"Oceans have about 200 times the mass of the atmosphere."Not...

"Oceans have about 200 times the mass of the atmosphere."

Not quite.

From Bob Carter's Climate: the Counter Consensus

The heat capacity of the ocean
The ocean covers more than 70 per cent of the Earth's surface, and
over much of its area it is 3-5 km deep. Comprising water, which is
one thousand times denser than air, the ocean has far more mass
than the atmosphere (1.5 x 1018 tonnes compared to 5 x 1015
tonnes) - notwithstanding that the atmosphere covers the entire
planet and is 50 km high to the top of the stratosphere. The result
of this is that the ocean has a much greater heat capacity than the
atmosphere, specifically 3,300 times more. Put another way, all the
heat energy contained in the atmosphere is matched by the heat
content of only the upper 3.2 metres (m) of the worldwide ocean.