Flip the order of the vertical levels in the POLCOMS data to match its depth array values (i.e. go from the seabed to the surface instead of the other way around). This changes means the POLCOMS data matches the convention in the FVCOM arrays (where the surface is the first index) and in the POLCOMS depth data. Also change the 1D interpolation to use the pchip interpolation method (shape-preserving piecewise cubic interpolation) instead of linear interpolation. The original change from pchip to linear was because I thought pchip didn't do extrapolation, but since we're scaling the POLCOMS vertical profiles to the FVCOM depths, it doesn't matter. Finally, some miscellaneous changes (moving the creation of the open boundary nodes array to outside the loops and tidying up some of the whitespace/figures code