First I want to point out something in your reply to Piasan
And: "The cloudiest regions are tropics (Indy: this surely seems to contradict what both Pi and Wibble have said). And the temperate midlatitude storm zones; the subtropics and the polar regions have 10-20% less cloud cover....
This is the original quote:
"The cloudiest regions are tropics and the temperate midlatitude storm zones; the subtropics and the polar regions have 10-20% less cloud cover."
Why did you split the sentence to make it look like it was saying that the tropics are cloudier than the temperate mid latitude storm zones ?
W:>>This suggests a positive feedback between surface temperatures and cloud development, the opposite to what you require.>>
I would think that positive feedback might mean MORE clouds. What you and Pi need to show is NEGATIVE feedback. If what is meant by "development" is "how tall they get" I could accept that as being true TODAY. That is, the warmer the ocean, the more tall/developed the clouds will be.
Yes taller clouds not more surface covered. So you accept that as true today, good.
But that is NOT saying what Pi says, (and what you have sometimes seemed to say) that there would be FEWER clouds when/where the ocean is warmer.
I think Piasan has expressed uncertainty, which is the correct thing. Warmer air can hold more moisture and therefore could potentially produce more cloud. On the other hand warmer air is able to hold more moisture without it condensing.
However, if we try to hypothesize about the post-flood time, rather than TODAY, I would go with what Oard said about how the much more uniformly warmer ocean (post-flood) would not allow for tall development of clouds.
The storm clouds produce their own cool, dry air from the top of the system. It's an engine working off the heat of the ocean to produce wind and rain. Doesn't matter how uniformly warm the ocean is.
And even IF you could show that the clouds were almost all of the cumulonimbus (tall, and "more developed") type, I believe you would agree with me that this would dramatically increase albedo...so all we have left to do is to discuss if the GE would be able to offset all the added albedo.
You’ve learnt since the early stages of this thread that tall clouds (like cumulonimbus) have a neutral effect on temperature. How have you now forgotten that ?
Besides, stratus already has a high albedo (although interestingly the Eastman paper states that it is only 40-50 %). Replacing that with cumulus type, as the paper indicates would happen as cooler ocean areas warm, would promote heating (neutral clouds plus more gaps in those clouds letting sunlight through)
MSC therefore have a cooling effect on climate [negative cloud radiative effect (CRE)]. Randall et al. estimated that a 4%increase in MSC cover could offset a 28–38Cglobal temperature rise.
WOW! Did you get that? It is saying that if you had a 32% increase in low clouds (from 25% today to 57%), you could expect that to be equal to 8 times that amount (8 times 28-32C) of cooling! That seems like a LOT.
Yes it is a lot if you completely change what was said in the paper. Here’s what it says:
Randall et al. (1984) estimated that a 4% increase in MSC cover could offset a 2-3°C global temperature rise.
I don’t understand how you’ve done that ?
It seems to me they are saying the CAUSE of the higher temps converting low level clouds to mid-level clouds is that the rising air pulls in (from the sides) the DRY air. However in a post-flood state there would not BE any dry air over the very warm ocean!
Oard has said there would be more LTS (stability)...with low amounts of convection...so that the warm/moist air would stay low. So with more stability then there would indeed be more lower clouds.
I refer you again to the chart earlier. If Oard really thinks that tall clouds can’t form over a warm oceans then he’s talking rubbish. No other meteorologist would say that.
“The central Pacific is the only one of the six regions in which cloud cover correlates positively with SST....It is likely that in this region convection is driven by SST, and the warmer the sea surface, the stronger and deeper the convection, leading to greater and more persistent cloud cover at all levels.”
I realize this says only one of 6 regions have positive correlation, however this region is the WARMEST...the central Pacific. So more warm air there WILL cause more lower level clouds.
It says cloud at all levels. Not just low clouds. So insignificant net feedback due to clouds on temperature.
"The process traps heat like a blanket and slows the rate at which the surface can cool by radiation. The blanketing effect warms Earth's surface by some 7°C (13°F)."
To me, this suggests that if you tripled the lower level clouds from about 28% now to 84%...that would cause a 21C warming effect.However, if you triple the albedo to 84%, then you get 90C worth of cooling (acc. to the albedo calc site). Subtracting the two gives you a net 69C of cooling. If you doubled, then there would be 14C of warming to offset 33C of cooling...for a net temp change of -19. Or a global avg temp of -4C. That's pretty close to the 0C figure I suggested during the ice age.
Cloud does not supply the entire albedo of the planet, Deserts for example have an albedo of 0.3, any surface will have some albedo. The average albedo of Earth is 0.31. So how is tripling clouds from 28% going to triple the total albedo ?
Also, talk of 90C cooling due to cloud albedo is nonsensical. The Earth would be 12C warmer if there were no clouds (net effect incl. GE is 5C cooling at the surface). So the albedo effect of current cloud cover of 60% allows for 12C cooling. Forgetting GE that suggests that 100% cover gives 100/60 x 12 = 20C
But none of that matters anyway because you still haven’t shown why low clouds would drastically increase and cirrus disappear in your hot ocean scenario. All the observational data that has been presented in this thread and the content of the Journal of Climatology paper shows that there is no justification for that idea (and that paper is no way equivocal as you bizarrely state).
You promised in post #210 that you would demonstrate how hot oceans produce your low cloud/no high cloud scenario....