Update Frequency - We update the LEO Composite SST charts daily. NOAA compiles and processes the data each day for the previous day, so the charts will always be one day behind. Generally the update is early in the AM, although times can vary depending on when the data is available.
Understanding the data - LEO stands for Low Earth Orbit. The LEO satellites are essentially the same ones that we get our individual SST and Chlorophyll data from. This includes VIIRS data from NPP, N20, and N21, AVHRR data from Metop-B and Metop-C, and MODIS data from Aqua. Each day NOAA Coastwatch compiles all the data (both AM and PM shots) for that day into a single composite dataset. Unlike the Cloudfree SST product, this is all high resolution 1km data.
Realize the Limitations - First, this is NOT Cloudfree data. On days where clouds obscure a region all day, or week, then no amount of compositing will make much difference. But when we have some clearing in an area in the morning, and clearing in another area later is the day or night, combining it all into a single image can create a very useful view. In addition, having a single daily image (instead of 6-8 individual shots) can make it much easier to follow the movement of the water. Try the loop tool with this data, see how you like it.
We're still in the development stage with this data. NOAA too is still working on more reliable delivery of the data, so there may be times when we just don't have it available. But for now, we feel like this data can be really helpful, so we're making it available now. As always, we welcome your feedback and suggestions.
