EARLINET: towards an advanced sustainable European aerosol lidar network

Abstract

Abstract. The European Aerosol Research Lidar Network, EARLINET, was founded in 2000 as a research project for establishing a quantitative, comprehensive, and statistically significant database for the horizontal, vertical, and temporal distribution of aerosols on a continental scale. Since then EARLINET has continued to provide the most extensive collection of ground-based data for the aerosol vertical distribution over Europe. This paper gives an overview of the network's main developments since 2000 and introduces the dedicated EAR-LINET special issue, which reports on the present innovative and comprehensive technical solutions and scientific results related to the use of advanced lidar remote sensing techniques for the study of aerosol properties as developed within the network in the last 13 years.Since 2000, EARLINET has developed greatly in terms of number of stations and spatial distribution: from 17 stations in 10 countries in 2000 to 27 stations in 16 countries in 2013. EARLINET has developed greatly also in terms of technological advances with the spread of advanced multiwavelength Raman lidar stations in Europe. The developments for the quality assurance strategy, the optimization of instruments and data processing, and the dissemination of data have contributed to a significant improvement of the network towards a more sustainable observing system, with an increase in the observing capability and a reduction of operational costs.Consequently, EARLINET data have already been extensively used for many climatological studies, long-range transport events, Saharan dust outbreaks, plumes from volcanic eruptions, and for model evaluation and satellite data validation and integration.Future plans are aimed at continuous measurements and near-real-time data delivery in close cooperation with other ground-based networks, such as in the ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network) www.actris.net, and with the modeling and satellite community, linking the research community with the operational world, with the aim of establishing of the atmospheric part of the European component of the integrated global observing system.

EARLINET Single Calculus Chain – technical – Part 2: Calculation of optical products

“…In case of weighted linear fit, data points with larger uncertainties weigh less than data points with lower uncertainties within the calculation of the linear fit (Press et al, 1992). Some groups in EARLINET use other methods for the retrieval of the derivative ( If the user decides to obtain an extinction only product, only the profile of the particle extinction coefficient is retrieved and exported to a NetCDF file together with the profile of its statistical error and effective vertical resolution according to EARLINET format of e-files.…”

“…They are inserted into the bfiles of the EARLINET database (Pappalardo et al, 2014). Profiles of particle extinction coefficients typically have a lower vertical resolution because extinction retrievals with the Raman method are associated with vertical smoothing.…”

“…In general, the range resolution of backscatter profiles is better than the resolution of the corresponding extinction profiles. Thus, in a second step, backscatter profiles are additionally smoothed with a second-order Savitzky-Golay (SG) polynomial filter (Press et al, 1992) in order to achieve the same vertical profile of effective range resolution as the corresponding extinction profile. The relation between the number of altitude bins used for this filter n β,SG and the resulting effective range resolution of the backscatter profile dr β,SG was obtained in the same way as for the extinction retrieval dr β,SG = 1.24n β,SG − 0.24 dr.…”

“…EARLINET consists of research lidars which have originally been designed for many different purposes. These instruments cover a large range with respect to complexity, temporal and range resolution, and vertical measurement range (Pappalardo et al, 2014;Freudenthaler et al, 2016). Thus, there are as many different analysis tools as distinct lidar systems in the network.…”

Ceilometer aerosol profiling versus Raman lidar in the frame of the INTERACT campaign of ACTRIS

“…http://www.dwd.de/ceilomap) represents a strong motivation to investigate the extent to which they can be used to fill the geographical gaps between advanced lidar stations within existing networks like EARLINET (European Aerosol Research Lidar Network; Pappalardo et al, 2014) and also how their continuous data flow can be linked to these networks. To fully exploit this observing capability, the E-PROFILE (http://www.eumetnet.eu/e-profile) observation program, run by the European Met Services, is developing a framework to exchange lidar backscatter data from automatic lidars and ceilometers stations across Europe.…”