scholarly journals Raman lidar measurement of water vapor and ice clouds associated with Asian dust layer over Tsukuba, Japan

2004 ◽  
Vol 31 (6) ◽  
pp. n/a-n/a ◽  
Author(s):  
Tetsu Sakai ◽  
Tomohiro Nagai ◽  
Masahisa Nakazato ◽  
Takatsugu Matsumura
Keyword(s):  
Water Vapor ◽  
Asian Dust ◽  
Lidar Measurement ◽  
Raman Lidar ◽  
Ice Clouds ◽  
Dust Layer

Implementation and validation of a Raman lidar measurement of middle and upper tropospheric water vapor

1999 ◽  
Vol 38 (27) ◽  
pp. 5838 ◽  
Author(s):  
Vanessa Sherlock ◽  
Anne Garnier ◽  
Alain Hauchecorne ◽  
Philippe Keckhut
Keyword(s):  
Water Vapor ◽  
Lidar Measurement ◽  
Raman Lidar

scholarly journals Multiwavelength and polarization lidar measurements of Asian dust layers over Tsukuba, Japan: a case study

2007 ◽  
Vol 7 (4) ◽  
pp. 10179-10203 ◽  
Author(s):  
T. Sakai ◽  
T. Nagai ◽  
T. Kobayashi ◽  
A. Yamazaki ◽  
A. Uchiyama ◽  
...  
Keyword(s):  
Asian Dust ◽  
Aerosol Layer ◽  
Lidar Measurement ◽  
Nonspherical Particles ◽  
Depolarization Ratio ◽  
Dust Layer ◽  
Coarse Mode ◽  
Fine Mode ◽  
Aerosol Properties

Abstract. Elastic and polarization lidar was used to measure the vertical profiles of aerosol backscattering coefficients at wavelengths of 355, 532, 735, and 1064 nm, and the depolarization ratio at 532 nm in order to study the aerosol properties in the free troposphere over Tsukuba, Japan, in 2006. An elevated dust layer was observed at altitudes between 3 and 8.5 km on 1 April during the Asian dust period. The wavelength exponents of the aerosol backscattering coefficient (k) were –0.1 to 0.5, and the depolarization ratio (δp) was 25% for the dust layer, suggesting the predominance of supermicrometer-sized (coarse mode) nonspherical particles. An aerosol layer observed at altitudes between 1.5 and 5 km on 19 October during the less-dust period exhibited the values of k=1.0 to 1.6 and δp=1 to 13%, suggesting the predominance of submicrometer-sized (fine mode) particles. In those layers, the values of k and δp varied with height; they were also negatively correlated, suggesting that the proportion of the coarse nonspherical particles to total particles varied. The particle size distributions estimated from the observed values and the theoretical computation revealed number mode radii of 0.3 &mum; for the coarse mode and 0.1 &mum; for the fine mode, assuming bimodal distribution. These results were consistent with those obtained from the sky-radiometer measurements, although they revealed another mode in the larger radius. The column volume concentration derived from the lidar was 48% lower than that derived from the sky-radiometer on 1 April and 16% lower on 19 October. The optical thickness derived from the lidar was 12% lower than that obtained from the sky-radiometer on 1 April and 29% higher on 19 October. Further case study is necessary to validate the method for estimating aerosol properties based on the lidar measurement.

scholarly journals Raman Lidar for Meteorological Observations, RALMO – Part 1: Instrument description

2013 ◽  
Vol 6 (5) ◽  
pp. 1329-1346 ◽  
Author(s):  
T. Dinoev ◽  
V. Simeonov ◽  
Y. Arshinov ◽  
S. Bobrovnikov ◽  
P. Ristori ◽  
...  
Keyword(s):  
Water Vapor ◽  
Optical Design ◽  
Lidar Measurement ◽  
Raman Lidar ◽  
Measurement Capability ◽  
Vertical Range ◽  
Federal Institute ◽  
Technical Realization ◽  
Meteorological Observations ◽  
Institute Of Technology

