Inter-comparison of ABL height estimates from different profiling sensors and models in the framework of HyMeX-SOP1

Abstract. This paper reports results from an inter-comparison effort involving different sensors/techniques used to measure the Atmospheric Boundary Layer (ABL) height. The effort took place in the framework of the first Special Observing Period of the Hydrological cycle of the Mediterranean Experiment (HyMeX-SOP1). Elastic backscatter and rotational Raman signals collected by the Raman lidar system BASIL were used to determine the ABL height and characterize its internal structure. These techniques were compared with co-located measurements from a wind profiler and radiosondes and with ECMWF-ERA5 data. In the effort we consider radiosondes launched in the proximity of the lidar site, as well as radiosondes launched from the closest radiosonde station included in the Integrated Global Radiosonde archive (IGRA). The inter-comparison effort considers data from October 2012. Results reveal a good agreement between the different approaches, with values of the correlation coefficient R2 in the range 0.52 to 0.94. Results clearly reveals that the combined application of different techniques to distinct sensors’ and model datasets allow getting accurate and cross-validated estimates of the ABL height over a variety of weather conditions. Furthermore, correlations between the ABL height and other atmospheric dynamic and thermodynamic variables as CAPE, friction velocity and relative humidity are also assessed to infer possible mutual dependences.

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Characterization of atmospheric thermodynamic variables by Raman lidar in the frame of the International Network for the Detection of Atmospheric Composition Change - NDACC

EPJ Web of Conferences ◽

10.1051/epjconf/201817604010 ◽

2018 ◽

Vol 176 ◽

pp. 04010

Author(s):

Benedetto De Rosa ◽

Paolo Di Girolamo ◽

Donato Summa

Keyword(s):

Water Vapour ◽

Atmospheric Temperature ◽

Atmospheric Composition ◽

Vertical Profiles ◽

Mixing Ratio ◽

Composition Change ◽

Raman Lidar ◽

Lidar System ◽

Thermodynamic Variables

In November 2012 the Raman Lidar system BASIL, located at the Univ. of Basilicata (Potenza), was approved to enter in NDACC, with the goal of providing accurate routine measurements of the vertical profiles of atmospheric temperature and water vapour mixing ratio. In this presentation we illustrate and discuss water vapour mixing ratio and temperature measurements carried out during these four years and their comparisons with the radiosondes launched from nearby Institute IMAA-CNR (7 km away).

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Characterization of atmospheric aerosol optical properties based on the combined use of a ground-based Raman lidar and an airborne optical particle counter in the framework of the Hydrological Cycle in the Mediterranean Experiment – Special Observation Period 1

Atmospheric Measurement Techniques ◽

10.5194/amt-12-2183-2019 ◽

2019 ◽

Vol 12 (4) ◽

pp. 2183-2199 ◽

Cited By ~ 1

Author(s):

Dario Stelitano ◽

Paolo Di Girolamo ◽

Andrea Scoccione ◽

Donato Summa ◽

Marco Cacciani

Keyword(s):

Hydrological Cycle ◽

Mean Value ◽

Raman Lidar ◽

Particle Counter ◽

Optical Particle Counter ◽

Multi Wavelength ◽

The Mediterranean ◽

Particle Backscattering ◽

Observation Period ◽

Good Agreement

Abstract. Vertical profiles of the particle backscattering coefficient at 355, 532 and 1064 nm measured by the University of Basilicata Raman lidar system (BASIL) have been compared with simulated particle backscatter profiles obtained through a Mie scattering code based on the use of simultaneous and almost co-located profiles provided by an airborne optical particle counter. Measurements were carried out during dedicated flights of the French research aircraft ATR42 in the framework of the European Facility for Airborne Research (EUFAR) project “WaLiTemp”, as part of the Hydrological Cycle in the Mediterranean Experiment – Special Observation Period 1 (HyMeX-SOP1). Results from two selected case studies are reported and discussed in the paper, and a dedicated analysis approach is illustrated and applied to the dataset. Results reveal a good agreement between measured and simulated multi-wavelength particle backscattering profiles. Specifically, simulated and measured particle backscattering profiles at 355 and 532 nm for the second case study are found to deviate less than 15 % (mean value =5.9 %) and 50 % (mean value =25.9 %), respectively, when considering the presence of a continental–urban aerosol component, while slightly larger deviation values are found for the first study. The reported good agreement between measured and simulated multi-wavelength particle backscatter profiles testifies to the ability of multi-wavelength Raman lidar systems to infer aerosol types at different altitudes.

