Climatology of the aerosol extinction-to-backscatter ratio from sun-photometric measurements
The elastic lidar equation contains two unknown atmospheric parameters, namely, the particulate optical extinction and backscatter coefficients, which are related through the lidar ratio (i.e., the particulate-extinction-to-backscatter ratio). So far, independent inversion of the lidar signal has be...
| Autores: | , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2010 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/10922 |
| Acceso en línea: | https://hdl.handle.net/2117/10922 https://dx.doi.org/10.1109/TGRS.2009.2027699 |
| Access Level: | acceso abierto |
| Palabra clave: | Aerosols Sun-Photometric Optical radar Signal theory (Telecommunication) back trajectories extinction-tobackscatter Sun photometer. Senyal, Teoria del (Telecomunicació) Àrees temàtiques de la UPC::Enginyeria de la telecomunicació |
| Sumario: | The elastic lidar equation contains two unknown atmospheric parameters, namely, the particulate optical extinction and backscatter coefficients, which are related through the lidar ratio (i.e., the particulate-extinction-to-backscatter ratio). So far, independent inversion of the lidar signal has been carried out by means of Raman lidars (usually limited to nighttime measurements), high-spectral-resolution lidars, or scanning elastic lidars under the assumption of a homogeneously vertically stratified atmosphere. In this paper, we present a procedure to obtain the lidar ratio at 532 nm by a combined Sunphotometer– aerosol-model inversion, where the viability of the solution is largely reinforced by assimilating categorized air-mass back-trajectory information. Thus, iterative lidar-ratio tuning to reconstruct the Sun-photometric aerosol optical depth (AOD) is additionally constrained by the air-mass back trajectories provided by the hybrid single-particle Lagrangian integratedtrajectory model. The retrieved lidar ratios are validated with inversions of lidar data based on the Klett–Fernald–Sasano algorithm and with the Aerosol Robotic Network (AERONET)- retrieved lidar ratios. The estimated lidar ratios concur with the AERONET-retrieved lidar ratios and with those of the well-known KFS inversion constrained with Sun-photometric AOD values and embedded single-scattering models. The proposed method can be applied to routinely extract climatological values of the lidar ratio using measurements of direct solar irradiance (more numerous than those of sky radiance). |
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