scholarly journals Detections and analyses of aerosol optical properties under different weather conditions using multi-wavelength Mie lidar

2014 ◽  
Vol 63 (24) ◽  
pp. 244206
Author(s):  
Di Hui-Ge ◽  
Hou Xiao-Long ◽  
Zhao Hu ◽  
Yan Lei-Jie ◽  
Wei Xin ◽  
...  
Keyword(s):  
Optical Properties ◽  
Weather Conditions ◽  
Aerosol Optical Properties ◽  
Multi Wavelength ◽  
Mie Lidar

scholarly journals Photoacoustic and nephelometric spectroscopy of aerosol optical properties with a supercontinuum light source

2013 ◽  
Vol 6 (12) ◽  
pp. 3501-3513 ◽  
Author(s):  
N. Sharma ◽  
I. J. Arnold ◽  
H. Moosmüller ◽  
W. P. Arnott ◽  
C. Mazzoleni
Keyword(s):  
Optical Properties ◽  
Light Source ◽  
Wavelength Dependence ◽  
Common Salt ◽  
Design Development ◽  
Aerosol Optical Properties ◽  
Scattering Coefficients ◽  
Aerosol Absorption ◽  
Multi Wavelength

Abstract. A novel multi-wavelength photoacoustic-nephelometer spectrometer (SC-PNS) has been developed for the optical characterization of atmospheric aerosol particles. This instrument integrates a white light supercontinuum laser with photoacoustic and nephelometric spectroscopy to measure aerosol absorption and scattering coefficients at five wavelength bands (centered at 417, 475, 542, 607, and 675 nm). These wavelength bands are selected from the continuous spectrum of the laser (ranging from 400–2200 nm) using a set of optical interference filters. Absorption and scattering measurements on laboratory-generated aerosol samples were performed sequentially at each wavelength band. To test the instrument we measured the wavelength dependence of absorption and scattering coefficients of kerosene soot and common salt aerosols. Results were favorably compared to those obtained with a commercial 3-wavelength photoacoustic and nephelometer instrument demonstrating the utility of the SC light source for studies of aerosol optical properties at selected wavelengths. Here, we discuss instrument design, development, calibration, performance and experimental results.

scholarly journals Retrieval of aerosol optical properties over Beijing: a comparison between SKYNET and AERONET

2019 ◽  
Author(s):  
Xianyi Yang ◽  
Huizheng Che ◽  
Hitoshi Irie ◽  
Quanliang Chen ◽  
Ke Gui ◽  
...  
Keyword(s):  
Optical Properties ◽  
Meteorological Data ◽  
Aerosol Particles ◽  
Fine Particulate Matter ◽  
Correlation Coefficients ◽  
Weather Conditions ◽  
Distribution Patterns ◽  
Single Scattering ◽  
Aerosol Optical Properties ◽  
Pollution Event

Abstract. This study assesses the performance of SKYNET in comparison to AERONET (Aerosol Robotic Network) for retrieving aerosol optical properties (AOPs) in Beijing, China. The results obtained from simultaneous measurements show high correlation coefficients (> 0.994) for aerosol optical depth (AOD) at each wavelength. The highest correlation coefficient for Ångström exponent is 0.825, at 500–870 nm. The single scattering albedo (SSA) of SKYNET is systematically larger than that of AERONET at each wavelength, and adjusting the SVA (solid view angle) and SA (surface albedo) input values can easily affect the value of SKYNET SSA. The volume size distribution patterns derived from the two networks’ instruments are both bimodal, which is typical, while the coarse-mode volume of SKYNET is larger than that of AERONET on average. According to the frequency distribution of aerosol particles, coarser aerosol particles often present in autumn and finer particles usually exist in winter, and there are more absorbent aerosol particles in winter. SKYNET data, combined with meteorological data, CALIPSO (Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations) data, backward trajectories, and WPSCF (weighted potential source contribution function) and WCWT (weighted concentrated weighted trajectory) analyses are used to analyze a serious pollution event in winter over Beijing. The results suggest that it was not only affected by local emissions but also by regional transport. The AOPs under three weather conditions (clean, dusty, haze) in Beijing are discussed. The values of AOD on haze days are about 10.3, 10.0, 8.7, 6.3 and 6.2 times larger than those on clean days at 400, 500, 670, 870 and 1020 nm, respectively; and under haze conditions, the PM2.5 (fine particulate matter) is about 7.6 times larger than that under clean conditions. The values of AOD on dusty days are about 7.1, 7.4, 7.0, 5.3 and 5.2 times larger than those on clean days at 400, 500, 670, 870 and 1020 nm, respectively; and under haze conditions, the PM2.5 is about 5.2 times larger than that under clean conditions.

