Optical and microphysical characterization of aerosol layers over South Africa by means of multi-wavelength depolarization and Raman lidar measurements

Abstract. Optical and microphysical properties of different aerosol types over South Africa measured with a multi-wavelength polarization Raman lidar are presented. This study could assist in bridging existing gaps relating to aerosol properties over South Africa, since limited long-term data of this type is available for this region. The observations were performed under the framework of the EUCAARI campaign in Elandsfontein. The multi-wavelength PollyXT Raman lidar system was used to determine vertical profiles of the aerosol optical properties, i.e. extinction and backscatter coefficients, Ångström exponents, lidar ratio and depolarization ratio. The mean microphysical aerosol proper ties, i.e. effective radius and single scattering, albedo were retrieved with an advanced inversion algorithm. Clear differences were observed for the intensive optical properties of atmospheric layers of biomass burning and urban/industrial aerosols. Our results reveal a wide range of optical and microphysical parameters for biomass burning aerosols. This indicates probable mixing of biomass burning aerosols with desert dust particles, as well as the possible continuous influence of urban/industrial aerosol load in the region. The lidar ratio at 355 nm, the linear particle depolarization ratio at 355 nm and the extinction-related Ångström exponent from 355 to 532 nm were 52 ± 7 sr; 0.9 ± 0.4 % and 2.3 ± 0.5, respectively for urban/industrial aerosols, while these values were 92 ± 10 sr; 3.2 ± 1.3 %; 2.0 ± 0.4 respectively for biomass burning aerosols layers. Biomass burning particles are larger and slightly less absorbing compared to urban/industrial aerosols. The particle effective radius were found to be 0.10 ± 0.03, 0.17 ± 0.04 and 0.13 ± 0.03 μm for urban/industrial, biomass burning, and mixed biomass burning and desert dust aerosols, respectively, while the single scattering albedo at 532 nm were 0.87 ± 0.06, 0.90 ± 0.06, and 0.88 ± 0.07 (at 532 nm), respectively for these three types of aerosols. Our results were within the same range of previously reported values.

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Optical and microphysical characterization of aerosol layers over South Africa by means of multi-wavelength depolarization and Raman lidar measurements

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-8109-2016 ◽

2016 ◽

Vol 16 (13) ◽

pp. 8109-8123 ◽

Cited By ~ 22

Author(s):

Elina Giannakaki ◽

Pieter G. van Zyl ◽

Detlef Müller ◽

Dimitris Balis ◽

Mika Komppula

Keyword(s):

South Africa ◽

Optical Properties ◽

Biomass Burning ◽

Single Scattering ◽

Effective Radius ◽

Depolarization Ratio ◽

Raman Lidar ◽

Multi Wavelength ◽

Lidar Ratio ◽

Aerosol Properties

Abstract. Optical and microphysical properties of different aerosol types over South Africa measured with a multi-wavelength polarization Raman lidar are presented. This study could assist in bridging existing gaps relating to aerosol properties over South Africa, since limited long-term data of this type are available for this region. The observations were performed under the framework of the EUCAARI campaign in Elandsfontein. The multi-wavelength PollyXT Raman lidar system was used to determine vertical profiles of the aerosol optical properties, i.e. extinction and backscatter coefficients, Ångström exponents, lidar ratio and depolarization ratio. The mean microphysical aerosol properties, i.e. effective radius and single-scattering albedo, were retrieved with an advanced inversion algorithm. Clear differences were observed for the intensive optical properties of atmospheric layers of biomass burning and urban/industrial aerosols. Our results reveal a wide range of optical and microphysical parameters for biomass burning aerosols. This indicates probable mixing of biomass burning aerosols with desert dust particles, as well as the possible continuous influence of urban/industrial aerosol load in the region. The lidar ratio at 355 nm, the lidar ratio at 532 nm, the linear particle depolarization ratio at 355 nm and the extinction-related Ångström exponent from 355 to 532 nm were 52 ± 7 sr, 41 ± 13 sr, 0.9 ± 0.4 % and 2.3 ± 0.5, respectively, for urban/industrial aerosols, while these values were 92 ± 10 sr, 75 ± 14 sr, 3.2 ± 1.3 % and 1.7 ± 0.3, respectively, for biomass burning aerosol layers. Biomass burning particles are larger and slightly less absorbing compared to urban/industrial aerosols. The particle effective radius were found to be 0.10 ± 0.03, 0.17 ± 0.04 and 0.13 ± 0.03 µm for urban/industrial, biomass burning, and mixed aerosols, respectively, while the single-scattering albedo at 532 nm was 0.87 ± 0.06, 0.90 ± 0.06, and 0.88 ± 0.07 (at 532 nm), respectively, for these three types of aerosols. Our results were within the same range of previously reported values.

