Retrieval of optical and microphysical properties of transported Saharan dust over Athens and Granada based on multi-wavelength Raman lidar measurements: Study of the mixing processes

This extended abstract reports measurements that were carried out by the Raman lidar system BASIL in the frame of the Hydrological Cycle in the Mediterranean Experiment – Special Observation Period 1 (HyMeX-SOP1). A specific case study was selected revealing the presence of variable aerosol properties at different altitudes. Specifically, Raman lidar measurements on 02 October 2012 reveal the presence of two distinct aerosol layers, a lower one extending up to ~3 km and an upper one extending from 3.5 km to 4.7 km. Aerosol and size microphysical properties are determined from multi-wavelength measurements of particle backscattering and extinction profiles based on the application of a retrieval scheme which employs Tikhonov’s inversion with regularization. Inversion results suggest a size distribution with the presence, in both the lower and upper aerosol layer, of two particle modes (a fine mode, with a radius of ~0.2 μm, and a coarse mode, with radii in the range 2-4 μm), volume concentration values of 2-4 mm3cm-3 and effective radii in the range 0.2-0.6 μm. This effort benefited from the dedicated flights of the French research aircraft ATR42, equipped with a variety of in situ sensors for measuring aerosol/cloud size and microphysical properties. Aerosol size and microphysical properties retrieved from multi-wavelength Raman lidar measurements were compared with simultaneous and co-located in-situ measurements.

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Characterization of Saharan dust, marine aerosols and mixtures of biomass-burning aerosols and dust by means of multi-wavelength depolarization and Raman lidar measurements during SAMUM 2

Tellus B ◽

10.1111/j.1600-0889.2011.00556.x ◽

2011 ◽

Vol 63 (4) ◽

pp. 706-724 ◽

Cited By ~ 153

Author(s):

Silke Groß ◽

Matthias Tesche ◽

Volker Freudenthaler ◽

Carlos Toledano ◽

Matthias Wiegner ◽

...

Keyword(s):

Biomass Burning ◽

Saharan Dust ◽

Marine Aerosols ◽

Raman Lidar ◽

Lidar Measurements ◽

Multi Wavelength

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Multi-wavelength Raman lidar observations of the Eyjafjallajökull volcanic cloud over Potenza, southern Italy

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-2229-2012 ◽

2012 ◽

Vol 12 (4) ◽

pp. 2229-2244 ◽

Cited By ~ 56

Author(s):

L. Mona ◽

A. Amodeo ◽

G. D'Amico ◽

A. Giunta ◽

F. Madonna ◽

...

Keyword(s):

Weather Conditions ◽

Saharan Dust ◽

Volcanic Aerosol ◽

Raman Lidar ◽

Angstrom Exponent ◽

Lidar Measurements ◽

Ångström Exponent ◽

Multi Wavelength ◽

532 Nm ◽

Ångstrom Exponent

Abstract. During the eruption of Eyjafjallajökull in April–May 2010 multi-wavelength Raman lidar measurements were performed at the CNR-IMAA Atmospheric Observatory (CIAO), whenever weather conditions permitted observations. A methodology both for volcanic layer identification and accurate aerosol typing has been developed. This methodology relies on the multi-wavelength Raman lidar measurements and the support of long-term lidar measurements performed at CIAO since 2000. The aerosol mask for lidar measurements performed at CIAO during the 2010 Eyjafjallajökull eruption has been obtained. Volcanic aerosol layers were observed in different periods: 19–22 April, 27–29 April, 8–9 May, 13–14 May and 18–19 May. A maximum aerosol optical depth of about 0.12–0.13 was observed on 20 April, 22:00 UTC and 13 May, 20:30 UTC. Volcanic particles were detected at low altitudes, in the free troposphere and in the upper troposphere. Occurrences of volcanic particles within the PBL were detected on 21–22 April and 13 May. A Saharan dust event was observed on 13–14 May: dust and volcanic particles were simultaneously detected at CIAO at separated different altitudes as well as mixed within the same layer. Lidar ratios at 355 and 532 nm, the Ångström exponent at 355/532 nm, the backscatter-related Ångström exponent at 532/1064 nm and the particle linear depolarization ratio at 532 nm measured inside the detected volcanic layers are discussed. The dependence of these quantities on relative humidity has been investigated by using co-located microwave profiler measurements. The measured values of these intensive parameters indicate the presence of volcanic sulfates/continental mixed aerosol in the volcanic aerosol layers observed at CIAO. In correspondence of the maxima observed in the volcanic aerosol load on 19–20 April and 13 May, different values of intensive parameters were observed. Apart from the occurrence of sulfate aerosol, these values indicate also the presence of some ash which is affected by the aging during transport over Europe.

