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Smethie
[1994] examined hydrographic F11, F12, and F113 data from the
Labrador Sea collected in 1991. He reconstructed the atmospheric
history of F113 (Figure 2c), to make effective use of the temporal
increase in the F113/F11 ratio for calculating ages. The
``purest'' LSW in the central and northern Labrador Sea was found
to have an age of two to three years, as compared with seven years
in the southern Labrador Sea. The age of the GFZW increases from
at most eight years south of Cape Farewell to eleven years at the
southern Labrador Sea station. The age of DSOW increases from at
most three years at Cape Farewell to six years in the southern
Labrador Sea. The transit time for the GFZW and the DSOW around
the Labrador Sea is about three years, giving a spreading rate of
3-4 cm/s. Smethie [1994] pointed out that the higher tracer
derived spreading rates in the Labrador Sea may reflect less time
spent in recirculation gyres, as compared with water south of the
Grand Banks. Since these waters are closer to the source regions,
it could also reflect less of an effect of mixing on the tracer
derived spreading rates (see discussion below).
U.S. National Report to IUGG, 1991-1994
Rev. Geophys. Vol. 33
Suppl., © 1995 American Geophysical Union