The Ordovician Period
Because clouds occur when water condenses from water vapour to tiny water droplets. Water condenses when it is cold enough, and higher up in the atmosphere, it is colder.
Although they can occur at any time of day, tornadoes are most common in the late afternoon and early evening. This is when the lower atmosphere is usually the warmest and thus the atmosphere is usually the most unstable. These conditions are conducive for the formation of strong thunderstorms which, given a few other conditions, can produce tornadoes.
The sun heats the surface of the Earth throughout the day, which in turn heats the lowest part of the atmosphere. The surface starts too cool down around sunset. As a result the lower atmosphere is generally warmest and thus the most unstable in the late afternoon. An unstable atmosphere is necessary for the formation of the strong thunderstorms that produce tornadoes.
the chromosphere
Mercury has almost no atmosphere
The Archean atmosphere is believed to have been free of free oxygen. Banded iron formations did not occur till near the end of the Archean period.
Ozone formation is a natural process. It is a chemical process. When oxygen is treated with UV radiations oxygen gets converted into ozone.
It is a byproduct of the life processes on Earth. Earth's early atmosphere contained no Oxygen, but Earth was slowly Terra-formed by life and obtained an Oxygen rich atmosphere.
If you mean how does it come to be in the atmosphere, oxygen is released into the atmosphere by plants, mostly by phytoplankton in the ocean. I you mean how is oxygen created in the first place, it is the result of lighter elements being fused together in the cores of stars.
An oxygen deficient atmosphere is one that lacks a sufficient amount of oxygen to support human or animal life. It can occur in environments where oxygen is depleted, such as in confined spaces or areas with high levels of carbon dioxide, gases, or chemicals that displace oxygen. Breathing in an oxygen deficient atmosphere can lead to suffocation or loss of consciousness.
Changes in the earth's atmosphere over a short period of time are referred to as climate change. These changes can occur naturally or because of humans.
If your question is really about oxygen then it is false. And oxygen is not increasing in the atmosphere. If you are talking about carbon dioxide, a gas that IS increasing in the atmosphere, then it is true. Carbon dioxide is causing the speeding up of global warming.
Because clouds occur when water condenses from water vapour to tiny water droplets. Water condenses when it is cold enough, and higher up in the atmosphere, it is colder.
I wouldn't say that many chemicals occur naturally in the air, however Oxygen and Nitrogen are the two main gases that make up the Earth's atmosphere.
Earthquakes occur at that moment
Although they can occur at any time of day, tornadoes are most common in the late afternoon and early evening. This is when the lower atmosphere is usually the warmest and thus the atmosphere is usually the most unstable. These conditions are conducive for the formation of strong thunderstorms which, given a few other conditions, can produce tornadoes.
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