Absorption cross-sections for some atmospherically important molecules at the H atom Lyman-α wavelength (121.567 nm)

Absolute values of gas-phase absorption cross-sections for some atmospherically important molecules (HCl, H2O, H2S, NH3, H2O2, HNCO, CH4, CH3Cl, CH2Cl2, CHCl3, CHF2Cl, CHBr3, CH3CF2Cl and CH3CFCl2) have been measured at the H atom Lyman-alpha wavelength (121.567 nm) employing narrow band (Delta lambda = 0.0006 nm) laser radiation generated by resonant third-order sum-difference frequency conversion. The present values can be used to access the uncertainty associated with Lyman-alpha absorption cross-section values derived from available literature absorption spectra which usually have been measured with quite different and sometimes with quite low spectral resolutions. (C) 2001 Elsevier Science B.V. All rights reserved.