RPM2

Ripple Predictor Mark 2

Time-dependent ripple geometry is implemented in subroutine RPM2 using the approach described in Soulsby and Whitehouse (2005). <wikitex> Ripple geometry is described by ripple height $\eta$ (m), wavelength $\lambda$ (m), and orientation $\theta$ (positive clockwise from the $y$-axis). The orientation is defined by the direction of horizontal momentum flux in the bottom boundary layer. In other words, under unidirectional flow (no waves), ripple orientation is the current direction, and under pure waves, ripple orientation is in the direction of wave propagation. In general, ripple orientation is perpendicular to the ripple crest. The ripple orientation is actually stored as $u$- and $v$- components.

</wikitex>