Earthdata Forum

Hello,

I am trying to understand how the CHLFAIL and CHLWARN flags are raised, when looking at MODIS L2 chlorophyll data.
I have been searching, but could not find a physical definition of those flags, such as which criteria and/or thresholds are applied.
The only thing I found in one Forum Post was the chl range from 0.01 to 100 for CHLWARN. Is this still valid?
What about CHLFAIL?

Thank you in advance for you help,
Carole

Carole,

CHLWARN is set when the retrieved chl value is outside the range of 0.0-100 mg/m3.
The CHLFAIL flag is set when the algorithm fails.   For the empirical algorithms, there are very few conditions that will cause this to happen - in fact only when the input Rrs values are invalid.

Sean

Thanks Sean for the explanations :-)
Carole