scholarly journals Lidar stand-alone retrieval of atmospheric aerosol microphysical properties during SLOPE

2018 ◽  
Vol 176 ◽  
pp. 05046 ◽  
Author(s):  
Pablo Ortiz-Amezcua ◽  
Stefanos Samaras ◽  
Christine Böckmann ◽  
Jose Antonio Benavent-Oltra ◽  
Juan Luis Guerrero-Rascado ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Atmospheric Aerosol ◽  
Volume Distribution ◽  
Raman Lidar ◽  
Particle Volume ◽  
Microphysical Properties ◽  
Lidar Measurements ◽  
Depolarization Ratios

Two cases from SLOPE campaign at Granada are analyzed in terms of particle microphysical properties using novel software developed at Potsdam University. Multiwavelength Raman lidar measurements of particle extinction and backscatter coefficients as well as linear particle depolarization ratios are used as input for the software. The result of the retrieval is a 2-dimensional particle volume distribution as a function of radius and aspect ratio, from which the particle microphysical properties are obtained.

scholarly journals CADEX and beyond: Installation of a new PollyXT site in Dushanbe

2019 ◽  
Vol 99 ◽  
pp. 02010
Author(s):  
Ronny Engelmann ◽  
Julian Hofer ◽  
Abduvosit N. Makhmudov ◽  
Holger Baars ◽  
Karsten Hanbuch ◽  
...  
Keyword(s):  
Asian Dust ◽  
Raman Lidar ◽  
Technical Institute ◽  
Lidar System ◽  
Microphysical Properties ◽  
Source Regions ◽  
Central Asian ◽  
Lidar Measurements ◽  
Academy Of Sciences

During the 18-month Central Asian Dust Experiment we conducted continuous lidar measurements at the Physical Technical Institute of the Academy of Sciences of Tajikistan in Dushanbe between 2015 and 2016. Mineral dust plumes from various source regions have been observed and characterized in terms of their occurrence, and their optical and microphysical properties with the Raman lidar PollyXT. Currently a new container-based lidar system is constructed which will be installed for continuous long-term measurements in Dushanbe.

Dual-field-of-view Raman lidar measurements for the retrieval of cloud microphysical properties

2013 ◽  
Vol 52 (11) ◽  
pp. 2235 ◽  
Author(s):  
Jörg Schmidt ◽  
Ulla Wandinger ◽  
Aleksey Malinka
Keyword(s):  
Field Of View ◽  
Raman Lidar ◽  
Microphysical Properties ◽  
Lidar Measurements

scholarly journals UV Raman lidar measurements of relative humidity for the characterization of cirrus cloud microphysical properties

2009 ◽  
Vol 9 (22) ◽  
pp. 8799-8811 ◽  
Author(s):  
P. Di Girolamo ◽  
D. Summa ◽  
R.-F. Lin ◽  
T. Maestri ◽  
R. Rizzi ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Cloud Model ◽  
Cirrus Clouds ◽  
Cloud Layer ◽  
Cirrus Cloud ◽  
Raman Lidar ◽  
Heating Rates ◽  
Night Time ◽  
Microphysical Properties ◽  
Lidar Measurements

Abstract. Raman lidar measurements performed in Potenza by the Raman lidar system BASIL in the presence of cirrus clouds are discussed. Measurements were performed on 6 September 2004 in the frame of the Italian phase of the EAQUATE Experiment. The major feature of BASIL is represented by its capability to perform high-resolution and accurate measurements of atmospheric temperature and water vapour, and consequently relative humidity, both in daytime and night-time, based on the application of the rotational and vibrational Raman lidar techniques in the UV. BASIL is also capable to provide measurements of the particle backscatter and extinction coefficient, and consequently lidar ratio (at the time of these measurements, only at one wavelength), which are fundamental to infer geometrical and microphysical properties of clouds. A case study is discussed in order to assess the capability of Raman lidars to measure humidity in presence of cirrus clouds, both below and inside the cloud. While air inside the cloud layers is observed to be always under-saturated with respect to water, both ice super-saturation and under-saturation conditions are found inside these clouds. Upper tropospheric moistening is observed below the lower cloud layer. The synergic use of the data derived from the ground based Raman Lidar and of spectral radiances measured by the NAST-I Airborne Spectrometer allows the determination of the temporal evolution of the atmospheric cooling/heating rates due to the presence of the cirrus cloud. Lidar measurements beneath the cirrus cloud layer have been interpreted using a 1-D cirrus cloud model with explicit microphysics. The 1-D simulations indicate that sedimentation-moistening has contributed significantly to the moist anomaly, but other mechanisms are also contributing. This result supports the hypothesis that the observed mid-tropospheric humidification is a real feature which is strongly influenced by the sublimation of precipitating ice crystals. Results illustrated in this study demonstrate that Raman lidars, like the one used in this study, can resolve the spatial and temporal scales required for the study of cirrus cloud microphysical processes and appear sensitive enough to reveal and quantify upper tropospheric humidification associated with cirrus cloud sublimation.

