Vertical Distribution of Aerosol Extinction Coefficient Detection in Boundary Layer Using CCD Lidar

Abstract. Two intense winter aerosol pollution events, which took place in winter 2016–2017 in Paris, were monitored using a ground-based N2-Raman lidar, in the framework of WASLIP (Winter Aerosol Survey by Lidar In Paris), a dedicated field campaign that was carried out in this area from 1 November 2016 to 31 January 2017. The data analysis uses the synergy between ground-based and spaceborne lidar observations and data from the air quality monitoring network Airparif. The first severe aerosol pollution event began on 30 November 2016 and ended on 2 December, concerning a circular area of ∼250 km in diameter around Paris. The maximum PM10 was 121±63 µg m−3 (regional spatial average ± SD) for the Airparif ground-based PM monitoring stations, and the aerosol extinction coefficient (AEC) ranged from 0.2 to 1 km−1. The second event took place from 20 to 23 January which covered all of the northwestern Europe, with maxima of PM10 around 156±33 µg m−3 and AEC between 0.6 and 1 km−1, within the winter atmospheric boundary layer. Although these two major aerosol pollution events did not occur under identical anticyclonic weather conditions, they share very low planetary boundary layer (PBL) heights, down to 300 m above ground level. Moreover, they are associated with significantly different aerosol lidar ratios: 72±15 and 56±15 sr, respectively in December and January. Such results are consistent with available spaceborne lidar data, 70±25 sr from CALIOP (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations), and values found in the literature. During these two events, the continuous temporal evolution of the aerosol extinction coefficient allows us to investigate the representativeness of optical parameters found in the planetary boundary layer to assess surface aerosol concentration. No one-to-one relationship between the aerosol optical thickness (AOT) and PM2.5 values stands out within our study. In contrast, the maximum aerosol extinction coefficient found within the planetary boundary layer correlates well with PM2.5 at the ground (R2∼0.75, specific extinction cross section of 9.4 m2 g−1) for these polluted events. Thus this lidar-derived aerosol extinction coefficient is identified as a consistent variable to monitor the pollution during winter events.

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Remote sensing of exceptional winter aerosol pollution events and representativeness of the surface – column relationship over Paris metropolitan area

10.5194/acp-2019-464 ◽

2019 ◽

Author(s):

Alexandre Baron ◽

Patrick Chazette ◽

Julien Totems

Keyword(s):

Boundary Layer ◽

Air Quality ◽

Planetary Boundary Layer ◽

Extinction Coefficient ◽

Aerosol Concentration ◽

Optical Parameters ◽

Aerosol Extinction ◽

Aerosol Pollution ◽

Pollution Events ◽

Aerosol Extinction Coefficient

Abstract. In this study an optical parameter derived from lidar measurements is found to be relevant to monitor the evolution of near-surface particulate concentrations. This highlights the opportunities offered by future spaceborne lidar missions in air quality assessment on a global scale. This work is carried out following a dedicated field campaign in the Paris area (France) during winter 2016–2017, from 1st November to 31st January. Two of the most intense winter aerosol pollution events occurring over the last decade were sampled using a ground-based N2-Raman. The lidar operated continuously at the wavelength of 355 nm, favourable to the measurement of submicron aerosols mainly linked to traffic emissions. The data analysis uses the synergy between ground-based and spaceborne lidar observations, and data from the air quality monitoring network Airparif. The first severe aerosol pollution event occurred on 1st December 2016; it concerned a circular area of 250 km in diameter around Paris with maximum PM10 (PMx is the mass concentration of particles with an aerodynamic diameter smaller than x µm) values of 121 ± 63 µg m-3. The second event took place from 21st to 22nd January which covered all of Western Europe, with maxima of PM10 (156 ± 33 µg m-3) and aerosol extinction coefficient (AEC) between 0.6 and 1 km-1, within the winter atmospheric boundary layer. These two major aerosol pollution events share very low boundary layer height, down to 300 m above ground level. However, they did not take place in the same weather condition; moreover, they are associated with significantly different lidar ratios: 72 ± 15 sr and 56 ± 15 sr, respectively in December and January. Such results are consistent with available spaceborne lidar data (70 ± 25 sr) and values found in the literature. During these two events, the continuous temporal evolution of the aerosol extinction coefficient allows us to investigate the representativeness of optical parameters found in the planetary boundary layer to assess surface aerosol concentration. No one-to-one relationship between the aerosol optical thickness (AOT) and PM2.5 values stands out within our study. In contrast, the maximum lidar-derived aerosol extinction coefficient found within the planetary boundary layer is identified as a consistent variable to assess the evolution of ground aerosol concentration.

