Nutrient concentration in the surface ocean using highly-sensitive colorimetry

The nitrate plus nitrite (NOX), ammonium (NH4) and phosphate (SRP) concentrations using the highly sensitive colorimetry in the surface of the Pacific and Indian Oceans. Nutrient data were acquired from the analytical system every 1 min (see Nuts_Highly_sensitive.csv), and the data were averaged into 0.5° × 0.5° grids of latitude and longitude for each year–month period after removing values exceeding 1500 nM (see nuts_data_05deg.csv). Differences in the number of measurements among parameters arose from the exclusion of unreliable data due to non-linear baseline drifts.