[1] A fresh biomass-burning pollution plume was monitored and characterized in terms of optical and microphysical properties for the first time with a combination of Raman lidar and star-and sun-photometers. Such an instrument combination is highly useful for 24-h monitoring of pollution events. The observations were made at Granada (37.16°N, 3.6°W), Spain. The fresh smoke particles show a rather pronounced accumulation mode and features markedly different from those reported for aged particles. We find lidar ratios around 60-65 sr at 355 nm and 532 nm, and particle effective radii below 0.20 mm. We find low values of the single-scattering albedo of 0.76-0.9 depending on measurement wavelength. The numbers are lower than what have been found for aged, long-range-transported smoke that originated from boreal fires in Canada and Siberia. Citation: Alados-Arboledas, L., D. Müller, J. L. Guerrero-Rascado, F. Navas-Guzmán, D. Pérez-Ramírez, and F. J. Olmo (2011), Optical and microphysical properties of fresh biomass burning aerosol retrieved by Raman lidar, and starand sun-photometry, Geophys. Res. Lett., 38, L01807,

28Knowledge of the scattering enhancement factor, f(RH), is important for an accurate 29 description of direct aerosol radiative forcing. This factor is defined as the ratio between the 30 scattering coefficient at enhanced relative humidity, RH, to a reference (dry) scattering

Abstract. This study investigates aerosol optical properties during the extreme Saharan dust event detected from 3 to 7 September 2007 over Granada, southern Iberian Peninsula, with both active and passive remote sensing instrumentation from surface and satellite. The intensity of the event was visualized on the aerosol optical depth series obtained by the sun-photometer Cimel CE 318-4 operated at Granada in the framework of AERONET from August 2004 until December 2008 (level 2 data). A combination of large aerosol optical depth (0.86-1.50) at 500 nm, and reduced Angström exponent (0.1-0.25) in the range 440-870 nm, was detected on 6 September during daytime. This Saharan dust event also affected other Iberian Peninsula stations included in AERONET (El Arenosillo andÉvora stations), and it was monitored by MODIS instrument on board Aqua satellite. Vertically resolved measurements were performed by a ground-based Raman Lidar and by CALIPSO satellite. During the most intense stage, on 6 September, maximum aerosol backscatter values were a factor of 8 higher than other maxima during this Saharan dust event. Values up to 1.5×10 −2 km −1 sr −1 at 355 and 532 nm were detected in the layer with the greatest aerosol load between 3-4 km a.s.l., although aerosol particles were also detected up to 5.5 km a.s.l. In this stage of the event, dust particles at these altitudes showed a backscatter-related Angström exponent between −0.44 and 0.53 for the two spectral intervals considered. The results from different measurements (active/passive and Correspondence to: L. Alados Arboledas (alados@ugr.es) ground-based/satellite) reveal the importance of performing multi-instrumental measurements to properly characterize the contribution of different aerosol types from different sources during extreme events. The atmospheric stabilization effect of the aerosol particles has been characterized by computing the solar heating rates using SBDART code.