Atmosphere of Earth that gas. The stratosphere defines a layer in which temperatures rise with increasing altitude. This rise in temperature is caused by the absorption of ultraviolet radiation (UV) radiation from the Sun by the ozone layer, which restricts turbulence and mixing. Although the temperature may be at the tropopause, the top of the stratosphere is much warmer, and may be near 0 °C. The stratospheric temperature profile creates very stable atmospheric conditions, so the stratosphere lacks the weather-producing air turbulence that is so prevalent in the troposphere. Consequently, the stratosphere is almost completely free of clouds and other forms of weather.
Atmospheric Chemistry Suite than the PFS spectrometer of Mars Express orbiter. Of particular interest to this astrobiology mission, is the detection and characterization of the atmospheric methane (), as it may be of geological or biological nature. Large differences in the abundances were measured between observations taken in 2003, 2006, and on 2014 NASA reported that the "Curiosity" rover detected a tenfold increase ('spike') in methane in the atmosphere in late 2013 and early 2014. This suggestes that the methane was locally concentrated and is probably seasonal. Because methane on Mars would quickly break down due to ultraviolet radiation from the Sun and