Designing and building a novel, ground-based lidar system for aerosol typing in the Planetary Boundary Layer

Abstract. This study presents an inter-comparison of two active remote sensors (lidar and ceilometer) in determining the structure of the Planetary Boundary Layer (PBL) and in retrieving tropospheric aerosol vertical profiles over Athens, Greece. This inter-comparison was performed under various strongly different aerosol concentrations (urban air pollution, biomass burning and Saharan dust event), implementing two different lidar systems (one portable Raymetrics S.A. lidar system running at 355 nm and one multi-wavelength Raman lidar system running at 355 nm, 532 nm and 1064 nm) and one CL31 Vaisala S.A. ceilometer (running at 910 nm). To convert the ceilometer data to data having the same wavelengths as those from the lidar, the backscatter-related Ångström exponent was estimated using ultraviolet multi-filter radiometer (UV-MFR) data. The inter-comparison was based on two parameters: the mixing layer structure and height determined by the presence of the suspended aerosols and the aerosol backscatter coefficient. Additionally, radiosonde data were used to derive the PBL height. In general a good agreement is found between the ceilometer and the lidar techniques in both inter-compared parameters in the height range from 500 m to 5000 m, while the limitations of each instrument are also examined.

Download Full-text

Improving Daytime Planetary Boundary Layer Height Determination from CALIOP: Validation Based on Ground-Based Lidar Station

Advances in Meteorology ◽

10.1155/2017/5759074 ◽

2017 ◽

Vol 2017 ◽

pp. 1-14 ◽

Cited By ~ 2

Author(s):

Zhao Liu ◽

Augustin Mortier ◽

Zhengqiang Li ◽

Weizhen Hou ◽

Philippe Goloub ◽

...

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Absolute Difference ◽

Aerosol Layer ◽

Planetary Boundary Layer Height ◽

Layer Height ◽

Boundary Layer Height ◽

Clear Sky ◽

Ground Based Lidar ◽

Sky Conditions

An integrated algorithm by combining the advantages of the wavelet covariance method and the improved maximum variance method was developed to determine the planetary boundary layer height (PBLH) from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) measurements, and an aerosol fraction threshold was applied to the integrated algorithm considering the applicability of the two methods. We compared the CALIOP retrieval with the measurements of PBLH derived from nine years of ground-based Lidar synchronous observations located in Lille, north of France. The results indicate that a good correlation (R≥0.79) exists between the PBLHs derived from CALIOP and ground-based Lidar under clear sky conditions. The mean absolute differences of PBLHs are, respectively, of 206 m and 106 m before and after the removal of the aloft aerosol layer. The results under cloudy sky conditions show a lower agreement (R=0.48) in regard of the comparisons performed under clear sky conditions. Besides, the spatial correlation of PBLHs decreases with the increasing spatial distance between CALIOP footprint and Lille observation platform. Based on the above analysis, the PBLHs can be effectively derived by the integrated algorithm under clear sky conditions, while larger mean absolute difference (i.e., 527 m) exists under cloudy sky conditions.

Download Full-text

A lidar system for monitoring planetary boundary layer aerosol in daytime

Acta Physica Sinica ◽

10.7498/aps.57.7390 ◽

2008 ◽

Vol 57 (11) ◽

pp. 7390

Author(s):

Zhang Gai-Xia ◽

Zhao Yue-Feng ◽

Zhang Yin-Chao ◽

Zhao Pei-Tao

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Lidar System

Download Full-text

Spatial and Temporal Variability of Aerosol Vertical Distribution Based on Lidar Observations: A Haze Case Study over Jinhua Basin

Advances in Meteorology ◽

10.1155/2015/349592 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Wanchun Zhang ◽

Mortier Augustin ◽

Ying Zhang ◽

Zhengqiang Li ◽

Hua Xu ◽

...

Keyword(s):

Boundary Layer ◽

Vertical Distribution ◽

Planetary Boundary Layer ◽

Vertical Section ◽

Lower Boundary ◽

Absolute Error ◽

Spatial And Temporal Variability ◽

Pollution Transport ◽

Ground Based Lidar ◽

Lidar Observations

The impacts of haze emphasized significance of hazards for human activities and importance of observations of aerosol vertical distribution. This study aimed to analyze the aerosol vertical distribution during a haze case at temporal and spatial aspects, using space-borne and ground-based Lidar observations over Jinhua Basin, Zhejiang province, as well as the Hybrid Single-Particle Lagrangian Integrated Trajectory (HSPLIT) model and optical situ monitoring at Jinhua site. The results highlight three pollution peaks above the surface located in the upper and lower boundary layer in Jinhua Basin. The trajectory analysis shows the pollutants inside and outside the planetary boundary layer from different sources. Planetary boundary layer height (PBLH) obtained from the space-borne Lidar observations was compared with that from ground-based Lidar observations. The absolute error between the two instruments is about 0.193 km. It is illustrated that the space-borne Lidar is an effective instrument for obtaining regional aerosol pollution in vertical section. Pollution transport near the ground is closely related with the terrain condition.

