Absorption cross section

From Glossary of Meteorology



absorption cross section

The area that, when multiplied by the irradiance of electromagnetic waves incident on an object, gives the radiant flux absorbed and dissipated by the object. Customary usage in radar describes the absorption cross section of an object as the area that, when multiplied by the power density of incident plane-wave radiation, gives the power absorbed and dissipated by the object.

The extinction cross section of an object is the sum of the absorption cross section and the scattering cross section. For a medium consisting of a dispersion of absorbing objects through which radiation propagates, the volume absorption coefficient (units: m2m-3 or m-1) at a given location in the medium is the sum of the absorption cross sections of all the objects in a unit volume centered at that location.


Copyright 2022 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact permissions@ametsoc.org. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S.Copyright Act (17 USC § 108) does not require AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, require written permission or a license from AMS. Additional details are provided in the AMS Copyright Policy statement.