| Volumes and Issues Contents of Issue 3 |
www.atmos-meas-tech-discuss.net/4/2883/2011/
doi:10.5194/amtd-4-2883-2011
© Author(s) 2011. This work is distributed
under the Creative Commons Attribution 3.0 License.
First correlated measurements of the shape and scattering properties of cloud particles using the new Particle Habit Imaging and Polar Scattering (PHIPS) probe
1Institute for Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany
2ETH Zurich Institute for Atmospheric and Climate Science, Universitaetstrasse 16, 8092 Zurich, Switzerland
3Centre for Atmospheric and Instrumentation Research, University of Hertfordshire, Hatfield, AL10 9AB, UK
4Jülich Research Center, ICG-1, Jülich, Germany
Abstract. Studying the radiative impact of cirrus clouds requires the knowledge of the link between their microphysics and the single scattering properties of the cloud particles. Usually, this link is created by modeling the optical scattering properties from in situ measurements of ice crystal size distributions. The measured size distribution and the assumed particle shape might be erroneous in case of non-spherical ice particles. We present here a novel optical sensor (the Particle Habit Imaging and Polar Scattering probe, PHIPS) designed to measure the 3-D morphology and the corresponding optical and microphysical parameters of individual cloud particles, simultaneously. Clouds containing particles ranging in size from a few micrometers to about 800 μm diameter can be systematically characterized with an optical resolution power of 2 μm and polar scattering resolution of 1° for forward scattering directions (from 1° to 10°) and 8° for side and backscattering directions (from 18° to 170°). The maximum acquisition rates for scattering phase functions and images are 262 KHz and 10 Hz, respectively. Some preliminary results collected in two ice cloud campaigns which were conducted in the AIDA cloud simulation chamber are presented. PHIPS showed reliability in operation and produced comparable size distributions and images to those given by other certified cloud particles instruments. A 3-D model of a hexagonal ice plate is constructed and the corresponding scattering phase function is compared to that modeled using the Ray Tracing with Diffraction on Facets (RTDF) program. PHIPS is candidate to be a novel air borne optical sensor for studying the radiative impact of cirrus clouds and correlating the particle habit-scattering properties which will serve as a reference for other single, or multi-independent, measurements instruments.
Discussion Paper (PDF, 19575 KB) Interactive Discussion (Closed, 13 Comments) Final Revised Paper (AMT)
Notice on Discussion StatusCitation: Abdelmonem, A., Schnaiter, M., Amsler, P., Hesse, E., Meyer, J., and Leisner, T.: First correlated measurements of the shape and scattering properties of cloud particles using the new Particle Habit Imaging and Polar Scattering (PHIPS) probe, Atmos. Meas. Tech. Discuss., 4, 2883-2930, doi:10.5194/amtd-4-2883-2011, 2011. Bibtex EndNote Reference Manager XML
