North Atlantic tritium

Ostlund, H.G. and C.G.H. Rooth. 1990. The North Atlantic Tritium and Radiocarbon Transients 1972-1983. Journal of Geophysical Research—Oceans 95 20,147-20,165. 

Figure 5 A North Atlantic tritium meridional section taken in the early 1980s.

Nuclear bomb produced " 002 and (as HTO) have been used to describe and model this rapid thermocline ventilation (Ostlund et ah, 1974 Sarmiento et ah, 1982 Fine et al., 1983). For example, changes in the distributions of tritium (Rooth and Ostlund, 1972) in the western Atlantic between 1972 (GEOSECS) and 1981 (TTO) are shown in Fig. 10-10 (Ostlund and Fine, 1979 Baes and Mulholland, 1985). In the 10 years following the atmospheric bomb tests of the early 1960s, a massive penetration of F1 (tritium) into the thermocline has occurred at all depths. Comparison of the GEOSECS and TTO data, which have a 9 year time difference, clearly shows the rapid ventilation of the North Atlantic and the value of such transient" tracers. A similar transient effect can be seen in the penetrative distribution of manmade chlorofluorocarbons, which have been released over a longer period (40 years) (Gammon et al., 1982). 

Ostlund, H. G., Dorsey, H. G. and Rooth, C. G. (1974). GEOSECS North Atlantic radiocarbon and tritium results. Earth Planet. Sci. Lett. 23,69-86. 

Weiss, W., Roether, W. Dreisigacker, E. (1979) Tritium in the North Atlantic Ocean Inventory input and transfer into deep water. In Behaviour of Tritium in the Environment, pp. 315-35. Vienna IAEA. 

Figure 2 The meridional distribution of tritium in the central North Atlantic in the early 1980s.

Figure 5 The tritium- He relationship for the subtropical North Atlantic in the early 1980s (solid dots). The different colored lines correspond to stream tube simulations with various values of Pcr.

Doney S. C. and Jenkins W. J. (1994) Ventilation of the deep western boundary current and abyssal western North Atlantic estimates from tritium and He distributions. J. Phys. Oceanogr. 24, 638-659. 

Jenkins W. J. and Rhines P. B. (1980) Tritium in the deep North Atlantic Ocean. Nature 286, 877-880. 

Robbins P. E. and Jenkins W. J. (1998) Observations of temporal changes of tritium- He age in the eastern North Atlantic thermocline evidence for changes in ventilation J. Mar. Res. 56, 1125-1161. 

Rooth C. G. and Ostlund H. G. (1972) Penetration of tritium into the North Atlantic thermocline. Deep-Sea Res. 19, 481-492. 

Dohnanyi JS (1976) Sources of interplanetary dust Asteroids. In Interplanetary dust and zodiacal light 48 187-206. H Elsasser, H Fechtig (eds) Springer-Verlag, Berhn Doney SC, Jenkins JW (1994) Ventilation of the deep western boundary current and abyssal western North Atlantic - Estimates from tritium and He-3 distributions. J Phys Oceanogr 24 638-659 Dreisigacker E, Roether W (1978) Tritium and Sr in north Atlantic surface water. Earth Planet Sci Lett 38 301-312... 

Robbins PE, Jenkins WJ (1998) Observations of temporal changes of tritium-He-3 age in the eastern North Atlantic thermocline Evidence for changes in ventilation J Mar Res 56 1125-1161 Robbins PE, Price JF, Owens WB, Jenkins WJ (2000) The importance of lateral diffusion for the ventilation of the lower thermocline in the subtropical North Atlantic. J Phys Oceanogr 30 67-89 Roether W, Fuchs G (1988) Water mass transport and ventilation in the Northeast Atlantic derived from tracer data. Philos Trans R Soc London, Ser. A 325 63-69 Roether W, Kromer B (1978) Field determination of air-sea gas-exchange by continuous measurement of Rn-222. Pure Appl Geophysics 116 476-485... 

Figure 3 The various modes of tritium deposition to the North Atlantic over time. Note that during the peak of bomb-testing, vapor deposition was dominant, but that after the early 1970s, the influx of fresh water from the Arctic plays a prominent role.

Figure 4 North Atlantic surface water tritium concentrations (A) geographical distribution in the early 1980s (B) variation with time in the subtropics.

Figure 8 The distribution of tritium-helium age on a constant density surface (26.4 kg m in the subtropical North Atlantic.

Doney SC, Jenkins WJ, and Ostlund HG (1993) A tritium budget for the North Atlantic. Journal of Geophysical Research 98(C10) 18069-18081. 

Figure 2 Aphotic zone oxygen consumption rates as a function of depfh for fwo locales in fhe subfropical North Atlantic. These consumption rates are based on tritium- He dating and other tracer techniques.

Radiocarbon has been used to study thermocline ventilation using tools ranging from simple 3-box models to full 3D ocean circulation models. Many of the ID and 2D models are based on work by W. Jenkins using tritium in the North Atlantic. In a recent example, R. Sonnerup and co-workers at the University of Washington used chlorofluorocarbon data to calibrate a ID (meridional) along-isopycnal advection-diffusion model in the North Pacific with WOCE data. [4] is the basic equation for the... 

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