Earthdata Forum

Hi,

I am trying to understand the current visualisation adopted by NASA WorldView in displaying the MODIS Aqua L2 Chlorophyll product available here:

https://worldview.earthdata.nasa.gov/?v=147.46599764250465,-28.249779953513993,167.90539911119384,-18.20370037985832&l=Reference_Labels_15m(hidden),Reference_Features_15m(hidden),Coastlines_15m,MODIS_Aqua_L2_Chlorophyll_A,MODIS_Aqua_CorrectedReflectance_Bands721,VIIRS_NOAA21_CorrectedReflectance_TrueColor(hidden),VIIRS_NOAA20_CorrectedReflectance_TrueColor(hidden),VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor(hidden)&lg=true&t=2023-09-01-T09%3A17%3A12Z

Can someone please help me with the flag structure adopted (basically the settings which cause the no data visualisations) to display this Chlorophyll product?

Thank you
Kesav

Hi Kesav,

For level 2 Chlorophyll products, the flags applied are listed on this webpage: https://oceancolor.gsfc.nasa.gov/resources/atbd/ocl2flags/

Guoqing

Thank you Guoqing.

I was also wondering where I could find the flag information for the VIIRS products (from Suomi NPP, NOAA 20 and NOAA 21) displayed on this webpage:

https://worldview.earthdata.nasa.gov/?v=146.68474689591284,-37.52545630564113,162.5667687540473,-29.793786613719774&l=Reference_Labels_15m(hidden),Reference_Features_15m(hidden),Coastlines_15m,VIIRS_SNPP_L2_Chlorophyll_A,VIIRS_NOAA21_Chlorophyll_a,VIIRS_NOAA20_Chlorophyll_a,MODIS_Aqua_L2_Chlorophyll_A,MODIS_Aqua_CorrectedReflectance_Bands721(hidden),VIIRS_NOAA21_CorrectedReflectance_TrueColor(hidden),VIIRS_NOAA20_CorrectedReflectance_TrueColor(hidden),VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor(hidden)&lg=true&t=2025-01-06-T01%3A41%3A50Z

Thank you
Kesav

Hi Kesav,

You can download the corresponding L2 files from Earthdata search (https://search.earthdata.nasa.gov/search), and view them in SeaDAS (https://seadas.gsfc.nasa.gov). There is a way to look at which flags were applied to which pixels in SeaDAS (https://www.youtube.com/watch?v=wx08vP2JorA&list=PLf60TttfDm31z76SS4l4neSOAbyjzyQhq).

Let us know if this helps.
Guoqing