Re: [Phys-l] Greenhouse effect / 2nd law

[John Denker <jsd@av8n.com>]

On 04/27/2011 04:49 PM, LaMontagne, Bob wrote:
> Also, if you check times at 4:00 AM at the site you linked us to, one
> finds that when the air is clear (CLR) a low Dew Point temperature
> (the real measure of the amount of water vapor in the air) is
> correlated with a low temperature and a higher Dew Point is
> correlates with a warmer temperature.
>
> DP 9 deg F -------  Temp = 30 deg F
>
> DP 23 deg F  -------- Temp = 46 deg F
>
> While this is a single anecdote, it can be seen over and over on station reports throughout the country. 

Well, maybe such a trend "can be seen over and over on station reports 
throughout the country" ... but it cannot be seen in the data I cited 
for Show Low, AZ.

Here is a scatter plot of temperature versus dewpoint.
  http://www.av8n.com/physics/img48/temp-dewpoint-ksow.png

I would not be in a big hurry to describe this data in terms of 
temperature and dewpoint being "correlated".

In other locales where there is more moisture and more lush vegetation 
the story will be different.

============

Rule of thumb:  Everything having to do with fluid dynamics is much
more complicated and much trickier than most people think it is.

This includes meteorology.