The European Aerosol Research Lidar Network (EARLINET): An Overview.
ABSTRACT The European Aerosol Research LIdar NETwork (EARLINET) is the first aerosol lidar network on a continental scale with the main goal to provide a comprehensive, quantitative, and statistically significant database for the aerosol distribution over Europe. Next, we present EARLINET along with the main network activities.
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ABSTRACT: A method is proposed that permits one to retrieve physical parameters of tropospheric particle size distributions, e.g., effective radius, volume, surface-area, and number concentrations, as well as the mean complex refractive index on a routine basis from backscatter and extinction coefficients at multiple wavelengths. The optical data in terms of vertical profiles are derived from multiple-wavelength lidar measurements at 355, 400, 532, 710, 800, and 1064 nm for backscatter data and 355 and 532 nm for extinction data. The algorithm is based on the concept of inversion with regularization. Regularization is performed by generalized cross-validation. This method does not require knowledge of the shape of the particle size distribution and can handle measurement errors of the order of 20%. It is shown that at least two extinction data are necessary to retrieve the particle parameters to an acceptable accuracy. Simulations with monomodal and bimodal logarithmic-normal size distributions show that it is possible to derive effective radius, volume, and surface-area concentrations to an accuracy of +/-50%, the real part of the complex refractive index to +/-0.05, and the imaginary part to +/-50%. Number concentrations may have errors larger than +/-50%.Applied Optics 05/1999; 38(12):2346-57. · 1.69 Impact Factor
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ABSTRACT: 1] The spread of mineral particles over southwestern, western, and central Europe resulting from a strong Saharan dust outbreak in October 2001 was observed at 10 stations of the European Aerosol Research Lidar Network (EARLINET). For the first time, an optically dense desert dust plume over Europe was characterized coherently with high vertical resolution on a continental scale. The main layer was located above the boundary layer (above 1-km height above sea level (asl)) up to 3–5-km height, and traces of dust particles reached heights of 7–8 km. The particle optical depth typically ranged from 0.1 to 0.5 above 1-km height asl at the wavelength of 532 nm, and maximum values close to 0.8 were found over northern Germany. The lidar observations are in qualitative agreement with values of optical depth derived from Total Ozone Mapping Spectrometer (TOMS) data. Ten-day backward trajectories clearly indicated the Sahara as the source region of the particles and revealed that the dust layer observed, e.g., over Belsk, Poland, crossed the EARLINET site Aberystwyth, UK, and southern Scandinavia 24–48 hours before. Lidar-derived particle depolarization ratios, backscatter-and extinction-related Å ngström exponents, and extinction-to-backscatter ratios mainly ranged from 15 to 25%, À0.5 to 0.5, and 40–80 sr, respectively, within the lofted dust plumes. A few atmospheric model calculations are presented showing the dust concentration over Europe. The simulations were found to be consistent with the network observations.Journal of Geophysical Research 12/2003; 108(4783-4783). · 3.17 Impact Factor
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ABSTRACT: An intercomparison of the algorithms used to retrieve aerosol extinction and backscatter starting from Raman lidar signals has been performed by 11 groups of lidar scientists involved in the European Aerosol Research Lidar Network (EARLINET). This intercomparison is part of an extended quality assurance program performed on aerosol lidars in the EARLINET. Lidar instruments and aerosol backscatter algorithms were tested separately. The Raman lidar algorithms were tested by use of synthetic lidar data, simulated at 355, 532, 386, and 607 nm, with realistic experimental and atmospheric conditions taken into account. The intercomparison demonstrates that the data-handling procedures used by all the lidar groups provide satisfactory results. Extinction profiles show mean deviations from the correct solution within 10% in the planetary boundary layer (PBL), and backscatter profiles, retrieved by use of algorithms based on the combined Raman elastic-backscatter lidar technique, show mean deviations from solutions within 20% up to 2 km. The intercomparison was also carried out for the lidar ratio and produced profiles that show a mean deviation from the solution within 20% in the PBL. The mean value of this parameter was also calculated within a lofted aerosol layer at higher altitudes that is representative of typical layers related to special events such as Saharan dust outbreaks, forest fires, and volcanic eruptions. Here deviations were within 15%.Applied Optics 11/2004; 43(28):5370-85. · 1.69 Impact Factor
EARLINET: the European aerosol
research lidar network
A coordinated network of advanced remote-sensing stations tracks,
measures, and characterizes atmospheric aerosol for use in climate and
Present knowledge concerning aerosols and their distribution
patterns in the earth’s atmosphere is far from adequate to prop-
erly assess their role in changing climate and environmental con-
ditions, both regionally and globally. Information about vertical
concentrations is particularly lacking. Lidar (light detection and
ranging) remote sensing is the most appropriate tool to close this
observational gap, and networks that deploy this technology are
fundamental to the scaled-up study of aerosol concentrations,
transport, and modification.1
work (EARLINET) currently comprises 25 stations and has as its
main objective the development of a qualitatively and quanti-
tatively significant database that details the horizontal, vertical,
and temporal distribution of atmospheric aerosol over the entire
continent (see Figure 1). Station observation capabilities vary.
