Stratosphere around at midlatitudes, and at about at the poles. Temperatures range from an average of near the tropopause to an average of near the mesosphere. Stratospheric temperatures also vary within the stratosphere as the seasons change, reaching particularly low temperatures in the polar night (winter). Winds in the stratosphere can far exceed those in the troposphere, reaching near in the Southern polar vortex. The mechanism describing the formation of the ozone layer was described by British mathematician Sydney Chapman in 1930. Molecular oxygen absorbs high energy sunlight in the UV-C region, at wavelengths shorter than about 240 nm. Radicals produced
S-Nitrosothiol exist for their synthesis. They can be synthesized from thiols using NaNO/H+, NO, NO, HNO, NOCl, RONO, NO, HNO, bovine aortic endothelial cells, among others. NaNO/H+ and "tert"-butyl nitrite (tBuONO) are commonly used. Once formed, these deeply colored compounds are often thermally unstable with respect to formation of the disulfide and nitric oxide: "S"-Nitrosothiols release NO upon treatment with acids: and they can transfer nitroso groups to other thiols: "S"-Nitrosothiols can be detected with UV-vis spectroscopy. S-Nitrosothiol "S"-Nitrosothiols, also known as thionitrites, are organic compounds or functional groups containing a nitroso group attached to the sulfur atom of a thiol.