Terms used in the Novice EKMA/OZIP Interface

The glossary contains definitions for terms in the novice version of the interface.

the initial values of various components of the modeling site at the beginning of the simulation. For the novice version, the base case includes:

the O₃ daily design value
the design ratio
the future decrease in NO_x emissions
the future decrease in CO (carbon monoxide) emissions

O₃ Daily design value

this is the ozone level that you currently have. This number is in units of parts per million, or ppm. The default value in the interface is 0.16 ppm. That means, that currently this community has a average ozone level of 0.16 ppm. The national standard is 0.12 ppm, so this community is not in compliance (not following federal laws) regarding its ozone levels.

Design ratio

before a scientist can use this model, the scientist must collect some information from the "field". Early in the morning (usually between 6 and 9 am), a scientist will measure the amount of VOCs in the air and the amount of NO_x in the air. He or she will do this a number of times, and then take an average. The scientist then takes the ratio of the VOCs to the NO_x, such as 15 parts of VOCs to one part of NO_x. This ratio helps the modeler to determine the best way to reduce O₃

iso- meaning "equal", and pleth, meaning concentration. An isopleth is a curve or line on a diagram showing the points at which the concentration of some species, such as ozone, is at a similar value.

imaginary lines of reference that run east-west on the globe

imaginary lines of reference that run north-south on the globe

nitrogen oxides; a general expression for nitric oxide (NO) and nitrogen dioxide (NO₂).

ozone (O₃)

triatomic oxygen exists in troposphere as a secondary pollutant and occurs naturally in the stratosphere where it protects us by filtering out the sun's harmful ultraviolet radiation

Ozone Isopleth Plotting Program

a package of FORTRAN programs that is used to implement the EKMA set of procedures. Fundamentally, the OZIP modeling tool prepares isopleth diagrams as a function of initial concentrations of ozone precursors such as hydrocarbons and nitrogen oxides.

parts per million, a unit of concentration. A concentration of 1 ppm means that there is 1 part of the species in 1,000,000 parts of volume, usually air.

parts per million of carbon, the typical concentration unit used to represent volatile organic compounds.

a pollutant which contributes, through one or several chemical reactions, to the formation of a new chemical, typically a secondary pollutant. Nitrogen oxides, for example, are precursors in the formation of the secondary pollutant ozone.

Volatile Organic Compounds (VOCs)

a class of organic compounds primarily made up of hydrocarbons; Some examples of VOCs are benzene, formaldehyde, chlorofluorocarbons (CFCs), and methane

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Copyright © 1997