Dissolved oxygen profiles made with an in situ polarographic
device reveal structure in the form of inversions and gradient
changes in the 100-600 meter depth zone off Oregon. Inversions
10-70 meters thick are traced over distances of 40 miles in some
cases and are bracketed by a distance of 8 miles in others. The
horizontal extent of these features agrees with observations of
similarly-sized temperature and salinity structure reported by
Stommel and Federov (1967) and by Hamon (1967).
Oxygen maxima are correlated with changes in the vertical
temperature gradient. Corresponding salinity minima are sometimes
found. This relationship between properties is consistent
with the formation of oxygen structure by a horizontal mixing process
off Oregon. The existence of significant horizontal gradients in
properties over distances of tens of miles favors the interleaving
of dissimilar waters along density surfaces. A quantitative example
of the horizontal mixing process yields temperature gradient changes
near oxygen maxima similar to those observed.
The in situ production of oxygen structure by layers of oxygen-consuming
materials is considered unlikely in the size range studied.
A transient state vertical model indicates that the consumption layers
required for this mechanism are more intense than is consistent
with recent biomass measurements.
Diffusion calculations are used to model the decay of oxygen
maxima. Calculated lifetimes range from 2.6 days for features 15
meters thick to 48.1 days for features 60 meters thick. These are
considered estimates of the time scales associated with the stratification
process. / Graduation date: 1973
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28405 |
| Date | 09 August 1972 |
| Creators | Jeter, Hewitt Webb |
| Contributors | Mesecar, Roderick S. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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