Seventeen-year systematic measurements of dust aerosol optical properties using the eole ntua lidar system (2000-2016)

Ourania Soupiona,Georgios Tsaknakis,Alexandros Papayannis,Panayotis Kokkalis,Maria Mylonaki,Athina Argyrouli,D Nicolae,M.P Mccormick,E Landulfo,C Senff,U Wandinger,A Comeron,A Makoto,I Veselovskii,A Vassilis,F Gibert,D Balis,A Behrendt

doi:10.1051/epjconf/201817605029

Abstract

A comprehensive analysis of the seasonal variability of the optical properties of Saharan dust aerosols over Athens, Greece, is presented for a 17-year time period (2000-2016), as derived from multi-wavelength Raman lidar measurements (57 dust events with more than 80 hours of measurements). The profiles of the derived aerosol optical properties (aerosol backscatter and extinction coefficients, lidar ratio and aerosol Ångström exponent) at 355 nm are presented. For these dust events we found a mean value of the lidar ratio of ~52±13 sr at 355 nm and of ~58±8 sr (not shown) at 532 nm (2-4 km a.s.l. height). For our statistical analysis, presented here, we used monthly-mean values and time periods under cloud-free conditions. The number of dust events was greatest in late spring, summer, and early autumn periods. In this paper we also present a selected case study (04 April 2016) of desert dust long-range transport from the Saharan desert.

Highlights

Dust events occur in the Eastern Mediterranean region mostly from early spring to early autumn, while during winter months dust transport over the area remains quite low as previously shown [1,2,3,4,5]
Each year Saharan dust events occurs that heavily influence the atmospheric conditions over the city of Athens
The lidar system is located at the Laser Remote Sensing Unit (LRSU) of National Technical University of Athens (NTUA) (37.9oN, 23.6oE, 200 m a.s.l.)

Summary

INTRODUCTION

Dust events occur in the Eastern Mediterranean region mostly from early spring to early autumn, while during winter months dust transport over the area remains quite low as previously shown [1,2,3,4,5]. Aerosol lidar measurements are carried out in Athens since the year 2000. Each year Saharan dust events occurs that heavily influence the atmospheric conditions over the city of Athens. The optical properties of the resulting dust aerosol for the time-period 2000-2016, are presented in this work

INSTRUMENTATION

METHODOLOGΥ

STATISTICAL ANALYSIS

CASE STUDY OF 04 APRIL 2016

Findings

CONCLUSIONS