scholarly journals In Situ Samplings and Remote Sensing Measurements to Characterize Aerosol Properties over Southeast Italy

2008 ◽  
Vol 25 (8) ◽  
pp. 1341-1356 ◽  
Author(s):  
V. Bellantone ◽  
I. Carofalo ◽  
F. De Tomasi ◽  
M. R. Perrone ◽  
M. Santese ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Eastern Mediterranean ◽  
Aluminum Silicate ◽  
Volume Distribution ◽  
Vertical Profiles ◽  
Backscatter Coefficient ◽  
Particle Volume ◽  
Microphysical Properties ◽  
Fine Mode

Abstract Ground-based particulate matter (PM) samplers, an XeF Raman lidar operating in the framework of the European Aerosol Research Lidar Network (EARLINET), and a sun/sky radiometer operating in the framework of the Aerosol Robotic Network (AERONET) have been used to characterize vertical profiles, optical and microphysical properties, and chemical composition of aerosols during the 29 June–1 July 2005 dust outbreak that occurred over the central-eastern Mediterranean. Aerosol backscatter coefficient, total depolarization, and lidar ratio vertical profiles revealed that a well-mixed dust layer extending from ∼0.5 to 6 km was present over southeastern Italy on 30 June. Sun/sky radiometer measurements revealed a bimodal lognormal size distribution during all measurement days. The particle volume distribution was found to be well correlated either to the PM mass distribution measured at ground by a seven-stage cascade impactor and to the fine to total suspended PM mass ratio measured by ground-based PM samplers. Scanning electron microscopy and ion chromatography analyses on PM samples revealed that coarse-mode aerosols were mainly made of carbonate, aluminum-silicate, and sea salt particles. Carbon, sulfate, and nitrate particles were the main components of fine-mode aerosols representing more than 50% of the total aerosol load; the significant role of fine-mode anthropogenic particles during a dust event is highlighted. Finally, the potential capabilities of complementary measurements by passive and active remote sensing techniques and in situ observations to retrieve the vertical distribution of the particle number and mass concentration are analyzed and discussed.

scholarly journals Ceilometer aerosol profiling vs. Raman lidar in the frame of INTERACT campaign of ACTRIS

2014 ◽  
Vol 7 (12) ◽  
pp. 12407-12447 ◽  
Author(s):  
F. Madonna ◽  
F. Amato ◽  
J. Vande Hey ◽  
G. Pappalardo
Keyword(s):  
Atmospheric Aerosol ◽  
Correction Function ◽  
Cloud Base ◽  
Raman Lidar ◽  
Lidar Measurements ◽  
Multi Wavelength ◽  
Strong Motivation ◽  
Technological Improvements ◽  
First Time ◽  
Cloud Tracking

Abstract. Despite their differences from more advanced and more powerful lidars, the low construction and operation cost of ceilometers, originally designed for cloud base height monitoring, has fostered their use for the quantitative study of aerosol properties. The large number of ceilometers available worldwide represents a strong motivation to investigate both the extent to which they can be used to fill in the geographical gaps between advanced lidar stations and also how their continuous data flow can be linked to existing networks of the more advanced lidars, like EARLINET (European Aerosol Research LIdar NETwork). In this paper, multi-wavelength Raman lidar measurements are used to investigate the capability of ceilometers to provide reliable information about atmospheric aerosol content through the INTERACT (INTERcomparison of Aerosol and Cloud Tracking) campaign carried out at the CNR-IMAA Atmospheric Observatory (760 m a.s.l., 40.60° N, 15.72° E), in the framework of ACTRIS (Aerosol Clouds Trace gases Research InfraStructure) FP7 project. This work is the first time that three different commercial ceilometers with an advanced Raman lidar are compared over a period of six months. The comparison of the attenuated backscatter profiles from a multi-wavelength Raman lidar and three ceilometers (CHM15k, CS135s, CT25K) reveals differences due to the expected discrepancy in the SNR but also due to effect of changes in the ambient temperature on the short and mid-term stability of ceilometer calibration. A large instability of ceilometers in the incomplete overlap region has also been observed, making the use of a single overlap correction function for the whole duration of the campaign critical. Therefore, technological improvements of ceilometers towards their operational use in the monitoring of the atmospheric aerosol in the low and free troposphere are needed.

