In geophysics, the radiation emitted by the atmosphere either upward into space or downward toward the Earth: Atmospheric radiation consists mainly of long-wavelength terrestrial radiation plus the small amount of short-wavelength solar radiation absorbed in the atmosphere.

Atmospheric radiation can also be said to be infrared radiation which is released by or also produced by the atmosphere.

1. A program involving the detection or measurement of electromagnetic radiation: ARM is applied in particular to devices used to measure infrared radiation.
2. Research including the detection of microwave thermal radiation and similar weak wide-band signals that resemble noise and are obscured by receiver noise: The primary atmospheric radiation measurement application using an atmospheric radiometer has been on board spacecraft measuring atmospheric and terrestrial radiation, and they are mostly used for meteorological or oceanographic remote-sensing.

Their secondary application is also meteorological, as zenith-pointing surface instruments that view the Earth's atmosphere in a region above the stationary instrument.

By understanding the physical processes associated with energy emission at these wavelengths, scientists can calculate a variety of surface and atmospheric parameters from these measurements, including air temperature, sea surface temperature, salinity, soil moisture, sea ice, precipitation, the total amount of water vapor and the total amount of liquid water in the atmospheric column directly above or below the instrument.

Radiation by cosmic rays, consisting chiefly of protons, with some electrons and atomic nuclei: Cosmic radiations involves their collision or reaction with particles in the atmosphere which includes a wide variety of secondary radiations known as a cosmic ray showers.

In quantum mechanics, a noncovariant gauge (not changing with another variable) in which there are commutation relations only for the space part of the vector potential.

All of these terms are descriptions of solar radiation that is received indirectly on the surface of the earth, rather than directly from solar rays: "Diffuse radiation, etc. are all caused by the scattering that is a result of clouds, fog, haze, dust, or other barriers in the atmosphere."

1. Noise in a communications system resulting from undesired electromagnetic radiation.
2. Any undesired electromagnetic disturbance.

1. The emission and propagation of radiation associated with a periodically varying electric and magnetic field traveling at the speed of light.

Types include gamma radiation, X-rays, ultraviolet, visible, and infrared radiation, and radar and radio waves.

2. Radiation that is produced with a combination of magnetic and electric forces.

It exists as a continuous spectrum of radiation, from that with the highest energy level and the shortest wavelength (gamma rays) to that with the lowest energy and longest wavelength (long radio waves).

All forms of electromagnetic radiation travel at the speed of light.

Light, radio waves, and X-rays are forms of electromagnetic radiation. Almost all of our knowledge of extraterrestrial objects comes from emitted or reflected electromagnetic radiation (visible light or radio waves).

The ideal amount of global horizontal radiation that a location on Earth would receive if there were no intervening atmosphere or clouds and used as the reference amount to which actual solar energy measurements are compared: Extraterrestrial radiation, known as “top-of-atmosphere” (TOA) and abbreviated as ETR, is a global radiation and is the sum of diffuse and direct radiation.

Radiation of gamma rays which consist of very high-frequency electromagnetic radiation, similar in nature to X-rays but of shorter wavelength emitted by the nuclei of radioactive substances during decay or by the interactions of high-energy electrons with matter.

Gamma emission usually occurs as part of alpha or beta emissions; however, they are less ionizing in their effect than alpha and beta particles, but are dangerous nevertheless because they can penetrate deeply into body tissues; such as, bone marrow.

Controlled application of gamma radiation is important in the diagnosis and treatment of various conditions, including skin cancer and malignancies deep within the body.

Gamma radiation is also used to kill bacteria and other micro-organisms, to sterilize medical devices, and to change the molecular structure of plastics to modify their properties.

Damage or ill effects suffered by exposure to ionizing radiation, including cellular harm resulting from radiation for diagnostic or therapeutic applications.

The risk of cell death or injury from radiation depends on the type of tissue cells, the stage of cell division at the time of exposure, the intensity and time span of exposure, and the type of radiation administered.

1. High-energy radiation capable of producing ionization in substances through which it passes.

It includes non-particulate radiation; such as. X-rays, and radiation produced by energetic charged particles; such as, alpha and beta rays, and by neutrons, as from a nuclear reaction.

2. Particulate or electromagnetic radiation that produces ionization in a medium through which it passes.
3. Any radiation; such as, a stream of alpha particles or x-rays, that produces ionization as it passes through a medium.
4. Particles or photons that have sufficient energy to produce ionization directly in their passage through a substance.
5. Particles that are capable of nuclear interactions in which sufficient energy is released to produce ionization.
6. Photons of high-energy electromagnetic radiation and particle forms of radiation that have sufficient energy to produce ions by removing electrons from atoms or molecules.

1. An organism displaying immunologic characteristics of both host and donor following whole-body radiation to neutralize an immune response to the donor's cells, as in a bone marrow graft.
2. A medical patient who has been subjected to whole body irradiation to lower immune responses to foreign donor cells and therefore has the immunological characteristics of both host and donor after a bone marrow graft from the antigenically different donor.

All the constituents that make up the total electromagnetic radiation emitted y the sun; about 99 percent of solar radiation is contained in a wavelength region from about 300 nanometers (ultraviolet) to 3,000 nanometers (near-infrared).

Electromagnetic radiation originating from Earth and its atmosphere: Terrestrial radiation is the total infrared energy emitted by the Earth and its atmosphere and is measured at wavelengths that are determined by their temperature.

Terrestrial radiation is the radiation that is released by naturally occurring radioactive materials in the Earth; such as uranium, thorium, and radon.

1. The emission of energy in the form of heat.
2. A process by which energy is emitted by a warm surface.

The energy is electromagnetic radiation and so travels at the speed of light and does not require a medium to carry it.

3. The energy radiated by solids, liquids, and gases as a result of their temperature.

Such radiant energy is in the form of electromagnetic waves and covers the entire electromagnetic spectrum, extending from the radio-wave portion of the spectrum through the infrared, visible, ultraviolet, x-ray, and gamma-ray portions.