Isopycnal test case with open boundary

[mrayson]

@zyaj is there an example case that uses isopycnal coordinate and has open boundaries? The iwave_** test cases all seem to be for an initial value problem. Cheers

[zyaj]

Hi Matt
Oliver and I are trying to running a test case with periodic BC under iso coordinate. And it seems that there is a bug on period BC when iso coordinate is turned on. Will keep you updated.
Yun