14 December 1998 High-spectral-resolution simulation of the impact on heating rates of cirrus clouds in the far infrared
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The far IR spectral region is fundamental for the understanding of the earth's radiation balance, in particular because of a strong cooling to space due to the water vapor rotation band and continuum. Cirrus clouds play an important but poorly characterized role in this spectral region. Using a line-by-line code to model at high resolution the atmospheric transmittance, in association with a multiple scattering radiative transfer scheme, we simulate the impact of cirrus clouds on the atmospheric heating rates in the spectral region from 100 to 1000 cm-1. Compared with clear sky conditions, we find that cirrus clouds induce a heating from the ground to the cloud base at all wave numbers. Within the cloud, a heating effect occurs in the window region, whereas a strong cooling occurs in the far-IR. The particles' shape are modeled with either a size distribution of spheres or randomly oriented spheroids. We show that, for a range of different ice water path and particles, size, for a same average volume of ice per particle, spheroids have a bigger impact than spheres at all wave numbers on the cooling/heating rates as well as for the top of the atmosphere radiances.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Catherine Naud, Catherine Naud, Jaqueline E. Russell, Jaqueline E. Russell, John E. Harries, John E. Harries, "High-spectral-resolution simulation of the impact on heating rates of cirrus clouds in the far infrared", Proc. SPIE 3495, Satellite Remote Sensing of Clouds and the Atmosphere III, (14 December 1998); doi: 10.1117/12.332673; https://doi.org/10.1117/12.332673

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