Long term (2007–2013) observations of columnar aerosol optical properties and retrieved size distributions over Anantapur, India using multi wavelength solar radiometer

2016 ◽  
Vol 142 ◽  
pp. 238-250 ◽  
Author(s):  
K. Raja Obul Reddy ◽  
G. Balakrishnaiah ◽  
K. Rama Gopal ◽  
N. Siva Kumar Reddy ◽  
T. Chakradhar Rao ◽  
...  
Keyword(s):  
Optical Properties ◽  
Size Distributions ◽  
Aerosol Optical Properties ◽  
Multi Wavelength

scholarly journals Intercomparison between aerosol optical properties by a PREDE skyradiometer and CIMEL sunphotometer over Beijing, China

2008 ◽  
Vol 8 (12) ◽  
pp. 3199-3214 ◽  
Author(s):  
H. Che ◽  
G. Shi ◽  
A. Uchiyama ◽  
A. Yamazaki ◽  
H. Chen ◽  
...  
Keyword(s):  
Optical Properties ◽  
Size Distribution ◽  
Complex Refractive Index ◽  
Weather Conditions ◽  
Single Scattering ◽  
Single Scattering Albedo ◽  
Aerosol Optical Properties ◽  
Significant Difference ◽  
Beijing China ◽  
Volume Size

Abstract. This study compares the aerosol optical and physical properties simultaneously measured by a SKYNET PREDE skyradiometer and AERONET/PHOTONS CIMEL sunphotometer at a location in Beijing, China. Aerosol optical properties (AOP) including the Aerosol Optical Depth (AOD), Angstrom exponent (α), volume size distribution, single scattering albedo (ω) and the complex refractive index were compared. The difference between the two types of instruments was less than 1.3% for the AOD and less than 4% for the single scattering albedo below the wavelength of 670 nm. There is a difference between the volume size distribution patterns derived from two instruments, which is probably due to difference of measurement protocols and inversion algorithms for the respective instruments. AOP under three distinct weather conditions (background, haze, and dust days) over Beijing were compared by using the retrieved skyradiometer and sunphotometer data combined with MODIS satellite results, pyranometer measurements, PM10 measurements, and backtrajectory analysis. The results show that the significant difference of AOP under background, haze, and dust days over Beijing is probably due to different aerosol components under distinct weather conditions.

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

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.

scholarly journals A new method to determine the aerosol optical properties from multiple-wavelength O<sub>4</sub> absorptions by MAX-DOAS observation

2019 ◽  
Vol 12 (6) ◽  
pp. 3289-3302 ◽  
Author(s):  
Chengzhi Xing ◽  
Cheng Liu ◽  
Shanshan Wang ◽  
Qihou Hu ◽  
Haoran Liu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Elevation Angle ◽  
Ground Surface ◽  
Correlation Coefficients ◽  
Weather Conditions ◽  
Optical Absorption Spectroscopy ◽  
Aerosol Optical Properties ◽  
Multiple Wavelength ◽  
Rainy Weather ◽  
Haze Days

Abstract. Ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) observation was carried out from November 2016 to February 2017 in Beijing, China, to measure the O4 absorptions in UV and visible bands and further to illustrate its relationship with aerosol optical properties (AOPs) under different weather types. According to relative humidity, visibility, and PM2.5, we classified the observation periods into clear, light-haze, haze, heavy-haze, fog, and rainy weather conditions. There are obvious differences for measured AOPs under different weather conditions, especially scattering coefficient (σsca) and absorption coefficient (σsca). It was also found that both the O4 differential slant column densities (DSCDs) at the UV and visible bands varied in the order of clear days > light-haze days > haze days > heavy-haze days > fog days. The correlation coefficients (R2) between O4 DSCDs at 360.8 and 477.1 nm mainly varied in the order of clear days > light-haze days > haze days > heavy-haze days. Based on the statistics of O4 DSCDs at an elevation angle 1∘ with the corresponding linear regression between UV and visible bands of segmental periods, the relationships between O4 DSCDs and AOPs were established. It should mainly be clear or light-haze days when the correlation slope is greater than 1.0, with a correlation coefficient (R2) greater than 0.9, and O4 DSCDs mainly greater than 2.5×1043 molec. cm−2. Meanwhile, σsca and σabs are less than 45 and 12 Mm−1, respectively. For haze or heavy-haze days, the correlation slope is less than 0.6, with an R2 less than 0.8, and O4 DSCDs mainly less than 1.3×1043 molec. cm−2, under which σsca and σabs are mainly located at 200–900 and 20–60 Mm−1. Additionally, the determination method was well validated based on another MAX-DOAS measurement at Gucheng from 19 to 27 November 2016. For more precise and accurate inversion of AOPs, more detailed look-up tables for O4 multiple-wavelength absorptions need to be developed. Since the ground surface AOPs were determined using MAX-DOAS observation at a 1∘ elevation in this study, we hope to highlight the potential of retrieved vertical spatially resolved AOPs being expected when multiple elevation angles of MAX-DOAS observation are used together.

scholarly journals Intercomparison between aerosol optical properties by a PREDE skyradiometer and CIMEL sunphotometer over Beijing, China

