Airborne lidar measurements of aerosol optical properties during SAFARI-2000

Abstract. Airborne lidar and in-situ measurements of the aerosol properties were conducted between Svalbard Island and Scandinavia in April 2008. Evidence of aerosol transport from Europe and Asia is given. The analysis of the aerosol optical properties based on a multiwavelength lidar (355, 532, 1064 nm) including depolarization at 355 nm aims at distinguishing the role of the different aerosol sources (Siberian wild fires, Eastern Asia and European anthropogenic emissions). Combining, first aircraft measurements, second FLEXPART simulations with a calculation of the PBL air fraction originating from the three different mid-latitude source regions, and third level-2 CALIPSO data products (i.e. backscatter coefficient, depolarisation and color ratio in aerosol layers) along the transport pathways, appears a valuable approach to identify the role of the different aerosol sources even after a transport time larger than 4 days. Above Asia, CALIPSO data indicate more depolarisation (up to 15%) and largest color ratio (>0.5) for the northeastern Asia emissions (i.e. an expected mixture of Asian pollution and dust), while low depolarisation together with smaller and quasi constant color ratio (≈0.3) are observed for the Siberian biomass burning emissions. A similar difference is visible between two layers observed by the aircraft above Scandinavia. The analysis of the time evolution of the aerosol optical properties revealed by CALIPSO between Asia and Scandinavia shows a gradual decrease of the aerosol backscatter, depolarisation ratio and color ratio which suggests the removal of the largest particles in the accumulation mode. A similar study conducted for a European plume has shown aerosol optical properties intermediate between the two Asian sources with color ratio never exceeding 0.4 and moderate depolarisation ratio being always less than 8%, i.e. less aerosol from the accumulation mode.

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Seventeen-year systematic measurements of dust aerosol optical properties using the eole ntua lidar system (2000-2016)

EPJ Web of Conferences ◽

10.1051/epjconf/201817605029 ◽

2018 ◽

Vol 176 ◽

pp. 05029

Author(s):

Ourania Soupiona ◽

Maria Mylonaki ◽

Alexandros Papayannis ◽

Athina Argyrouli ◽

Panayotis Kokkalis ◽

...

Keyword(s):

Optical Properties ◽

Mean Value ◽

Saharan Dust ◽

Aerosol Optical Properties ◽

Mean Values ◽

Time Period ◽

Lidar Measurements ◽

Multi Wavelength ◽

Lidar Ratio ◽

Dust Events

A comprehensive analysis of the seasonal variability of the optical properties of Saharan dust aerosols over Athens, Greece, is presented for a 17-year time period (2000-2016), as derived from multi-wavelength Raman lidar measurements (57 dust events with more than 80 hours of measurements). The profiles of the derived aerosol optical properties (aerosol backscatter and extinction coefficients, lidar ratio and aerosol Ångström exponent) at 355 nm are presented. For these dust events we found a mean value of the lidar ratio of ~52±13 sr at 355 nm and of ~58±8 sr (not shown) at 532 nm (2-4 km a.s.l. height). For our statistical analysis, presented here, we used monthly-mean values and time periods under cloud-free conditions. The number of dust events was greatest in late spring, summer, and early autumn periods. In this paper we also present a selected case study (04 April 2016) of desert dust long-range transport from the Saharan desert.

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Airborne lidar measurements of aerosol spatial distribution and optical properties over the Atlantic Ocean during a European pollution outbreak of ACE-2

Tellus B ◽

10.3402/tellusb.v52i2.17126 ◽

2000 ◽

Vol 52 (2) ◽

pp. 662-677 ◽

Cited By ~ 15

Author(s):

Cyrille Flamant ◽

Jacques Pelon ◽

Patrick Chazette ◽

Vincent Trouillet ◽

Patricia K. Quinn ◽

...

Keyword(s):

Optical Properties ◽

Spatial Distribution ◽

Atlantic Ocean ◽

Airborne Lidar ◽

Lidar Measurements

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Aerosol optical properties from multiwavelength lidar measurements in Romania

10.1117/12.830707 ◽

2009 ◽

Author(s):

Doina Nicolae ◽

Camelia Talianu ◽

Emil Carstea ◽

Anca Nemuc

Keyword(s):

Optical Properties ◽

Aerosol Optical Properties ◽

Lidar Measurements ◽

Multiwavelength Lidar

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Vertical profiles of aerosol optical properties and the solar heating rate estimated by combining sky radiometer and lidar measurements

10.5194/amt-2016-65 ◽

2016 ◽

Cited By ~ 1

Author(s):

