Chlorophyll <i>a</i>algorithms for oligotrophic oceans: A novel approach based on three‐band reflectance difference

A new empirical algorithm is proposed to estimate surface chlorophyll a (Chl) concentrations in the global ocean for Chl ≤ 0.25 mg m −3 (∼78% of the global ocean area). The algorithm is based on a color index (CI), defined as the difference between remote‐sensing reflectance ( R rs , sr −1 ) in the ... View More