e.g. by 0.02 °C and 0.004 psu on γ = 28.0; 0.01 °C and 0.002 psu on γ = 28.2). Along the south Indian I03/I04 lines, Subantarctic Mode Water was found warmer and saltier to the west of 95°E (e.g. by 0.2 °C and 0.05 psu on γ = 26.8) and cooler and fresher to the east (e.g. a difference of −0.2 °C and −0.05 psu on γ = 26.8).