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Forest Fire Smoke Layers Observed in the Free Troposphere over Portugal with a Multiwavelength Raman Lidar: Optical and Microphysical Properties

The Scientific World JOURNAL ◽

10.1155/2014/421838 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11 ◽

Cited By ~ 12

Author(s):

Sérgio Nepomuceno Pereira ◽

Jana Preißler ◽

Juan Luis Guerrero-Rascado ◽

Ana Maria Silva ◽

Frank Wagner

Keyword(s):

Single Scattering ◽

Effective Radius ◽

Free Troposphere ◽

Depolarization Ratio ◽

Raman Lidar ◽

Extinction Coefficients ◽

Smoke Particles ◽

Microphysical Properties ◽

Fire Smoke ◽

Lidar Ratio

Vertically resolved optical and microphysical properties of biomass burning aerosols, measured in 2011 with a multiwavelength Raman lidar, are presented. The transportation time, within 1-2 days (or less), pointed towards the presence of relatively fresh smoke particles over the site. Some strong layers aloft were observed with particle backscatter and extinction coefficients (at 355 nm) greater than 5 Mm−1 sr−1and close to 300 Mm−1, respectively. The particle intensive optical properties showed features different from the ones reported for aged smoke, but rather consistent with fresh smoke. The Ångström exponents were generally high, mainly above 1.4, indicating a dominating accumulation mode. Weak depolarization values, as shown by the small depolarization ratio of 5% or lower, were measured. Furthermore, the lidar ratio presented no clear wavelength dependency. The inversion of the lidar signals provided a set of microphysical properties including particle effective radius below 0.2 μm, which is less than values previously observed for aged smoke particles. Real and imaginary parts of refractive index of about 1.5-1.6 and 0.02i, respectively, were derived. The single scattering albedo was in the range between 0.85 and 0.93; these last two quantities indicate the nonnegligible absorbing characteristics of the observed particles.

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Optical and Microphysical Properties of Aged Biomass Burning Aerosols and Mixtures, Based on 9-Year Multiwavelength Raman Lidar Observations in Athens, Greece

Remote Sensing ◽

10.3390/rs13193877 ◽

2021 ◽

Vol 13 (19) ◽

pp. 3877

Author(s):

Maria Mylonaki ◽

Alexandros Papayannis ◽

Dimitra Anagnou ◽

Igor Veselovskii ◽

Christina-Anna Papanikolaou ◽

...

Keyword(s):