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Evidence for the predictability of changes in the stratospheric aerosol size following volcanic eruptions of diverse magnitudes using space-based instruments

10.5194/acp-2020-480 ◽

2020 ◽

Author(s):

Larry W. Thomason ◽

Mahesh Kovilakam ◽

Anja Schmidt ◽

Christian von Savigny ◽

Travis Knepp ◽

...

Keyword(s):

Size Distribution ◽

Extinction Coefficient ◽

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Global Climate Models ◽

Aerosol Size Distribution ◽

Aerosol Layer ◽

Aerosol Extinction ◽

Volcanic Event ◽

Aerosol Extinction Coefficient

Abstract. An analysis of multiwavelength stratospheric aerosol extinction coefficient data from the Stratospheric Aerosol and Gas Experiment II and III/ISS instruments is used to demonstrate a coherent relationship between the perturbation in extinction coefficient in an eruption's main aerosol layer and an apparent change in aerosol size distribution that spans multiple orders of magnitude in the stratospheric impact of a volcanic event. The relationship is measurement-based and does not rely on assumptions about the aerosol size distribution. We note limitations on this analysis including that the presence of significant amounts of ash in the main aerosol layer may significantly modulate these results. Despite this limitation, these findings represent a unique opportunity to verify the performance of interactive aerosol models used in Global Climate Models and Earth System Model and may suggest an avenue for improving aerosol extinction coefficient measurements from single channel observations such the Optical Spectrograph and Infrared Imager System as they rely on a priori assumptions about particle size.

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An evaluation of the SAGE III Version 4 aerosol extinction coefficient and water vapor data products

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-9-22177-2009 ◽

2009 ◽

Vol 9 (5) ◽

pp. 22177-22222

Author(s):

L. W. Thomason ◽

J. R. Moore ◽

M. C. Pitts ◽

J. M. Zawodny ◽

E.-W. Chiou

Keyword(s):

Water Vapor ◽

Extinction Coefficient ◽

Stratospheric Aerosol ◽

Data Sets ◽

Aerosol Extinction ◽

Data Products ◽

Mean Differences ◽

Aerosol Extinction Coefficient ◽

Polar Ozone

Abstract. Herein, we provide an assessment of the data quality of Stratospheric Aerosol and Gas Experiment (SAGE III) Version 4 aerosol extinction coefficient and water vapor data products. The evaluation is based on comparisons with data from four instruments: SAGE II, the Polar Ozone and Aerosol Measurement (POAM III), the Halogen Occultation Experiment (HALOE), and the Microwave Limb Sounder (MLS). Since only about half of the SAGE III channels have a direct comparison with measurements by other instruments, we have employed some empirical techniques to evaluate measurements at some wavelengths. We find that the aerosol extinction coefficient measurements at 449, 520, 755, 869, and 1021 nm are reliable with accuracies and precisions on the order of 10% in the primary aerosol range of 15 to 25 km. We also believe this to be true of the aerosol measurements at 1545 nm though we cannot exclude some positive bias below 15 km. We recommend use of the 385 nm measurements above 16 km where the accuracy is on par with other aerosol channels. The 601 nm measurement is much noisier (~20%) than other channels and we suggest caution in the use of these data. We believe that the 676 nm data are clearly defective particularly above 20 km (accuracy as poor as 50%) and the precision is also low (~30%). We suggest excluding this channel under most circumstances. The SAGE III Version 4 water vapor data product appears to be high quality and is recommended for science applications in the stratosphere below 45 km. In this altitude range, the mean differences with all four corroborative data sets are no bigger than 15% and often less than 10% with exceptional agreement with POAM III and MLS. Above 45 km, it seems likely that SAGE III water vapor values are increasingly too large and should be used cautiously or avoided. We believe that SAGE III meets its preflight goal of 15% accuracy and 10% precision between 15 and 45 km. We do not currently recommend limiting the SAGE III water vapor data utility in the stratosphere by aerosol loading.

