##### Volume

- Volume of the atmosphere: not really meaningful.
- Volume of Earth’s oceans: 1.335×10
^{18}m^{3}

##### Mass

- Mass of the atmosphere: 5.15×10
^{18}Kg - Mass of the oceans: ~1.4×10
^{21}Kg- Average salinity: 0.035 Kg salt per Kg water, so 3.5% by mass.

- The oceans are 272x the mass of the atmosphere.

##### Specific Heat

- Specific heat of “air” at 250K is 1005 J/KgK
- Specific heat of ocean water is ~4000 J/KgK

##### Total Heat Capacity

- Total heat capacity of the atmosphere: 5.2×10
^{21}J/K - Total heat capacity of the oceans: 5.6×10
^{24}J/K - The heat capacity of the oceans is ~1,077x the heat capacity of the atmosphere.

I think it’s interesting that the ocean is only 272x the mass of the atmosphere. That is knowable intuitively if you know the approximate pressure deep-sea subs deal with or know that 10m of water is equal to about 1 atmosphere of presure.

Another interesting scale to put in perspective is that the hydrosphere is about 0.023% of Earth’s total mass. So the Earth mass is about the mass of 4,300 oceans.