Earthdata Forum

Posted: **Thu Dec 09, 2021 12:34 am America/New_York**

Hello,

I want to derive chlorophyll data from L1 data from MODIS AQUA it is possible?
If okay, Kindly suggest procedure.

Thank you

Posted: **Thu Dec 09, 2021 11:04 am America/New_York**

Chlor_a is available in L2 data - https://oceandata.sci.gsfc.nasa.gov. (/directaccess/MODIS-Aqua/L2/)

You can also use SeaDAS to process MODIS AQUA L1A data to L2:
modis_GEO: L1A -> geo https://seadas.gsfc.nasa.gov/help-8.1.0/processors/ProcessModis_GEO.html
ModiS_L1B: L1A + geo - > L1B https://seadas.gsfc.nasa.gov/help-8.1.0/processors/ProcessModis_L1B.html
l2gen: L1B + geo -> L2 https://seadas.gsfc.nasa.gov/help-8.1.0/processors/ProcessL2gen.html

Posted: **Thu Dec 09, 2021 11:25 am America/New_York**

Thanks for your time...and how to do atmosphere corrections in seadas

Posted: **Thu Dec 09, 2021 1:11 pm America/New_York**

In SeaDAS l2gen GUI, click Processing Option tab, you can toggle "atmocor" on -- https://seadas.gsfc.nasa.gov/help-8.1.0/processors/ProcessL2gen.html#PROCESSING_OPTIONS_TAB

Here is more regarding aer_opt: https://oceancolor.gsfc.nasa.gov (/forum/oceancolor/topic_show.pl?tid=7026)

Posted: **Fri Dec 10, 2021 1:59 am America/New_York**

I could not find L1 MODIS AQUA L1 data in EarthData , How to find L1 data ?

Posted: **Fri Dec 10, 2021 8:46 am America/New_York**

You can find MODIS Aqua L1 data on Earthdata Seach by using the search bar and facets on the left side of the screen as seen in the image attached. the URL will be appended with your selections for quick reference as seen above.

: Screen Shot 2021-12-10 at 8.45.30 AM.png (321.5 KiB) Not viewed yet

Posted: **Fri Dec 10, 2021 10:29 am America/New_York**

Here is direct access to MODIS AQUA Data --https://oceandata.sci.gsfc.nasa.gov. (/directaccess/MODIS-Aqua/) or you can use the Level 1& 2 Browser -- https://oceancolor.gsfc.nasa.gov (/cgi/browse.pl?sen=amod)

If you are not familiar with SeaDAS or NASA OB.DACC, here is an intro -- https://seadas.gsfc.nasa.gov/docs/SeaDAS_Intro.pdf. Current SeaDAS version is 8.1.0 and you can download it here -- https://seadas.gsfc.nasa.gov/downloads/

Earthdata Forum

Deriving chlorophyll from MODIS AQUA L1 data is Advisable

Deriving chlorophyll from MODIS AQUA L1 data is Advisable

Re: Deriving chlorophyll from MODIS AQUA L1 data is Advisable

Re: Deriving chlorophyll from MODIS AQUA L1 data is Advisable

Re: Deriving chlorophyll from MODIS AQUA L1 data is Advisable

Re: Deriving chlorophyll from MODIS AQUA L1 data is Advisable

Re: Deriving chlorophyll from MODIS AQUA L1 data is Advisable

Re: Deriving chlorophyll from MODIS AQUA L1 data is Advisable