MODISA Level 3 Mask question

[jessicaborgespost]

Hello, I have been currently downloading MODISA Level 3 SST data for the Pacific region using entire composite missions. However, I noticed that for most islands the entire ___domain has 0 quality flags. Can I just confirm what it means?
Also, most of the islands are not masked in the output data, I would just like to confirm if indeed MODIS was not able to capture the land within its resolution of if there is a mask product I can additionally use?
Thank you.

[OB General Science - guoqingw]

Sorry for the delayed response. There is no flag information on level 3 data. As binned data from level 2, level 3 data only used l2flags for quality control purpose in the binning procedure. Here are some documents that you can refer to about the details:
https://oceancolor.gsfc.nasa.gov/atbd/sst/flag/
https://oceancolor.gsfc.nasa.gov/docs/format/Ocean_Level-3_Binned_Data_Products.pdf
https://oceancolor.gsfc.nasa.gov/docs/format/Ocean_Level-3_SMI_Products.pdf

So, to answer your question, it's better to look at the level 2 data of the region to see whether there is a land mask for the islands. You probably will find the l1/l2 browser a helpful tool: https://oceancolor.gsfc.nasa.gov/cgi/browse.pl?sub=level3&per=CU&day=19507&set=10&ndx=0&mon=19448&sen=amod&rad=0&frc=0&dnm=D@M&prm=SST