Black Sea, DIVAnd 4D 6-year seasonal analysis of Water body dissolved inorganic nitrogen 1990/2023 v2025 [time][depth][lat][lon], 0.05deg, 1992-2020

The horizontal resolution of the produced DIVAnd maps grids is 0.05 degrees. The vertical resolution is 12 depth levels: 0, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100m. The horizontal correlation length: 80km.

The vertical correlation length (in meters): twice the vertical resolution (10, 10, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20). The error variance (epsilon2): 1 An anamorphosis transformation was applied to the data: threshold value=200. Background field: not used.

Quality control of the observations was applied using the interpolated field: QCMETHOD=3 and visual inspection (Observations with residuals outside the minimum and maximum values of the 99% quantile were discarded from the analysis after thoroughly visual inspection).