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Geothermal heat flux and its influence on the oceanic abyssal circulation and radiocarbon distribution
Author(s) -
Hofmann M.,
Morales Maqueda M. A.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl036078
Subject(s) - abyssal zone , antarctic bottom water , geology , oceanography , geothermal gradient , geothermal heating , deep ocean water , bottom water , north atlantic deep water , thermohaline circulation , shutdown of thermohaline circulation , ocean current , deep sea , water mass , abyssal plain , boundary current , circumpolar deep water , geophysics , geothermal energy , sediment , paleontology
Geothermal heating of abyssal waters is rarely regarded as a significant driver of the large‐scale oceanic circulation. Numerical experiments with the Ocean General Circulation Model POTSMOM‐1.0 suggest, however, that the impact of geothermal heat flux on deep ocean circulation is not negligible. Geothermal heating contributes to an overall warming of bottom waters by about 0.4°C, decreasing the stability of the water column and enhancing the formation rates of North Atlantic Deep Water and Antarctic Bottom Water by 1.5 Sv (10%) and 3 Sv (33%), respectively. Increased influx of Antarctic Bottom Water leads to a radiocarbon enrichment of Pacific Ocean waters, increasing Δ 14 C values in the deep North Pacific from −269‰ when geothermal heating is ignored in the model, to −242‰ when geothermal heating is included. A stronger and deeper Atlantic meridional overturning cell causes warming of the North Atlantic deep western boundary current by up to 1.5°C.