Three-Dimensional Radiative Transfer Modeling of Tropospheric Atmospheres

Three-Dimensional Radiative Transfer Modeling of Tropospheric Atmospheres
Author: United States. Army Research Laboratory
Publisher:
Total Pages: 126
Release: 1998-03-01
Genre:
ISBN: 9781423563075

Physically accurate visualizations of tropospheric atmospheres require three-dimensional (3D) radiative transfer (RT) codes capable of simulating scattering and absorption effects in and around natural clouds. This report describes an adaptation of the discrete ordinates technique for handling both thin (haze) and thick (natural cloud) optical media in a consistent manner. Media are modeled via uniform density cubical scattering cells (assuming that incident diffuse streams have uniform radiance over each input face). These assumptions allow the analytic evaluation of transmission factors and volume- averaged unscat- tered illumination across a cell in evaluating scattered streaming energies at each cell exit face. This initial analysis leads to an energy accounting technique which replaces energy not accounted for via transmission and diffuse single scattering with a surface scattering effect. Solar/lunar direct irradiance and graybody radiation are also considered. Monte Carlo analyses were used to determine the accuracy of the proposed methods. Path point-to-point calculations are described that adapt the outputs of the RT code to provide limiting path radiance information for visualization of could fields. An analysis of the scattering properties of aerosols as scale transformed Legendre polynomial expansions is also provided.

3D Radiative Transfer in Cloudy Atmospheres

3D Radiative Transfer in Cloudy Atmospheres
Author: Alexander Marshak
Publisher: Springer Science & Business Media
Total Pages: 688
Release: 2006-05-27
Genre: Science
ISBN: 3540285199

Developments in three-dimensional cloud radiation over the past few decades are assessed and distilled into this contributed volume. Chapters are authored by subject-matter experts who address a broad audience of graduate students, researchers, and anyone interested in cloud-radiation processes in the solar and infrared spectral regions. After two introductory chapters and a section on the fundamental physics and computational techniques, the volume extensively treats two main application areas: the impact of clouds on the Earth's radiation budget, which is an essential aspect of climate modeling; and remote observation of clouds, especially with the advanced sensors on current and future satellite missions.

Three-dimensional Modeling of Radiative and Convective Exchanges in the Urban Atmosphere

Three-dimensional Modeling of Radiative and Convective Exchanges in the Urban Atmosphere
Author: Yongfeng Qu
Publisher:
Total Pages: 0
Release: 2011
Genre:
ISBN:

In many micrometeorological studies, building resolving models usually assumea neutral atmosphere. Nevertheless, urban radiative transfers play an important role because of their influence on the energy budget. In order to take into account atmospheric radiation and the thermal effects of the buildings in simulations of atmospheric flow and pollutant dispersion in urban areas, we have developed a three-dimensional (3D) atmospheric radiative scheme, in the atmospheric module of the Computational Fluid Dynamics model Code_Saturne. The radiative scheme was previously validated with idealized cases, using as a first step, a constant 3D wind field. In this work, the full coupling of the radiative and thermal schemes with the dynamical model is evaluated. The aim of the first part is to validate the full coupling with the measurements of the simple geometry from the 'Mock Urban Setting Test' (MUST) experiment. The second part discusses two different approaches to model the radiative exchanges in urban area with a comparison between Code_Saturne and SOLENE. The third part applies the full coupling scheme to show the contribution of the radiative transfer model on the airflow pattern in low wind speed conditions in a 3D urban canopy. In the last part we use the radiative-dynamics coupling to simulate a real urban environment and validate the modeling approach with field measurements from the 'Canopy and Aerosol Particle Interactions in Toulouse Urban Layer' (CAPITOUL).

