An experimental observation of microcathode thruster plasma plume is described. An effect of the magnetic field on the plume expansion is considered. Two observation techniques are employed––charge-coupled-device camera and the concentric Langmuir probe. It is found that magnetic field significantly affects the plasma plume, and the strong magnetic field can lead to hollow plume formation.

Design of optimal plans for environmental planning and management applications should ideally consider the multiple quantitative and qualitative criteria relevant to the problem. For example, in ground water monitoring design problems, qualitative criteria such as acceptable spatial extent and shape of the contaminant plume predicted from the monitored locations can be equally important as the ...

The effectiveness of removal of nonaqueous phase liquids (NAPLs) from the entrapment source zone of the subsurface has been limited by soil heterogeneity and the inability to locate all entrapped sources. The goal of this study was to demonstrate the uncertainty of degree of source removal associated with aquifer heterogeneity. In this demonstration, source zone NAPL removal using surfactant-en...

S. Didi Kuo John R. Schott Chia Y. Chang Rochester Institute of Technology Center for Imaging Science 1 Lomb Memorial Drive Rochester, New York 14623 Abstract. Remote sensing of factory stack plumes may provide unique information on the constituents of the plume. Potential information on the chemical composition of the factory products may be gathered from thermal emission/absorption in the inf...

The influence of the Columbia River plume on the distributions of nitrate and iron and their sources to coastal and shelf waters were examined. In contrast to other large estuaries, the Columbia River is a unique study area as it supplies very little nitrate (5 AM) and iron (14–30 nM) at salinities of 1–2 to coastal waters. Elevated nitrate and dissolved iron concentrations (as high as 20 AM an...

[1] After coastal upwelling, the water properties in the nearshore coastal region close to estuaries is determined by the race between the new estuarine plume traveling along the coast and the upwelled front (a marker for the old upwelled plume and the coastal pycnocline) returning to the coast under downwelling winds. Away from an estuary, downwelling winds can return the upwelled front to the...

Simulations with a dual permeability model show that a few discrete fractures can have a Ž . major influence on plume geometry. A limited number of truncated fractures 1–4 within a permeable matrix can create nearly circular plumes, with about the same degree of spreading in the direction transverse to the average hydraulic gradient as in the longitudinal direction. By comparison, continuous fr...

The quantification of tropospheric O3 production in the downwind of the Mexico City plume is a major objective of the MIRAGE-Mex field campaign. We used a regional chemistry-transport model (WRF-Chem) to predict the distribution of O3 and its precursors in Mexico City and the surrounding region during March 2006, and compared the model with in-situ aircraft measurements of O3, CO, VOCs, NOx, an...

[1] Synoptic-scale pollution plumes in the free troposphere can preserve their identity as well-defined structures for a week or more while traveling around the globe. Eulerian chemical transport models (CTMs) have difficulty reproducing these layered structures due to numerical plume dissipation. We show that this dissipation is much faster than would be expected from the order of the advectio...

[1] Model hindcasts of the Columbia River (CR) plume and coastal ocean circulation in summer 2004 are used to describe the subtidal evolution of plume patterns in response to local wind and to examine the plume influence on shelf circulation. It is found that a bi-directional plume occurs frequently on the Washington/Oregon shelf, during weak upwelling favorable wind events, during weakening of...