Earthdata Forum

Hello,

When I calculated chl-gsm from 8-day L3 bin GSM datasets, I notice the maximum value can reach 10e10. I know there is an old post answered by Bryan that chlorohpyll value larger than 100 mg/m^e was rejected when binning. The equation I used is sum / weight which I suppose right to get the mean values.

Any explanations would be helpful.

Thanks in advance,
Haipeng

Haipeng,

That statement by Bryan is true for the standard chlorophyll product (and most of the non-standard band ratio / empirical variants).  However it does not apply to the GSM (or any of the IOP inversion variants) products.

So, yes, it is possible to find exceptionally unreasonable chlorophyll retrievals in the GSM (QAA and GIOP) outputs. 
While it is true that the data are binned excluding the CHLWARN and CHLFAIL flags, these are not set by the GSM code in l2gen.

Hope this helps,
Sean

Thank you!