Observations of Local Seychelles Circulation
Abstract
The physical oceanography of the Seychelles is dominated by two distinctive features: strong shifts in monsoonal forcing that drive significant changes in regional circulation; and its unique geographic location atop the Mascarane Plateau, a broad shallow shelf bordered on all sides by deep ocean. These two components represent significant challenges for predictive modeling at local scales and point towards a number of important physical phenomena that are likely to be important. The islands thus present a valuable venue for development of analytical and numerical modeling capabilities for flow in complex environments. Seasonal changes in boundary conditions at the edges of the Mascarane Plateau suggest an important role for internal waves, with associated mixing and with residual energy radiation towards the center of the plateau. At longer timescales, we can expect that changes in the larger scale mesoscale structure will propagate inwards on the plateau via low-mode waves driving a phase-shifted seasonal relaxation of the low frequency local circulation. At shorter timescales, the shallow depths and complex bathymetry suggest that bottom friction, form drag and flow separation will play important roles in local scale momentum balances. Despite dedicated local efforts to sustainable marine resource use, Seychelles has been lacking in an observation physical oceanography program. Local physical oceanographic data for the Seychelles is scarce and little or no efforts have been undertaken for local modeling. Here we propose to address this data scarcity via an observational campaign focused on local Seychelles circulation, providing input for a separate numerical modeling effort. In addition, we propose a focused outreach effort that aims to develop local observational capabilities that can provide relevant basic data as input to operational modeling at local scales. The work will be closely coordinated with other ONR funded researchers to maximize the value of observations towards modeling efforts. The overarching goal for the proposed work is to develop predictive capabilities for physical oceanography for the Seychelles region in support of locally relevant marine applications while providing context for larger scale NASCar efforts. A key objective for the project is to establish local capacity for ocean observations in the Seychelles region that will lead to sustained longterm data collection efforts. In collaboration with local partners, we aim to further carry out an observational program that will provide a foundational data set for regional and local scale modeling efforts. The data set will be critical in identifying primary forcing mechanisms for local oceanography in a complex and relatively undersampled environment.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512303
Entities
People
- Eugene Pawlak
Organizations
- Office of Naval Research
- United States Navy
- University of California, San Diego