Aerosol lidar intercomparison in the framework of the EARLINET project 1 Instruments

Abstract

In the framework of the European Aerosol Research Lidar Network to Establish an Aerosol Climatology (EARLINET), 19 aerosol lidar systems from 11 European countries were compared. Aerosol extinction or backscatter coefficient profiles were measured by at least two systems for each comparison. Aerosol extinction coefficients were derived from Raman lidar measurements in the UV (351 or 355 nm), and aerosol backscatter profiles were calculated from pure elastic backscatter measurements at 351 or 355, 532, or 1064 nm. The results were compared for height ranges with high and low aerosol content. Some systems were additionally compared with sunphotometers and starphotometers. Predefined maximum deviations were used for quality control of the results. Lidar systems with results outside those limits could not meet the quality assurance criterion. The algorithms for deriving aerosol backscatter profiles from elastic lidar measurements were tested separately, and the results are described in Part 2 of this series of papers [Appl. Opt. 43, 977-989 (2004)]. In the end, all systems were quality assured, although some had to be modified to improve their performance. Typical deviations between aerosol backscatter profiles were 10% in the planetary boundary layer and 0.1 x 10(-6) m(-1) sr(-1) in the free troposphere.

Ground-Based Mie-Scattering Lidar Measurements of Aerosol Extinction Profiles during ABC-EAREX 2005: Comparisons of Instruments and Inversion Algorithms

“…The comparison results of this study, deviations of approximately 3.0% and 11.6% due to the different lidar systems and lidar retrieval algorithms, respectively, are comparable with those listed by Böckmann et al (2004), Matthais et al (2004), and Schmid et al (2006). Böckmann et al (2004) and Matthais et al (2004), who performed an intercomparison of an aerosol backscatter lidar and its algorithms within the framework of the EARLINET in order to study aerosol climatology, showed that the typical deviations between aerosol backscatter profiles among networked instruments were approximately 10% in the planetary bound- Table 2 provide details on the manner in which the statistical results were calculated.…”

“…With regard to the measurement of the vertical distribution of aerosols, a groundbased lidar technique is apparently one of the appropriate methods to measure the vertical profile of ambient aerosol extinction. In the past decades, several lidar systems dedicated to the observation of the vertical profiles of aerosols have been successfully operated (Welton et al 2000;Murayama et al 2001;Ansmann et al 2003;Campbell et al 2003;Kim et al 2004;Matthais et al 2004) and have been used for comparing airborne in situ measurements (Murayama et al 2003;Schmid et al 2006). Numerous inversion methods have also been proposed for the determination of aerosol extinction (Fernald et al 1974;Klett 1981;Fernald 1984;Welton et al 2000;Campbell et al 2002;Sicard et al 2002) because for the evaluation of the aerosol extinction from the lidar return signal, researchers must be able to solve the ambiguity between light scattering and absorption (or extinction) of the laser beam by atmospheric aerosols.…”

“…Numerous inversion methods have also been proposed for the determination of aerosol extinction (Fernald et al 1974;Klett 1981;Fernald 1984;Welton et al 2000;Campbell et al 2002;Sicard et al 2002) because for the evaluation of the aerosol extinction from the lidar return signal, researchers must be able to solve the ambiguity between light scattering and absorption (or extinction) of the laser beam by atmospheric aerosols. Within the framework of the European Aerosol Research Lidar Network (EARLINET), which was established to study aerosol climatology, Böckmann et al (2004) and Matthais et al (2004) compared 19 independently operated aerosol lidar systems distributed over 11 European countries, but not at similar locations. More recently, Schmid et al (2006) concluded that the typical systematic error associated with measuring the tropospheric vertical profile of aerosol extinction with current state-of-the-art instrumentations (e.g., airborne nephelometer/absorption photometer, airborne Sun photometer, ground-based elastic and Raman lidars) is 15~20% at visible wavelengths and potentially larger in the UV and near-infrared regions.…”

Typical tropospheric aerosol backscatter profiles for Southern Ireland: The Cork Raman lidar

“…The system (named UCLID) was setup to contribute to the 'European Aerosol Research Lidar Network' (EARLINET) (Böckmann et al, 2004;Matthias et al, 2004b;Pappalardo et al, 2004) consisting of over 25 stations distributed across Europe [http://www.earlinet.org];…”

Development of Three-Wavelength Polarization-Raman Lidar and Application to Shipborne Measurements

“…Aerosol optical and microphysical properties by ground-based sunphotometer measurements and aerosol vertical profiles by lidar measurements, performed within AERONET [4] and MPLNET [5] , are used to analyze aerosols effects on radiative budget and atmospheric heating rate profiles. Within the European Aerosol Lidar Research Network (EARLINET) [6] , now part of the Aerosols, Clouds, and Trace gases Research InfraStructure Network (ACTRIS), more than 30 lidar systems were used to monitor the aerosol vertical distribution over Europe.…”