Rei Kudo ◽

Tomoaki Nishizawa ◽

Toshinori Aoyagi

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Heating Rate ◽

Extinction Coefficient ◽

Single Scattering ◽

Solar Heating ◽

Asymmetry Factor ◽

Vertical Profiles ◽

Aerosol Optical Properties ◽

Lidar Measurements

Abstract. The SKYLIDAR algorithm was developed to estimate vertical profiles of aerosol optical properties from sky radiometer (SKYNET) and lidar (AD-Net) measurements. The solar heating rate was also estimated from the SKYLIDAR retrievals. The algorithm consists of two retrieval steps: (1) columnar properties are retrieved from the sky radiometer measurements and the vertically mean depolarization ratio obtained from the lidar measurements, and (2) vertical profiles are retrieved from the lidar measurements and the results of the first step. The derived parameters are the vertical profiles of the size distribution, refractive index (real and imaginary parts), extinction coefficient, single-scattering albedo, and asymmetry factor. Sensitivity tests were conducted by applying the SKYLIDAR algorithm to the simulated sky radiometer and lidar data for vertical profiles of three different aerosols, continental average, transported dust, and pollution aerosols. The vertical profiles of the size distribution, extinction coefficient, and asymmetry factor were well estimated in all cases. The vertical profiles of the refractive index and single-scattering albedo of transported dust were well estimated but not those of transported pollution aerosol. To demonstrate the performance and validity of the SKYLIDAR algorithm, we applied the SKYLIDAR algorithm to the actual measurements at Tsukuba, Japan. The detailed vertical structures of the aerosol optical properties and solar heating rate of transported dust and smoke were investigated. Examination of the relationship between the solar heating rate and the aerosol optical properties showed that the vertical profile of the asymmetry factor played an important role in creating vertical variation in the solar heating rate. We then compared the columnar optical properties between SKYLIDAR and SKYRAD.PACK retrievals, and the surface solar irradiance calculated from the SKYLIDAR retrievals was compared with pyranometer measurement. The results showed good agreements: The columnar values of the SKYLIDAR retrievals agreed with reliable SKYRAD.PACK retrievals, and the SKYLIDAR retrievals were sufficiently accurate to evaluate the surface solar irradiance.

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Vertical profiles of aerosol optical properties and the solar heating rate estimated by combining sky radiometer and lidar measurements

Atmospheric Measurement Techniques ◽

10.5194/amt-9-3223-2016 ◽

2016 ◽

Vol 9 (7) ◽

pp. 3223-3243 ◽

Cited By ~ 8

Author(s):

Rei Kudo ◽

Tomoaki Nishizawa ◽

Toshinori Aoyagi

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Heating Rate ◽

Extinction Coefficient ◽

Single Scattering ◽

Solar Heating ◽

Asymmetry Factor ◽

Vertical Profiles ◽

Aerosol Optical Properties ◽

Lidar Measurements

Abstract. The SKYLIDAR algorithm was developed to estimate vertical profiles of aerosol optical properties from sky radiometer (SKYNET) and lidar (AD-Net) measurements. The solar heating rate was also estimated from the SKYLIDAR retrievals. The algorithm consists of two retrieval steps: (1) columnar properties are retrieved from the sky radiometer measurements and the vertically mean depolarization ratio obtained from the lidar measurements and (2) vertical profiles are retrieved from the lidar measurements and the results of the first step. The derived parameters are the vertical profiles of the size distribution, refractive index (real and imaginary parts), extinction coefficient, single-scattering albedo, and asymmetry factor. Sensitivity tests were conducted by applying the SKYLIDAR algorithm to the simulated sky radiometer and lidar data for vertical profiles of three different aerosols, continental average, transported dust, and pollution aerosols. The vertical profiles of the size distribution, extinction coefficient, and asymmetry factor were well estimated in all cases. The vertical profiles of the refractive index and single-scattering albedo of transported dust, but not those of transported pollution aerosol, were well estimated. To demonstrate the performance and validity of the SKYLIDAR algorithm, we applied the SKYLIDAR algorithm to the actual measurements at Tsukuba, Japan. The detailed vertical structures of the aerosol optical properties and solar heating rate of transported dust and smoke were investigated. Examination of the relationship between the solar heating rate and the aerosol optical properties showed that the vertical profile of the asymmetry factor played an important role in creating vertical variation in the solar heating rate. We then compared the columnar optical properties retrieved with the SKYLIDAR algorithm to those produced with the more established scheme SKYRAD.PACK, and the surface solar irradiance calculated from the SKYLIDAR retrievals was compared with pyranometer measurement. The results showed good agreements: the columnar values of the SKYLIDAR retrievals agreed with reliable SKYRAD.PACK retrievals, and the SKYLIDAR retrievals were sufficiently accurate to evaluate the surface solar irradiance.

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