In stratosphere, there is ozone layer which absorb UV radiation and temperature of that layer rises due to absorption of UV rays by ozone molecules,since UV radiation are absorbed, inside ozone molecules, why temperature rises.
From 10 to 20 kilometers the atmosphere is stable. This region is called the tropopause. From 20 to about 50 kilometers is the stratosphere. In this region the air actually warms with height! Ozone is concentrated in this part of the atmosphere and it absorbs ultraviolet light from the Sun. More light is absorbed at higher altitudes compared to the lower stratosphere, so the temperature increases.
Hi,
In troposphere the temperature decreases, in stratosphere the temperature increases due to Ozone, and the maximum amount of ozone is located in the 25Km. The Ozone layer absorbs the shortwave radiation with high energy so this action produce heats and it is a " Exothermic process".
By the way, I want to know: what is your idea about the third layer: " mesosphere" , why the temperature does decrease in this layer?
Cheers,
Nasrin
In answer to the question why the temperature does decreases in the mesosphere I found this:
"In the lower atmosphere CO2 acts as a so called greenhouse gas by absorbing infrared radiation radiated by the earth’s surface. In the rarefied mesosphere CO2 actually cools the atmosphere by radiating heat into space*.
...
* The summer mesopause is getting colder, possibly because of the cooling effect of increased anthropogenic carbon dioxide and methane emissions." http://www.atoptics.co.uk/highsky/hmeso.htm
I think that should say " * In the summer the mesopause gets colder, possibly because of the cooling effect of the natural decrease in carbon dioxide produced by the increase in photosynthesis." At least that is what happens in Beijing:
Article Seasonal variations of night mesopause temperature in Beijin...
or
https://link.springer.com/article/10.1007/s11431-012-4779-8
Xiong, J., Wan, W., Ning, B., Liu, L., Wu, B., Hu, L. and Xu, T. (2012) ‘Seasonal variations of night mesopause temperature in Beijing observed by SATI4’, Science China Technological Sciences, vol. 55, no. 5, pp. 1295–1301 [Online]. DOI: 10.1007/s11431-012-4779-8.
when energy is absorbed, we consider such type of reactions as endothermic, in which heat is not given out by the reacting molecules, but how ozone molecules absorb short wavelength radiation that this process generate heat in the surrounding?
Ozone absorbs the energy of photons with wavelengths in the UV area and converts them into heat.
The process involves that ozone first split into O and O2 which contain the energy of the photon. These transfer this energy to other gas molecules (mostly N2) before they can react to reform O3. It is the energy transfer that causes the higher temperature.
Dear Alastair
Many thanks for your descriptions about the temperature in the mesosphere.
Warm Regards,
Nasrin
Dear Alastair Bain McDonald
in mesoshpere CO2 molecules why could not uv radiation and they radiate heat in the space because next layer is thermosphere.. and again in thermosphere when gas molecules get absorb incoming solar radiation why temperatur rise there....thanks in advance
Hi Aiman,
Are you asking why the thermosphere is hot and the mesosphere is cold?
I think that the answer is that the mesosphere is heated from below by longwave radiation, which is mostly absorbed in the lower layers. The thermosphere is heated from above by solar radiation and so the outer layers are warmer than the inner layers.
But I am pretty sure it is more much more complicated than that. See:
https://scied.ucar.edu/shortcontent/mesosphere-overview
and
https://scied.ucar.edu/shortcontent/thermosphere-overview
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