Atmos. Chem. Phys. Discuss., 9, 12027-12064, 2009
www.atmos-chem-phys-discuss.net/9/12027/2009/
doi:10.5194/acpd-9-12027-2009
© Author(s) 2009. This work is distributed
under the Creative Commons Attribution 3.0 License.
Review Status
This discussion paper has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP.
Retrieval of cloud liquid water distributions from a single scanning microwave radiometer aboard a moving platform – Part 1: Field trial results from the Wakasa Bay experiment
D. Huang1, A. Gasiewksi2, and W. Wiscombe1,3
1Brookhaven National Laboratory, Upton, NY 11973, USA
2University of Colorado, Boulder, CO 80309, USA
3NASA Goddard Space Flight Center (code 913), Greenbelt, MD 20771, USA

Abstract. Tomographic methods offer a new promise for retrieving three-dimensional distributions of cloud liquid water from path-integrated radiometric measurements by passive sensors. A mobile cloud tomography system using only a single scanning microwave radiometer has many advantages over a fixed system using multiple distinctly-located radiometers, e.g., efficient and flexible data collection. Part 1 (this paper) examines the results from a limited cloud tomography trial carried out during the 2003 AMSR-E validation campaign at Wakasa Bay of the Sea of Japan. During the tomographic test, the Polarimetric Scanning Radiometer (PSR) and Microwave Imaging Radiometer (MIR) aboard the NASA P-3 research aircraft scanned through a system of low-level clouds and thus provided a useful dataset for testing the cloud tomography method. We conduct three retrieval runs with a constrained inversion algorithm using, respectively the PSR, MIR, and combined PSR and MSR data. The liquid water paths calculated from the PSR retrieval are consistent with that from the MIR retrieval. The retrieved cloud field based on the combined data appears to be physically plausible and consistent with the cloud image obtained by a cloud radar. It is unfortunate that there were no in-situ cloud measurements during the experiment that can be used to quantitatively validate the tomographic retrievals. Nevertheless, we find that some vertically-uniform clouds appear at high altitudes in the retrieved fields where the radar image shows clear sky. This is likely due to flawed data collection geometry, which, in turn, is determined by the radiometer scan strategy, and aircraft altitude and moving speed. This sets the stage for Part 2 of this study that aims at possible improvements of the mobile cloud tomography approach by a group of sensitivity studies using observation system simulation experiments.

Citation: Huang, D., Gasiewksi, A., and Wiscombe, W.: Retrieval of cloud liquid water distributions from a single scanning microwave radiometer aboard a moving platform – Part 1: Field trial results from the Wakasa Bay experiment, Atmos. Chem. Phys. Discuss., 9, 12027-12064, doi:10.5194/acpd-9-12027-2009, 2009.
 
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