Report of the

U.S. GLOBEC Georges Bank

Science Meeting

18 - 20 November 2003, Rhode Island

 


Cover Page

Acknowledgements

Introduction

Narrative

Presentation Abstracts

Poster Presentations

Appendix I: Agenda

Appendix II: List of Participants

Appendix III: List of Planned Publications


Preliminary Results of Model Dye Experiments on Georges Bank

Chen, C.1, R. Houghton2, R. C. Beardsley3, Q. Xu1, and H. Liu1
1School for Marine Science and Technology, University of Massachusetts-Dartmouth, New Bedford, MA 025430
2Lamont Doherty Earth Observatory of Columbia University, Palisades, NY 10964
3Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA 02543.

Process-oriented experiments with the finite-volume coastal ocean model FVCOM were conducted to examine the physical processes controlling water movement on the southern flank of Georges Bank. The experiments were focused on the mid-May/early June 1999 period when fluorescent dye was released and tracked. Preliminary model results show that the model dye movement is closely related to vertical stratification. Once the dye mixes up in the entire water column, it moves like a "Taylor column" that tends to follow the near-surface Lagrangian current. Onset of vertical stratification tends to slow down the upward diffusion of dye and traps the dye in the mixed bottom boundary layer. In this case, the dye movement is controlled mainly by the vertical shear of the Lagrangian current throughout the dye-occupied water column. Horizontal resolution plays an essential role in the spatial distribution and movement of the dye. A 500-m horizontal resolution seems to be the minimum requirement to resolve the spatia l size of the dye. A nudging data-assimilation approach is being used to merge the model-computed temperature and salinity with in-situ measurements made during the dye field experiment. Direct comparison between model-predicted and observed dye distribution and movement is also providing an independent objective validation of FVCOM to study physical processes on Georges Bank.

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