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Characterization of Saharan dust, marine aerosols and mixtures of biomass-burning aerosols and dust by means of multi-wavelength depolarization and Raman lidar measurements during SAMUM 2

Tellus B ◽

10.3402/tellusb.v63i4.16369 ◽

2011 ◽

Vol 63 (4) ◽

Cited By ~ 3

Author(s):

Silke Groß ◽

Matthias Tesche ◽

Volker Freudenthaler ◽

Carlos Toledano ◽

Matthias Wiegner ◽

...

Keyword(s):

Biomass Burning ◽

Saharan Dust ◽

Marine Aerosols ◽

Raman Lidar ◽

Lidar Measurements ◽

Multi Wavelength

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The potential of the synergistic use of passive and active remote sensing measurements for the validation of a regional dust model

Annales Geophysicae ◽

10.5194/angeo-27-3155-2009 ◽

2009 ◽

Vol 27 (8) ◽

pp. 3155-3164 ◽

Cited By ~ 42

Author(s):

V. Amiridis ◽

M. Kafatos ◽

C. Perez ◽

S. Kazadzis ◽

E. Gerasopoulos ◽

...

Keyword(s):

Remote Sensing ◽

Three Dimensional ◽

Atmospheric Modeling ◽

Saharan Dust ◽

Free Troposphere ◽

Raman Lidar ◽

Dust Event ◽

Lidar Measurements ◽

Multi Wavelength ◽

Regional Atmospheric Modeling

Abstract. A long-lasting Saharan dust event affected Europe on 18–23 May 2008. Dust was present in the free troposphere over Greece, in height ranges between the surface and approximately 4–5 km above sea level. The event was monitored by ground-based CIMEL sunphotometric and multi-wavelength combined backscatter/Raman lidar measurements over Athens, Greece. The dust event had the maximum of its intensity on 20 May. Three-dimensional dust spatial distribution over Greece on that day is presented through satellite synergy of passive and active remote sensing using MODIS and CALIPSO data, respectively. For the period under study, the ground-based measurements are used to characterize the dust event and evaluate the latest version of the BSC Dust Regional Atmospheric Modeling (BSC-DREAM) system. Comparisons of modeled and measured aerosol optical depths over Athens show that the Saharan dust outbreak is fairly well captured by BSC-DREAM simulations. Evaluation of BSC-DREAM using Raman lidar measurements on 20 May shows that the model consistently reproduces the dust vertical distribution over Athens.

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Determination of aerosol size and microphiysical proprierties based on multi-wavelength raman lidar measurements in the framework of HyMeX-SOP1

10.5194/egusphere-egu2020-17218 ◽

2020 ◽

Author(s):

Benedetto De Rosa ◽

Paolo Di Girolamo ◽

Donato Summa

Keyword(s):

Hydrological Cycle ◽

Radiation Budget ◽

Aerosol Layer ◽

Raman Lidar ◽

Good Opportunity ◽

Microphysical Properties ◽

Lidar Measurements ◽

Multi Wavelength ◽

In Situ Sensors

Tropospheric aerosols&#160; are a fundamental component of the Earth&#8217;s radiation budget. In order to properly estimate their direct and indirect effect, accurate measurements of aerosol size and microphysical properties are required.A limited number of techniques are presently available and capable to provide these measurements.Multi-wavelength Raman lidars Raman lidars have strong potential. However,theireffectiveness and reliability of need to be assessed and verified against independent measurements.This abstract reports measurements that were carried out by the Raman lidar system BASIL in the frame of the Hydrological Cycle in the Mediterranean Experiment &#8211; Special Observation Period 1 (HyMeX-SOP1).The considered dataset represents a good opportunity to verify the quality of retrievals in terms of size and microphysical properties obtained from multi-wavelength Raman lidars.A specific case study was selected revealing the presence of variable aerosol properties at different altitudes. Specifically, Raman lidar measurements on 02 October 2012 show the presence of two distinct aerosol layers, a lower one extending up to ~3 km and an upper one extending from 3.5 km to 4.7 km. Aerosol and size microphysical properties are determined from multi-wavelength measurements of particle backscattering and extinction profiles based on the application of&#160; a retrieval scheme which employs Tikhonov&#8217;s inversion with regularization. Inversion results suggest a size distribution with the presence, in both the lower and upper aerosol layer, of two particle modes (a fine mode, with a radius of ~0.2 mm, and a coarse mode, with radii in the range 2-4 mm), volume concentration values of 2-4 mm3cm-3and effective radii in the&#160; range 0.2-0.6 mm.This effort benefited from the dedicated flights of the French research aircraft ATR42, equipped with a variety of in situ sensors for measuring aerosol/cloud size and microphysical properties. Aerosol size and microphysical properties retrieved from multi-wavelength Raman lidar measurements were compared with simultaneous and co-located in-situ measurements.

