TY - JOUR
T1 - Ocean nutrient distribution and oxygenation
T2 - limits on the formation of warm saline bottom water over the past 91 m.y.
AU - Herbert, T. D.
AU - Sarmiento, Jorge Louis
PY - 1991/1/1
Y1 - 1991/1/1
N2 - It has been proposed that deep-water formation in the oceans would be quite different during geologic intervals with reduced equator to pole temperature gradients. Salinity, rather than temperature, differences might drive the deep-ocean circulation. Saline water would tend to form at subtropical latitudes where evaporation exceeds precipitation. We point out a likely consequence of warm saline bottom-water formation on ocean chemistry - the tendency to drive the ocean toward anoxia. This effect is due to the increased efficiency with which plankton will extract nutrients from convecting waters at low latitudes. A simple ocean chemical model makes explicit the tradoffs between mean ocean nutrient content and circulation parameters that will satisfy the geologic observations of an oxygenated ocean since the mid-Cretaceous. Barring decreases of ocean phosphate on the order of 30%-50%, deep-water formation at high latitudes was a major source of ocean ventilation in the warmer past. -from Authors
AB - It has been proposed that deep-water formation in the oceans would be quite different during geologic intervals with reduced equator to pole temperature gradients. Salinity, rather than temperature, differences might drive the deep-ocean circulation. Saline water would tend to form at subtropical latitudes where evaporation exceeds precipitation. We point out a likely consequence of warm saline bottom-water formation on ocean chemistry - the tendency to drive the ocean toward anoxia. This effect is due to the increased efficiency with which plankton will extract nutrients from convecting waters at low latitudes. A simple ocean chemical model makes explicit the tradoffs between mean ocean nutrient content and circulation parameters that will satisfy the geologic observations of an oxygenated ocean since the mid-Cretaceous. Barring decreases of ocean phosphate on the order of 30%-50%, deep-water formation at high latitudes was a major source of ocean ventilation in the warmer past. -from Authors
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U2 - 10.1130/0091-7613(1991)019<0702:ONDAOL>2.3.CO;2
DO - 10.1130/0091-7613(1991)019<0702:ONDAOL>2.3.CO;2
M3 - Article
AN - SCOPUS:84874964036
SN - 0091-7613
VL - 19
SP - 702
EP - 705
JO - Geology
JF - Geology
IS - 7
ER -