## New Computer Fund ## Saturday, May 5, 2012

### More on the Atmospheric R-value

The R-value used to rate the insulation quality of construction materials and clothing is pretty simple. R=delta T/delta Q where T is the temperature, Q is the heat flow and delta is the difference of rate of change in either. If you have a room you want to be at 72 degrees with an outside air temperature of 32 degrees and only what to use 12.0 MBTH, then R=40/12=3.33 minimum R-value for the space. 3.33 is about the R value of a 3/4" airspace with some of that radiant reflective barrier stuff added. Not a very high R-value, but that was just an example. The atmosphere can have an R-value from one point to another. Since there are seldom dead air spaces, it is pretty low. It is like a house with no walls or roof, pretty hard to air condition. Adding greenhouse gases is supposed to increase the R-value of the atmosphere. If there were dead air spaces, the GHGs would do a fine job. Without dead air spaces, it is s touch more difficult to figure out how good a job they will do. Part of the R-value calculation is delta T. Since we have pretty good temperature data for the atmosphere at differing altitudes, we can get part of the R-value information. That plot is for the University of Alabama, Huntsville, middle troposphere data minus the lower stratosphere data for the Northern and Southern extents. Adding CO2, CH4 and other gases and particles while change the temperature relationship between these atmospheric layers. As you can see, the differential for both is increasing with time. Since the delta T part of the equation between these two layers is increasing, the R-value would be increasing if the delta Q part remained the same or decreased. For global warming theory, delta Q should decrease as delta T increases. This plot is just for the Northern Extent from 1995 with the estimated R-value included in yellow. I based the flux on a surface temperature of 273K (zero C degrees or 32 degrees F) and the differential based on 255K degrees. This is not an actual value of R but should give a trend. In this case the R estimate decreases very slightly. There would not be a radical change in the R-value, but it should be increasing. Of course these are only two regions with large assumptions made, but it could be an indication that the R-value is not linear with altitude. Which is what I suspect.