Download Full-text

Transport of aerosols over the French Riviera – link between ground-based lidar and spaceborne observations

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-3885-2019 ◽

2019 ◽

Vol 19 (6) ◽

pp. 3885-3904 ◽

Cited By ~ 1

Author(s):

Patrick Chazette ◽

Julien Totems ◽

Xiaoxia Shang

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Extinction Ratio ◽

Orthogonal Polarization ◽

Free Troposphere ◽

Back Trajectories ◽

Multidisciplinary Program ◽

Ground Based Lidar ◽

Dust Events ◽

French Riviera

Abstract. For the first time, a 355 nm backscatter N2-Raman lidar has been deployed on the western part of the French Riviera to investigate the vertical aerosol structure in the troposphere. This lidar system, based at the AERONET site of Toulon–La Garde, performed continuous measurements from 24 June to 17 July 2014, within the framework of the multidisciplinary program Mediterranean Integrated Studies at the Regional and Local Scales (MISTRALS). By coupling these observations with those of the spaceborne instruments Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP), Spinning Enhanced Visible and InfraRed Imager (SEVIRI), and Moderate Resolution Imaging Spectroradiometers (MODIS), the spatial extents of the aerosol structures are investigated. The origins of the aerosol plumes are determined using back trajectories computed by the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT). This synergy allowed us to highlight plumes of particulate pollutants moving in the low and medium free troposphere (up to ∼5 km above the mean sea level) towards the French Riviera. This pollution originates from the Spanish coast, more particularly from Costa Blanca (including Murcia) and Costa Brava–Costa Daurada (including Barcelona). It is mainly due to traffic, but also to petrochemical activities in these two regions. Desert aerosol plumes were also sampled by the lidar. The sources of desert aerosols have been identified as the Grand Erg Occidental and Grand Erg Oriental. During desert dust events, we highlight significant differences in the optical characteristics in terms of the backscatter-to-extinction ratio (BER, inverse of the lidar ratio) between the planetary boundary layer, with 0.024 sr−1 (∼42 sr), and the free troposphere, with 0.031 sr−1 (∼32 sr). These differences are greatly reduced in the case of pollution aerosol plume transport in the free troposphere (i.e., 0.021 and 0.025 sr−1). Transported pollution aerosols appear to have similar BER to what is emitted locally. Moreover, using the correlation matrix between lidar aerosol extinction profiles as a function of altitude, we find that during transport events in the low free troposphere, aerosols may be transferred into the planetary boundary layer. We also note that the relative humidity, which is generally higher in the planetary boundary layer (>80 %), is found to have no significant effect on the BER.

Download Full-text

Planetary boundary layer height from CALIOP compared to radiosonde over China

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-9951-2016 ◽

2016 ◽

Vol 16 (15) ◽

pp. 9951-9963 ◽

Cited By ~ 43

Author(s):

Wanchun Zhang ◽

Jianping Guo ◽

Yucong Miao ◽

Huan Liu ◽

Yong Zhang ◽

...

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Large Scale ◽

Accurate Estimation ◽

Orthogonal Polarization ◽

Planetary Boundary Layer Height ◽

Layer Height ◽

Boundary Layer Height ◽

Spatial Coverage ◽

Ground Based Lidar

Abstract. Accurate estimation of planetary boundary layer height (PBLH) is key to air quality prediction, weather forecast, and assessment of regional climate change. The PBLH retrieval from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) is expected to complement ground-based measurements due to the broad spatial coverage of satellites. In this study, CALIOP PBLHs are derived from combination of Haar wavelet and maximum variance techniques, and are further validated against PBLHs estimated from ground-based lidar at Beijing and Jinhua. Correlation coefficients between PBLHs from ground- and satellite-based lidars are 0.59 at Beijing and 0.65 at Jinhua. Also, the PBLH climatology from CALIOP and radiosonde are compiled over China during the period from 2011 to 2014. Maximum CALIOP-derived PBLH can be seen in summer as compared to lower values in other seasons. Three matchup scenarios are proposed according to the position of each radiosonde site relative to its closest CALIPSO ground tracks. For each scenario, intercomparisons were performed between CALIOP- and radiosonde-derived PBLHs, and scenario 2 is found to be better than other scenarios using difference as the criteria. In early summer afternoon over 70 % of the total radiosonde sites have PBLH values ranging from 1.6 to 2.0 km. Overall, CALIOP-derived PBLHs are well consistent with radiosonde-derived PBLHs. To our knowledge, this study is the first intercomparison of PBLH on a large scale using the radiosonde network of China, shedding important light on the data quality of initial CALIOP-derived PBLH results.

