Abyssal recipes
Abstract--Vertical distributions in the interior Pacific (excluding tbe top and bottom kilometer) are not inzonsistent with a simple model involving aconstant upward vertical velozity w ~ 1-2 cm clu y-t and eddy diffusivity, ¢ ~ 1.3 cm ~- sec-1. Thus temperature and salinity can be fitted by exponen...
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| Format: | Text |
| Language: | English |
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1966
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.607.7646 http://flux.ocean.washington.edu/WQ2009/munk.abyssal.recipes66.pdf |
| Summary: | Abstract--Vertical distributions in the interior Pacific (excluding tbe top and bottom kilometer) are not inzonsistent with a simple model involving aconstant upward vertical velozity w ~ 1-2 cm clu y-t and eddy diffusivity, ¢ ~ 1.3 cm ~- sec-1. Thus temperature and salinity can be fitted by exponential-like solutions to [,¢- d"-/dz:-- w. d/d:] T, S = 0, with,c/w ~ 1 km the appropriate " ' scale height." For Carbon 14 a decay term must be included, [ ]:~C = ~ 1~C; a fitting of the solution to the ob-served 1~C distribution yields,,/w2 ~ 200 years for the appropriate " ' scale time, " and permits w and, ~ to be separately determined. Using the foregoing values, the upward flux of Radium in deep water is found to be roughly 1.5 x 10-~-~gcm-~-sec-L as compared to 3 x 10-Z~gcm--~sec-I from sedimentary measurements by GOLOaF.RG and KOtDE (1963). Oxygen consumption is computed at 0-004 (ml/I) year-L The vertical distributions of7', S, t4C and O: are consistent with the corresponding south-north gradients in the deep Pacific, provided there is an average northward rift of at least a few millimetres per second. How can one meaningfully interpret the inferred rates of upwelling and diffusion? The annual freezing of 2.1 x 10 to g of Antarctic pack ice is associated with bottom water formation in the ratio 43: 1, yielding an estimated 4 × 10:0 g year-t of Pacific bottom water; the value w = 1"2 cm day-t implies 6 x 10 ~0 g year-L I have attempted, without much success, to interpret x from a variety of viewpoints: from mixing along the ocean boundaries, from thermodynamic and biological processes, and from internal tides. Following the work of Cox and SA,'qr~STROM (1962), it is found that surface tides are scattered by the irregular bottom into internal modes with an associated energy flux of 4 x 10- ~ ergs g- ~ see-: (one sixth the total tidal dissipation). Such internal modes can produce shear instability in the Richardson sense. It is found that internal tides provide a marginal but not impossible me:hanism for turbulent ... |
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