What causes long-term temporal changes in the South Atlantic?
Holfort,J., M.Vanicek and G. Siedler, 2000:
Geophys. Res. Lett. 27, No.8., 1187-1190
Two zonal sections at 11°S in the South Atlantic, separated in time
by 11 years, provide temperature differences in the deep ocean. The aim of
this case study is to check
whether intrinsic temperature changes are sufficiently large to identify long-term water
mass property variations which could be related to climate change. Potential temperature
differences on isobaric surfaces in the deep ocean here reach several tenths of °C.
They can be caused by vertical (cross-isopycnal) or horizontal (isopycnal) advection and
mixing, or by intrinsic water mass changes. The effect of vertical transport is removed
by using neutral (density) surfaces. The effect of horizontal transport is determined
by using a mixing parameterization for temperature and silica on neutral surfaces. The
residual intrinsic temperature changes are, with a few local exceptions, within the
range of the ±0.05°C uncertainty, and the temperature changes can thus be
explained by advection and mixing alone.