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Tetrafluoromethane in the deep North Pacific Ocean
Author(s) -
Deeds Daniel A.,
Mühle Jens,
Weiss Ray F.
Publication year - 2008
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 - 10.1029/2008gl034355
Subject(s) - atmosphere (unit) , geology , lithosphere , deep ocean water , seawater , oceanography , deep sea , flux (metallurgy) , water mass , climatology , atmospheric sciences , meteorology , paleontology , physics , materials science , metallurgy , tectonics
Dissolved tetrafluoromethane (CF 4 ) has been measured for the first time in the North Pacific Ocean. Surface water collected during calm weather is near equilibrium with the modern atmosphere. Deep water, isolated from atmospheric exchange for centuries, is near equilibrium with the preindustrial atmosphere, after accounting for an expected 5% addition of this low‐solubility gas due to air injection during high‐latitude deep‐water formation. These results strongly suggest that dissolved CF 4 is conservative in seawater and that the oceanic imprint of anthropogenic increases in atmospheric CF 4 can be used as a time‐dependent tracer of ocean ventilation and subsurface circulation processes. Although the continental lithosphere is a source of natural atmospheric CF 4 , we find no evidence of an oceanic lithospheric CF 4 input into deep Pacific waters. The estimated upper limit of a potential oceanic lithospheric CF 4 flux to the global atmosphere is on the order of 4% of that from the continental lithosphere.