Journal ArticleDOI
Examination of the traditional Raman lidar technique. I. Evaluating the temperature-dependent lidar equations.
TLDR
The results indicate that, for the range of temperatures encountered in the troposphere, the magnitude of the temperature-dependent effect can reach 10% or more for narrowband Raman water-vapor measurements.Abstract:
The essential information required for the analysis of Raman lidar water vapor and aerosol data acquired by use of a single laser wavelength is compiled here and in a companion paper [Appl. Opt. 42, 2593 (2003)]. Various details concerning the evaluation of the lidar equations when Raman scattering is measured are covered. These details include the influence of the temperature dependence of both pure rotational and vibrational-rotational Raman scattering on the lidar profile. The full temperature dependence of the Rayleigh-Mie and Raman lidar equations are evaluated by use of a new form of the lidar equation where all the temperature dependence is carried in a single term. The results indicate that, for the range of temperatures encountered in the troposphere, the magnitude of the temperature-dependent effect can reach 10% or more for narrowband Raman water-vapor measurements. Also, the calculation of atmospheric transmission, including the effects of depolarization, is examined carefully. Various formulations of Rayleigh cross-section determination commonly used in the lidar field are compared and reveal differences of as much as 5% among the formulations. The influence of multiple scattering on the measurement of aerosol extinction with the Raman lidar technique is considered, as are several photon pulse pileup-correction techniques.read more
Citations
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Proceedings ArticleDOI
Statistical considerations on the Raman inversion algorithm: data inversion and error assessment
Francesc Rocadenbosch,Michaël Sicard,Albert Ansmann,Ulla Wandinger,Volker Matthias,Gelsomina Pappalardo,Christine Böckmann,Adolfo Comerón,Alejandro Rodríguez,Constantino Munoz,Miguel Angel Lopez,David García +11 more
TL;DR: The statistical approach presented here analytically quantifies the range-dependent MSE performance as a function of the estimated signal-to-noise ratio of the Raman channel, thus, becoming a straightforward general formulation of algorithm errorbars.
Development of a 1-Dimensional Data Assimilation to Determine Temperature and Relative Humidity Combining Raman Lidar Backscatter Measurements And a Reanalysis Model
Mahagammulla Gamage,Shayamila N +1 more
TL;DR: In this paper, the optimal estimation method (OEM) was used for temperature and relative humidity (RH) retrieval from the Raman Lidar for Meteorological Observations (RALMO) instrument at Payerne, Switzerland.
Journal ArticleDOI
Analysis of a warehouse fire smoke plume over Paris with an N 2 Raman lidar and an optical thickness matching algorithm
TL;DR: In this paper, the authors used a top-down aerosol optical thickness matching (TDAM) approach to characterize the aerosols that formed the fire smoke aerosol layer, and found a lidar descriptor close to 50±10 ˚sr for this fire smoke layer, suggesting the presence of either small particles or spherical hydrated aerosols.
Posted ContentDOI
Low-Level, Liquid-Only and Mixed-Phase Cloud Identification byPolarimetric Lidar
Robert A. Stillwell,Ryan R. Neely,Jeffrey P. Thayer,Matthew D. Shupe,Matthew D. Shupe,Michael O'Neill +5 more
TL;DR: The Clouds Aerosol Polarization and Backscatter Lidar (CAPABL) at Summit, Greenland employs multiple planes of linear polarization, and photon counting and analog detection schemes, to self evaluate, correct, and optimize signal combinations to improve cloud classification as mentioned in this paper.
References
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Journal ArticleDOI
Variability of Absorption and Optical Properties of Key Aerosol Types Observed in Worldwide Locations
Oleg Dubovik,Brent N. Holben,Thomas F. Eck,Thomas F. Eck,Alexander Smirnov,Yoram J. Kaufman,Michael D. King,Didier Tanré,Ilya Slutsker +8 more
TL;DR: In this paper, the AERONET network of ground-based radiometers were used to remotely sense the aerosol absorption and other optical properties in several key locations, and the results showed robust differentiation in both the magnitude and spectral dependence of the absorption, a property driving aerosol climate forcing.
Models for the aerosols of the lower atmosphere and the effects of humidity variations on their optical properties
Eric P. Shettle,Robert W. Fenn +1 more
TL;DR: In this paper, a review of the optical properties of these models are discussed and some comparisons of the model with experimental measurements are presented, as well as a comparison of their experimental basis.
Journal ArticleDOI
Rayleigh-scattering calculations for the terrestrial atmosphere
TL;DR: The dispersion of the depolarization factor is shown to affect the Rayleigh phase function slightly, by approximately 1% in the forward, backscattered, and 90° scattering-angle directions.
Journal ArticleDOI
Independent measurement of extinction and backscatter profiles in cirrus clouds by using a combined Raman elastic-backscatter lidar
TL;DR: Examples covering the measured range of extinction-to-backscatter ratios (lidar ratios) in ice clouds are presented and simple backscatter lidars can provide reliable information about the cloud optical depth and the mean cloud lidar ratio.