Temperature dependence of the absorption cross sections of formaldehyde between 223 and 323 K in the wavelength range 225-375 nm

Abstract

UV absorption cross sections of formaldehyde (HCHO) have been measured with a spectral resolution of 0.025 nm in the wavelength range 225-375 nm at 298 K using a diode array detector. At selected temperatures ranging from 223 to 323 K, measurements have been conducted to obtain temperature gradients in the wavelength range 250-356 nm. Error limits for the reported absorption cross sections are ±5% but at least ±3 × 10-22 cm2 molecule-1. For the temperature gradients, uncertainties are <8%. Spectra and temperature gradients are compared with earlier measurements. Copyright 2000 by the American Geophysical Union.