scholarly journals Depolarization and lidar ratios at 355, 532, and 1064 nm and microphysical properties of aged tropospheric and stratospheric Canadian wildfire smoke

2018 ◽  
Vol 18 (16) ◽  
pp. 11847-11861 ◽  
Author(s):  
Moritz Haarig ◽  
Albert Ansmann ◽  
Holger Baars ◽  
Cristofer Jimenez ◽  
Igor Veselovskii ◽  
...  
Keyword(s):  
Wavelength Dependence ◽  
Particle Radius ◽  
Depolarization Ratio ◽  
Particle Volume ◽  
Wildfire Smoke ◽  
Smoke Particles ◽  
Microphysical Properties ◽  
532 Nm ◽  
Tropospheric Layer ◽  
Depolarization Ratios

Abstract. We present spectrally resolved optical and microphysical properties of western Canadian wildfire smoke observed in a tropospheric layer from 5–6.5 km height and in a stratospheric layer from 15–16 km height during a record-breaking smoke event on 22 August 2017. Three polarization/Raman lidars were run at the European Aerosol Research Lidar Network (EARLINET) station of Leipzig, Germany, after sunset on 22 August. For the first time, the linear depolarization ratio and extinction-to-backscatter ratio (lidar ratio) of aged smoke particles were measured at all three important lidar wavelengths of 355, 532, and 1064 nm. Very different particle depolarization ratios were found in the troposphere and in the stratosphere. The obviously compact and spherical tropospheric smoke particles caused almost no depolarization of backscattered laser radiation at all three wavelengths (<3 %), whereas the dry irregularly shaped soot particles in the stratosphere lead to high depolarization ratios of 22 % at 355 nm and 18 % at 532 nm and a comparably low value of 4 % at 1064 nm. The lidar ratios were 40–45 sr (355 nm), 65–80 sr (532 nm), and 80–95 sr (1064 nm) in both the tropospheric and stratospheric smoke layers indicating similar scattering and absorption properties. The strong wavelength dependence of the stratospheric depolarization ratio was probably caused by the absence of a particle coarse mode (particle mode consisting of particles with radius >500 nm). The stratospheric smoke particles formed a pronounced accumulation mode (in terms of particle volume or mass) centered at a particle radius of 350–400 nm. The effective particle radius was 0.32 µm. The tropospheric smoke particles were much smaller (effective radius of 0.17 µm). Mass concentrations were of the order of 5.5 µg m−3 (tropospheric layer) and 40 µg m−3 (stratospheric layer) in the night of 22 August 2017. The single scattering albedo of the stratospheric particles was estimated to be 0.74, 0.8, and 0.83 at 355, 532, and 1064 nm, respectively.

scholarly journals Characterization of Aerosol Size and Microphysical Properties from Multi-Wavelength Raman Lidar Measurements: Inter-Comparison with in Situ Sensors Onboard the ATR 42 in the Framework of HyMEX-SOP1

2020 ◽  
Vol 237 ◽  
pp. 02009
Author(s):  
Benedetto De Rosa ◽  
Paolo Di Girolamo ◽  
Donato Summa ◽  
Dario Stellitano
Keyword(s):  
Hydrological Cycle ◽  
Aerosol Layer ◽  
Raman Lidar ◽  
Microphysical Properties ◽  
Lidar Measurements ◽  
Retrieval Scheme ◽  
Research Aircraft ◽  
Multi Wavelength ◽  
In Situ Sensors

This extended abstract reports measurements that were carried out by the Raman lidar system BASIL in the frame of the Hydrological Cycle in the Mediterranean Experiment – Special Observation Period 1 (HyMeX-SOP1). A specific case study was selected revealing the presence of variable aerosol properties at different altitudes. Specifically, Raman lidar measurements on 02 October 2012 reveal the presence of two distinct aerosol layers, a lower one extending up to ~3 km and an upper one extending from 3.5 km to 4.7 km. Aerosol and size microphysical properties are determined from multi-wavelength measurements of particle backscattering and extinction profiles based on the application of a retrieval scheme which employs Tikhonov’s inversion with regularization. Inversion results suggest a size distribution with the presence, in both the lower and upper aerosol layer, of two particle modes (a fine mode, with a radius of ~0.2 μm, and a coarse mode, with radii in the range 2-4 μm), volume concentration values of 2-4 mm3cm-3 and effective radii in the range 0.2-0.6 μm. This effort benefited from the dedicated flights of the French research aircraft ATR42, equipped with a variety of in situ sensors for measuring aerosol/cloud size and microphysical properties. Aerosol size and microphysical properties retrieved from multi-wavelength Raman lidar measurements were compared with simultaneous and co-located in-situ measurements.

