Raman lidar measurements of Pinatubo aerosols over southeastern Kansas during November-December 1991

1992 ◽  
Vol 19 (15) ◽  
pp. 1599-1602 ◽  
Author(s):  
R. A. Ferrare ◽  
S. H. Melfi ◽  
D. N. Whiteman ◽  
K. D. Evans
Keyword(s):  
Raman Lidar ◽  
Lidar Measurements

scholarly journals EARLINET dust observations vs. BSC-DREAM8b modeled profiles: 12-year-long systematic comparison at Potenza, Italy

2014 ◽  
Vol 14 (16) ◽  
pp. 8781-8793 ◽  
Author(s):  
L. Mona ◽  
N. Papagiannopoulos ◽  
S. Basart ◽  
J. Baldasano ◽  
I. Binietoglou ◽  
...  
Keyword(s):  
Center Of Mass ◽  
Saharan Dust ◽  
Raman Lidar ◽  
Dust Layer ◽  
Systematic Comparison ◽  
Dust Extinction ◽  
Lidar Measurements ◽  
Order Of Magnitude ◽  
Lidar Ratio ◽  
532 Nm

Abstract. In this paper, we report the first systematic comparison of 12-year modeled dust extinction profiles vs. Raman lidar measurements. We use the BSC-DREAM8b model, one of the most widely used dust regional models in the Mediterranean, and Potenza EARLINET lidar profiles for Saharan dust cases, the largest one-site database of dust extinction profiles. A total of 310 dust cases were compared for the May 2000–July 2012 period. The model reconstructs the measured layers well: profiles are correlated within 5% of significance for 60% of the cases and the dust layer center of mass as measured by lidar and modeled by BSC-DREAM8b differ on average 0.3 ± 1.0 km. Events with a dust optical depth lower than 0.1 account for 70% of uncorrelated profiles. Although there is good agreement in terms of profile shape and the order of magnitude of extinction values, the model overestimates the occurrence of dust layer top above 10 km. Comparison with extinction profiles measured by the Raman lidar shows that BSC-DREAM8b typically underestimates the dust extinction coefficient, in particular below 3 km. Lowest model–observation differences (below 17%) correspond to a lidar ratio at 532 nm and Ångström exponent at 355/532 nm of 60 ± 13 and 0.1 ± 0.6 sr, respectively. These are in agreement with values typically observed and modeled for pure desert dust. However, the highest differences (higher than 85%) are typically related to greater Ångström values (0.5 ± 0.6), denoting smaller particles. All these aspects indicate that the level of agreement decreases with an increase in mixing/modification processes.

scholarly journals Tropospheric water vapour and relative humidity profiles from lidar and microwave radiometry

2014 ◽  
Vol 7 (5) ◽  
pp. 1201-1211 ◽  
Author(s):  
F. Navas-Guzmán ◽  
J. Fernández-Gálvez ◽  
M. J. Granados-Muñoz ◽  
J. L. Guerrero-Rascado ◽  
J. A. Bravo-Aranda ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Water Vapour ◽  
Microwave Radiometer ◽  
Radiosonde Data ◽  
Mixing Ratio ◽  
Raman Lidar ◽  
Night Time ◽  
New Approach ◽  
Lidar Measurements ◽  
Humidity Profiles

Abstract. In this paper, we outline an iterative method to calibrate the water vapour mixing ratio profiles retrieved from Raman lidar measurements. Simultaneous and co-located radiosonde data are used for this purpose and the calibration results obtained during a radiosonde campaign in summer and autumn 2011 are presented. The water vapour profiles measured during night-time by the Raman lidar and radiosondes are compared and the differences between the methodologies are discussed. Then, a new approach to obtain relative humidity profiles by combination of simultaneous profiles of temperature (retrieved from a microwave radiometer) and water vapour mixing ratio (from a Raman lidar) is addressed. In the last part of this work, a statistical analysis of water vapour mixing ratio and relative humidity profiles obtained during 1 year of simultaneous measurements is presented.

scholarly journals Synchronous polar winter starphotometry and lidar measurements at a High Arctic station

2015 ◽  
Vol 8 (9) ◽  
pp. 3789-3809 ◽  
Author(s):  
K. Baibakov ◽  
N. T. O'Neill ◽  
L. Ivanescu ◽  
T. J. Duck ◽  
C. Perro ◽  
...  
Keyword(s):  
Optical Properties ◽  
Aerosol Optical Depth ◽  
Research Laboratory ◽  
Recent Progress ◽  
High Arctic ◽  
Raman Lidar ◽  
Backscatter Coefficient ◽  
Atmospheric Research ◽  
Lidar Measurements ◽  
Fine Mode

Abstract. We present recent progress on nighttime retrievals of aerosol and cloud optical properties over the PEARL (Polar Environmental Atmospheric Research Laboratory) station at Eureka (Nunavut, Canada) in the High Arctic (80° N, 86° W). In the spring of 2011 and 2012, a star photometer was employed to acquire aerosol optical depth (AOD) data, while vertical aerosol and cloud backscatter profiles were measured using the CANDAC Raman Lidar (CRL). We used a simple backscatter coefficient threshold (βthr) to distinguish aerosols from clouds and, assuming that aerosols were largely fine mode (FM)/sub-micron, to distinguish FM aerosols from coarse mode (CM)/super-micron cloud or crystal particles. Using prescribed lidar ratios, we computed FM and CM AODs that were compared with analogous AODs estimated from spectral star photometry. We found (βthr dependent) coherences between the lidar and star photometer for both FM events and CM cloud and crystal events with averaged, FM absolute differences being

