The absorption cross section on the ordinate of the ozone
Last updated: 6/28/2023
The absorption cross section on the ordinate of the ozone absorption spectrum is defined by Transmittance T e b where n is the number of absorbing molecules per cubic centimeter is the absorption cross section in square centimeters cm and b is the panthlength in centimeters cm The total ozone in the atmosphere is approximately 8 x 10 8 molecules above each square centimeter of Earth s surface from the surface up to the top of the atmosphere If this were compressed into a pathlength of a 1 cm thick layer the concentration would be 8 x 10 8 molecules cm Ultraviolet radiation in the 200 to 280 nm range is essentially completely blocked by ozone in the atmosphere but barely absorbed in the 315 to 400 nm range Using the ozone spectrum estima the transmittance T and absorbance A of this 1 cm sample at 280 and at 340 nm Question 11 of 15 T at 280 nm A at 280 nm T740 Absorption cross section 10 19 cm 100 0 60 0 60 0 x 1000 250 CIO H CO 300 Wavelength nm Harris Lucy Quantitative Chemical Analysis 10e 2020 W H Freeman and Company 350 Spectra of trace gases in the atmosphere At ozone s maximum absorption at a wavelength near 260 nm a layer of ozone is more opaque than a layer of gold of the same mass Data from U Platt and J Stutz Differential Absorption Spectroscopy Berlin Heidelberg Springer Verlag 2008