In the tropics, large warm pools of near-surface water are enclosed by continental land boundaries and constant annual mean temperature surfaces at depth. Water which enters such a volume is of the same temperature as the water which leaves it and hence no net heat can accumulate by mean advection; the ocean surface heat flux into this volume is balanced by turbulent transport out of it....
Niiler, Pearn, and James Stevenson. 1982. "The heat budget of tropical ocean warm-water pools." Journal of Marine Research 40, (S). https://elischolar.library.yale.edu/journal_of_marine_research/1652