Long-Term EARLINET Dust Observations
L. Mona1*, V. Amiridis2, A. Amodeo1, G. D’amico1, A. Schwarz 3, N.
Papagiannopoulos1, A. Papayannis 4, M. Sicard5, U. Wandinger3, A.
Comeron5, G. Pappalardo1
1CNR-IMAA,
Potenza, Italy
2 National Observatory of Athens
Greece
3TROPOS, Leipzig, Germany
4 NTUA, Athens, Greece
5Universitat Politècnica de Catalunya, Barcelona, Spain
and
the EARLINET team
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
EARLINET (European Aerosol Research LIdar NETwork)
●
since 2000
●
27 lidar stations
-10 multiwavelength Raman lidar
stations
-10 Raman lidar stations
- 7 single backscatter lidar stations
●
comprehensive, quantitative, and
statistically significant data base
●
Continental and long-term scale
EARLINET-ASOS
www.earlinet.org
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
EARLINET
EARLINET started in 2000 under FP5 based on research
aerosol lidar stations already available around Europe.
Different lidar set-ups and software analysis around the
network.
Main strengths of the network: sharing the single station
know-how for a continuous improvement of the network as
a whole and acting as a single body.
EARLINET pillars:
 Quality assurance
 Optimization of the instruments
 Optimization of the data processing
 Centralized measurements scheduling
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
EARLINET products
Lidar Range Corrected Signal:
almost raw signal unless background subtraction and multiple by range^2
provides rapid snapshot of temporal - vertical evolution of aerosol layers
6000
3
2
4000
a.u.
Altitude (m)
5000
1
3000
2000
13:20
6000
0
17:40
22:00
02:20
06:40
11:00
15:20
19:40
X 10-6
ude (m)
5000
4000
Aerosol Backsca
Etna 2002 Volcanic eruption – Potenza, Southern Italy
5
Pappalardo et al., GRL, 2004, Villani et al., JGR 2006,
Wang et al., Atm. Env. 2008
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
3
=35
EARLINET products
EARLINET standard products :
-Aerosol backscatter coefficient
(355, 532 and 1064 nm)
-Aerosol extinction coefficient
(355 and 532nm)
-Linear particle depolarization ratio
(355 and 532 nm)
These quantities are reported in the EARLINET database in the netcdf
standardized format.
-Lidar Ratio
(355 and 532 nm)
-Angstrom exponent
(355 and 532nm)
-Backscatter related Angstrom exponent
(355 -532 nm , 532-1064 nm)
These are important for the aerosol typing because do not depend
on aerosol quantity.
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
EARLINET products
AODUV=0.26
AODVIS=0.19
FT layer
AODUV=0.17
AODVIS=0.11
SUV=51±10 sr
SVIS=53±8 sr
Å = 0.9 ± 0.2
PBL
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
δ=0.12±0.03
EARLINET desert dust observations
A suitable observing methodology has been established within
the network for studying Saharan dust events.
Measurements are performed in correspondence of alerts based
on the operational model outputs diffused 24 to 36 hours prior to
the arrival of dust aerosols .
Typically measurements are performed for more than 3 hours to
investigate the temporal evolution of the dust events.
All these data are collected in the Saharan dust EARLINET subset.
Subset published on CERA database:
doi:10.1594/WDCC/EN_SaharanDust_2000-2010
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
Systematic dust observations over Europe
First study on the impact of Saharan dust on European aerosol
content during the first period of operation of the network (2000–
2002)
Central Europe shows low dust transport activity
Papayannis
al.
DUST 2014, 1-6 June 2014, Castellaneta
Marina, et
Italy
JGR 2008
Systematic dust observations over Europe
AOD at 351–355nm inside the dust lofted layers
Values in 0.1 -0.25 range with a standard deviation of the order of 20–
100% that clearly indicates the high variability of the dust outbreaks
DUST 2014, 1-6 June
2014,
Castellaneta Marina, Italy
over
Europe.
Systematic dust observations over Europe
Papayannis et al. JGR 2008
S values ranged between 38 and 60 sr inside the dust layer,
while their standard deviation is of the order of 20–30%.
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
Typical values of intensive properties
Northern Europe
 linear particle depolarization ratio values range from 10 to 25% at
532nm
 approximately constant A° (β355/532) values (−0.5 to 1)
 approximately constant S values (30 to 80 sr)
Southern Europe
 S (20 to 100 sr) with high variability
 A° (β355/532) (−0.5 to 3) highly variable
 linear particle depolarization ratio values as high as 35 % at 532nm
Cyprus: a new EARLINET station for Arabian dust
Papayannis et al. JGR 2008
 S at 532 nm between 34 – 39 sr for dust event in 2011
 28%–35% linear particle depolarization ratio
Mamouri et al., GRL 2013
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
Dust mixture
Among cases in May 2008–October 2009 period:
• only 12% of cases pure Saharan dust cases
• Mixing of dust with others in 88% of the cases
• The mixtures of dust, pollution, and marine aerosol are the most
frequently obtained.