Abstract. A new Raman lidar for unattended, round-the-clock measurement of vertical water vapor profiles for operational use by the MeteoSwiss has been developed during the past years by the Swiss Federal Institute of Technology, Lausanne. The lidar uses narrow field-of-view, narrowband configuration, a UV laser, and four 30 cm in diameter mirrors, fiber-coupled to a grating polychromator. The optical design allows water vapor retrieval from the incomplete overlap region without instrument-specific range-dependent corrections. The daytime vertical range covers the mid-troposphere, whereas the nighttime range extends to the tropopause. The near range coverage is extended down to 100 m AGL by the use of an additional fiber in one of the telescopes. This paper describes the system layout and technical realization. Day- and nighttime lidar profiles compared to Vaisala RS92 and Snow White® profiles and a six-day continuous observation are presented as an illustration of the lidar measurement capability.

Enhanced water vapor in Asian dust layer: Entrainment processes and implication for aerosol optical properties

2006 ◽  
Vol 40 (13) ◽  
pp. 2409-2421 ◽  
Author(s):  
Soon-Chang Yoon ◽  
Sang-Woo Kim ◽  
Jiyoung Kim ◽  
Byung-Ju Sohn ◽  
Anne Jefferson ◽  
...  
Keyword(s):  
Optical Properties ◽  
Water Vapor ◽  
Asian Dust ◽  
Aerosol Optical Properties ◽  
Dust Layer

scholarly journals Raman Lidar for Meteorological Observations, RALMO – Part I: Instrument description

2012 ◽  
Vol 5 (5) ◽  
pp. 6867-6914 ◽  
Author(s):  
T. S. Dinoev ◽  
V. B. Simeonov ◽  
Y. F. Arshinov ◽  
S. M. Bobrovnikov ◽  
P. Ristori ◽  
...  
Keyword(s):  
Water Vapor ◽  
Optical Design ◽  
Time Range ◽  
Lidar Measurement ◽  
Raman Lidar ◽  
Night Time ◽  
Measurement Capability ◽  
Vertical Range ◽  
Federal Institute ◽  
Institute Of Technology

Abstract. A new Raman lidar for unattended, round the clock measurement of vertical water vapor profiles for operational use by the MeteoSwiss has been developed during the past years by the Swiss Federal Institute of Technology- Lausanne. The lidar uses narrow-field-of-view, narrow-band configuration, a UV laser, and four 30 cm in diameter mirrors, fiber-coupled to a grating polychromator. The optical design allows water vapor retrieval from the incomplete overlap region without instrument-specific range-dependent corrections. The daytime vertical range covers the mid-troposphere, whereas the night-time range extends to the tropopause. The near range coverage is extended down to 100 m AGL by the use of an additional fiber in one of the telescopes. This paper describes the system layout and technical realization. Day and night time lidar profiles compared to Vaisala RS-92 and Snow White® profiles and a six-day-continuous observation are presented as an illustration of the lidar measurement capability.

scholarly journals Hydrogen gas concentration measurement in small area using raman lidar measurement technnology

2018 ◽  
Vol 176 ◽  
pp. 01019 ◽  
Author(s):  
Sachiyo Sugimoto ◽  
Ippei Asahi ◽  
Tatuso Shiina
Keyword(s):  
Small Area ◽  
Gas Flow ◽  
Hydrogen Gas ◽  
Measurement Technology ◽  
Lidar Measurement ◽  
Measurement Point ◽  
Raman Lidar ◽  
Gas Concentration ◽  
Scattering Light ◽  
Temporal And Spatial

When change of hydrogen(H2) gas concentration in a certain point is measured, non-contact measurement technology with high temporal and spatial resolution is necessary. In this study, H2 concentration in the small area of <1cm2 under the gas flow was measured by using a Raman lidar. Raman scattering light at the measurement point of 750mm ahead was detected by the Raman lidar. As a result, it was proved that the H2 concentration of more than 100ppm could be successfully measured.

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.

Narrow-band, narrow-field-of-view Raman lidar with combined day and night capability for tropospheric water-vapor profile measurements

1999 ◽  
Vol 38 (9) ◽  
pp. 1841 ◽  
Author(s):  
Scott E. Bisson ◽  
John E. M. Goldsmith ◽  
Mark G. Mitchell
Keyword(s):  
Water Vapor ◽  
Narrow Band ◽  
Field Of View ◽  
Raman Lidar
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