Why it is that high altitude areas are colder than low altitude areas? Is it because the air pressure or any other? If we consider it with the sun rays, high altitudes receive sun rays earlier than low altitude so low altitudes must receive rays with less amount of energy relative to high altitude rays. Therefore low altitude must have low temperature. Can any one explain theory behind the scene?
$\begingroup$
$\endgroup$
Add a comment
|
2 Answers
$\begingroup$
$\endgroup$
3
The principal physical mechanisms in the troposphere, stratosphere, etc are different. Since it's the troposphere where we live, and where weather occurs, let's guess that's what you're asking about.
Then google adiabatic lapse rate for the somewhat elaborate thermodynamic explanation that's been exhaustively studied and worked out over the last hundred-plus years.
As often, wikipedia's https://en.wikipedia.org/wiki/Lapse_rate isn't a bad place to start. In particular, note the pretty straightforward derivation from the first law of thermodynamics in the https://en.wikipedia.org/wiki/Lapse_rate#Convection_and_adiabatic_expansion section. The first three paragraphs of that section contain an extremely clear and concise words-only explanation, which is then followed by the corresponding math.
-
$\begingroup$ does gravity affects temprature or not or what else affects. But in Lapse Rate equation there is ' g ' so i dont get it. $\endgroup$ Commented Dec 28, 2017 at 9:18
-
$\begingroup$ seems like you have knowledge about this matter, so can you please give me explanation for question. $\endgroup$ Commented Dec 28, 2017 at 9:18
-
$\begingroup$ @user7549997 Gravity affects temperature through hydrostatic equilibrium (as per the link on the page I already pointed you to). Briefly, hydrostatic equilibrium just says that the pressure at any place in the atmosphere is simply due to the weight of all the air above it. And weight is $\mbox{mass}\times g$. In other words, if the Earth's gravity suddenly doubled, so would atmospheric pressure. And that would indeed affect the $\Gamma_d$ lapse rate as shown at the bottom of that section. (But the change of gravitational force due to distance from the Earth's center is negligible.) $\endgroup$– user89220Commented Dec 29, 2017 at 4:54
$\begingroup$
$\endgroup$
6
Reasons
- The greater the altitude, the further the air molecules are from the ground. This means that there is a weaker gravitational force, leading to air molecules accumulating at lower altitudes. Thus, less molecules are at higher altitudes, so they retain less heat. Hence, it is colder at higher altitudes.
- Air also contains dust and water molecules, which trap heat. However, the weaker gravitational force at high altitudes and stronger gravitational force at lower altitudes cause these molecules to be present in smaller amounts at higher altitudes. This will allow heat to escape more easily at higher altitudes, and thus trapping less heat, leading to a lower temperature at higher altitudes.
Misconceptions
You said: "If we consider it with the sun rays, high altitudes receive sun rays earlier than low altitude so low altitudes must receive rays with less amount of energy relative to high altitude rays. Therefore low altitude must have low temperature. Can any one explain theory behind the scene?"
However, you have ignored the fact that gravity is different at different altitudes. Furthermore, the distance between different altitudes is negligible when compared to how far the light from the sun travels before reaching Earth. Hence, the about of heat and light energy received at different altitudes is negligible. Thus, gravity is the main factor here.
answered Dec 28, 2017 at 5:15
-
$\begingroup$ thnks for explanation, further can you explain, is gravity affecting changing seasons like autmn,summer, winter, spring. $\endgroup$ Commented Dec 28, 2017 at 6:46
-
1$\begingroup$ First please note that I'm >>not<< the downvoter. The extremely clear and concise words-only explanation is given by the first three paragraphs of that wikipdeia link I cited in my answer, en.wikipedia.org/wiki/… (which is then followed by the corresponding math). And maybe I'm missing something, but I'm not seeing those same ideas in your answer. $\endgroup$– user89220Commented Dec 28, 2017 at 7:38
-
4$\begingroup$ you were downvoted because your answer is demonstrably incorrect; gravity has nothing to do with the tropospheric temperature profile, except inasmuch as it is responsible for holding the atmosphere in place around the earth. John Forkosh's answer (the adiabatic lapse rate) is correct. $\endgroup$ Commented Dec 28, 2017 at 7:41
-
$\begingroup$ Leave your answer up -- just to illustrate that teacher's sometimes don't know what they're talking about, especially when talking about topics which they're not qualified to teach. And maybe point out this question to other kids at your school. (P.S. And when you have your own kids, send them to a different school:) $\endgroup$– user89220Commented Dec 28, 2017 at 7:44
-
$\begingroup$ And yeah, your "thenakedscientists" link is a simplified version of the third paragraph in my wikipedia llink. $\endgroup$– user89220Commented Dec 28, 2017 at 7:48