EARLINET currently includes 10 single backscatter stations and
8 stations with a UV Raman channel for independent measure-
ments of aerosol extinction and backscatter. In addition, for re-
trieval of aerosol microphysical properties, 7 multiwavelength
Raman stations include elastic channels at 1064, 532, and 355nm,
with Raman channels at 532 and 355nm, and a depolarization
channel at 532nm.
Network-wide observations take place systematically on a
fixed schedule. For collection of unbiased data, all stations per-
form measurements three fixed days per week. Lidar surveil-
lance adheres to a regular timetable: once each week around
noon when the boundary layer is usually well developed, and
twice weekly at night under low background light conditions
in order to perform Raman extinction measurements. Other net-
work activities monitor special events such as Saharan dust out-
breaks (see Figure 2), forest fires, photochemical smog, and vol-
both instruments and evaluation algorithms,2–4and a standard-
Figure 1. Stations in the European Aerosol Research Lidar Network
ized data exchange format has been implemented. EARLINET
measurements, which began in May 2000, represent the largest
database for the aerosol distribution on a continental scale in the
The EARLINET Advanced Sustainable Observation System
(ASOS), a project inaugurated in 2006 and funded under the
European Commission’s Sixth Framework Programme, will fur-
ther improve observations and methodological developments
urgently needed for the multiyear, continental-scale data set
that is required to assess the impact of aerosols on the Eu-
ropean and global environment, and to support future satel-
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10.1117/2.1200809.1265 Page 2/3
Figure 2. Saharan dust observed at altitudes up to 9km via the Potenza
EARLINET station on 26 June 2006.
lite missions. EARLINET data has been already used to make
the first climatological studies of aerosol optical properties over
Europe.5The data set has also helped evaluate long-range trans-
port and to investigate the implications of dust in weather fore-
cast modeling.6–8Retrieval algorithms for aerosol microphysi-
cal properties have been developed and extensively tested with
both synthetic and natural multiwavelength lidar data.9
In addition, EARLINET represents the best available tool for
validation and exploitation of data from the Cloud-Aerosol Li-
dar and Infrared Pathfinder Satellite Observation (CALIPSO)
mission. In particular, extinction and lidar ratio measurements10
will be important for aerosol retrievals from the backscatter
Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP)
that rides on board CALIPSO. Since CALIOP began operating
in June 2006, EARLINET has made approximately 2000 correl-
ative measurements. Initial comparisons between EARLINET
and CALIPSO level 1 data show considerable promise for space-
borne lidar investigation of aerosols and clouds.11
In cooperation with a number of networks distributed world-
wide, EARLINET is also making a significant contribution to-
ward implementation of the Global Atmosphere Watch (GAW)
Atmospheric Lidar Observation Network (GALION). Other par-
ticipating networks include the Molecular Pathology Laboratory
Network (MPLNET), the Asian Lidar Network (ALN), the Com-
monwealth of Independent States Lidar Network (CIS-LINET),
Americas Lidar Network (ALINE).
EARLINET will also contribute to future satellite mis-
sions with lidar instrumentations aboard, such as Atmospheric
Dynamics Mission (ADM)-Aeolus and the joint European-
Japanese mission EarthCARE. The multiwavelength EAR-
LINET data represents validation for these missions and
provides the conversion factors that allow aerosol data at
532 and 1064nm from CALIPSO to link with data at 355nm from
ADM-Aeolus and EarthCARE, with a view to creating a consis-
tent long-term global data set.
In brief, climatological measurements and analysis continue
within EARLINET, in consonance with the aim of developing
the most comprehensive data source for 4D spatiotemporal dis-
tribution of aerosols on a continental scale.
Financial support by the European Commission under grant RICA-
025991 is gratefully acknowledged.
CNR - Istituto di Metodologie per l’Analisi Ambientale
Tito Scalo, Italy
Gelsomina Pappalardo is a physicist whose main research inter-
ests include lidar remote sensing of aerosols, clouds, and water
vapor. She is the EARLINET speaker and coordinator of the EC
FP6 EARLINET-ASOS project.12
1. U. Wandinger, I. Mattis, M. Tesche, A. Ansmann, J. B¨ osenberg, A. Chaikovski,
V. Freudenthaler, L. Komguem, H. Linn´ e, V. Matthias, J. Pelon, L. Sauvage,
P. Sobolewski, G. Vaughan, and M. Wiegner, Air-mass modification over Europe: EAR-
LINET aerosol observations from Wales to Belarus, J. Geophys. Res. 109, p. D24205,
2. V. Matthias, J. B¨ osenberg, V. Freudenthaler, A. Amodeo, D. Balis, A. Chaikovsky,
G. Chourdakis, A. Comeron, A. Delaval, F. de Tomasi, R. Eixmann, A. H˚ ag˚ ard, L.
Komguem, S. Kreipl, R. Matthey, I. Mattis, V. Rizi, J. A. Rodriguez, V. Simeonov,
and X. Wang, Aerosol lidar intercomparison in the framework of the EARLINET project.
