Absorption coefficients of ozone for use in the determination of atmospheric ozone

Laboratory measurements at low temperatures of the ozone absorption coefficient differences required in the standard spectroscopic measurement of atmospheric ozone are described. The measurements were made with a Dobson spectrophotometer and a quartz‐iodine source. The results at the standard wavelength pairs are The effective temperature was – 42°C (± 2°C). These results are compared with those of other workers. The error in measured total ozone amount caused by changes in stratospheric temperatures is discussed. Maximum errors of about 4 per cent seem possible in spring warmings, the apparent ozone amount being too low.