Measurements of Saharan dust aerosols over the Eastern Mediterranean using elastic backscatter-Raman lidar, spectrophotometric and satellite observations in the frame of the EARLINET project

Abstract

Abstract. We report on the vertical distributions of Saharan dust aerosols over the N.E. Mediterranean region, which were obtained during a typical dust outbreak on August 2000, by two lidar systems located in Athens and Thessaloniki, Greece, in the frame of the European EARLINET project. MODIS and ground sun spectrophotometric data, as well as air-mass backward trajectories confirmed the existence of Saharan dust in the case examined, which was also successfully forecasted by the DREAM dust model. The lidar data analysis for the period 2000-2002 made possible, for the first time, an estimation of the vertical extent of free tropospheric dust layers [mean values of the aerosol backscatter and extinction coefficients and the extinction-to-backscatter ratio (lidar ratio, LR) at 355 nm], as well as a seasonal distribution of Saharan dust outbreaks over Greece, under cloud-free conditions. A mean value of the lidar ratio at 355 nm was obtained over Athens (53±1 sr) and over Thessaloniki (44±2 sr) during the Saharan dust outbreaks. The corresponding aerosol optical thickness (AOT) at 355 nm, in the altitude range 0-5 km, was 0.69±0.12 and 0.65±0.10 for Athens and Thessaloniki, respectively (within the dust layer the AOT was 0.23 and 0.21, respectively). Air-mass back-trajectory analysis Correspondence to: A. Papayannis (apdlidar@central.ntua.gr) performed in the period 2000-2002 for all Saharan dust outbreaks over the N.E. Mediterranean indicated the main pathways followed by the dust aerosols.

Physical and optical properties of 2010 Eyjafjallajökull volcanic eruption aerosol: ground-based, Lidar and airborne measurements in France

“…The optical receiver is a Cassegrainian reflecting telescope with a primary mirror of 300 mm diameter and a focal length of 600 mm, directly coupled, through an optical fibre, to the Lidar signal multichannel detection box (Papayannis et al, 2005). The vertical resolution of the raw signals is 7.5 m. The Lidar is positioned on the roof of the OPGC, (45.76 • N, 3.11 • E) at 425 m a.s.l.…”

Overview of the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Forcing on the Mediterranean Climate (ChArMEx/ADRIMED) summer 2013 campaign

“…Several sites are equipped with aerosol lidar systems and carry out regular observations in a coordinated way within EARLINET (European Aerosol Research Lidar Network; Pappalardo et al, 2014;Wang et al, 2014). Numerous studies have been specifically dedicated to the vertical distribution of Saharan dust during extended time periods and/or selected events from various Mediterranean regions, mainly from ground-based systems: (i) the eastern basin in Thessaloniki (Hamonou et al, 1999;Balis et al, 2004), Crete (Balis et al, 2006), the Aegean Sea (Dulac and Chazette, 2003), and Athens plus Thessaloniki (Papayannis et al, 2005;Balis et al, 2006); (ii) the central basin in Lampedusa (Di Meloni et al, 2004), Lecce (Tafuro et al, 2006), and at Etna (Tafuro et al, 2006); and (iii) across the western basin with the first spaceborne lidar (Berthier et al, 2006) and at Observatoire de Haute Provence (Hamonou et al, 1999), and Barcelona Sicard et al, 2011). Finally, using data from 20 EARLINET lidar stations, Papayannis et al (2008) indicate that African dust transport over the Mediterranean basin is layered.…”

AIRUSE-LIFE +: estimation of natural source contributions to urban ambient air PM<sub>10</sub> and PM<sub>2. 5</sub> concentrations in southern Europe – implications to compliance with limit values

“…Most of these particles are very coarse (diameter ≥ 10 µm) and are thus deposited close to the source region, while a significant amount of coarse particles (diameter around 1-10 µm) can be transported over long distances. An estimation of the emission flux of desert aerosols that is subject to long-range transport is of the order of 1500 Tg yr −1 (Papayannis et al, 2005).…”