The Mass of the Oceans is about 1.4x10^21 kilograms. Since there are 1000 grams per kilogram, that would be about 1.4X10^24 grams of salt water. The energy stored in a gram of salt water (~35g/kg) at 4 C degree is about 16 Joules. That would make the approximate total energy contained in the world's oceans about 2.2X10^25 Joules if the true average temperature of the oceans is ~4 C and the average salinity ~35g/kg.
The approximate total area of the World's oceans is 361 X 10^6 km Squared with an average depth of about 3794 meters. Since there are 1000 meters per kilometer and 10^6 meters squared per kilometer squared, the approximate area of the World's oceans is 361X10^12 m^2. A layer of the ocean one meter deep and covering the entire World oceans would contain 361X10^12 meters cubed. Since there are 1000 kilograms per cubic meter and 1000 grams per kilogram, a one meter deep surface layer of the
World oceans would contain 361x10^18 grams. With the average temperature of that one meter deep surface layer of the World's oceans between 17 and 21 degrees C, and there being ~4 Joules per gram per degree C, the average energy contained in the one meter surface layer of the World's oceans would be between 2.4X10^22 Joules to 3.0X10^22 Joules.
If we consider the top 100 meters of the World's oceans to be the "mixing" layer, then the average energy contained in the 100m deep mixing layer of the World's oceans would be 2.4 to 3.0 X10^24 Joules if the average temperature of that 100 meter deep mixing layer is between 17 and 21 C degrees.
Since 1955, it is estimated that the total heat content of the World's oceans have increased by approximately 14X10^22 to 25x10^22 Joules. If all of that energy increase was limited to just the 100 meter "mixing" layer, that layer's heat content would increase from approximately 2.414 to 3.25 X10^24 Joules.
The 25X10^22 Joule increase in the heat content of the 0 to 2000 meter depth of the World's oceans, a little more than half of the total depth of the World's oceans, is two orders of magnitude lower (1/100th) than the total heat capacity of the World's oceans, if the average temperature is 4 C and the average salinity is 35g/kg.
Since the "pause that refocuses" in surface temperature, that huge 14X10^22 to 25X10^22 Joules or global ocean heat uptake since 1955 is the refocus of many in the climate debate.
Now if the average Surface temperature of the World's oceans is 17 C degrees, which would be 290 K degrees which has a Stefan-Boltzman equivalent energy of 400Wm-2 which is equal 400 Joules per second.
The Berkeley Earth Surface Temperature project estimates the 1951 to 1980 absolute land surface temperature to be 8.93 C or 282 K degrees with an S-B equivalent of 288Wm-2. Since the total area of land surface is 146X10^12 m^2 of the 510X10^12 m^2 of the World's surface, if the Best average is correct for land and the 17C is correct for the oceans, the average surface temperature of the World would be ~287.6K degrees. If the 21C degrees is correct for the average temperature of the World's oceans is correct, the average surface temperature of the World would be ~290.5 K degrees.
With the approximate average surface temperature of the World between 287.6 and 290.5 K degrees, the approximate average surface energy flux would be between 388 and 404 Wm-2 or an average of 396 Wm-2.
Just trying to organize some thoughts.