To help with smoothing boundaries that go from coarse parent to fine child there needs to be more smoothing and taking into account a larger number of parent grid points. In the extreme case taking the 9 points around can mean a staircase effect as the bdy point crosses from one src point to another. This can lead to unrealistic density gradients and currents on the boundary.
- Increase points taken to 16 or 25 instead of 9 in extract.
- get_ind() probably need take an extra point around too.
To help with smoothing boundaries that go from coarse parent to fine child there needs to be more smoothing and taking into account a larger number of parent grid points. In the extreme case taking the 9 points around can mean a staircase effect as the bdy point crosses from one src point to another. This can lead to unrealistic density gradients and currents on the boundary.