Dobson unit

in atmospheric chemistry
https://doi.org/10.1351/goldbook.D01827
Unit sometimes used in the description of the total ozone in a column of air overhead. It is given as the thickness (in units of \(10^{-3}\ \text{cm}\) or \(10^{-5}\ \text{m}\)) of that layer which would be formed by the total ozone in a column reduced to the pressure of \(760\ \text{Torr}\) and temperature of \(0\ ^{\,\unicode{x26ac}}\text{C}\).
Source:
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2185 [Terms] [Paper]