On Wednesday, August 17, 2016 at 4:01:53 PM UTC-7, Michael J. Strickland wrote:
> On Sat, 13 Aug 2016 09:44:18 -0700 (PDT), Claudius Denk
https://tallbloke.wordpress.com/2015/06/11/atmospheric-convection-what-does-it-mean/comment-page-8/#comment-115527
JMcG
The vast majority of the moist, warm air--upwards of 95%--is within 1,000 meters of the surface. All the air above is cooler and drier. This observation is perfectly consistent with my model which says moist air is heavier than dry air and that also says convection plays no role in atmospheric flow. It blatantly contradicts the convection model with pretends moist air is lighter and pretends convection is an active element in our atmosphere.
MS:
Thunderheads go to 50-60 thousand feet and they must have some
moisture. I don't think hail can form only 1000 meters up in hot
summer air.
JMcG:
Michael, I agree with what you are saying here but it doesn't change what I am saying. There is kind of an illusion involved. When droplet sizes are very small suspended water is invisible. Moreover it doesn't even feel wet when we encounter it (this is due to the fact that the high surface tension of H2O causes smaller droplets to be harder, like pellets). It looks and feels like dry air (except maybe it feels slightly thicker and is much less able to effectuate cooling). And so, if you go outside and look up on a cloudy day you may come to the conclusion that there is more moisture high above than there is below. But what is actually happening is that the droplet size is smaller in air at lower altitude because of higher pressure and higher temperature, creating the illusion.
What determines droplet size? H2O droplets are constantly combining to form larger droplets. At one and the same time, however, collisions with with air molecules are bisecting them. At higher pressures and temperatures (as found at lower altitudes) there are more collisions with air molecules and the air molecules are more energetic. Thus the rate of droplets bisecting overwhelms the rate of recombination. And so, even though there is much more H2O suspended in the air at lower altitudes it is much less visible.
MS:
Water vapor rises because water (H2O at 18 grams/mole) is less dense
than air which is predominately nitrogen (N2 at 28 grams/mole).
JMcG:
This is bullshit. H2O droplets never get smaller than 10 molecules per droplet. Thus the minimum weight of an H2O microdroplet is 180 (10 x 18) not 18.
MS:
When mixed with regular air (non-moist), this brings the air's
average/overall density down and causes it to rise above non-moist
air.
JMcG:
Nonsense. This is just a bad myth. Air moves from places of higher pressure to places of lower pressure. Vortice activity--which is especially prominent at higher altitude--creates the low pressure that causes uplift. Moisture is suspended in the air (probably due to static electricity) and just goes along for the ride.
So, moist air does rise. But it doesn't rise because of convection (convection is a myth). It rises because it is suspended in air that is moving toward low pressure that is created by vortices.
It is important to understand that water is the most misunderstood substance in all of nature and this has caused a lot of desperation for theorist. Desperation leads to cognitive dissonance and cognitive dissonance causes people to glom onto false certainty.
Convection is superstition:
http://www.thunderbolts.info/forum/phpBB3/viewtopic.php?f=8&t=16306
James McGinn / Genius