Gradient

Rate of change; expre ed in hydraulics as fall of so many inches to the mile, but in meteorological barometry as so many millimeters of pre ure per degree of a great circle or so many hundredths of inches per quarter of a degree, and in meteorological thermometry as so many degrees of temperature per degree of a great circle or 60 geographical miles. A vertical gradient in meteorology is the rate of change of temperature, pre ure, etc. (in degrees or millimeters), per 100 feet or meters of vertical ascent. In Engineering, same as grade, but generally applied to water surfaces. See HYDRAULIC GRADIENT.