Meridional /sup 14/C and /sup 39/Ar section in northeast Atlantic deep water
/sup 14/C, /sup 39/Ar, and complementary hydrographic and nutrient data are presented for deep water below 2500 m depth, from stations along a meridional section (8/sup 0/S to 45/sup 0/N) through the Romanche Trench and along the deep northest Atlantic basins (F/S Meteor, cruise 56, leg 5). The large-scale /sup 14/C distribution along the section is resolved at the /sup 14/C data precision of +- 2%. Bottom water ..delta../sup 14/C decreases by 6% from the equator to 45/sup 0/N, and farther up there is a weak ..delta../sup 14/C minimum (-123%) over much of the section. The /sup 14/C data are interpreted as giving a turnover time of about 30 years for the waters below the depth of the /sup 14/C minimum (approx.4250 m). It is found that water of 1.50 +- 0.05/sup 0/C potential temperature enters the East Atlantic from the west through the Romanche Trench (sill depth about 4000 m), and a preliminary value for the inflow rate of 3.6 x 10/sup 6/ m/sup 3//s is deduced. This rate greatly exceeds estimated deep inflow rates through the Vem fracture zone or across the northern boundary of the East Atlantic. /sup 39/Ar data that cover an entire deep-ocean circulation system are presented for the first time. The observed /sup 14/C and /sup 39/Ar distributions are mutually consistent. Transit times from the source regions to the equator for water from northern and southern deepwater sources are estimated to be about 170 and 105 years, respectively, and the /sup 39/Ar concentration of young Antarctic Bottom Water is deduced as 60 +- 7% modern. The /sup 39/Ar-/sup 14/C correlation in the ocean appears to be affected by mixing of waters of different age and by more efficient raising of /sup 39/Ar in the deepwater formation processes.
- Research Organization:
- Intitut fuer Umweltphysik, Universitaet Heidelberg, Federal Republic of Germany
- OSTI ID:
- 5360100
- Journal Information:
- J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 90:C10; ISSN JGREA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Renewal rates of east Atlantic deep water estimated by inversion of /sup 14/C data
/sup 14/C distribution in the Atlantic Ocean
Related Subjects
Aquatic-- Radioactive Materials Monitoring & Transport-- Water-- (1987)
54 ENVIRONMENTAL SCIENCES
ARGON 39
ARGON ISOTOPES
ATLANTIC OCEAN
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON 14
CARBON ISOTOPES
ENVIRONMENTAL TRANSPORT
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FLOW RATE
GEOGRAPHICAL VARIATIONS
ISOTOPES
LATITUDE EFFECT
LIGHT NUCLEI
MASS TRANSFER
MIXING
NUCLEI
NUTRIENTS
RADIOISOTOPES
RADIONUCLIDE MIGRATION
SEAS
SURFACE WATERS
VARIATIONS
YEARS LIVING RADIOISOTOPES