I need some help here. In particular, I’m looking for people who have at least an undergraduate level of training in thermodynamics generally and energy flow specifically, or self taught equivalent. (I have studied energy transfer in a number of university courses, but that was many years ago now. I’m pretty confident in my ability to perform an energy balance, but I’m stumped by this one).
Here, in a nutshell, is my conundrum:
Why is the ocean so cold?
Our friends at BEST, CRU, GISS, etc. going all the way back to Fourier, all agree that the “surface temperature” of the earth is more than 10 celcius or 283 kelvin. Further, it is hypothesized that the “surface temperature” of the earth has always been at least 10 celcius and often more.
So how is it that the temperature of the ocean, which is in direct contact with this “surface” is at least 6 degrees colder than the “surface temperature”? Not only is the ocean in direct contact with this “surface”, but the earth itself is constantly shedding thermal energy into the ocean from the crust.
If someone can show me a complete energy balance that allows the ocean to be at a steady state temperature that is lower than the “surface temperature”, I would be grateful. If there isn’t such a balance, one of two things must be true. The “surface temperature” is colder than estimated or the laws of thermodynamics don’t apply to the oceans.
Just to be clear, it is an absolute certainty that the laws of thermodynamics
apply to the oceans.
No hand waving allowed. I’ve seen a number of debating point style arguments. I would like to see some math on this. I’m working on my math on this. My first run approximation has the oceans boiling away a few billion years ago, so something is not right. If you are not sure how the oceans should have boiled away billions of years ago, add 0.1 W/m² of energy to a 4 km column of water for 1 billion years and determine what the temperature that of the water should be. That is lower than the approximation of the rate of energy transfer from the crust to the bottom of the ocean.
I’ve had two exchanges with Dr. Gavin Schmidt at RealClimate. Thanks Dr. Schmidt. His short answer is there is no short answer. In order to understand the mechanisms for the heat transfer that occurs, I must first learn a GCM. This answer is exactly correct and exactly useless. So it seems the answer is: The ocean is so cold because of reasons that are too complicated to explain.
I am going back to my little explanation of the greenhouse effect using engineering methods for now. When that is done I’ll look at the ocean again.