* Corresponding Author: cordobajc@inta.es ISSN: 2283-5954 © 2014 The Authors. Published by Digilabs Selection and peer-review under responsibility of DUST2014 Scientific Committee DOI:10.14644/dust.2014.040 Lidar ratio discrimination retrieval in a two-layer aerosol system from elastic lidar measurements in synergy with sun-photometry data Carmen Córdoba-Jabonero 1* , José Antonio Adame 1 , Daniel Grau 1 , Emilio Cuevas 1 , Manuel Gil-Ojeda 1 1 Instituto Nacional de Técnica Aeroespacial (INTA), Atmospheric Research and Instrumentation Branch, Torrejón de Ardoz, 28850-Madrid, Spain 2 Agencia Estatal de Meteorología (AEMET), Izaña Atmospheric Research Centre, Santa Cruz de Tenerife, Spain Abstract The extinction-to-backscattering coefficient ratio (Lidar Ratio, LR) is an aerosol-type dependent parameter associated to the chemical composition, particle shape and size distribution of aerosols. Hence, the LR estimation from lidar measurements is a crucial task in aerosol research. However, the elastic approach for LR data inversion must be carefully applied to realistic aerosol conditions when a multiple contribution of different types of aerosols can coexist. This is the case for aerosols present in the Boundary Layer (BL), where a mixing of different particles can be expected. In this work, we present an experimental LR discrimination elastic inversion procedure focused on the LR estimation for both pure dust particles and BL mixed dust aerosols under Saharan dust intrusion occurrence. In addition, the importance of the selected aerosol scenario (“pure dust”, PDS, vs. “mixed dust”, MDS) applied together to the elastic dust LR retrieval in a two-layer (BL and Free Troposphere, FT) aerosol system is examined. Synergetic lidar and sun-photometry measurements carried out in two AEMET (Spanish Meteorological Agency) stations in the Tenerife Island, close to Saharan dust sources: the Sta. Cruz de Tenerife (SCO, 28.5ºN 16.2ºW, 52 m a.s.l.) and Izaña (IZO, 28.3ºN 16.5ºW, 2400 m a.sl.) observatories, and placed at a relatively close horizontal distance and distant altitudes, are used for that propose. Dusty cases observed during 2009 (55.4 % occurring in summertime) with simultaneous lidar/sun-photometry data are analyzed. In general, in a Saharan-dust influenced region as Tenerife area, LR values of 56 sr and 43 sr could be used in elastic lidar retrievals of the optical properties for particles present, respectively, in ‘pure dust’ and ‘BL mixed dust aerosols’ scenarios. ProScience 1 (2014) 243-248 Available at www.scientevents.com/proscience/