Abstract
New laboratory measurements and theoretical calculations of integrated line intensities for water vapour bands in the nearβinfrared and visible regions (8600β15 000 cm^β1^) show a systematic 6β26% increase in band intensities compared to the HITRAN96 database. We have used the GENLN2 lineβbyβline code to assess the effects of such changes in the water vapour spectral database on calculations of clearβsky shortβwave fluxes and heating rates. Three standard atmospheres were used and it was found that, compared with HITRAN96 results, the absorbed downward solar fluxes increase (including the effects of theoretically predicted weak water lines in the region) by 5.5, 4.8 and 2.2 W m^β2^ (solar zenith angle = 30Β°) and by 2.4, 2.1 and 1.1 W m^β2^ (solar zenith angle = 75Β°) respectively. The maximum change in heating rate is about 4%. The effects are about five to eight times larger than those produced by using the Giver et al. corrections. The combined effects of the revised description of the spectroscopy of water vapour account for approximately 30β90% of the absorption currently ascribed to the water vapour continuum in this spectral region.