18.4.1 Altering the code

Changes can be made by hard wiring to specific values in the USER INPUT section of module topog. For example

kmt_37,82 = 0 (18.12)

sets all T-cells at location given by indices (i,jrow) = (37,82) from $k=1\;\;to\;\;km$ to land cells. Setting large areas of to land or ocean cells may be handled using routine setkmt as is done when generating the idealized dataset. Note that idealized geometries are readily constructed by blocking out areas of with the aid of subroutine setkmt. Refer to option idealized_kmt in Section 18.2 for usage. The two problems mentioned above are remedied automatically using guidance given in the form of options. Those options are:

• If option fill_isolated_cells is enabled, isolated T-cells are made into land cells. Isolated T-cells are deeper than nearest neighbor T-cells. Think of them as potholes or one cell wide trenches in the topography. They cannot communicate with horizontal neighbors through advection because all surrounding velocities are zero.

  A sub-option of fill_isolated_cells is  fill_isolated_dont_change_landmask which restores any which was set to zero in the process of filling cells. Using this sub-option allows the land/sea areas to be preserved when filling isolated cells.

• Limit the minimum number of vertical levels in the ocean to parameter kmt_min = 2. This parameter may be increased but not decreased. There is some choice for altering to meet this condition. The choice is made by enabling one of the following options:
  •  fill_shallow makes land cells where there are fewer than  kmt_min vertical levels
  •  deepen_shallow sets $kmt_{i,jrow}=kmt\_min$ where there are fewer than  kmt_min vertical levels
  •  round_shallow sets to either 0 or kmt_min depending on which is closest