Influence of 3D Effects on 1D Aerosol Retrievals in Synthetic, Partially Clouded Scenes

Abstract:

Most satellite measurements of the microphysical and radiative properties of
aerosol near clouds are either strictly screened for, or hindered by sub-pixel cloud contamination.
This may change with the advent of a new generation of aerosol retrieval algorithms,
intended for multi-angle, multi-wavelength photo-polarimetric instruments such as POLDER3
on board PARASOL, which show ability to separate between aerosol and cloud particles.
In order to obtain the required computational efficiency these algorithms typically
make use of 1D radiative transfer models and are thus unable
to account for the 3D effects that occur in actual, partially clouded scenes.
Here, we apply an aerosol retrieval algorithm, which employs a 1D radiative
transfer code and the independent pixel approximation, on synthetic, 3D, partially clouded
scenes calculated with the Monte Carlo radiative transfer code MYSTIC.
The influence of the 3D effects due to clouds on the retrieved microphysical and optical
aerosol properties is presented and the ability of the algorithm to retrieve these
properties in partially clouded scenes will be discussed.