Earthdata Forum

Dear all,
I am working with MODIS Aqua SST data and detected some strange values in a particualr file (A2002192). The AOI comprises tropical waters in the Western Indian Ocean but the file shows temperatures below 0°C. Please have a look at the attached screenshot of the statistics. In order to check on this, I plotted the file in R. These results are also attached and show even lower temperature values.
What could be the reason for these low temperatures displayed in an image of tropical waters?
Thanks for your help!

attachment 2

Most likely clouds.  In order to properly interpret the SST product, you must use the SST quality flags.   The quality flags are in inverse order, with quality zero being the best.  You definitely should exclude anywith a quality of 3 or higher, and may want to exclude quality 2 depending upon your needs. 

Sean