scholarly journals Intercomparison of aerosol measurements performed with multi-wavelength Raman lidars, automatic lidars and ceilometers in the frame of INTERACT-II campaign

2017 ◽  
Author(s):  
Fabio Madonna ◽  
Marco Rosoldi ◽  
Simone Lolli ◽  
Francesco Amato ◽  
Joshua Vande Hey ◽  
...  
Keyword(s):  
Atmospheric Aerosol ◽  
Trace Gases ◽  
Average Difference ◽  
Raman Lidar ◽  
Simultaneous Measurements ◽  
Lidar Measurements ◽  
Multi Wavelength ◽  
Micro Pulse Lidar ◽  
Aerosol Properties ◽  
Cloud Tracking

Abstract. Following on from the previous efforts of INTERACT (INTERcomparison of Aerosol and Cloud Tracking), the INTERACT-II campaign used multi-wavelength Raman lidar measurements to assess the performance of an automatic compact micro-pulse lidar (MiniMPL) and two ceilometers (CL51 and CS135), respectively, to provide reliable information about optical and geometric atmospheric aerosol properties. The campaign took place at the CNR-IMAA Atmospheric Observatory (760 m asl, 40.60° N, 15.72° E), in the framework of the ACTRIS-2 (Aerosol Clouds Trace gases Research InfraStructure) H2020 project. Co-located simultaneous measurements involving a MiniMPL, two ceilometers, and two EARLINET multi-wavelength Raman lidars (MUSA and PEARL) were performed from July to December 2016. Range-corrected signals (RCS) of MiniMPL showed an average difference with respect to MUSA/PEARL RCS of less than 10–15 % below 3.0 km above sea level, largely due to the use of an inaccurate overlap correction, and smaller than 5 % in the free troposphere. For the CL51, the average difference with respect to MUSA/PEARL attenuated backscatter is

Determination of aerosol size and microphiysical proprierties based on multi-wavelength raman lidar measurements in the framework of HyMeX-SOP1

2020 ◽  
Author(s):  
Benedetto De Rosa ◽  
Paolo Di Girolamo ◽  
Donato Summa
Keyword(s):  
Hydrological Cycle ◽  
Radiation Budget ◽  
Aerosol Layer ◽  
Raman Lidar ◽  
Good Opportunity ◽  
Microphysical Properties ◽  
Lidar Measurements ◽  
Multi Wavelength ◽  
In Situ Sensors

&lt;p&gt;Tropospheric aerosols&amp;#160; are a fundamental component of the Earth&amp;#8217;s radiation budget. In order to properly estimate their direct and indirect effect, accurate measurements of aerosol size and microphysical properties are required.A limited number of techniques are presently available and capable to provide these measurements.&lt;/p&gt;&lt;p&gt;Multi-wavelength Raman lidars Raman lidars have strong potential. However,theireffectiveness and reliability of need to be assessed and verified against independent measurements.&lt;/p&gt;&lt;p&gt;This abstract reports measurements that were carried out by the Raman lidar system BASIL in the frame of the Hydrological Cycle in the Mediterranean Experiment &amp;#8211; Special Observation Period 1 (HyMeX-SOP1).The considered dataset represents a good opportunity to verify the quality of retrievals in terms of size and microphysical properties obtained from multi-wavelength Raman lidars.&lt;/p&gt;&lt;p&gt;A specific case study was selected revealing the presence of variable aerosol properties at different altitudes. Specifically, Raman lidar measurements on 02 October 2012 show the presence of two distinct aerosol layers, a lower one extending up to ~3 km and an upper one extending from 3.5 km to 4.7 km. Aerosol and size microphysical properties are determined from multi-wavelength measurements of particle backscattering and extinction profiles based on the application of&amp;#160; a retrieval scheme which employs Tikhonov&amp;#8217;s inversion with regularization. Inversion results suggest a size distribution with the presence, in both the lower and upper aerosol layer, of two particle modes (a fine mode, with a radius of ~0.2 mm, and a coarse mode, with radii in the range 2-4 mm), volume concentration values of 2-4 mm&lt;sup&gt;3&lt;/sup&gt;cm&lt;sup&gt;-3&lt;/sup&gt;and effective radii in the&amp;#160; range 0.2-0.6 mm.&lt;/p&gt;&lt;p&gt;This effort benefited from the dedicated flights of the French research aircraft ATR42, equipped with a variety of in situ sensors for measuring aerosol/cloud size and microphysical properties. Aerosol size and microphysical properties retrieved from multi-wavelength Raman lidar measurements were compared with simultaneous and co-located in-situ measurements.&lt;/p&gt;

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