“…Except for the two terms u'du,/ax = -yu' and u'dv,/dy = yu' in (15), the equations for ( u ' , 0 ' ) in the R system are formally identical to the equations for (u, u ) in the regular system. This makes it easy to adapt existing model code (Bleck and Boudra 1981) to the present task. Note that spatial derivatives in (15), (16) and (17) are evaluated in x, rather than R, coordinates.…”