Impact of cirrus clouds heterogeneities on top-of-atmosphere thermal infrared radiation
Item
Title (Dublin Core)
Impact of cirrus clouds heterogeneities on top-of-atmosphere thermal infrared radiation
Description (Dublin Core)
This paper presents a study of the impact of cirrus cloud heterogeneities on the thermal infrared brightness temperatures at the top of the atmosphere (TOA). Realistic 3-D cirri are generated by a cloud generator based on simplified thermodynamic and dynamic equations and on the control of invariant scale properties. The 3-D thermal infrared radiative transfer is simulated with a Monte Carlo model for three typical spectral bands in the infrared atmospheric window. Comparisons of TOA brightness temperatures resulting from 1-D and 3-D radiative transfer show significant differences for optically thick cirrus (τ > 0.3 at 532 nm) and are mainly due to the plane-parallel approximation (PPA). At the spatial resolution of 1 km × 1 km, two principal parameters control the heterogeneity effects on brightness temperatures: i) the optical thickness standard deviation inside the observation pixel, ii) the brightness temperature contrast between the top of the cirrus~and the clear-sky atmosphere. Furthermore, we show that the difference between 1-D and 3-D brightness temperatures increases with the zenith view angle from two to ten times between 0° and 60° due to the tilted independent pixel approximation (TIPA).
Creator (Dublin Core)
Fauchez, T.
Cornet, C.
Szczap, F
Dubuisson, P.
Rosambert, T.
Date (Dublin Core)
2018-01-15
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.5194/acp-14-5599-2014
https://acp.copernicus.org/articles/14/5599/2014/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