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Multi-wavelength Raman lidar observations of the Eyjafjallajökull volcanic cloud over Potenza, Southern Italy

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-12763-2011 ◽

2011 ◽

Vol 11 (4) ◽

pp. 12763-12803 ◽

Cited By ~ 12

Author(s):

L. Mona ◽

A. Amodeo ◽

G. D'Amico ◽

A. Giunta ◽

F. Madonna ◽

...

Keyword(s):

Southern Italy ◽

Saharan Dust ◽

Depolarization Ratio ◽

Raman Lidar ◽

Lidar Measurements ◽

Ångström Exponent ◽

Multi Wavelength ◽

Lidar Ratio ◽

Linear Depolarization Ratio ◽

532 Nm

Abstract. Multi-wavelength Raman lidar measurements were performed at CNR-IMAA Atmospheric Observatory (CIAO) during the entire Eyjafjallajökull explosive eruptive period in April–May 2010, whenever weather conditions permitted. A methodology for volcanic layer identification and accurate aerosol typing has been developed on the basis both of the multi-wavelength Raman lidar measurements and EARLINET measurements performed at CIAO since 2000. The aerosol mask for lidar measurements performed at CIAO during the 2010 Eyjafjallajökull eruption has been obtained. Volcanic aerosol layers have been observed in different periods: 19–22 April, 27–29 April, 8–9 May, 13–14 May and 18–19 May. A maximum aerosol optical depth of about 0.12–0.13 was observed on 20 April, 22:00 UTC and 13 May, 20:30 UTC. Volcanic particles have been detected both at low altitudes, in the free troposphere and in the upper troposphere. Intrusions into the PBL have been revealed on 21–22 April and 13 May. In the April–May period Saharan dust intrusions typically occur in Southern Italy. For the period under investigations, a Saharan dust intrusion was observed on 13–14 May: dust and volcanic particles have been simultaneously observed at CIAO both at separated different levels and mixed within the same layer. Lidar ratios at 355 and 532 nm, Ångström exponent at 355/532 nm, backscatter related Ångström exponent at 532/1064 nm and particle linear depolarization ratio at 532 nm measured inside the detected volcanic layers have been discussed. The dependence of these quantities on relative humidity (RH) has been investigated by using co-located microwave profiler measurements. The particle linear depolarization ratio increasing with RH, lidar ratio values at 355 nm around 80 sr, and values of the ratio of lidar ratios greater than 1 suggest the presence of sulfates mixed with continental aerosol. Lower lidar ratio values (around 40 sr) increasing with RH and values of the ratio of lidar ratios lower than 1 indicate the presence of some aged ash inside these sulfate layers.

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EARLINET dust observations vs. BSC-DREAM8b modeled profiles: 12-year-long systematic comparison at Potenza, Italy

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-8781-2014 ◽

2014 ◽

Vol 14 (16) ◽

pp. 8781-8793 ◽

Cited By ~ 39

Author(s):

L. Mona ◽

N. Papagiannopoulos ◽

S. Basart ◽

J. Baldasano ◽

I. Binietoglou ◽

...

