Stratospheric Chemistry
Résumé
The stratosphere is the region of the atmosphere that lies above the tropopause, the altitude where the temperature ceases to decrease with altitude to be constant or starts to grow with altitude. The driving factor for the presence of this so-called dynamic barrier is mostly related to the concentration of ozone, in the so-called “ozone layer”, which increases with altitude. Ozone in the troposphere is a greenhouse gas that is dangerous to human health and vegetation growth. Passive nadir sounders like Infrared Atmospheric Sounding Interferometer have only limited capability to probe the stratospheric composition of the atmosphere with good enough vertical resolution. In a complementary manner, limb sounders in various regions of the electromagnetic spectrum have been providing and continue to provide very important information on the vertical distribution of a large number of chemical species.