2007 ◽  
Vol 7 (6) ◽  
pp. 16023-16053 ◽  
Author(s):  
H. Che ◽  
G. Shi ◽  
A. Uchiyama ◽  
A. Yamazaki ◽  
H. Chen ◽  
...  
Keyword(s):  
Optical Properties ◽  
Size Distribution ◽  
Complex Refractive Index ◽  
Weather Conditions ◽  
Single Scattering ◽  
Single Scattering Albedo ◽  
Aerosol Optical Properties ◽  
Significant Difference ◽  
Beijing China ◽  
Volume Size

Abstract. This study compares the aerosol optical and physical properties simultaneously measured by a SKYNET PREDE skyradiometer and AERONET/PHOTONS CIMEL sunphotometer at a location in Beijing, China. Aerosol optical properties (AOP) including the Aerosol Optical Depth (AOD), Angstrom exponent (α), volume size distribution, single scattering albedo (ω) and the complex refractive index were compared. The difference between the two types of instruments was less than 1.3% for the AOD and less than 4% for the single scattering albedo below the wavelength of 670 nm. There is a difference between the volume size distribution patterns derived from two instruments, which is probablely due to difference of measurement protocols and inversion algorithms for the respective instruments. AOP under three distinct weather conditions (background, haze, and dust days) over Beijing were compared by using the retrieved skyradiometer and sunphotometer data combined with MODIS satellite results, pyranometer measurements, PM10 measurements, and backtrajectory analysis. The results show that the significant difference of AOP under background, haze, and dust days over Beijing is probablely due to different aerosol components under distinct weather conditions.

scholarly journals Aerosol optical properties variability during biomass burning events observed by the eole-aias depolarization lidars over Athens, Greece (2007-2016)

2018 ◽  
Vol 176 ◽  
pp. 05022
Author(s):  
Maria Mylonaki ◽  
Alexandros Papayannis ◽  
Rodanthi Mamouri ◽  
Athina Argyrouli ◽  
Panagiotis Kokkalis ◽  
...  
Keyword(s):  
Optical Properties ◽  
Biomass Burning ◽  
Vertical Profiles ◽  
Aerosol Optical Properties ◽  
Smoke Particles ◽  
Range Transport ◽  
Multi Wavelength ◽  
Lidar Ratio ◽  
Sun Photometer ◽  
532 Nm

The EOLE multi-wavelength aerosol Ramandepolarization lidar, and the AIAS depolarization lidar, in synergy with a sun photometer (CIMEL), were used, in the period 2007-2016, to provide the vertical profiles of the aerosol optical properties over Athens, Greece. More than 30 biomass burning events (fresh and aged smoke particles) were observed, with smoke layers between 1.5 up to 4-5 km height, while their duration ranged from 1-3 days. Lidar ratio (LR) values ranged from 40-105 sr (at 355 nm) and from 40-100 sr (at 532 nm), while the linear particle depolarization ratio (LPDR) at both 355 and 532 nm, remained <7%. The extinction-related Ångström exponent (AEa) at 355 nm/532 nm) ranged from 0.3 to 2.1. Additionally, a case of a near-range transport of biomass burning aerosols arriving over Athens up to 4 km height, between 27 and 28 June 2016, was studied. For this case, we found LRs of the order of 70±5 sr (355 nm) and 65±15 sr (532 nm) and AEa(355 nm/532 nm) around 1.

Dual pure-rotational Raman channel design and implementation in a multiwavelength lidar system for the monitoring of aerosol optical properties.

2021 ◽  
Author(s):  
José-Alex Zenteno-Hernández
Keyword(s):  
Optical Properties ◽  
Cross Sections ◽  
State Of The Art ◽  
Aerosol Optical Properties ◽  
Lidar System ◽  
Separation Unit ◽  
Interference Filters ◽  
Multi Wavelength ◽  
Expected Signal

&lt;p&gt;Pure-rotational Raman (PRR) scattering has proven to be an efficient technique for the determination of atmospheric aerosol optical properties for lidar applications. We present the implementation of a UV-PRR and the design of a VIS-PRR in the EARLINET/UPC multi-wavelength lidar system (Barcelona, Spain). State-of-the-art computations of N&lt;sub&gt;2&lt;/sub&gt; and O&lt;sub&gt;2&lt;/sub&gt; differential backscatter cross-sections weighted by the optical losses inside the optical separation unit of the system allow for the theoretical estimation of the expected signal-to-noise ratios (SNR) in both UV and VIS channels. By means of customized optical interference filters UV-PRR signals from atmospheric N&lt;sub&gt;2&lt;/sub&gt; and O&lt;sub&gt;2&lt;/sub&gt; were detected and compared to the classical vibro-rotational Raman signals. UV-PRR detected signals have shown to possess high SNR and relative uncertainty levels lower than a tolerable 15% for daytime and nighttime measurements. The theoretical analysis of the VIS-PRR channel augurs improvements similar to those observed with the UV-PRR channel.&lt;/p&gt;

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