1. Instruments, Appl. Opt. 43 (12), pp. 2578–2579, 2004. doi:10.1364/AO.43.002578
3. C. B¨ ockmann, U. Wandinger, A. Ansmann, J. B¨ osenberg, V. Amiridis, A.
Boselli, A. Delaval, F. De Tomasi, M. Frioud, A. H˚ ag˚ ard, M. Horvat, M. Iar-
lori, L. Komguem, S. Kreipl, G. Larchevˆ eque, V. Matthias, A. Papayannis, G.
Pappalardo, F. Rocadembosch, J. A. Rodriguez, J. Schneider, V. Shcherbakov,
and M. Wiegner, Aerosol lidar intercomparison in the framework of the EARLINET
project. 2. Aerosol backscatter algorithms, Appl. Opt. 43 (4), pp. 977–989, 2004.
4. G. Pappalardo, A. Amodeo, M. Pandolfi, U. Wandinger, A. Ansmann, J.
B¨ osenberg, V. Matthias, V. Amiridis, F. De Tomasi, M. Frioud, M. Iarlori, L.
Komguem, A. Papayannis, F. Rocadenbosch, and X. Wang, Aerosol lidar inter-
comparison in the framework of the EARLINET project. 3. Raman lidar algorithm for
aerosol extinction, backscatter, and Lidar ratio, Appl. Opt. 43 (28), pp. 5370–5385, 2004.
5. V. Matthias, D. Balis, J. B¨ osenberg, R. Eixmann, M. Iarlori, L. Komguem, I. Mat-
tis, A. Papayannis, G. Pappalardo, M. R. Perrone, and X. Wang, The vertical aerosol
distribution over Europe: statistical analysis of Raman lidar data from 10 EARLINET sta-
tions, J. Geophys. Res. 109, p. D18201, 2004. doi:10.1029/2004JD004638
Continued on next page
10.1117/2.1200809.1265 Page 3/3
6. D. M¨ uller, I. Mattis, U. Wandinger, A. Ansmann, D. Althausen, and A. Stohl,
Raman lidar observations of aged Siberian and Canadian forest fire smoke in the free tro-
posphereover Germanyin 2003:microphysicalparticle characterization,J.Geophys. Res.
110, p. D17201, 2005. doi:10.1029/2004JD005756
7. G. Pappalardo, A. Amodeo, L. Mona, M. Pandolfi, N. Pergola, and V. Cuomo,
Raman lidar observations of aerosol emitted during the 2002 Etna eruption, Geophys.
Res. Lett. 31, p. L05120, 2004. doi:10.1029/2003GL019073
8. A. Papayannis, V. Amiridis, L. Mona, G. Tsaknakis, D. Balis, J. B¨ osenberg, A.
Chaikovski, F. De Tomasi, I. Grigorov, I. Mattis, V. Mitev, D. M¨ uller, S. Nickovic, C.
P´ erez, A. Pietruczuk, G. Pisani, F. Ravetta, V. Rizi, M. Sicard, T. Trickl, M. Wiegner,
M. Gerding, R. E. Mamouri, G. D’Amico, and G. Pappalardo, Systematic lidar obser-
Res. 113, p. D10204, 2008. doi:10.1029/2007JD009028
9. C. B¨ ockmann, I. Mironova, D. M¨ uller, L. Schneidenbach, and R. Nessler, Micro-
physical aerosol parameters from multiwavelength lidar, J. Opt. Soc. Am. A 22, pp. 518–
528, 2005. doi:10.1364/JOSAA.22.000518
10. D. M¨ uller, A. Ansmann, I. Mattis, M. Tesche, U. Wandinger, D. Althausen, and
G. Pisani, Aerosol-type-dependent lidar ratios observed with Raman lidar, J. Geophys.
Res. 112, p. D16202, 2007. doi:10.1029/2006JD008292
11. I. Mattis, L. Mona, D. Muller, G. Pappalardo, L. Alados Arboledas, G.
D’Amico, A. Amodeo, A. Apituley, J. M. Baldasano, C. Bockmann, J. Bosenberg,
A. Chaikovsky, A. Comeron, E. Giannakaki, I. Grigorov, J. L. Guerrero Rascado, O.
Gustafsson, M. Iarlori, H. Linne, V. Mitev, F. M. Menendez, D. Nicolae, A. Papayan-
nis, C. P. Garcia-Pando, M. R. Perrone, A. Pietruczuk, J. P. Putaud, F. Ravetta, A.
Rodrıguez, P. Seifert, M. Sicard, V. Simeonov, P. Sobolewski, N. Spinelli, K. Stebel,
A. Stohl, M. Tesche, T. Trickl, X. Wang, and M. Wiegner, EARLINET correlative mea-
surements for CALIPSO, Proc. SPIE 6750, p. 67500Z, 2007. doi:10.1117/12.738090
12. http://www.earlinet.org EARLINET home page. Accessed 24 September 2008.
c ? 2008 SPIE