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...

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...

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...

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...

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...

Detailed direct simulation Monte Carlo/Particle in Cell simulations involving the interaction of a hydrazine chemical rocket plume with the rarefied ambient magnetosphere are presented for steady thruster firings in geostationary Earth orbit (GEO). The hydrazine chemical rocket plume is modeled as a neutral gas mixture with thruster exit conditions corresponding to a mass flow rate of 5.0 × 10−...

We incorporate CO2 dissolution due to convective mixing into a sharp-interface mathematical model for the post-injection migration of a plume of CO2 in a saline aquifer. The model captures CO2 migration due to groundwater flow and aquifer slope, as well as residual trapping and dissolution. We also account for the tongued shape of the plume at the end of the injection period. We solve the model...

Mathematical models of natural processes can be used as inversion tools to predict unobserved properties from measured quantities. Uncertainty in observations and model formulation impact on the efficacy of inverse modelling. We present a general methodology, history matching, that can be used to investigate the effect of observational and model uncertainty on inverse modelling studies. We demo...

Plume rise is the height smoke plumes can reach. This information is needed by air quality models such as the Community Multiscale Air Quality (CMAQ) model to simulate physical and chemical processes of point-source fire emissions. This study seeks to understand the importance of plume rise to CMAQ air quality simulation of prescribed burning to plume rise. CMAQ simulations are compared between...

An infrared imaging prediction model of exhaust plume was developed to understanding the infrared characteristics of exhaust plume. The method is based on the irradiance calculation of all pixels on the focal plane array. In order to compute the irradiance incident on each pixel, the gas radiation transfer path in the plume for the instantaneous field of view (IFOV) corresponds to the pixel was...