MODIS AQUA SST unit

[shorion]

Hi all,

I have downloaded the monthly SST time series from Aqua. The values are supposed to be unit of degree Celsius but they are way out of normal ranges (+5000).
I assume that i need to scale them to get to real numbers but I cannot find the information.

Anyone that could help.

Many thanks!

Stephanie

[OB.DAACx - SeanBailey]

Did you apply the scaling factor? The SST mapped product is stored as a scaled short integer. To get the correct floating point value, you need to apply the scale_factor and add_offset (although the offset is zero for this product):

short sst(lat, lon) ;
sst:long_name = "Sea Surface Temperature" ;
sst:scale_factor = 0.005f ;
sst:add_offset = 0.f ;
sst:units = "degree_C" ;

Many netCDF readers will automatically apply the scaling, but if your API doesn't you will need to do so after reading in the data:
geophysical_value = scale_factor * scaled_integer + add_offset

Regards,
Sean

[shorion]

Great - makes total sense.

Have a great day :)