Biomass Burning ◽

Single Scattering ◽

Volume Density ◽

Raman Lidar ◽

Climatic Effects ◽

Data Set ◽

Microphysical Properties ◽

Lidar Ratio ◽

532 Nm ◽

Aerosol Properties

Mean optical and microphysical aerosol properties of long-range transported biomass burning (BB) particles and mixtures are presented from a 9-year (2011–2019) data set of multiwavelength Raman lidar data, obtained by the EOLE lidar over the city of Athens (37.58° N, 23.47° E), Greece. We studied 34 aerosol layers characterized as: (1) smoke; (2) smoke + continental polluted, and (3) smoke + mixed dust. We found, mainly, small-sized aerosols with mean backscatter-related (355 nm/532 nm, 532 nm/1064 nm) values and Ångström exponent (AE) values in the range 1.4–1.7. The lidar ratio (LR) value at 355 nm was found to be 57 ± 10 sr, 51 ± 5 sr, and 38 ± 9 sr for the aerosol categories (1), (2), and (3), respectively; while at 532 nm, we observed LR values of 73 ± 11 sr, 59 ± 10 sr, and 62 ± 12 for the same categories. Regarding the retrieved microphysical properties, the effective radius (reff) ranged from 0.24 ± 0.11 to 0.24 ± 0.14 μm for all aerosol categories, while the volume density (vd) ranged from 8.6 ± 3.2 to 20.7 ± 14.1 μm−3cm−3 with the higher values linked to aerosol categories (1) and (2); the real part of the refractive index (mR) ranged between 1.49 and 1.53, while for the imaginary part (mI), we found values within 0.0108 i and 0.0126 i. Finally, the single scattering albedo (SSA) of the propped particles varied from 0.915 to 0.936 at all three wavelengths (355–532–1064 nm). The novelty of this study is the provision of typical values of BB aerosol properties from the UV to the near IR, which can be used in forecasting the aerosol climatic effects in the European region.

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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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One year of Raman lidar observations of free-tropospheric aerosol layers over South Africa

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-5429-2015 ◽

2015 ◽

Vol 15 (10) ◽

pp. 5429-5442 ◽

Cited By ~ 16

Author(s):

E. Giannakaki ◽

A. Pfüller ◽

K. Korhonen ◽

T. Mielonen ◽

L. Laakso ◽

...

Keyword(s):

South Africa ◽

Optical Properties ◽

Biomass Burning ◽

Mean Value ◽

Aerosol Layer ◽

Raman Lidar ◽

Tropospheric Aerosol ◽

Wide Range ◽

Significant Difference ◽

532 Nm

Abstract. Raman lidar data obtained over a 1 year period has been analysed in relation to aerosol layers in the free troposphere over the Highveld in South Africa. In total, 375 layers were observed above the boundary layer during the period 30 January 2010 to 31 January 2011. The seasonal behaviour of aerosol layer geometrical characteristics, as well as intensive and extensive optical properties were studied. The highest centre heights of free-tropospheric layers were observed during the South African spring (2520 ± 970 m a.g.l., also elsewhere). The geometrical layer depth was found to be maximum during spring, while it did not show any significant difference for the rest of the seasons. The variability of the analysed intensive and extensive optical properties was high during all seasons. Layers were observed at a mean centre height of 2100 ± 1000 m with an average lidar ratio of 67 ± 25 sr (mean value with 1 standard deviation) at 355 nm and a mean extinction-related Ångström exponent of 1.9 ± 0.8 between 355 and 532 nm during the period under study. Except for the intensive biomass burning period from August to October, the lidar ratios and Ångström exponents are within the range of previous observations for urban/industrial aerosols. During Southern Hemispheric spring, the biomass burning activity is clearly reflected in the optical properties of the observed free-tropospheric layers. Specifically, lidar ratios at 355 nm were 89 ± 21, 57 ± 20, 59 ± 22 and 65 ± 23 sr during spring (September–November), summer (December–February), autumn (March–May) and winter (June–August), respectively. The extinction-related Ångström exponents between 355 and 532 nm measured during spring, summer, autumn and winter were 1.8 ± 0.6, 2.4 ± 0.9, 1.8 ± 0.9 and 1.8 ± 0.6, respectively. The mean columnar aerosol optical depth (AOD) obtained from lidar measurements was found to be 0.46 ± 0.35 at 355 nm and 0.25 ± 0.2 at 532 nm. The contribution of free-tropospheric aerosols on the AOD had a wide range of values with a mean contribution of 46%.

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The characterization of Taklamakan dust properties using a multi-wavelength Raman polarization lidar in Kashi, China

10.5194/acp-2020-375 ◽

2020 ◽

Cited By ~ 1

Author(s):

Qiaoyun Hu ◽

Haofei Wang ◽

Philippe Goloub ◽

Zhengqiang Li ◽

Igor Veselovskii ◽

...

