"It looks like we might be in a situation at the moment where sea temperature is rising but the air temperature doesn't seem to be."

This has been explained many times here on this very forum. See Pacific Ring of Fire activity in the last 20 years or so. Way up.

Volcanic activity on the ocean floor warms the ocean waters, increases water vapor, warms the Antarctic ice (the part that is not above land), changes some ocean current paths, etc.