OC4331-Mesoscale Oceanography
Final Project Summary

Topic Area

LT Mike Vancas, USNR

The Norwegian Coastal Current interacts in a complex manner with the Atlantic current running along the coast of Norway. The authors studied several mesoscale meanders and eddies produced by the NCC during February 1986.

The primary goal of this study was to create a simple computer model allowing the accurate hind-casting of the eddies found during the study. The model was based on a two layer quasi-geostrophic equation set, which the authors note created some discrepancies in their results. Two sets of computer modelling runs were conducted, the first to validate the model beginning with a flat bottom topography, with a simple baroclinic jet in the upper 25m. The model's complexity was increased bathymetrically with the same baroclinic jet. The model was run several times with first just a baroclinic jet, then a barotropic under current, then with both the upper level jet and the under current. Once the model was validated (producing the same types of features as found in nature at around the same times and locations) the model was initiated with realistic bathymetry and flow. The flow was chosen as a mixture of the upper level jet and lower level flow in order to simulate the conditions found in nature at the beginning of the study period. Then the model was run studying the formation and life- cycle of features produced.

The most important aspects of the NCC model include:

• 2 Layer QG model, a better model would have used primitive equations (computing power limited).
• Mesoscale features are well reproduced, some behavior is incorrect due to model limitations.
• Frictional and viscous forces would provide a more accurate model.