It is a 2d array which will serve to mask the field we will trace after with CONTOUR,
...TRIANGULATION=triangule(mask)
If this argument is not specified, the function use tmask
Keywords
BASIC
Specify that the mask is on a basic grid (use the triangulation for vertical cuts and hovmoellers)
COINMONTE
type:array
To obtain the array of "ascending land corner" to be treated with
completecointerre.pro in the variable array instead of make it pass by the global
variable twin_corners_up.