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Toronto Water Vapor Lidar Inter-Comparison Campaign

Remote Sensing ◽

10.3390/rs12193165 ◽

2020 ◽

Vol 12 (19) ◽

pp. 3165

Author(s):

Zen Mariani ◽

Noah Stanton ◽

James Whiteway ◽

Raisa Lehtinen

Keyword(s):

Water Vapor ◽

Weather Conditions ◽

Horizontal Displacement ◽

Raman Lidar ◽

Night Time ◽

Operational Program ◽

Comparison Field ◽

Atmospheric Backscatter ◽

Good Agreement

This study presents comparisons between vertical water vapor profile measurements from a Raman lidar and a new pre-production broadband differential absorption lidar (DIAL). Vaisala’s novel DIAL system operates autonomously outdoors and measures the vertical profile of water vapor within the boundary layer 24 h a day during all weather conditions. Eight nights of measurements in June and July 2018 were used for the Toronto water vapor lidar inter-comparison field campaign. Both lidars provided reliable atmospheric backscatter and water vapor profile measurements. Comparisons were performed during night-time observations only, when the York Raman lidar could measure the water vapor profile. The purpose was to validate the water vapor profile measurements retrieved by the new DIAL system. The results indicate good agreement between the two lidars, with a mean difference (DIAL–Raman) of 0.17 ± 0.14 g/kg. There were two main causes for differences in their measurements: horizontal displacement between the two lidar sites (3.2 km) and vertical gradients in the water vapor profile. A case study analyzed during the campaign demonstrates the ability for both lidars to measure sudden changes and large gradients in the water vapor’s vertical structure due to a passing frontal system. These results provide an initial validation of the DIAL’s measurements and its ability to be implemented as part of an operational program.

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Raman lidar system for methane gas concentration measurements

Applied Optics ◽

10.1364/ao.25.002115 ◽

1986 ◽

Vol 25 (13) ◽

pp. 2115 ◽

Cited By ~ 14

Author(s):

J. Douglas Houston ◽

Sebastian Sizgoric ◽

Arkady Ulitsky ◽

John Banic

Keyword(s):

Raman Lidar ◽

Lidar System ◽

Gas Concentration ◽

Methane Gas ◽

Concentration Measurements

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Spectrally-Resolved Raman Lidar to Measure Atmospheric Three-Phase Water Simultaneously

EPJ Web of Conferences ◽

10.1051/epjconf/202023706017 ◽

2020 ◽

Vol 237 ◽

pp. 06017

Author(s):

Fuchao Liu ◽

Fan Yi

Keyword(s):

Water Vapor ◽

Raman Spectra ◽

Weather Conditions ◽

Cloud Microphysics ◽

Raman Lidar ◽

Atmospheric Water ◽

Three Phase ◽

Phase Water ◽

Spectrally Resolved ◽

Ice Water

We report on a spectrally-resolved Raman lidar that can simultaneously profile backscattered Raman spectrum signals from water vapor, water droplets and ice crystals as well as aerosol fluorescence in the atmosphere. The lidar emits a 354.8-nm ultraviolet laser radiation and samples echo signals in the 393.0-424.0 nm wavelength range with a 1.0-nm spectral resolution. A spectra decomposition method is developed to retrieve fluorescence spectra, water vapor Raman spectra and condensed (liquid and/or ice) water Raman spectra successively. Based on 8 different clear-sky nighttime measurement results, the entire atmospheric water vapor Raman spectra are for the first time obtained by lidar. The measured normalized water vapor Raman spectra are nearly invariant and can serve as background reference for atmospheric water phase state identification under various weather conditions. For an ice virga event, it’s found the extracted condensed water Raman spectra are highly similar in shape to theoretical ice water Raman spectra reported by Slusher and Derr (1975). In conclusion, the lidar provides an effective way to measure three-phase water simultaneously in the atmosphere and to study of cloud microphysics as well as interaction between aerosols and clouds.

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Validation of aerosol backscatter profiles from Raman lidar and ceilometer using balloon-borne measurements

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-2267-2021 ◽

2021 ◽

Vol 21 (3) ◽

pp. 2267-2285

Author(s):

Simone Brunamonti ◽

Giovanni Martucci ◽

Gonzague Romanens ◽

Yann Poltera ◽

Frank G. Wienhold ◽

...

