interpolate woa13 no3 field onto NAA grid using SOSIE

I had little trouble interpolating the woa13 no3 data onto NAA grid. SOSIE was creating high values (first figure; set to the prescribed vmax of 100. in this plot) along the coast lines. I was not sure why, but what solved this issue was to change ldrown from F to T:

cf_lsm_in = 'missing_value' ! we use 'missing_value' of input field to determine

cv_lsm_in = ''                ! the land-sea-mask

ldrown    = F            ! we want to propagate sea values onto the land-sea mask

Here, the last line is modified as follows:

ldrown    = T 

Then the interpolation improved (second figure).

Furthermore, the interpolation is not too bad compared to the original file (third figure), although it may underestimate no3 in the beaufort region.

interpolated field with ldrown = F

interpolated field with ldrown = T

comparison between the original 1x1 degree data (left) and the interpolated data (right)