نتایج جستجو برای: gaussian plume model

تعداد نتایج: 2157254  

2014
F. Waquet F. Peers P. Goloub F. Ducos F. Thieuleux Y. Derimian J. Riedi M. Chami

Total and polarized radiances provided by the Polarization and Directionality of Earth Reflectances (POLDER) satellite sensor are used to retrieve the microphysical and optical properties of the volcanic plume observed during the Eyjafjallajökull volcano eruption in 2010, over cloud-free and cloudy ocean scenes. We selected two plume conditions, fresh aerosols near the sources (three cases) and...

2009
Ondřej Šrámek

Introduction: The crustal dichotomy and the Tharsis volcanic province are dominant features at Martian surface. Both exogenic (giant impact) and endogenic (e.g., degree-1 convection) were proposed to explain the dichotomy. In a recent study Zhong [1] proposed a unified model for the Tharsis rise and the dichotomy. A lithospheric thickness variations of hemispherical pattern is assumed, consiste...

2012
Gary L. Achtemeier

Smoke plume rise is critically dependent on plume updraft structure. Smoke plumes from landscape burns (forest and agricultural burns) are typically structured into “sub-plumes” or multiple-core updrafts with the number of updraft cores depending on characteristics of the landscape, fire, fuels, and weather. The number of updraft cores determines the efficiency of vertical transport of heat and...

2004
Dongxiao Zhang Qinjun Kang

[1] We investigate the effects of the porosity (and thus permeability) of porous matrix and the fracture aperture on transport in fractured porous media. We do so with detailed lattice Boltzmann simulations on constructed porous media with a single fracture. Both plume spatial moments (the average plume velocity and the dispersion coefficients) and mass transfer coefficients between the facture...

2013
Mary A. Cameron Mark Z. Jacobson Alexander D. Naiman Sanjiva K. Lele

[1] This is a study to examine the impact of modeling photochemistry from aircraft emissions in an expanding plume versus at the grid scale in an atmospheric model. Differences in model treatments for a single flight occurred at all altitudes during takeoff, cruise, and landing. After 10 h, the plume treatment decreased grid-scale ozone production by 33%, methane destruction by 30%, and carbon ...

Journal: :Environmental science & technology 2007
Ke Du Mark J Rood Byung J Kim Michael R Kemme Bill Franek Kevin Mattison

The United States Environmental Protection Agency (USEPA) developed Method 9 to describe how plume opacity can be quantified by humans. However, use of observations by humans introduces subjectivity, and is expensive due to semiannual certification requirements of the observers. The Digital Opacity Method (DOM) was developed to quantify plume opacity at lower cost, with improved objectivity, an...

2002
M. Bursik

A theoretical model of a volcanic plume, based on applying the equations of motion in a plume-centered coordinate system, suggests that the interaction between a volcanic plume and wind causes enhanced entrainment of air and horizontal momentum, plume bending, and a decrease in plume rise height at constant eruption rate. Because of rapid dilution in the high windspeeds of the polar jet, plumes...

2015
Ana P Oliveira Marcos D Mateus Graça Cabeçadas Ramiro Neves

BACKGROUND Estuarine plumes are frequently under strong influence of land-derived inputs of organic matter. These plumes have characteristic physical and chemical conditions, and their morphology and extent in the coastal area depends strongly on physical conditions such as river discharge, tides and wind action. In this work we investigate the physical dynamics of the Tagus estuary plume and t...

2003
H. A. Scheeren J. Lelieveld G. J. Roelofs J. Williams H. Fischer M. De Reus J. A. De Gouw C. Warneke R. Holzinger H. Schlager M. de Reus J. A. de Gouw

A major objective of the Mediterranean INtensive Oxidant Study (MINOS) was to investigate long-range transport of pollutants (notably ozone precursor species). Here we present trace gas measurements from the DLR (German Aerospace Organization) Falcon aircraft in the eastern Mediterranean troposphere. Ten day backward trajectories and a coupled chemistry-climate model (ECHAM4) were used to study...

2008
Jiayi Pan David A. Jay

River plume front-generated internal solitons play an important role in the interaction between the plume and coastal waters. The internal solitons drive a non-harmonic velocity field, resulting in a horizontal transport that carries plume water seaward and redistributes nutrients and sediments. In this study, we present observations of internal solitons generated at the Columbia River plume fr...

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