We report results from the participation of the Imperial College TAFTS instrument in the CAVIAR and RHUBC field campaigns, validating a derived water vapor continuum parameterization in the far-IR spectral region.

We present a new derivation of the foreign-broadened water vapour continuum in the far-infrared (far-IR) pure rotation band between 24 μm and 120 μm (85–420 cm −1 ) from field data collected in flight campaigns of the Continuum Absorption by Visible and IR radiation and Atmospheric Relevance (CAVIAR) project with Imperial College's Tropospheric Airborne Fourier Transform Spectrometer (TAFTS) far-IR spectro-radiometer instrument onboard the Facility for Airborne Atmospheric Measurement (FAAM) BAe-146 research aircraft; and compare this new derivation with those recently published in the literature in this spectral band. This new dataset validates the current Mlawer–Tobin-Clough–Kneizys–Davies (MT-CKD) 2.5 model parametrization above 300 cm −1 , but indicates the need to strengthen the parametrization below 300 cm −1 , by up to 50 per cent at 100 cm −1 . Data recorded at a number of flight altitudes have allowed measurements within a wide range of column water vapour environments, greatly increasing the sensitivity of this analysis to the continuum strength.

We report results from the second CAVIAR and first RHUBC field campaigns, comparing a derived water vapor continuum parametrisation in the far-IR spectral region with those in the mid-IR and the literature.

The objectives and component parts of the CAVIAR consortium are described. Preliminary data from the recent UK-based airborne field campaign are discussed, with a description of the analysis method and its expected scientific merit.