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7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Long-term EARLINET dust observations
Lucia Mona,V. Amiridis, A. Amodeo, G. D’Amico, A. Hiebsch, N.
Papagiannopoulos, A. Papayannis, M. Sicard, U. Wandinger, A. Comeron ,
and G. Pappalardo
CNR-IMAA Consiglio Nazionale delle Ricerche - Istituto di Metodologie per l’Analisi Ambientale,
Tito Scalo (Potenza) I-85050, Italy
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
● since 2000
● 27 lidar stations
- 10 multiwavelength Raman lidar stations
backscatter (355, 532 and 1064 nm) + extinction (355
and 532 nm) + depol ratio (532 nm)
- 10 Raman lidar stations
- 7 single backscatter lidar stations
● comprehensive, quantitative, and statistically significant data base
● Continental and long-term scale
EARLINET-ASOS
European Aerosol Research Lidar Network
www.earlinet.org
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
EARLINET is an optimal observation tool for Saharan dust events
- dust profiling
- stations located in Southern Europe
- high performance lidar stations
- coverage at continental scale to study transport and modification processes
- a suitable observing methodology has been established within the network
forecasting scheme [DREAM, Skiron]
alert (warnings: 24-48 h)
- use of air-mass back-trajectory analysis [German Meteorological Service
(DWD/GME Model) and NOAA HYSPLIT] and satellite data analysis
(EP/TOMS AI, SeaWiFS AOT, NOAA/AVHRR AOT, MODIS AOT,
CALIPSO)
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
EARLINET measurements
Saharan dust
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 outputs of the DREAM (Dust REgional Atmospheric
Model), and the Skiron models distributed to all EARLINET stations by
the NTUA (National Technical University of Athens) group
The alerts are diffused 24 to 36 hours prior to the arrival of dust aerosols
over the EARLINET sites.
Typically runs of measurements longer than the typical 3-hour observations
performed for the EARLINET systematic measurements are performed
at the EARLINET stations in order to investigate the temporal
evolution of the dust events.
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Lidar raw signal (unless of the background subtraction) provides information about particle layers (aerosol and/or clouds) and their temporal evolution. Information about intrusion into the Planetary boundary Layer can be obtained.
Potenza, 19-22 April 2010 – Eyjafjallajokull eruption
Arrival of volcanic plume and its intrusion into the PBL Mona et al., ACP2012
EARLINET products
Quicklook images typically avaialble through a link from www.earlinet.org
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Example of EARLINET measurements
FT layer
PBL
AODUV=0.26
AODVIS=0.19
AODUV=0.17
AODVIS=0.11
SUV=51±10 sr
SVIS=53±8 sr
Å = 0.9 ± 0.2
δ=0.12±0.03
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
All Climatol Calipso Saharan Volcanic DiurnalCycle Cirrus Others
0
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10000
15000
20000
25000
30000
35000
40000
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EARLINET database
Devoted database in a standardized NetCDF format (CF compliant dataformat).
EARLINET database is organised into 10 categories (climatology, saharan, volcanic, forest fires , calipso, etc)
3 level of data availability: internal (1 year From data acquisition)
External freely available www.earlinet.org and
ACTRIS data portal
DOI database with quality checked files in publication
2000 2002 2004 2006 2008 2010 2012
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7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
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) Papayannis et al. JGR 2008
North and Western regions show low dust transport activity
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
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 over Europe.
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Systematic dust observations over Europe
S values ranged between 38 and 60 sr inside the dust layer,
while their standard deviation is of the order of 20–30%.
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Systematic dust observations over Europe
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
S at 532 nm between 34t – 39 sr for dust event in 2011
28%–35% linear particle depolarization ratio Mamouri et al., GRL 2013
Papayannis et al. JGR 2008
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Dust: mixing and typing
Among cases of Saharan dust intrusions observed over EARLINET in May 2008–
October 2009 period, we found that:
• only 12% of cases can be considered pure Saharan dust cases
• 88% of the cases, mixing of dust with different aerosol types cannot be excluded.
The mixtures of dust, pollution, and marine aerosol are the most frequently obtained.
All mixtures lie on nearly straight
connecting lines between their
constituents.
Such a clear behavior is not necessarily
expected and could indicate external
mixtures.
It seems possible defining
“trajectories” between pure aerosol
types in a multi-dimensional
parameter space on which the
mixtures occur.
Wandinger, Executive summary ESTEC, 2011
Satellite validation & exploitation
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Satellite validation & exploitation
Evaluation of CALIPSO Lev 2 aerosol opticla profiles within 100 km of distance from
EARLINET stations. Leipzig, Evora, Granada, Napoli and Potenza selected for
having the largest single station databases.
A total amount of about 150 extinction comparison is achieved.
Mona et al., in preparation
In the middle altitude range (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.
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Satellite validation & exploitation
Observations (airborne in situ + lidar ) performed in pure dust in the Saharan
dust plume over Southern Morocco and Cape Verde during SAMUM campaign
showed that:
• 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 optical depth, by 10%–40% is caused
Wandinger et al GRL 2011
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Models evaluation
A method for a quantitative evaluation of the dust modeled profiles is explored
starting from the 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.
Potenza EARLINET file : typically 30min as temporal resolution –
vertical resolution 60 m for backscatter –
240 m for extinction profiles
BSC-DREAM8b profiles: 3h as temporal resolution
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 ACPD 2013
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Models evaluation
Geometrical features of dust layer is well described by the model in terms of center
of mass.
Good correlation between optical properties and concentration profiles apart from
cases with low dust amount (AOD
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Models evaluation
Future plans
The methodology and software for this comparison 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 mass concentration profiles with
models.
Binietoglou et al POSTER n. O4
BSC-DREAM8b
predicts
exceptionally well the
start of the event.
After 5 days the
prediction is not so
good.
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Instruments synergy
LIRIC integrates co-located sun-photometer and lidar measurements.
Integration with in situ measurements was stimulated by the 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) was appropriately scheduled for taking
the most from the potential cooperation with other CHARMEX and PEGASOS
measurement campaigns which took place in selected regions of Europe in the same
period.
Papagiannopoulos et al POSTER n. O14
Two intense African dust outbreaks were observed: 18-21June, and 28
June – 6 July.
EALINET stations situated in the Mediterranean basin, identified the
plume as it propagated from the source region to Spain and then towards
Italy.
Agreement with mineral dust analyses performed by EMEP stations
(EMEP status report 2/2013), on the levels and composition of PM10.
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
NRT data and data assimilation
EARLINET operationality exercise:
• 72h of continouos measurements
• Range corrected signals were assimilated in an Air Quality Model
• A centralized and automatic procedure for ldiar 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)
Wang et al in preparation
PM10:
No significant improvement on the
whole Europe
AOD:
1:1 better correlation when lidar data
were assimilated
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Future plans
EARLINET long term observations will be used for systematic models evaluations
Synergistic approach with other remote sensing sensors will be exploited for ICN and
NWP studies
After first promising results, NRT lidar data and assimilation will be investigated
Intensive properties vs mixing and source regions are under investigation.
7th
International Workshop on Sand/Duststorms and Associated Dustfall, ESRIN, Frascati, 2-4 December 2013
Thanks for your attenction!!!
The online abstract submission closes on 20th December.