Download Full-text

Inter-comparison of lidar and ceilometer retrievals for aerosol and Planetary Boundary Layer profiling over Athens, Greece

Atmospheric Measurement Techniques ◽

10.5194/amt-4-1261-2011 ◽

2011 ◽

Vol 4 (6) ◽

pp. 1261-1273 ◽

Cited By ~ 66

Author(s):

G. Tsaknakis ◽

A. Papayannis ◽

P. Kokkalis ◽

V. Amiridis ◽

H. D. Kambezidis ◽

...

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Mixing Layer ◽

Radiosonde Data ◽

Lidar System ◽

Height Range ◽

Layer Height ◽

Tropospheric Aerosol ◽

Filter Radiometer ◽

Mixing Layer Height

Abstract. This study presents an inter-comparison of two active remote sensors (lidar and ceilometer) to determine the mixing layer height and structure of the Planetary Boundary Layer (PBL) and to retrieve tropospheric aerosol vertical profiles over Athens, Greece. This inter-comparison was performed under various strongly different aerosol loads/types (urban air pollution, biomass burning and Saharan dust event), implementing two different lidar systems (one portable Raymetrics S.A. lidar system running at 355 nm and one multi-wavelength Raman lidar system running at 355 nm, 532 nm and 1064 nm) and one CL31 Vaisala S.A. ceilometer (running at 910 nm). Spectral conversions of the ceilometer's data were performed using the Ångström exponent estimated by ultraviolet multi-filter radiometer (UV-MFR) measurements. The inter-comparison was based on two parameters: the mixing layer height determined by the presence of the suspended aerosols and the attenuated backscatter coefficient. Additionally, radiosonde data were used to derive the PBL height. In general, a good agreement was found between the ceilometer and the lidar techniques in both inter-compared parameters in the height range from 500 m to 5000 m, while the limitations of each instrument are also examined.

Download Full-text

Transport of aerosols over the French Riviera – Link between ground- based lidar and spaceborne observations

10.5194/acp-2018-971 ◽

2018 ◽

Author(s):

Patrick Chazette ◽

Julien Totems ◽

Xiaoxia Shang

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Extinction Ratio ◽

Orthogonal Polarization ◽

Free Troposphere ◽

Back Trajectories ◽

Infrared Imager ◽

Ground Based Lidar ◽

Dust Events ◽

French Riviera

Abstract. For the first time, a backscatter N2-Raman lidar has been deployed on the western part of the French Riviera to investigate the vertical aerosol structure in the troposphere. This lidar system, based at the AERONET site of Toulon-La Garde, performed continuous measurements from 24 June to 17 July 2014, within the framework of the multidisciplinary programme Mediterranean Integrated Studies at the Regional and Local Scales (MISTRALS). By coupling these observations with those of the spaceborne instruments Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP), Spinning Enhanced Visible and InfraRed Imager (SEVIRI) and Moderate Resolution Imaging Spectroradiometers (MODIS), the spatial extents of the aerosol structures are investigated. The origins of the aerosol plumes are determined using back trajectories computed by the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT). This synergy allowed to highlight plumes of particulate pollutants moving in the low and medium free troposphere (up to ~ 5 km above the mean sea level) towards the French Riviera. This pollution originates from the Spanish coast, and more particularly from Costa Blanca (including Murcia) and Costa Brava/Costa Daurada (including Barcelona). It is mainly due to traffic, but also to petrochemical activities in these two regions. Desert aerosol plumes were also sampled by the lidar. The sources of desert aerosols have been identified as the Grand Erg Occidental and Grand Erg Oriental. During desert dust events, we highlight significant differences in the optical characteristics, in terms of backscatter to extinction ratio (BER, inverse of the lidar ratio), between the planetary boundary layer, with 0.024 sr−1 (~ 42 sr), and the free troposphere, with 0.031 sr−1 (~ 32 sr). These differences are greatly reduced in the case of pollution aerosol plumes transport in the free troposphere (i.e. 0.021 and 0.025 sr−1). Transported pollution aerosols appear as having similar BER to what is emitted locally. Moreover, using the correlation matrix between lidar aerosol extinction profiles as a function of altitude, we find that during transport events in the low free troposphere, aerosols may be transferred into the planetary boundary layer. We note also that the relative humidity, which is generally higher in the planetary boundary layer (> 80 %), is found to have no significant effect on the BER.

