Publication Abstracts
Chowdhary et al. 2005
, , , P.V. Hobbs, G.F. Cota, J. Redemann, K. Rutledge, B.N. Holben, and E. Russell, 2005: Retrieval of aerosol scattering and absorption properties from photopolarimetric observations over the ocean during the CLAMS experiment. J. Atmos. Sci., 62, 1093-1117, doi:10.1175/JAS3389.1.
The extensive set of measurements performed during the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) experiment provides a unique opportunity to evaluate aerosol retrievals over the ocean from multiangle, multispectral photometric and polarimetric remote sensing observations by the airborne Research Scanning Polarimeter (RSP) instrument.
Previous studies have shown the feasibility of retrieving particle size distributions and real refractive indices from such observations for visible wavelengths without prior knowledge of the ocean color. This work evaluates the fidelity of the aerosol retrievals using RSP measurements during the CLAMS experiment against aerosol properties derived from in situ measurements, sky radiance observations and sun photometer measurements, and further extends the scope of the RSP retrievals by using a priori information about the ocean color to constrain the aerosol absorption and vertical distribution.
It is shown that the fine component of the aerosol observed on 17 July 2001 consisted predominantly of dirty sulfate-like particles with an extinction optical thickness of several tenths in the visible, an effective radius of 0.15±0.025 µm and a single scattering albedo of 0.91±0.03 at 550 nm. Analyses of the ocean color and sky radiance observations favor the lower boundary of aerosol single scattering albedo, while in situ measurements favor its upper boundary. Both analyses support the polarimetric retrievals of fine-aerosol effective radius and the consequent spectral variation in extinction optical depth. The estimated vertical distribution of this aerosol component depends on assumptions regarding the waterleaving radiances, and is consistent with the top of the aerosol layer being close to the aircraft height (3500 m) with the bottom of the layer being between 2.7 km and the surface. The aerosol observed on 17 July 2001 also contained coarse-mode particles. Comparison of RSP data with sky radiance and in situ measurements suggest that this component consists of non-spherical particles with an effective radius in excess of 1 µm, and with the extinction optical depth being much less than one tenth at 550 nm.
Export citation: [ BibTeX ] [ RIS ]
BibTeX Citation
@article{ch00600k, author={Chowdhary, J. and Cairns, B. and Mishchenko, M. I. and Hobbs, P. V. and Cota, G. F. and Redemann, J. and Rutledge, K. and Holben, B. N. and Russell, E.}, title={Retrieval of aerosol scattering and absorption properties from photopolarimetric observations over the ocean during the CLAMS experiment}, year={2005}, journal={Journal of the Atmospheric Sciences}, volume={62}, pages={1093--1117}, doi={10.1175/JAS3389.1}, }
[ Close ]
RIS Citation
TY - JOUR ID - ch00600k AU - Chowdhary, J. AU - Cairns, B. AU - Mishchenko, M. I. AU - Hobbs, P. V. AU - Cota, G. F. AU - Redemann, J. AU - Rutledge, K. AU - Holben, B. N. AU - Russell, E. PY - 2005 TI - Retrieval of aerosol scattering and absorption properties from photopolarimetric observations over the ocean during the CLAMS experiment JA - J. Atmos. Sci. JO - Journal of the Atmospheric Sciences VL - 62 SP - 1093 EP - 1117 DO - 10.1175/JAS3389.1 ER -
[ Close ]