All mixtures lie on nearly
straight connecting lines
between their constituents.
Wandinger, Executive summary ESTEC, 2011
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
Satellite validation: CALIOP Lev2 data
Criteria: 100 km of distance (maximum)
largest single station databases.
2.5-5km: Scal=41.1 sr vs Sear=47.7sr with 7 sr bias. This is probably
due to the Saharan dust occurrences at this altitude range and
stations.
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
Satellite validation: CALIOP Lev2 data
Observations (airborne in situ + lidar ) in pure dust in the Saharan
plume (SAMUM campaign) :
•
in the CALIPSO retrieval of backscatter coefficients, the a
priori lidar ratios from the lookup table of 40 sr used for
dust represents an effective value that accounts well for the
reduced attenuation caused by multiple scattering
•
the CALIPSO extinction values calculated by multiplying
the backscatter values with the effective lidar ratio, a
systematic underestimation of extinction, and thus in
optical depth by 10%–40%
Wandinger et al GRL 2011
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
EARLINET vs BSCDREAM-8b
12-year one site systematic comparison
Potenza (Italy) station selected as the site with the largest database of
dust profiles.
Comparison for May 2000 – June 2012 period between lidar
observations and BSC-DREAM8b forecasts over Potenza.
Only cases in which a Saharan dust layer is identified in the lidar
profiles are compared.
Comparison is performed in terms of dust layer geometrical properties
(base, top, extension and center of mass) and of dust extinction
properties.
Mona et al. ACP 2014 - on review
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
EARLINET vs BSCDREAM-8b
12-year one site systematic comparison
Geometrical features of dust layer are well described by the model in
terms of center of mass.
Mona et al. ACP 2014 - on review
Good correlation between optical properties and concentration
profiles apart from cases with low dust load (AOD <0.1)
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
EARLINET vs BSCDREAM-8b
Differences below
17%:
S: 60 ± 13 sr
Angstrom 0.1 ± 0.6
Differences higher
than 85%:
Angstrom 0.5 ± 0.6
Mona et al. ACP 2014 - on review
All these aspects indicate that the level of agreement decreases
with increasing of mixing/modification processes.
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
Relative difference
in extinction
12-year one site systematic comparison
Models evaluation
The methodology will be used to extend the study to all EARLINET
stations but also to other models.
• BSC-DREAM8b and DREAM8-SEEVCCC
• Granada Potenza Napoli Athens Thessaloniki and Leipzig are
selected for temporal coverage and geographical position.
• Currently in progress, the comparison of LIRIC
(lidar+sunphotometer) mass concentration profiles with models.
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
Models evaluation
BSC-DREAM8b predicts exceptionally well the start of
the event. After 5 days the prediction is not so good.
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
NRT data provision
ACTRIS Summer 2012 campaign.
ACTRIS and EMEP have worked close together to coordinate this
intensive field campaign mainly devoted to study Saharan dust
particles.
The observation period (8 June – 17 July) scheduled for cooperation
with CHARMEX and PEGASOS measurement campaigns
Two intense African dust outbreaks were observed: 18-21June, and
28 June – 6 July.
Qualitative agreement with mineral dust analyses performed by
EMEP stations (EMEP status report 2/2013), on the levels and
composition of PM10.
Papagiannopoulos et al POSTER MondayTuesday MF2
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
ACTRIS Summer 2012 campaign
EARLINET operationality exercise:
•72h of continouos measurements
•Range corrected signals were assimilated in an Air Quality Model
•A centralized and automatic procedure for lidar data pre-processing
and analysis was used (Single Calculus Chain - SCC)
•Chemistry transport model POLAIR3D of the AQ platform Polyphemus
(K. Sartelet / M. Bocquet, CEREA, France)
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
ACTRIS Summer 2012 campaign
Comparison with EMEP model.
VISUAL COMPARISON
Tsyro et al ORAL Thrusday
Model
Lidar
Structures well captured. Some delay in structures for eastern
mediterranean stations
Limassol, Cyprus
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
ACTRIS Summer 2012 campaign
Comparison
model.
with
EMEP
QUANTITAVE COMPARISON
Good agreement for Central
Med
Some discrepancies moving
toward East
Tsyro et al ORAL Thrusday
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
Way forward
EARLINET long term observations will be used for
systematic models evaluations
EARLINET stations could be used as “core sites” for the
operational networks based on less advanced lidar
instruments.
After first promising results,
assimilation will be investigated
NRT
lidar
data
and
Develop new EARLINET data products related to dust
(e.g. dust backscatter profile)
Synergistic approach with other remote sensing sensors
will be exploited for ICN and NWP studies
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy
Thank you!
lucia.mona@imaa.cnr.it
www.earlinet.org
DUST 2014, 1-6 June 2014, Castellaneta Marina, Italy