I am comparing two methods for estimating Chl-a using Sentinel-2 data
1- Chlorophyll a concentration (µg/l) using the red edge algorithm by Gons et al.
2- Chlorophyll a using C2CRR method
I am observing that Chl-a concentration output in one area is similar using both methods. However on other area its reverse, where Chl-a is high using Gons et al.(2002) (First image) there chl-a is low using C2CRR (red color shows low values and Blue corresponds to high Chl-a) (second image)
true color image of S2 (after atmospheric correction)
Chl-a (during bloom) in below area is depicted same by both methods.