Using S2 MCI Processor!

Dear Marco Peters:
I want to process Sentinel-2 A MSI data with "Optical/Thematic Water Processing/S2 MCI Processor’ menu, to retrieve chlorophyll information in a eutrophic lake in my province. But I don’t know how to
select the processing parameters. More specifically,the ‘Preset’ dropdown listbox only shows S2MSI l1b MCI,S2MSI l2 MCI.,does it mean I should use l1b or l2 S2 data products? But the data I downloaded from Sentinel Data Hub are
only l1c products. Should I first perform a sen2cor atmospheric correction and get the bottom of atmosphere reflectance (BOA) data product, and then set as the l2 S2 data input in S2 MCI processor?
Another puzzling question: the literature of J. F. R. GOWER 'Interpretation of the 685 nm peak in water-leaving radiance spectra in terms of fluorescence, absorption and scattering, and its observation by MERIS ’ (int. j. remote sensing, 1999, vol. 20, no. 9, 1771~ 1786) indicated the baseline calculator is based on water-leaving radiance, but the TOA or BOA S2 data products are reflectance., shall I convert the reflectance (either TOA or BOA) to radiance with ‘Optical/Thematic land processing/reflectance to radiance’ menu?
The Help of SNAP is not concurrent and up-to-date with the dialog of S2 MCI processor, your guidance is greatly appreciated.

It seems that you are still using an old version. There was an issue with the preset name. You should install the latest major version and then check for module updates too.

The help is not yet updated. This will come with the next update.

The MCI algorithm is applicable on the reflectance values too.
Doing the atmospheric correction before the MCI might improve the results a bit.
You can give it a try and compare the results with some in-situ measurements.

Hello Mr.
If We want to estimate the amount of chlorophyll a in MATLAB software by using data Sentinel-2 Level1C, do we would need to correct the atmospheric correction data or do not need an atmospheric correction?

If you are using MCI processor is not necessary to fully correct the L1C.

Hello mrs.
I dont want to use the snap processors.
I would like to estimate chlorophyll-A in MATLAB software.
Does for input the Sentinel-2 L1C (TOA) data in MATLAB software require the atmospheric correction of Sentinel-2 L1C (TOA)?:thinking:
Thank you mrs.

If you are going to calibrate your algorithm with chl-a in situ data, you will need atmospherically corrected data, yes. If not, it depends on the basis of your algo.