scholarly journals PAH in Vectorized Three Dimensional Monte Carlo Dust Radiative Transfer Models

2020 ◽  
pp. 285-290
Author(s):  
R. Siebenmorgen ◽  
F. Heymann ◽  
E. Krugel
2008 ◽  
Vol 482 (1) ◽  
pp. 67-80 ◽  
Author(s):  
M. Schartmann ◽  
K. Meisenheimer ◽  
M. Camenzind ◽  
S. Wolf ◽  
K. R. W. Tristram ◽  
...  

2011 ◽  
Vol 729 (2) ◽  
pp. 111 ◽  
Author(s):  
David G. Whelan ◽  
Kelsey E. Johnson ◽  
Barbara A. Whitney ◽  
Rémy Indebetouw ◽  
Kenneth Wood

2009 ◽  
Vol 2 (1) ◽  
pp. 113-124 ◽  
Author(s):  
T. Wagner ◽  
S. Beirle ◽  
T. Deutschmann

Abstract. We present a new technique for the quantitative simulation of the "Ring effect" for scattered light observations from various platforms and under different atmospheric situations. The method is based on radiative transfer calculations at only one wavelength λ0 in the wavelength range under consideration, and is thus computationally fast. The strength of the Ring effect is calculated from statistical properties of the photon paths for a given situation, which makes Monte Carlo radiative transfer models in particular appropriate. We quantify the Ring effect by the so called rotational Raman scattering probability, the probability that an observed photon has undergone a rotational Raman scattering event. The Raman scattering probability is independent from the spectral resolution of the instrument and can easily be converted into various definitions used to characterise the strength of the Ring effect. We compare the results of our method to the results of previous studies and in general good quantitative agreement is found. In addition to the simulation of the Ring effect, we developed a detailed retrieval strategy for the analysis of the Ring effect based on DOAS retrievals, which allows the precise determination of the strength of the Ring effect for a specific wavelength while using the spectral information within a larger spectral interval around the selected wavelength. Using our technique, we simulated synthetic satellite observation of an atmospheric scenario with a finite cloud illuminated from different sun positions. The strength of the Ring effect depends systematically on the measurement geometry, and is strongest if the satellite points to the side of the cloud which lies in the shadow of the sun.


2020 ◽  
Author(s):  
Constanze Wellmann ◽  
Christin Proß ◽  
Katja Bigge ◽  
André Butz

<pre>Remote sensing is an important measurement technique when probing the atmosphere as it is rather flexible and <br />allows for the measurement of numerous variables. For example, spectrometers are commonly used to quantify the <br />concentrations of trace gases by recording spectra of direct or scattered sunlight. Due to scattering, the light <br />paths between sun and detector can be rather complicated and radiative transfer models are necessary to retrieve <br />the information contained in the spectra. <br />Since these spectrometer measurements have to be made in spectral regions with strong absorption, it is necessary <br />to model many wavelengths to reach a sufficiently accurate representation of the absorption lines and their effects <br />on the light paths. <br />Thus, 1D models are often implemented for a fast analysis of the recorded spectra. However, this approach assumes <br />horizontal homogeneity and local sources cannot be resolved. In contrast, 3D Monte Carlo models are more realistic <br />and are able to represent this inhomogeneity, but they are computationally expensive and are not suitable for <br />operational use.</pre> <pre>We improve an existing Monte Carlo model by implementing efficient algorithms for the simultaneous calculation of <br />several wavelengths to decrease the required computation time. <br />Furthermore, we examine to which scatter order the 3D model provides more detailed results while maintaining a <br />reasonable run time.<br />This finally leads to a coupling of these two types of radiative transfer models via the scatter order into one <br />efficient model which performs realistic simulations at a computational cost comparable to 1D models.<br />So we are able to detect sources along the line of sight of ground-based measurements of scattered sunlight.<br />Here, we present our objective and first results.</pre>


2004 ◽  
Vol 350 (2) ◽  
pp. 565-574 ◽  
Author(s):  
Tim J. Harries ◽  
John D. Monnier ◽  
Neil H. Symington ◽  
Ryuichi Kurosawa

2021 ◽  
Author(s):  
Daniel Heestermans Svendsen ◽  
Daniel Hernández-Lobato ◽  
Luca Martino ◽  
Valero Laparra ◽  
Álvaro Moreno-Martínez ◽  
...  

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