USGS Science⌕ Search

Geology topics

R. Davis

Publications and source records attributed to R. Davis.

2 recordsLinked to original sources

Coastal ocean dynamics

The main objective of the Coastal Ocean Dynamics Experiment (CODE) is to observe and describe the response of continental shelf waters to strong atmospheric forcing in a relatively simple geomorphological setting. In order to achieve this goal, CODE has been designed (1) to define the different space and time scales of the physical parameters important to the shelf flow field and (2) to identify and describe the essential kinematical and dynamical processes governing wind‐driven circulation on the continental shelf. A variety of models exist for the wind‐forced response of continental shelf waters. The salient differences among these models lies in the assumed balances between terms in the governing equations. For example, Gill and Schumann [1974] in a barotropic model assume a geostrophic cross‐shelf momentum balance but include the time‐dependent and surface and bottom stress terms in the along‐shelf momentum balance. Csanady [1978] in his arrested topographic wave model involving bottom friction assumes a quasisteady alongshelf response neglecting advective terms and retaining the geostrophic cross‐shelf balance. Various shelf wave models assume inviscid dynamics and other models assume a simple balance between surface and bottom stress in shallow water. To test the different assumptions behind these models, all terms in the governing equations need to be accurately estimated.

California↗

Distribution of seabirds in the northern Gulf of Mexico in relation to mesoscale features: Initial observations

The presence of seabirds was related to offshore surface eddies and the freshwater plume of the Mississippi River in the northern Gulf of Mexico during autumn, winter, spring, and summer 1992-1993. Skuas (Stercorarius spp.) were the most common bird seen in autumn, whereas skuas and gulls (Larus spp.) were the most common in winter. Few birds were seen in the spring, and terns (Sterna spp.) were the most common birds seen in late summer. During summer, terns were associated with the freshwater plume of the Mississippi River. In the winter, herring (Larus argentatus) and laughing gulls (L. artricilla) were associated with areas with steep thermoclines, while pomarine skuas (Stercorarius pomarinus) were found in areas of low productivity. Herring and laughing gulls in the winter, all birds in the spring, and terns in the summer were more common outside eddies. Only pomarine skuas in the winter were seen more commonly inside warm-core eddies.

Conference Paper↗