Rayleigh scattering depolarization ratio and molecular polarizability anisotropy for gases

1978 ◽  
Vol 74 (0) ◽  
pp. 3008 ◽  
Author(s):  
Martin P. Bogaard ◽  
A. David Buckingham ◽  
Raymond K. Pierens ◽  
Allan H. White
Keyword(s):  
Rayleigh Scattering ◽  
Molecular Polarizability ◽  
Polarizability Anisotropy ◽  
Depolarization Ratio

scholarly journals Molecular polarizability anisotropy of cyclopropane

1968 ◽  
Vol 21 (10) ◽  
pp. 2551 ◽  
Author(s):  
MJ Aroney ◽  
RJW Le Fevre ◽  
W Luttke ◽  
GLD Ritchie ◽  
PJ Stiles
Keyword(s):  
Molecular Polarizability ◽  
Polarizability Anisotropy

Depolarization ratio measurement of Rayleigh scattering in high field electric strength

1975 ◽  
Vol 55 (3) ◽  
pp. 199-200 ◽  
Author(s):  
F. Aussenegg ◽  
M. Lippitsch ◽  
R. Möller ◽  
J. Wagner
Keyword(s):  
High Field ◽  
Rayleigh Scattering ◽  
Electric Strength ◽  
Depolarization Ratio ◽  
Ratio Measurement

Validation for ESA’s Aeolus Mission using the in-situ instruments at Canadian Arctic and reanalysis data

2020 ◽  
Author(s):  
Chih-Chun Chou ◽  
Paul Kushner ◽  
Zen Mariani ◽  
Peter Rodriguez ◽  
Christopher Fletcher
Keyword(s):  
Climate Change ◽  
Rayleigh Scattering ◽  
Line Of Sight ◽  
Horizontal Line ◽  
Vertical Resolution ◽  
Doppler Lidar ◽  
Depolarization Ratio ◽  
Ka Band ◽  
Wind Profiles

<p>ESA’s Aeolus mission, launched in August 2018, is designed to capture tropospheric wind profiles on a global scale in near-real time. The Aeolus lidar system, Atmospheric LAser Doppler INstrument (ALADIN), uses two modes of lidar-driven active scattering, Mie and Rayleigh scattering channels, to retrieve horizontal line-of-sight (HLOS) winds under both clear and cloudy conditions. ESA Aeolus aims to improve numerical weather and climate prediction, and to advance understanding of atmospheric circulation and weather systems.</p><p>This presentation will describe the Canadian validation activities for ESA Aeolus level-2B product, coordinated by the University of Toronto’s Department of Physics and Environment and Climate Change Canada (ECCC). The main focus is the evaluation of Aeolus overpasses using the fifth major global reanalysis produced by the European Centre for Medium-Range Weather Forecasts (ECMWF ERA5), and in-situ measurements at Environment and Climate Change Canada’s (ECCC) Iqaluit and Whitehorse supersites where several wind sensing instruments are co-located. It will compare the Aeolus HLOS winds with the profiles of wind vector from regular radiosonde launches, line-of-sight winds from Doppler Lidar and Ka-Band Radar. The accuracy of the Aeolus measurements is analyzed based on the type of scattering and natural variability of the wind on different levels.</p><p>The radiosonde measures the profiles of temperature, relative humidity, pressure, and winds twice a day with a vertical resolution of 15 m up to 30 km. On the other hand, the Mie scattered 1.5 micron Doppler Lidar retrieves LOS winds at every 3 m as well as aerosol backscatter and depolarization ratio every 5 minutes up to 3 km. Lastly, for every 10 minutes, the dual-polarization Doppler Ka-Band Radar measures the LOS wind speed and direction, cloud and fog backscatter, and depolarization ratio up to a range of 25 km with a vertical resolution of 10 m.</p><p>The wind profiles were directly compared to the profiles derived from other instruments or reanalysis. The vertical structure of the Aeolus winds, for example the wind shear, will also be compared and discussed. The validation results showed that Aeolus is providing some promising initial products and that the ERA5 reanalysis is the most consistent dataset with the Aeolus wind measurements from level-2B product.</p>

An Optical Study on Orientational Order Parameter and Molecular Polarizability in Benzylidene Anilines

2011 ◽  
Vol 181-182 ◽  
pp. 102-105 ◽  
Author(s):  
M. Ramakrishna Nanachara Rao ◽  
P.V. Datta Prasad ◽  
V.G.K.M. Pisipati ◽  
D. Madhavi Latha
Keyword(s):  
Order Parameter ◽  
Nematic Phase ◽  
Field Model ◽  
Orientational Order ◽  
Internal Field ◽  
Molecular Polarizability ◽  
Refractive Indices ◽  
Polarizability Anisotropy ◽  
Optical Study ◽  
Molecular Polarizabilities

Refractive indices measurements are carried out in four alkoxy benzylidene anilines viz., N-(p-n-methoxy and ethoxy benzaldehyde)-p-n-dodecyl and tetra decyl anilines, 1O.12, 1O.14, 2O.12 and 2O.14. First three compounds exhibit monovariant nematic phase while the last compound exhibits nematic and SmA phases with variable thermal ranges. The molecular polarizabilities are calculated from the refractive indices and the density using the well known internal field models by Vuks and Neugebauer. The molecular polarizability anisotropy is estimated from the Lippincott δ-function model as well as molecular vibrational methods. The order parameter is estimated using a) from the Haller’s extrapolation from molecular polarizabilities, b) from the scaling factors obtained from the equations by Vuks and Neugbeaur and c) directly from the birefringence - a method developed by Kuczynski et al without considering any internal field model to the liquid crystal molecule. The results evaluated from these methods are compared from one another and the limitations of the methods used are discussed.

scholarly journals Molecular polarizability anisotropy of liquid water revealed by terahertz-induced transient orientation

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Peter Zalden ◽  
Liwei Song ◽  
Xiaojun Wu ◽  
Haoyu Huang ◽  
Frederike Ahr ◽  
...  
Keyword(s):  
Liquid Water ◽  
Molecular Polarizability ◽  
Polarizability Anisotropy

scholarly journals Measurement of molecular polarizability anisotropy via alignment-induced spatial focusing and defocusing

2012 ◽  
Vol 85 (5) ◽  
Author(s):  
Hao Li ◽  
Wenxue Li ◽  
Yahui Feng ◽  
Jia Liu ◽  
Haifeng Pan ◽  
...  
Keyword(s):  
Molecular Polarizability ◽  
Polarizability Anisotropy ◽  
Spatial Focusing
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