Sea surface temperature (SST)

The temperature of the top skin of the ocean. Satellites measure it across the whole globe, far beyond where ships and buoys can reach.

Why it matters

SST drives weather and hurricanes, signals climate patterns like El Niño, and shapes marine ecosystems — warm water can fuel storms and bleach coral, so tracking it is vital for forecasting and fisheries.

Where you’ll meet it

• MODIS and VIIRS measure SST in the infrared, giving sharp detail under clear skies.
• AMSR2 retrieves SST with passive microwaves, seeing through clouds at coarser resolution.
• MUR SST is a popular blended product that merges many sensors into a gap-free daily map.

In plain terms

It’s like taking the ocean’s temperature with a thermometer the size of a continent — reading the warmth of the water’s surface everywhere at once.