Glossary

Dew Point – Dew point, sometimes called dew point temperature, is the temperature to which air would have to cool, without adding or removing any moisture, before it became saturated with respect to liquid water and dew would begin to condense.

Dew Point Depression – The difference between air temperature and the dew point temperature, obtained by subtracting the dew point temperature from the air temperature. Expressed in degrees Celsius in this climatology.

Millibar – A unit of measurement for pressure. Equal to one one-thousandth of a “bar,” which is approximately the pressure of the atmosphere measured at sea level.

Plume Dominated – Conventional practice is to describe wildland fires as either “plume dominated” or “wind driven.” The terms are often subjective, but the key concern behind the distinction is that a fire subject to strong winds has a relatively well defined direction of greatest spread, where the head is most active.

Stability – The tendency of the atmosphere to resist vertical motion. Unstable atmospheric conditions have been associated with turbulence, gusty winds, and sudden changes in the spread or behavior of wildland fires.