Water body dissolved inorganic nitrogen (DIN) - - Seasonal Climatology for Danube Delta (NW Black Sea) for the period 1980-2018 on the domain: Lon E28.5-30.5°E, Lat N43.7-45.6°N. (winter: December-February, - spring: March-May, - summer: June-August, - autumn: September-November). Data Sources: observational data from SeaDataNet/EMODNet Chemistry Data Network. Description of DIVA analysis: The computation was done with the DIVAnd (Data-Interpolating Variational Analysis in n dimensions), version 2.7.5, using GEBCO 30sec topography for the spatial connectivity of water masses. Horizontal correlation length of 47.730km and vertical correlation length of 45m were applied. Depth range: 0, 2.0, 4.0, 6.0, 8.0, 10.0, 15.0, 20.0, 25.0, 30.0, 40.0, 50.0. Units: umol/l. The horizontal resolution of the produced DIVAnd maps grids is 0.01 degrees.