Keyword(s):

Fine Particles ◽

Depolarization Ratio ◽

Taklamakan Desert ◽

Multi Wavelength ◽

Lidar Ratio ◽

Linear Depolarization Ratio ◽

Dust Events ◽

532 Nm ◽

Depolarization Ratios

Abstract. The Taklamakan desert is an important dust source for the global atmospheric dust budget and a cause of the dust weather in Eastern Asia. The characterization of the properties and vertical distributions of Taklamakan dust in the source region is still very limited. To fill this gap, the DAO (Dust Aerosol Observation) was conducted in Kashi, China in 2019. Kashi site is about 150 km to the west rim of the Taklamakan desert and is strongly impacted by desert dust aerosols, especially in spring time, i.e. April and May. Apart from dust, fine particles coming from local anthropogenic emissions or/and transported aerosols are also a non-negligible aerosol component. In this study, we provide the first profiling of the 2α + 3β + 3δ lidar profiles of Taklamakan dust based on a multi-wavelength Raman polarization lidar. Four cases, including two Taklamakan dust events (Case 1 and 2) and two polluted dust events (Case 3 and 4) are presented. The lidar ratio in the Taklamakan dust outbreak is found to be 51 ± 8–56 ± 8 sr at 355 nm and 45 ± 7 sr at 532 nm. The particle linear depolarization ratios are about 0.28 ± 0.04–0.32 ± 0.05 at 355 nm, 0.35 ± 0.05 at 532 nm and 0.31 ± 0.05 at 1064 nm. The observed polluted dust is commonly featured with reduced particle linear depolarization ratio and enhanced extinction and backscatter Angstrom exponent. In Case 3, the lidar ratio of polluted dust is about 42 ± 6 sr at 355 nm and 40 ± 6 sr at 532 nm. The particles linear depolarization ratios decrease to about 0.25, with a weak spectral dependence. In Case 4, the variability of lidar ratio and particle linear depolarization ratio is higher than in Case 3, which reflects the complexity of the nature of mixed pollutant and the mixing state. The results provide the first reference for the characteristics of Taklamakan dust measured by Raman lidar. The data could contribute to complementing the dust model and improving the accuracy of climate modeling.

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Detection and characterization of birch pollen in the atmosphere using multi-wavelength Raman lidar in Finland

10.5194/acp-2019-635 ◽

2019 ◽

Author(s):

Stephanie Bohlmann ◽

Xiaoxia Shang ◽

Elina Giannakaki ◽

Maria Filioglou ◽

Annika Saarto ◽

...

Keyword(s):

Birch Pollen ◽

Pollen Grains ◽

Mean Value ◽

Forest Site ◽

Depolarization Ratio ◽

Atmospheric Conditions ◽

Raman Lidar ◽

Pollen Types ◽

Multi Wavelength ◽

532 Nm

Abstract. We present the results of birch pollen characterization using lidar measurements based on a 11-day period of birch pollination from 5 to 15 May 2016 at the European Aerosol Research Lidar Network (EARLINET) station in Vehmasmäki (Kuopio, 62°44′ N, 27°33′ E), Finland. The ground-based multi-wavelength Raman lidar PollyXT performed continuous measurements at this rural forest site and has been combined with a Hirst-type volumetric air sampler which measured the pollen type and concentration on roof level (4 m). The period was separated into two parts due to different atmospheric conditions and detected pollen types. During the first period, high concentrations of birch pollen were measured with a maximum two-hour average pollen concentration of 3700 grains/m³. Other pollen types represented less than 3 % of the total pollen count. In observed pollen layers, the mean particle depolarization ratio at 532 nm was 10 ± 6 % during the intense birch pollination period. Mean lidar ratios were found to be 45 ± 7 and 55 ± 16 sr at 355 and 532 nm, respectively. During the second period, birch pollen was still dominant but a significant contribution of spruce pollen was observed. Spruce pollen grains are highly non-spherical, leading to a larger mean depolarization ratio of 26 ± 7 % of the birch-spruce pollen mixture. Furthermore, higher lidar ratios were observed during this period with a mean value of 60 ± 3 and 62 ± 10 sr at 355 and 532 nm, respectively. The presented study shows the potential of the particle depolarization ratio to track pollen grains in the atmosphere.