Non-LTE Radiative Transfer in the Atmosphere

Non-LTE Radiative Transfer in the Atmosphere
Author: Manuel L¢pez-Puertas
Publisher: World Scientific
Total Pages: 506
Release: 2001
Genre: Science
ISBN: 9810245661

During the last three decades, it has become increasingly clear that atmospheric modelling and remote sounding of the atmosphere from space, to name just two important application areas, are affected by non-equilibrium processes which have not been incorporated into traditional radiative transfer calculations. These processes, dubbed ?non-LTE?, are therefore the subject of growing interest among scholars and researchers dealing with the upper atmosphere. This important book provides the first comprehensive and ?global? description of non-LTE infrared emissions in the atmosphere of the Earth and other planets, starting with the theoretical foundations and progressing to the most important applications. Besides giving an introduction to this complex subject, it is a guide to the state-of-the-art in incorporating non-LTE processes into radiative transfer algorithms and computer models of the atmosphere. Numerous examples are presented of the application of these methods to (a) atmospheric remote sensing, (b) atmospheric energy budget (cooling and heating rate) calculations, and (c) atmospheres other than the Earth's.

Preliminary Results of a Three-dimensional Radiative Transfer Model

Preliminary Results of a Three-dimensional Radiative Transfer Model
Author:
Publisher:
Total Pages: 4
Release: 1995
Genre:
ISBN:

Clouds act as the primary modulator of the Earth`s radiation at the top of the atmosphere, within the atmospheric column, and at the Earth`s surface. They interact with both shortwave and longwave radiation, but it is primarily in the case of shortwave where most of the uncertainty lies because of the difficulties in treating scattered solar radiation. To understand cloud-radiative interactions, radiative transfer models portray clouds as plane-parallel homogeneous entities to ease the computational physics. Unfortunately, clouds are far from being homogeneous, and large differences between measurement and theory point to a stronger need to understand and model cloud macrophysical properties. In an attempt to better comprehend the role of cloud morphology on the 3-dimensional radiation field, a Monte Carlo model has been developed. This model can simulate broadband shortwave radiation fluxes while incorporating all of the major atmospheric constituents. The model is used to investigate the cloud absorption anomaly where cloud absorption measurements exceed theoretical estimates and to examine the efficacy of ERBE measurements and cloud field experiments. 3 figs.

Radiative Transfer in Coupled Environmental Systems

Radiative Transfer in Coupled Environmental Systems
Author: Knut Stamnes
Publisher: John Wiley & Sons
Total Pages: 368
Release: 2016-03-18
Genre: Science
ISBN: 3527696628

This book is dedicated to the formulation and solution of forward and inverse problems related to coupled media, and provides examples of how to solve concrete problems in environmental remote sensing of coupled atmosphere-surface systems. The authors discuss radiative transfer in coupled media such as the atmosphere-ocean system with Lambertian as well non-Lambertian reflecting surfaces at the lower boundary. The spectral range from the ultraviolet to the microwave region of the electromagnetic spectrum is considered, as are multi-spectral as well as hyperspectral remote sensing, while solutions of the forward problem for unpolarized and polarized radiation are discussed in detail.

Tropospheric Chemistry

Tropospheric Chemistry
Author: W. Seiler
Publisher: Springer Science & Business Media
Total Pages: 508
Release: 2012-12-06
Genre: Science
ISBN: 9401003998

The formation, transport and impact of photo-oxidants, e.g., ozone, is a major environmental problem in densely populated areas with corresponding high emissions of ozone precursor substances such as NOx and volatile organic carbon compounds (VOC). Although major progress has been achieved within the last decade, there are still significant uncertainties in our understanding of the chemical behavior of the polluted atmosphere, in particular the interaction between cities and surrounding areas as well as the contribution of pollution to the global changes, e.g., the oxidation capacity of the troposphere. This book focuses on specific issues related to the chemistry of polluted atmospheres. The main issues cover areas such as modelling, emission inventories, chemical transformation as well as transport of pollutants on an urban/regional scale. The overall topic of the book is addressed in an interdisciplinary approach. The book is of specific interest for advanced researchers in tropospheric chemistry, from the PhD or post-doctoral levels and beyond.

Radiative Transfer in the Atmosphere and Ocean

Radiative Transfer in the Atmosphere and Ocean
Author: Gary E. Thomas
Publisher: Cambridge University Press
Total Pages: 554
Release: 2002-01-28
Genre: Nature
ISBN: 9780521890618

Provides a foundation of the theoretical and practical aspects of radiative transfer, for the atmospheric, oceanic and environmental sciences.