Compare the mask file format for different model configurations

[surbhigoel77]

OM4: is a global configuration of MOM6 and the data from OM6 is used by Samudra, grid is tripolar

DINO: is a regional configuration of NEMO and present eval code is built around DINO data, grid is curvilinear

ORCA2: is a global configuration of NEMO, grid is tripolar

From what it looks at first, Samudra mask file has just one masking variable (wetmask - 0:Land, 1:Ocean), whereas DINO mask has different masking variables for different ocean variables (t,u,v etc). So, in that case, even if we want to run DINO data on we need to
most of the existing metrics we have right now will not work on Samudra data, and would require some changes

Samudra masking variables:

• wetmask : binary flag for Ocean/not-ocean points
• areacello : area of the cell

DINO masking variables:

• tmask : land–sea mask at T-points on grid, masks out land cells
• e1t : grid spacing/distance between two adjacent T-points along longitude
• e2t : grid spacing/distance between two adjacent T-points along latitude