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Optical and geometrical aerosol particle properties over the United Arab Emirates

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-8909-2020 ◽

2020 ◽

Vol 20 (14) ◽

pp. 8909-8922 ◽

Cited By ~ 3

Author(s):

Maria Filioglou ◽

Elina Giannakaki ◽

John Backman ◽

Jutta Kesti ◽

Anne Hirsikko ◽

...

Keyword(s):

Aerosol Particle ◽

United Arab Emirates ◽

Mineral Dust ◽

Depolarization Ratio ◽

Raman Lidar ◽

Particle Properties ◽

Measurement Site ◽

Ångström Exponent ◽

Lidar Ratio ◽

532 Nm

Abstract. One year of ground-based night-time Raman lidar observations has been analysed under the Optimization of Aerosol Seeding In rain enhancement Strategies (OASIS) project, in order to characterize the aerosol particle properties over a rural site in the United Arab Emirates. In total, 1130 aerosol particle layers were detected during the 1-year measurement campaign which took place between March 2018 and February 2019. Several subsequent aerosol layers could be observed simultaneously in the atmosphere up to 11 km. The observations indicate that the measurement site is a receptor of frequent dust events, but predominantly the dust is mixed with aerosols of anthropogenic and/or marine origin. The mean aerosol optical depth over the measurement site ranged at 0.37 ± 0.12 and 0.21 ± 0.11 for 355 and 532 nm, respectively. Moreover, mean lidar ratios of 43 ± 11 sr at a wavelength of 355 nm and 39 ± 10 sr at 532 nm were found. The average linear particle depolarization ratio measured over the course of the campaign was 15 ± 6 % and 19 ± 7 % at the 355 and 532 nm wavelengths, respectively. Since the region is both a source and a receptor of mineral dust, we have also explored the properties of Arabian mineral dust of the greater area of the United Arab of Emirates and the Arabian Peninsula. The observed Arabian dust particle properties were 45 ± 5 (42 ± 5) sr at 355 (532) nm for the lidar ratio, 25 ± 2 % (31 ± 2 %) for the linear particle depolarization ratio at 355 (532) nm, and 0.3 ± 0.2 (0.2 ± 0.2) for the extinction-related Ångström exponent (backscatter-related Ångström exponent) between 355 and 532 nm. This study is the first to report comprehensive optical properties of the Arabian dust particles based on 1-year long observations, using to their fullest the capabilities of a multi-wavelength Raman lidar instrument. The results suggest that the mineral dust properties over the Middle East and western Asia, including the observation site, are comparable to those of African mineral dust with regard to the particle depolarization ratios, but not for lidar ratios. The smaller lidar ratio values in this study compared to the reference studies are attributed to the difference in the geochemical characteristics of the soil originating in the study region compared to northern Africa.

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Evaluation of the Lidar/Radiometer Inversion Code (LIRIC) to determine microphysical properties of volcanic and desert dust

Atmospheric Measurement Techniques ◽

10.5194/amt-6-1707-2013 ◽

2013 ◽

Vol 6 (7) ◽

pp. 1707-1724 ◽

Cited By ~ 64

Author(s):

J. Wagner ◽

A. Ansmann ◽

U. Wandinger ◽

P. Seifert ◽

A. Schwarz ◽

...

