add 2-D "interior" mask (Center, Western & Southern) (i.e., zero beyond OB)  (for now, keep "maskH" during the transition, but will be remove later)
add 2-D "interior" mask (Center, Western & Southern) (i.e., zero beyond OB)
 (for now, keep "maskH" during the transition, but will be remove later)

altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h