Event Detail

Event Type: 
Applied Mathematics and Computation Seminar
Date/Time: 
Friday, February 22, 2013 - 04:00
Location: 
GLK 104

Speaker Info

Institution: 
CEOAS
Abstract: 

The impact of assimilation of wave-averaged flow velocities on the bathymetric
correction is studied in tests with synthetic (model-generated) data using
tangent-linear and adjoint components of a one-way coupled nearshore wave-circulation
model. The tangent linear model is build using line-by-line differentiation of the
nonlinear code. The adjoint model is also constructed line-by-line as a transpose of
the tangent linear code. Weakly and strongly nonlinear regimes are considered,
featuring energetic unsteady along-beach flows responding to time-independent
wave-averaged forcing due to breaking waves. It is found that assimilation of
time-averaged velocities on a regular grid (mimicking an array of remotely-sensed data)
provides sensible corrections to bathymetry. The adjoint-based representer formalism
allows separating contributions of the circulation and wave adjoint model components to
the bathymetric correction. The array mode analysis reveals that there are very few
modes that can be effectively corrected, given the assumed data error level. Additional
tests show the utility of different observational arrays in providing the bathymetric
correction.