whlipscomb
commented
6 years ago @billsacks and @gunterl, This is a PR for changes I just made to the basal melting GLP. @gunterl, could you please review the code changes and run a full mismip+ test suite before we merge the request? Thanks!
This PR includes two new options for which_ho_ground_bmlt, which controls the treatment of basal melting near the grounding line. Also, it includes a new option for which_ho_ground, the main GLP option.
For which_ho_ground_bmlt, the three available options (including option 0, which existed before and remains the default) are now: (0) Set bmlt = 0 where floating_mask = 0. (1) In cells with f_ground > 0, let bmlt -> bmlt * (1 - f_ground). (2) In cells with f_ground > 0, set bmlt = 0. Options (1) and (2) require computing f_ground in each grid cell. Previously, f_ground was computed only at vertices.
For which_ho_ground, there is a new option 2, in which the grounded fraction is first computed in the four quadrants of each cell. Then it is summed over vertices to obtain f_ground, and over cells to obtain the new variable f_ground_cell. As compared to which_ho_ground = 1, values of f_ground at vertices are very similar, but values of f_ground_cell can differ substantially.
The new options were tested in suites of MISMIP+ experiments, and results look correct. Answers are BFB except when using the new options (which_ho_ground_bmlt = 1 or 2, and/or which_ho_ground = 2).