Keyword(s):

Center Of Mass ◽

Saharan Dust ◽

Raman Lidar ◽

Dust Layer ◽

Systematic Comparison ◽

Dust Extinction ◽

Lidar Measurements ◽

Order Of Magnitude ◽

Lidar Ratio ◽

532 Nm

Abstract. In this paper, we report the first systematic comparison of 12-year modeled dust extinction profiles vs. Raman lidar measurements. We use the BSC-DREAM8b model, one of the most widely used dust regional models in the Mediterranean, and Potenza EARLINET lidar profiles for Saharan dust cases, the largest one-site database of dust extinction profiles. A total of 310 dust cases were compared for the May 2000–July 2012 period. The model reconstructs the measured layers well: profiles are correlated within 5% of significance for 60% of the cases and the dust layer center of mass as measured by lidar and modeled by BSC-DREAM8b differ on average 0.3 ± 1.0 km. Events with a dust optical depth lower than 0.1 account for 70% of uncorrelated profiles. Although there is good agreement in terms of profile shape and the order of magnitude of extinction values, the model overestimates the occurrence of dust layer top above 10 km. Comparison with extinction profiles measured by the Raman lidar shows that BSC-DREAM8b typically underestimates the dust extinction coefficient, in particular below 3 km. Lowest model–observation differences (below 17%) correspond to a lidar ratio at 532 nm and Ångström exponent at 355/532 nm of 60 ± 13 and 0.1 ± 0.6 sr, respectively. These are in agreement with values typically observed and modeled for pure desert dust. However, the highest differences (higher than 85%) are typically related to greater Ångström values (0.5 ± 0.6), denoting smaller particles. All these aspects indicate that the level of agreement decreases with an increase in mixing/modification processes.

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CADEX and beyond: Installation of a new PollyXT site in Dushanbe

E3S Web of Conferences ◽

10.1051/e3sconf/20199902010 ◽

2019 ◽

Vol 99 ◽

pp. 02010

Author(s):

Ronny Engelmann ◽

Julian Hofer ◽

Abduvosit N. Makhmudov ◽

Holger Baars ◽

Karsten Hanbuch ◽

...

Keyword(s):

Asian Dust ◽

Raman Lidar ◽

Technical Institute ◽

Lidar System ◽

Microphysical Properties ◽

Source Regions ◽

Central Asian ◽

Lidar Measurements ◽

Academy Of Sciences

During the 18-month Central Asian Dust Experiment we conducted continuous lidar measurements at the Physical Technical Institute of the Academy of Sciences of Tajikistan in Dushanbe between 2015 and 2016. Mineral dust plumes from various source regions have been observed and characterized in terms of their occurrence, and their optical and microphysical properties with the Raman lidar PollyXT. Currently a new container-based lidar system is constructed which will be installed for continuous long-term measurements in Dushanbe.

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Multi-Sensor Observation of a Saharan Dust Outbreak over Transylvania, Romania in April 2019

Atmosphere ◽

10.3390/atmos11040364 ◽

2020 ◽

Vol 11 (4) ◽

pp. 364 ◽

Cited By ~ 1

Author(s):

Nicolae Ajtai ◽

Horațiu Ștefănie ◽

Alexandru Mereuță ◽

Andrei Radovici ◽

Camelia Botezan

Keyword(s):

Complex Analysis ◽

Remote Sensing Data ◽

Ground Level ◽

Global Scale ◽

Saharan Dust ◽

Back Trajectories ◽

Microphysical Properties ◽

Multi Wavelength ◽

Degree Of Certainty

Mineral aerosols are considered to be the second largest source of natural aerosol, the Saharan desert being the main source of dust at global scale. Under certain meteorological conditions, Saharan dust can be transported over large parts of Europe, including Romania. The aim of this paper is to provide a complex analysis of a Saharan dust outbreak over the Transylvania region of Romania, based on the synergy of multiple ground-based and satellite sensors in order to detect the dust intrusion with a higher degree of certainty. The measurements were performed during the peak of the outbreak on April the 24th 2019, with instruments such as a Cimel sun-photometer and a multi-wavelength Raman depolarization lidar, together with an in-situ particle counter measuring at ground level. Remote sensing data from MODIS sensors on Terra and Aqua were also analyzed. Results show the presence of dust aerosol layers identified by the multi-wavelength Raman and depolarization lidar at altitudes of 2500–4000 m, and 7000 m, respectively. The measured optical and microphysical properties, together with the HYSPLIT back-trajectories, NMMB/BSC dust model, and synoptic analysis, confirm the presence of lofted Saharan dust layers over Cluj-Napoca, Romania. The NMMB/BSC dust model predicted dust load values between 1 and 1.5 g/m2 over Cluj-Napoca at 12:00 UTC for April the 24th 2019. Collocated in-situ PM monitoring showed that dry deposition was low, with PM10 and PM2.5 concentrations similar to the seasonal averages for Cluj-Napoca.

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