Abstract

The Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) is a high resolution (0.02 cm⁻¹) instrument covering the 750-4400 cm⁻¹ spectral range in solar occultation mode. ACE was launched by NASA in August 2003 and the FTS continues to operate without any degradation in performance. The primary ACE mission goal is the study of ozone chemistry in the stratosphere although it is making a wide range of other measurements, for example the detection of organic molecules in the upper troposphere/lower stratosphere such as methane, methanol, formaldehyde, ethane, ethene and ethyne. The ACE-FTS records spectra in the 3 micron region, which is particularly suitable for the retrieval of hydrocarbons (C-H stretches). Since atmospheric spectroscopic databases do not contain appropriate spectroscopy for many organic molecules, we have recorded quantitative laboratory infrared spectra of these molecules as mixtures with synthetic air over a range of temperatures and pressures. These have been used to derive sets of high-resolution absorption cross sections, which in turn are used to retrieve atmospheric concentration profiles from ACE spectra.

© 2011 Optical Society of America