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Glossary


Aerosols - Liquid or solid particles suspended in a gaseous medium such as air. Examples of common aerosols are dust, fog, and smoke.

Climate Change - Variations in climate ranging from decades to geological time scales.

Convective Vortex - A vortex caused by a thermal plume.

Corona Discharge - The electrical breakdown of the isolating properties of a gas that generally causes the emission of light and a hissing sound.

Dust Devil - A convective vortex that is strong enough to produce saltation and lift dust particles.

Dust Electrification - The transfer of charges that occur when dust particles collide with each other, sand particles or the surface.

Dust Lifting - The ejection of dust particles into the air, usually by saltation.

Dust Storm - Weather phenomena that lift large amounts of dust reducing the visibility to nearly zero over large areas. They are usually associated with gust fronts moving ahead of thunderstorms in arid and semi-arid areas.

Dusty Phenomena - The general term to describe the various kind of dust lifting phenomena, including dust devils, dust storms and windblown dust.

Electric Field/e-Field, E = F/q - The distribution in space of the electric forces (F) per unit charge that would be exerted on charged particles (q) placed at each point. The direction of the e-field is defined as that of the force exerted on a positively charged particle. Thus, the e-field points toward a negatively charged object.

Electrostatic Discharge, ESD - The rapid transfer of charge that can occur when objects at different potential come close to each other.

Electrostatics - The charge build up that usually occurs because of electron imbalance at the surface of materials.

Erosion - The abrasion of material caused by the action of the wind (also called deflation) or flow of water.

Field Mill - Instrument that measures the electric field through the current induced by electrodes moving on it. Most modern electric field mills use a rotating slotted disk to alternately expose and shields the electrodes and measure the component of the electric field perpendicular to it. EngXT uses a cylindrical field mill design in which a conducting cylinder is split along its axis and electrodes on opposite side rotates into the electric field. This device measures the 2-dimensional electric field perpendicular to the cylinder’s axis of rotation.

Ion Currents - The electrical current resulting from the motion of ions.

Ionizers - A device that charge the air creating ions that increases its conductivity.

Ions - Electrically charged atoms or molecules.

Particulates - Small solid particles, granular materials or powder.

Plumes - A portion of air moving coherently.

Saltation - The skipping motion of sand particles forced to move by wind.

Thermals - A rising plume of warm air.

Windblown Charge Transfer - Charge transfer by the collision of windblown particles with each other or the surface.