This study concentrates on analysis of LongEZ aircraft data taken offshore
of the Atlantic Coast of the United States. Due to the land structure of the
region, it was possible to isolate the effect of narrow land on air as it flows
offshore. The narrow land (Outer Banks) separates inland water from the
sea. With greater land fetch, the internal boundary layer (IBL) over land
grows deeper and the eddies presumably grow larger. Larger eddies typically
decay more slowly than smaller eddies, and so the turbulence advected from
land with a larger land fetch should survive longer over the sea and be greater
in magnitude than that with smaller land fetch. The turbulence is studied
using aircraft eddy correlation data as the flow is advected over the water. As
expected, greater and longer-lasting turbulence is present downstream from
greater land widths.
Aircraft data taken over the Gulf Stream (GS) boundary are analyzed to
study the effects of the sea surface temperature (SST) front on downstream
boundary layer structure. Unstable and stable flows are studied in this region.
The stable flow case is found to have an upside-down structure, with
greater turbulence aloft causing stress convergence at the surface, which acts
to accelerate the flow. The local thermally generated pressure gradient is important
in the momentum budget across the GS front in both flow cases. A
synthetic aperture radar (SAR) image is analyzed qualitatively in the region
between the Atlantic Coast and the Gulf Stream front for intercomparison
of data and to examine the influences of varying static stabilities and surface
conditions upon the backscatter shown in satellite images.
The growth rates of the internal boundary layer due to flow over a heterogeneous
surface including flow from land over the water and flow between
cooler water and warmer water are calculated. These results are compared
to similar calculations of growth rates from previous experiments. It is found
that the growth rate of an internal boundary layer is dependent on surface
roughness, despite the inclusion of σ[subscript w] in the normalization of the growth
rate. / Graduation date: 2003
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28736 |
| Date | 25 July 2002 |
| Creators | Moore, Erin M. |
| Contributors | Mahrt, Larry |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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