How Atmospheric Pressure Drives Temperatures, Not Trace Gases
This is on similar lines to the ongoing studies of Nikolov & Zeller, featured here at the Talkshop on several occasions. The ‘standard’ tropopause pressure of ~0.1 bar is an interesting factor.
By looking at the temperature of every planet with sufficient atmospheres, we see temps rise along with atmospheric pressure, and not from a trace gas, says Alan Siddons at ClimateChangeDispatch.
Early in the 19th century, scientists began to speculate that the Earth, surrounded by the frigid vacuum of space, was habitable because its atmosphere contained special molecules like CO₂ and water vapor, molecules that can absorb heat rays emanating from the Earth and thereby trap its heat.
That the Earth was warmer than one might expect was apparently confirmed when Kirchhoff’s blackbody concept was adopted.
Today it is considered a matter of course that the Earth’s blackbody temperature is minus 18° Celsius, i.e., around 255 Kelvin, whereas its average temperature is 288 Kelvin.
By the early-20th century, this temperature disparity started to be called The Greenhouse Effect.
NASA lists the predicted blackbody temperatures for the planets in our solar system at Planetary Fact Sheets. What’s intriguing, though, is that through the efforts of NASA and other such agencies, we now have some insight into the atmospheres of these other solar system bodies.
Here, for instance, is the atmospheric temperature profile for Jupiter.
via Tallbloke’s Talkshop
May 17, 2018 at 09:39AM