Numerical Study of Glacial and Meltwater Global Ocean Thermohaline Conveyor
Fig. Sa, b. Diagrams of convection
a The HM
b The MWE. The heights of the bars are equal to the depth of convection
97
of convection would represent the volume of convectively mixed water. Fig. Sa
indicates the dipole nature of deep ocean ventilation at present. The southern
deep water sources around the Antarctic and particular in the Weddell and Ross
Seas are counterbalanced by the northern NA source only, that is NADW balances AABW to form upper-to-deep ocean forward conveyor and deep-to-abyssal
ocean reversed conveyor. Clearly, the LGM deep water production in the central
NA, and reduced but still running convection in the Nordic Seas, led to somewhat curtailed but still running forward and abyssal reversed conveyors. The
most important feature of the global HM and LGM forward conveyor is the coherent deep flow starting in the Nordic Seas and northern NA and flowing
around the globe in the Antarctic Circumpolar Current with branches penetrating to the Indian and Pacific Oceans. Fig. 5b implies that the deep ocean circulation must have changed radically because at MWE the bipolar convection regime was replaced by a regime with only southern deep ventilation. The whole
northern NA and the Nordic Seas were convection-free at the MWE.
Fig.6 shows the present-day velocity vectors at 150 m (a) and 2500 m (b)
depths. Figs. 7 and 8 depict the same for LGM and MWE, respectively. A comparison of the MWE and HM and LGM deep ocean currents (Figs. 6b, 7b, and 8b)
Fig. Sa, b. Diagrams of convection
a The HM
b The MWE. The heights of the bars are equal to the depth of convection
97
of convection would represent the volume of convectively mixed water. Fig. Sa
indicates the dipole nature of deep ocean ventilation at present. The southern
deep water sources around the Antarctic and particular in the Weddell and Ross
Seas are counterbalanced by the northern NA source only, that is NADW balances AABW to form upper-to-deep ocean forward conveyor and deep-to-abyssal
ocean reversed conveyor. Clearly, the LGM deep water production in the central
NA, and reduced but still running convection in the Nordic Seas, led to somewhat curtailed but still running forward and abyssal reversed conveyors. The
most important feature of the global HM and LGM forward conveyor is the coherent deep flow starting in the Nordic Seas and northern NA and flowing
around the globe in the Antarctic Circumpolar Current with branches penetrating to the Indian and Pacific Oceans. Fig. 5b implies that the deep ocean circulation must have changed radically because at MWE the bipolar convection regime was replaced by a regime with only southern deep ventilation. The whole
northern NA and the Nordic Seas were convection-free at the MWE.
Fig.6 shows the present-day velocity vectors at 150 m (a) and 2500 m (b)
depths. Figs. 7 and 8 depict the same for LGM and MWE, respectively. A comparison of the MWE and HM and LGM deep ocean currents (Figs. 6b, 7b, and 8b)