Keyword(s):

Spherical Particle ◽

Dust Particles ◽

Depolarization Ratio ◽

Particle Fraction ◽

Raman Lidar ◽

Desert Dust ◽

Microphysical Properties ◽

Coarse Mode ◽

Fine Mode ◽

Lidar Ratio

Abstract. The Lidar/Radiometer Inversion Code (LIRIC) combines the multiwavelength lidar technique with sun/sky photometry and allows us to retrieve vertical profiles of particle optical and microphysical properties separately for fine-mode and coarse-mode particles. After a brief presentation of the theoretical background, we evaluate the potential of LIRIC to retrieve the optical and microphysical properties of irregularly shaped dust particles. The method is applied to two very different aerosol scenarios: a strong Saharan dust outbreak towards central Europe and an Eyjafjallajökull volcanic dust event. LIRIC profiles of particle mass concentrations for the coarse-mode as well as for the non-spherical particle fraction are compared with results for the non-spherical particle fraction as obtained with the polarization-lidar-based POLIPHON method. Similar comparisons for fine-mode and spherical particle fractions are presented also. Acceptable agreement between the different dust mass concentration profiles is obtained. LIRIC profiles of optical properties such as particle backscatter coefficient, lidar ratio, Ångström exponent, and particle depolarization ratio are compared with direct Raman lidar observations. Systematic deviations between the LIRIC retrieval products and the Raman lidar measurements of the desert dust lidar ratio, depolarization ratio, and spectral dependencies of particle backscatter and lidar ratio point to the applied spheroidal-particle model as main source for these uncertainties in the LIRIC results.

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Optical and geometrical aerosol particle properties over the United Arab Emirates

10.5194/acp-2020-133 ◽

2020 ◽

Author(s):

Maria Filioglou ◽

Elina Giannakaki ◽

John Backman ◽

Jutta Kesti ◽

Anne Hirsikko ◽

...

Keyword(s):

Aerosol Particle ◽

United Arab Emirates ◽

Mineral Dust ◽

Depolarization Ratio ◽

Raman Lidar ◽

Particle Properties ◽

Measurement Site ◽

Lidar Ratio ◽

One Year ◽

532 Nm

Abstract. One-year of ground-based night-time Raman lidar observations have been analysed under the Optimization of Aerosol Seeding In rain enhancement Strategies (OASIS) project, in order to characterize the aerosol particle properties over a rural site in the United Arab Emirates. In total, 1130 aerosol particle layers were detected during the one-year measurement campaign which took place between March 2018 and February 2019. Several subsequent aerosol layers could be observed simultaneously in the atmosphere up to 11 km. The observations indicate that the measurement site is a receptor of frequent dust events but predominantly the dust is mixed with aerosols of anthropogenic and/or marine origin. The mean aerosol optical depth over the measurement site ranged at 0.37 ± 0.12 and 0.21 ± 0.11 for the 355 and 532 nm, respectively. Moreover, a mean lidar ratio of 43 ± 11 sr at a wavelength of 355 nm and 39 ± 10 sr at 532 nm was found. The average linear particle depolarization ratio measured over the course of the campaign was 15 ± 6 % and 19 ± 7 % at 355 nm and 532 nm wavelengths, respectively. Since the region is both a source and a receptor of mineral dust, we have also explored the properties of Arabian mineral dust of the greater area of United Arab of Emirates and the Arabian Peninsula. The observed Arabian dust particle properties were 45 ± 5 (42 ± 5) sr at 355 (532) nm for the lidar ratio, 25 ± 2 % (31 ± 2 %) for the linear particle depolarization ratio at 355 (532) nm, and 0.3 ± 0.2 (0.2 ± 0.2) for the extinction‑related Ångström exponent (backscatter‑related Ångström exponent) between 355 and 532 nm. This study is the first to report comprehensive optical properties of the Arabian dust particles based on long term observations, using at the fullest the capabilities of a multi wavelength Raman lidar instrument. The results suggest that the mineral dust properties over the Middle East and western Asia, including the observation site, are comparable to those of African mineral dust with regard to the particle depolarization ratios but not for lidar ratios. The smaller lidar ratio values in this study compared to the reference studies are attributed to the difference in the geochemical characteristics of the soil originating in the study region compared to Northern Africa.

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