scholarly journals Optical properties of aerosol and cloud particles measured by a single-line-extracted pure rotational Raman lidar

2021 ◽  
Author(s):  
Liang Peng ◽  
Fan Yi ◽  
Fuchao Liu ◽  
ZP Yin ◽  
Yun He
Keyword(s):  
Optical Properties ◽  
Single Line ◽  
Raman Lidar ◽  
Cloud Particles

scholarly journals One year of Raman lidar observations of free-tropospheric aerosol layers over South Africa

2015 ◽  
Vol 15 (10) ◽  
pp. 5429-5442 ◽  
Author(s):  
E. Giannakaki ◽  
A. Pfüller ◽  
K. Korhonen ◽  
T. Mielonen ◽  
L. Laakso ◽  
...  
Keyword(s):  
South Africa ◽  
Optical Properties ◽  
Biomass Burning ◽  
Mean Value ◽  
Aerosol Layer ◽  
Raman Lidar ◽  
Tropospheric Aerosol ◽  
Wide Range ◽  
Significant Difference ◽  
532 Nm

Abstract. Raman lidar data obtained over a 1 year period has been analysed in relation to aerosol layers in the free troposphere over the Highveld in South Africa. In total, 375 layers were observed above the boundary layer during the period 30 January 2010 to 31 January 2011. The seasonal behaviour of aerosol layer geometrical characteristics, as well as intensive and extensive optical properties were studied. The highest centre heights of free-tropospheric layers were observed during the South African spring (2520 ± 970 m a.g.l., also elsewhere). The geometrical layer depth was found to be maximum during spring, while it did not show any significant difference for the rest of the seasons. The variability of the analysed intensive and extensive optical properties was high during all seasons. Layers were observed at a mean centre height of 2100 ± 1000 m with an average lidar ratio of 67 ± 25 sr (mean value with 1 standard deviation) at 355 nm and a mean extinction-related Ångström exponent of 1.9 ± 0.8 between 355 and 532 nm during the period under study. Except for the intensive biomass burning period from August to October, the lidar ratios and Ångström exponents are within the range of previous observations for urban/industrial aerosols. During Southern Hemispheric spring, the biomass burning activity is clearly reflected in the optical properties of the observed free-tropospheric layers. Specifically, lidar ratios at 355 nm were 89 ± 21, 57 ± 20, 59 ± 22 and 65 ± 23 sr during spring (September–November), summer (December–February), autumn (March–May) and winter (June–August), respectively. The extinction-related Ångström exponents between 355 and 532 nm measured during spring, summer, autumn and winter were 1.8 ± 0.6, 2.4 ± 0.9, 1.8 ± 0.9 and 1.8 ± 0.6, respectively. The mean columnar aerosol optical depth (AOD) obtained from lidar measurements was found to be 0.46 ± 0.35 at 355 nm and 0.25 ± 0.2 at 532 nm. The contribution of free-tropospheric aerosols on the AOD had a wide range of values with a mean contribution of 46%.

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 Lidar Overlap Function Determination Using the Raman Lidar Signals

2020 ◽  
Vol 237 ◽  
pp. 07018
Author(s):  
Jaswant ◽  
Shishir Kumar Singh ◽  
Radhakrishnan S.R. ◽  
Devesh Shukla ◽  
Chhemendra Sharma
Keyword(s):  
Optical Properties ◽  
Simple Technique ◽  
Near Field ◽  
Lower Atmosphere ◽  
Raman Lidar ◽  
Lidar System ◽  
Field Range ◽  
The Mean ◽  
Overlap Factor

The determination of vertical distribution of optical properties of clouds and aerosols using the lidar system is affected by the incomplete overlap between the field of view of transmitter i.e. laser beam & the receiver in the near‐field range. Thus, the study of vertical profiles of aerosol optical properties in the lower atmosphere is erroneous without the correction of lidar overlap function. Here we have analysed the effect of overlap using a simple technique proposed by Ansmann and Wandinger to determine overlap function. We have determined the overlap factor for 5 different days of June 2016 and then calculated the mean overlap profile and determined the relative deviation of each day with respect to mean overlap factor. Results reveal that the complete overlap was achieved beyond 300 meters.

scholarly journals 2014 iAREA campaign on aerosol in Spitsbergen – Part 2: Optical properties from Raman-lidar and in-situ observations at Ny-Ålesund

2016 ◽  
Vol 141 ◽  
pp. 1-19 ◽  
Author(s):  
C. Ritter ◽  
R. Neuber ◽  
Alexander Schulz ◽  
K.M. Markowicz ◽  
I.S. Stachlewska ◽  
...  
Keyword(s):  
Optical Properties ◽  
Raman Lidar ◽  
In Situ Observations

scholarly journals Joint elastic side-scattering LIDAR and Raman LIDAR measurements of aerosol optical properties in south east Colorado

2017 ◽  
Vol 12 (03) ◽  
pp. P03008-P03008 ◽  
Author(s):  
L. Wiencke ◽  
V. Rizi ◽  
M. Will ◽  
C. Allen ◽  
A. Botts ◽  
...  
Keyword(s):  
Optical Properties ◽  
Raman Lidar ◽  
Aerosol Optical Properties ◽  
Lidar Measurements

scholarly journals Investigation of Aerosol Properties and Structures in Two Representative Meteorological Situations over the Vipava Valley Using Polarization Raman LiDAR

Atmosphere ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 128 ◽  
Author(s):  
Longlong Wang ◽  
Samo Stanič ◽  
William Eichinger ◽  
Griša Močnik ◽  
Luka Drinovec ◽  
...  
Keyword(s):  
Optical Properties ◽  
Hot Spot ◽  
Weather Conditions ◽  
Raman Lidar ◽  
Backscatter Coefficient ◽  
First Case ◽  
Lidar Ratio ◽  
Bora Wind ◽  
Aerosol Types ◽  
Aerosol Properties

Vipava valley in Slovenia is a representative hot-spot for complex mixtures of different aerosol types of both anthropogenic and natural origin. Aerosol loading distributions and optical properties were investigated using a two-wavelength polarization Raman LiDAR, which provided extinction coefficient, backscatter coefficient, depolarization ratio, backscatter Ångström exponent and LiDAR ratio profiles. Two different representative meteorological situations were investigated to explore the possibility of identifying aerosol types present in the valley. In the first case, we investigated the effect of strong downslope (Bora) wind on aerosol structures and characteristics. In addition to observing Kelvin–Helmholtz instability above the valley, at the height of the adjacent mountain ridge, we found new evidence for Bora-induced processes which inject soil dust aerosols into the free troposphere up to twice the height of the planetary boundary layer (PBL). In the second case, we investigated aerosol properties and distributions in stable weather conditions. From the observed stratified vertical aerosol structure and specific optical properties of different layers we identified predominant aerosol types in these layers.

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