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PROCESSING JUMP POINT OF LIDAR DETECTION DATA AND INVERSING THE AEROSOL EXTINCTION COEFFICIENT

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-3-w9-227-2019 ◽

2019 ◽

Vol XLII-3/W9 ◽

pp. 227-232

Author(s):

H. L. Zhang ◽

H. Zhao ◽

Y. P. Liu ◽

X. K. Wang ◽

C. Shu

Keyword(s):

Atmospheric Aerosols ◽

Extinction Coefficient ◽

Interpolation Method ◽

Linear Interpolation ◽

Mie Scattering ◽

Inversion Method ◽

Aerosol Extinction ◽

Detection Range ◽

Long Time ◽

Aerosol Extinction Coefficient

Abstract. For a long time, the research of the optical properties of atmospheric aerosols has aroused a wide concern in the field of atmospheric and environmental. Many scholars commonly use the Klett method to invert the lidar return signal of Mie scattering. However, there are always some negative values in the detection data of lidar, which have no actual meaning，and which are jump points. The jump points are also called wild value points and abnormal points. The jump points are refered to the detecting points that are significantly different from the surrounding detection points, and which are not consistent with the actual situation. As a result, when the far end point is selected as the boundary value, the inversion error is too large to successfully invert the extinction coefficient profile. These negative points are jump points, which must be removed in the inversion process. In order to solve the problem, a method of processing jump points of detection data of lidar and the inversion method of aerosol extinction coefficient is proposed in this paper. In this method, when there are few jump points, the linear interpolation method is used to process the jump points. When the number of continuous jump points is large, the function fitting method is used to process the jump points. The feasibility and reliability of this method are verified by using actual lidar data. The results show that the extinction coefficient profile can be successfully inverted when different remote boundary values are chosen. The extinction coefficient profile inverted by this method is more continuous and smoother. The effective detection range of lidar is greatly increased using this method. The extinction coefficient profile is more realistic. The extinction coefficient profile inverted by this method is more favorable to further analysis of the properties of atmospheric aerosol. Therefore, this method has great practical application and popularization value.

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Statistical Comparison of Regional-Scale Tropospheric Aerosol Extinction Coefficient across China Based on CALIPSO Data

Aerosol and Air Quality Research ◽

10.4209/aaqr.2017.10.0385 ◽

2018 ◽

Vol 18 (5) ◽

pp. 1351-1359 ◽

Cited By ~ 1

Author(s):

Yujun Qiu ◽

Leiming Zhang ◽

Yongsheng Chen

Keyword(s):

Extinction Coefficient ◽

Regional Scale ◽

Aerosol Extinction ◽

Statistical Comparison ◽

Tropospheric Aerosol ◽

Aerosol Extinction Coefficient

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Evidence for the predictability of changes in the stratospheric aerosol size following volcanic eruptions of diverse magnitudes using space-based instruments

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-1143-2021 ◽

2021 ◽

Vol 21 (2) ◽

pp. 1143-1158 ◽

Cited By ~ 1

Author(s):

Larry W. Thomason ◽

Mahesh Kovilakam ◽

Anja Schmidt ◽

Christian von Savigny ◽

Travis Knepp ◽

...

Keyword(s):

Extinction Coefficient ◽

Climate Models ◽

Single Channel ◽

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Global Climate Models ◽

Aerosol Size Distribution ◽

Aerosol Layer ◽

Aerosol Extinction ◽

Aerosol Extinction Coefficient

Abstract. An analysis of multiwavelength stratospheric aerosol extinction coefficient data from the Stratospheric Aerosol and Gas Experiment II and III/ISS instruments is used to demonstrate a coherent relationship between the perturbation in extinction coefficient in an eruption's main aerosol layer and the wavelength dependence of that perturbation. This relationship spans multiple orders of magnitude in the aerosol extinction coefficient of stratospheric impact of volcanic events. The relationship is measurement-based and does not rely on assumptions about the aerosol size distribution. We note limitations on this analysis including that the presence of significant amounts of ash in the main sulfuric acid aerosol layer and other factors may significantly modulate these results. Despite these limitations, the findings suggest an avenue for improving aerosol extinction coefficient measurements from single-channel observations such as the Optical Spectrograph and Infrared Imager System as they rely on a prior assumptions about particle size. They may also represent a distinct avenue for the comparison of observations with interactive aerosol models used in global climate models and Earth system models.

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