Download Full-text

Validation of aerosol and cloud layer structures from the space-borne lidar CALIOP using a ground-based lidar in Seoul, Korea

Atmospheric Chemistry and Physics ◽

10.5194/acp-8-3705-2008 ◽

2008 ◽

Vol 8 (13) ◽

pp. 3705-3720 ◽

Cited By ~ 107

Author(s):

S.-W. Kim ◽

S. Berthier ◽

J.-C. Raut ◽

P. Chazette ◽

F. Dulac ◽

...

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Signal To Noise Ratio ◽

Extinction Ratio ◽

Cirrus Clouds ◽

Cloud Layer ◽

Atmospheric Conditions ◽

Night Time ◽

Layer Structures ◽

Ground Based Lidar

Abstract. We present initial validation results of the space-borne lidar CALIOP onboard CALIPSO satellite using coincidental observations from a ground-based lidar in Seoul National University (SNU), Seoul, Korea (37.46° N, 126.95° E). We analyze six selected cases between September 2006 and February 2007, including 3 daytime and 3 night-time observations and covering different types of clear and cloudy atmospheric conditions. Apparent scattering ratios calculated from the two lidar measurements of total attenuated backscatter at 532 nm show similar aerosol and cloud layer structures both under cloud-free conditions and in cases of multiple aerosol layers underlying semi-transparent cirrus clouds. Agreement on top and base heights of cloud and aerosol layers is generally within 0.10 km, particularly during night-time. This result confirms that the CALIPSO science team algorithms for the discrimination of cloud and aerosol as well as for the detection of layer top and base altitude provide reliable information in such atmospheric conditions. This accuracy of the planetary boundary layer top height under cirrus cloud appears, however, limited during daytime. Under thick cloud conditions, however, information on the cloud top (bottom) height only is reliable from CALIOP (ground-based lidar) due to strong signal attenuations. However, simultaneous space-borne CALIOP and ground-based SNU lidar (SNU-L) measurements complement each other and can be combined to provide full information on the vertical distribution of aerosols and clouds. An aerosol backscatter-to-extinction ratio (BER) estimated from lidar and sunphotometer synergy at the SNU site during the CALIOP overpass is assessed to be 0.023±0.004 sr−1 (i.e. a lidar ratio of 43.2±6.2 sr) from CALIOP and 0.027±0.006 sr−1 (37.4±7.2 sr) from SNU-L. For aerosols within the planetary boundary layer under cloud-free conditions, the aerosol extinction profiles from both lidars are in agreement within about 0.02 km−1. Under semi-transparent cirrus clouds, such profiles also show good agreement for the night-time CALIOP flight, but large discrepancies are found for the daytime flights due to a small signal-to-noise ratio of the CALIOP data.

Download Full-text

Planetary boundary layer height from CALIOP compared to radiosonde over China

10.5194/acp-2016-250 ◽

2016 ◽

Cited By ~ 1

Author(s):

Wanchun Zhang ◽

Jianping Guo ◽

Yucong Miao ◽

Huan Liu ◽

Zhengqiang Li ◽

...

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Large Scale ◽

Early Summer ◽

Accurate Estimation ◽

Planetary Boundary Layer Height ◽

Layer Height ◽

Boundary Layer Height ◽

Spatial Coverage ◽

Ground Based Lidar

Abstract. The accurate estimation of boundary layer height is key to air quality prediction, weather forecast and so on. The planetary boundary layer height (PBLH) retrieval from CALIOP is expected to complement the ground-based site measurement due to its large spatial coverage. To such end, we estimated PBLHs from CALIOP, using the combination of Haar wavelet and maximum variance techniques, which was validated against PBLHs from ground-based lidar at Beijing and Jinhua. Comparison between ground-based and satellite lidar shows good agreement with a correlation coefficient of 0.59 in Beijing and 0.65 in Jinhua. The PBLH climatology from CALIOP was compiled over China during 2011 to 2014. Maximum PBLH was seen in summer as compared to lower value in other seasons. Prior to intercomparisons between CALIOP- and radiosonde-derived PBLHs, three matchup scenarios were proposed according to the position of each radiosonde site relative to its closest CALIPSO ground tracks. The CALIOP observations belonging to Scenario 2 were found to be better for comparison with radiosonde-derived PBLH, owing to smaller difference between them. The PBLHs at early summer afternoon range from 1.6 km to 2.0 km, accounting for over 70 % of the total radiosonde sites. Overall, CALIOP-derived PBLHs seem to be well consistent with radiosonde-derived PBLHs. To our knowledge, this study is the first intercomparison study of PBLH over large scale using the radiosonde network of China, shedding important light on the data quality of initial CALIOP-derived PBLH results.

Download Full-text