Keyword(s):

Remote Sensing ◽

In Situ Measurements ◽

Aerosol Size Distribution ◽

Spatial And Temporal Variability ◽

Raman Lidar ◽

Backscatter Coefficient ◽

Custom Made ◽

Aerosol Backscatter ◽

Good Agreement

Abstract. Remote-sensing measurements by light detection and ranging (lidar) instruments are fundamental for the monitoring of altitude-resolved aerosol optical properties. Here we validate vertical profiles of aerosol backscatter coefficient (βaer) measured by two independent lidar systems using co-located balloon-borne measurements performed by Compact Optical Backscatter Aerosol Detector (COBALD) sondes. COBALD provides high-precision in situ measurements of βaer at two wavelengths (455 and 940 nm). The two analyzed lidar systems are the research Raman Lidar for Meteorological Observations (RALMO) and the commercial CHM15K ceilometer (Lufft, Germany). We consider in total 17 RALMO and 31 CHM15K profiles, co-located with simultaneous COBALD soundings performed throughout the years 2014–2019 at the MeteoSwiss observatory of Payerne (Switzerland). The RALMO (355 nm) and CHM15K (1064 nm) measurements are converted to 455 and 940 nm, respectively, using the Ångström exponent profiles retrieved from COBALD data. To account for the different receiver field-of-view (FOV) angles between the two lidars (0.01–0.02∘) and COBALD (6∘), we derive a custom-made correction using Mie-theory scattering simulations. Our analysis shows that both lidar instruments achieve on average a good agreement with COBALD measurements in the boundary layer and free troposphere, up to 6 km altitude. For medium-high-aerosol-content measurements at altitudes below 3 km, the mean ± standard deviation difference in βaer calculated from all considered soundings is −2 % ± 37 % (−0.018 ± 0.237 Mm−1 sr−1 at 455 nm) for RALMO−COBALD and +5 % ± 43 % (+0.009 ± 0.185 Mm−1 sr−1 at 940 mm) for CHM15K−COBALD. Above 3 km altitude, absolute deviations generally decrease, while relative deviations increase due to the prevalence of air masses with low aerosol content. Uncertainties related to the FOV correction and spatial- and temporal-variability effects (associated with the balloon's drift with altitude and different integration times) contribute to the large standard deviations observed at low altitudes. The lack of information on the aerosol size distribution and the high atmospheric variability prevent an accurate quantification of these effects. Nevertheless, the excellent agreement observed in individual profiles, including fine and complex structures in the βaer vertical distribution, shows that under optimal conditions, the discrepancies with the in situ measurements are typically comparable to the estimated statistical uncertainties in the remote-sensing measurements. Therefore, we conclude that βaer profiles measured by the RALMO and CHM15K lidar systems are in good agreement with in situ measurements by COBALD sondes up to 6 km altitude.

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

E3S Web of Conferences ◽

10.1051/e3sconf/20199902010 ◽

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.

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Evaluation of LIRIC Algorithm Performance Using Independent Sun-Sky Photometer Data at Two Altitude Levels

Remote Sensing ◽

10.3390/rs12050842 ◽

2020 ◽

Vol 12 (5) ◽

pp. 842

Author(s):

María J. Granados-Muñoz ◽

José Antonio Benavent-Oltra ◽

Daniel Pérez-Ramírez ◽

Hassan Lyamani ◽

Juan Luis Guerrero-Rascado ◽

...

Keyword(s):

Volume Concentration ◽

Observational Period ◽

Lidar System ◽

Algorithm Performance ◽

Microphysical Properties ◽

A Value ◽

Large Databases ◽

Self Consistency ◽

System Operating ◽

Good Agreement

This work evaluates the Lidar-Radiometer Inversion Code (LIRIC) using sun-sky photometers located at different altitudes in the same atmospheric column. Measurements were acquired during an intensive observational period in summer 2012 at Aerosols, Clouds, and Trace gases Research InfraStructure Network (ACTRIS)/Aerosol Robotic Network (AERONET) Granada (GRA; 37.16°N, 3.61°W, 680 m above sea level (a.s.l.)) and Cerro Poyos (CP; 37.11°N, 3.49°W, 1820 m a.s.l.) sites. Both stations operated AERONET sun-photometry, with an additional lidar system operating at Granada station. The extended database of simultaneous lidar and sun-photometry measurements from this study allowed the statistical analysis of vertically resolved microphysical properties retrieved with LIRIC, with 70% of the analyzed cases corresponding to mineral dust. Consequently, volume concentration values were 46 μm3/cm3 on average, with a value of ~30 μm3/cm3 corresponding to the coarse spheroid mode and concentrations below 10 μm3/cm3 for the fine and coarse spherical modes. According to the microphysical properties’ profiles, aerosol particles reached altitudes up to 6000 m a.s.l., as observed in previous studies over the same region. Results obtained from comparing the LIRIC retrievals from GRA and from CP revealed good agreement between both stations with differences within the expected uncertainties associated with LIRIC (15%). However, larger discrepancies were found for 10% of the cases, mostly due to the incomplete overlap of the lidar signal and/or to the influence of different aerosol layers advected from the local origin located between both stations, which is particularly important in cases of low aerosol loads. Nevertheless, the results presented here demonstrate the robustness and self-consistency of LIRIC and consequently its applicability to large databases such as those derived from ACTRIS-European Aerosol Research Lidar Network (EARLINET) observations.

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