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.

scholarly journals Retrieval of the tropospheric aerosol microphysical characteristics from the data of multifrequency lidar sensing

2018 ◽  
Vol 176 ◽  
pp. 05055 ◽  
Author(s):  
S. Samoilova ◽  
M. Sviridenkov ◽  
I. Penner ◽  
G. Kokhanenko ◽  
Yu. Balin
Keyword(s):  
Refractive Index ◽  
Distribution Function ◽  
Complex Refractive Index ◽  
Size Distribution Function ◽  
Coarse Fraction ◽  
Optical Parameters ◽  
Raman Lidar ◽  
Tropospheric Aerosol ◽  
Lidar Measurements ◽  
The Vertical Distribution

Regular lidar measurements of the vertical distribution of aerosol optical parameters are carried out in Tomsk (56°N, 85°E) since April, 2011. We present the results of retrieval of microphysical characteristics from the data of measurements by means of Raman lidar in 2013. Section 2 is devoted to the theoretical aspects of retrieving the particle size distribution function U(r) (SDF) assuming a known complex refractive index m (CRI). It is shown that the coarse fraction cannot be retrieved unambiguously. When estimating U(r) and m together (section 3), the retrieved refractive index is non-linearly related to the optical coefficients and the distribution function, which leads to appearance of different, including false values of m. The corresponding U(r) differs only slightly, so the inaccuracy in m does not essentially affect the retrieval of the distribution function.

scholarly journals Towards continuous monitoring of aerosol hygroscopicity by Raman lidar measurements at the EARLINET station of Payerne

2019 ◽  
Author(s):  
Francisco Navas Guzmán ◽  
Giovanni Martucci ◽  
Martine Collaud Coen ◽  
María José Granados Muñoz ◽  
Maxime Hervo ◽  
...  
Keyword(s):  
Continuous Monitoring ◽  
Raman Lidar ◽  
Backscatter Coefficient ◽  
Lidar System ◽  
Remote Sensing Technique ◽  
Accuracy And Precision ◽  
Lidar Measurements ◽  
Constant Altitude ◽  
Aerosol Backscatter ◽  
Aerosol Hygroscopicity

Abstract. This study focuses on the analysis of aerosol hygroscopicity using remote sensing technique. Continuous observations of aerosol backscatter coefficient, temperature and water vapour mixing ratio are performed by means of a Raman lidar system at the aerological station of MeteoSwiss at Payerne (Switzerland) since 2008. These measurements allow us to monitor in a continuous way any change of aerosol properties as a function of the relative humidity (RH). These changes can be observed either in time at constant altitude or in altitude at a constant time. The accuracy and precision of RH measurements from the lidar have been evaluated using the radiosonde (RS) technique as reference. A total of 172 RSs were used in this intercomparison which revealed a small bias (

scholarly journals Retrieval of temperature from a multiple channel pure rotational Raman backscatter lidar using an optimal estimation method

2019 ◽  
Vol 12 (11) ◽  
pp. 5801-5816 ◽  
Author(s):  
Shayamila Mahagammulla Gamage ◽  
Robert J. Sica ◽  
Giovanni Martucci ◽  
Alexander Haefele
Keyword(s):  
Estimation Method ◽  
Optimal Estimation ◽  
Uncertainty Budget ◽  
Temperature Measurements ◽  
New Method ◽  
Retrieval Algorithm ◽  
Coupling Constant ◽  
Raman Lidar ◽  
Multiple Channel ◽  
Lidar Measurements

Abstract. We present a new method for retrieving temperature from pure rotational Raman (PRR) lidar measurements. Our optimal estimation method (OEM) used in this study uses the full physics of PRR scattering and does not require any assumption of the form for a calibration function nor does it require fitting of calibration factors over a large range of temperatures. The only calibration required is the estimation of the ratio of the lidar constants of the two PRR channels (coupling constant) that can be evaluated at a single or multiple height bins using a simple analytic expression. The uncertainty budget of our OEM retrieval includes both statistical and systematic uncertainties, including the uncertainty in the determination of the coupling constant on the temperature. We show that the error due to calibration can be reduced significantly using our method, in particular in the upper troposphere when calibration is only possible over a limited temperature range. Some other advantages of our OEM over the traditional Raman lidar temperature retrieval algorithm include not requiring correction or gluing to the raw lidar measurements, providing a cutoff height for the temperature retrievals that specifies the height to which the retrieved profile is independent of the a priori temperature profile, and the retrieval's vertical resolution as a function of height. The new method is tested on PRR temperature measurements from the MeteoSwiss RAman Lidar for Meteorological Observations system in clear and cloudy sky conditions, compared to temperature calculated using the traditional PRR calibration formulas, and validated with coincident radiosonde temperature measurements in clear and cloudy conditions during both daytime and nighttime.

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