perarea

Perarea is a term used to describe a quantity that is expressed as a rate or density per unit area. It is not a formal mathematical definition with a fixed notation, but rather a descriptive concept that captures the idea of dividing a quantity by an area to obtain a surface-related measure. The notion is widely used in science and engineering whenever a surface, rather than a volume, governs the measurement.

In practice, perarea corresponds to quantities normalized by area. Examples include population density (people per square kilometer), surface fluxes of substances (amount per unit area per unit time), and irradiance or flux of energy (power per unit area). When time is involved, the units become per area per time, such as amount per square meter per second.

In data analysis and programming, perarea may appear as a variable label or descriptor indicating that a value has been normalized by surface area. The underlying operation is a simple division: total quantity divided by the surface area over which it is distributed.

See also: density, areal density, surface flux, irradiance, flux density, surface area.