Upper-atmosphere cooling down and what does it mea
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Topic: Upper-atmosphere cooling down and what does it mea
Posted By: Dutch Josh
Subject: Upper-atmosphere cooling down and what does it mea
Date Posted: October 14 2018 at 2:29am
https://www.wunderground.com/resources/climate/strato_cooling.asp" rel="nofollow - https://www.wunderground.com/resources/climate/strato_cooling.asp
Global temperatures during January - August 2011 were the third coldest on record in the lower stratosphere, according to the National Climatic Data Center, and have been generally declining in recent decades (Figure 1). Why is this important? Well, the stratosphere is that layer of the upper atmosphere approximately 14-22 km (9-14 miles) above the surface that contains our protective ozone layer. The main reason for the recent stratospheric cooling is due to the destruction of ozone by human-emitted CFC gases. Ozone absorbs solar UV radiation, which heats the surrounding air in the stratosphere. Loss of ozone means that less UV light gets absorbed, resulting in cooling of the stratosphere. Cooling of the stratosphere results in the formation of more polar stratospheric clouds, which require very cold temperatures to form. The presence of these clouds allows even more ozone destruction to occur, since the reactions responsible for ozone destruction occur much faster in clouds than in dry air. Thus, the recent cooling of the stratosphere allows high levels of harmful UV light to reach the surface. As CFC gases begin to decline in coming years thanks to banning of these substances in 1987, the stratosphere should start to warm, and ozone levels will recover.
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A significant portion of the observed stratospheric cooling is also due to human-emitted greenhouse gases like carbon dioxide and methane. Climate models predict that if greenhouse gases are to blame for heating at the surface, compensating cooling must occur in the upper atmosphere. We need only look as far as our sister planet, Venus, to see the truth of this theory. Venus's atmosphere is 96.5% carbon dioxide, which has triggered a run-away greenhouse effect of truly hellish proportions. The average surface temperature on Venus is a very toasty 894 °F! However, Venus's upper atmosphere is a much colder than Earth's upper atmosphere. The explanation of this greenhouse gas-caused surface heating and upper air cooling is not simple, but good discussions can be found at Max Planck Institute for Chemistry and realclimate.org for those unafraid of radiative transfer theory. One way to think about the problem is that the amount of infrared heat energy radiated out to space by a planet is roughly equal to the amount of solar energy it receives from the sun. If the surface atmosphere warms, there must be compensating cooling elsewhere in the atmosphere in order to keep the amount of heat given off by the planet the same. As emissions of greenhouse gases continue to rise, their cooling effect on the stratosphere will increase. This will make recovery of the stratospheric ozone layer much slower.
Greenhouse gases cause cooling higher up, too
Greenhouse gases have also led to the cooling of the atmosphere at levels higher than the stratosphere. Over the past 30 years, the Earth's surface temperature has increased 0.2-0.4 °C, while the temperature in the mesosphere, about 50-80 km above ground, has cooled 5-10 °C (Beig et al., 2006). There is no appreciable cooling due to ozone destruction at these altitudes, so nearly all of this dramatic cooling is due to the addition of greenhouse gases to the atmosphere. Even greater cooling of 17 °C per decade has been observed high in the ionosphere, at 350 km altitude. This has affected the orbits of orbiting satellites, due to decreased drag, since the upper atmosphere has shrunk and moved closer to the surface (Lastovicka et al., 2006). The density of the air has declined 2-3% per decade the past 30 years at 350 km altitude. So, in a sense, the sky IS falling!
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We cannot solve our problems with the same thinking we used when we created them.
~Albert Einstein
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Replies:
Posted By: Dutch Josh
Date Posted: October 14 2018 at 2:34am
https://www.quora.com/Why-does-temperature-decrease-in-the-mesosphere-and-increase-in-the-thermosphere" rel="nofollow - https://www.quora.com/Why-does-temperature-decrease-in-the-mesosphere-and-increase-in-the-thermosphere and https://www.quora.com/How-is-the-temperature-of-the-thermosphere-measured" rel="nofollow - https://www.quora.com/How-is-the-temperature-of-the-thermosphere-measured
http://www.theclimateconsensus.com/content/satellite-data-show-a-cooling-trend-in-the-upper-atmosphere-so-much-for-global-warming-right" rel="nofollow - http://www.theclimateconsensus.com/content/satellite-data-show-a-cooling-trend-in-the-upper-atmosphere-so-much-for-global-warming-right :
We can think of our troposphere as an insulating blanket that keeps energy close to the surface of the earth. However, by increasing the amount of greenhouse gases in our atmosphere, primarily in the form of CO2, our troposphere is quickly becoming a more efficient blanket. While the amount of energy that enters our climate system from the sun has remained relatively constant, the amount of energy that is allowed to escape to space is decreasing. The result? More energy is sticking around near the surface of the earth as shown by increasing temperatures in the lower part of the troposphere.
The amount of energy that enters our climate system has remained relatively constant. However, because of greenhouse gas emissions, the amount of energy that is allowed to escape to space is decreasing.
So why do scientist expect temperatures to cool in the upper part of the atmosphere when they are warming at the surface? Considering that about 80% of the atmosphere is located within the troposphere, we can think of the stratosphere as sitting on top of our atmospheric blanket.
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We cannot solve our problems with the same thinking we used when we created them.
~Albert Einstein
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Posted By: Dutch Josh
Date Posted: October 14 2018 at 3:58am
https://en.wikipedia.org/wiki/Atmosphere_of_Earth" rel="nofollow - https://en.wikipedia.org/wiki/Atmosphere_of_Earth
DJ-"Global warming" remains in the lower part of the atmosphere ( https://en.wikipedia.org/wiki/Atmosphere_of_Earth#Principal_layers" rel="nofollow - https://en.wikipedia.org/wiki/Atmosphere_of_Earth#Principal_layers ) the more upper layers cool down. Green house gases store the heat close to the Earth, less heat reaches the upper (+12km) atmosphere.
As a result those upper layers cool down and get less dense.
-Ozone layers get less dense=more UV-A, B, and even C (and other cosmic rays) will get to the lower layers. This may cause DNA damage on living creatures, wich will cause mutations sometimes leading to mutations in species, but also an increase in cancers.
-Growing temperature differences also will give extra energy to extreme weather. ( https://en.wikipedia.org/wiki/Low-pressure_area" rel="nofollow - https://en.wikipedia.org/wiki/Low-pressure_area )
https://en.wikipedia.org/wiki/Hurricane_dynamics_and_cloud_microphysics" rel="nofollow - https://en.wikipedia.org/wiki/Hurricane_dynamics_and_cloud_microphysics :Tropical convective clouds play an important part in the Earth's climate system. Convection and release of latent heat transports energy from the surface into the upper atmosphere. Clouds have a higher albedo than the underlying ocean, which causes more incoming solar radiation to be reflected back to space. Since the tops of tropical systems are much cooler than the surface of the Earth, the presence of high convective clouds cools the climate system.
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We cannot solve our problems with the same thinking we used when we created them.
~Albert Einstein
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