Derivation of cumulus cloud dimensions and shape from the airborne measurements by the Research Scanning Polarimeter

- Cumulus cloud shapes are derived from the Research Scanning Polarimeter (RSP) data.
- Cloud dimensions, top and bottom heights are also retrieved.
- The retrieval method is tested on 3D radiative transfer simulations using LES clouds.
- Analysis of cloud shapes observed by RSP during NASA DEVOTE campaign is presented.

The Research Scanning Polarimeter (RSP) is an airborne instrument, whose measurements have been extensively used for retrievals of microphysical properties of clouds. In this study we show that for cumulus clouds the information content of the RSP data can be extended by adding the macroscopic parameters of the cloud, such as its geometric shape, dimensions, and height above the ground. This extension is possible by virtue of the high angular resolution and high frequency of the RSP measurements, which allow for geometric constraint of the cloud's 2D cross section between a number of tangent lines of view. The retrieval method is tested on realistic 3D radiative transfer simulations and applied to actual RSP data.