atmo-, atm- +

An expression for early steam engine designs: The term atmospheric engine was given this name because the pressure of the steam was the same as, or near, the envelop of gasses surrounding the Earth.

When Irene was in England, she visited the transportation museum and was impressed with the large atmospheric steam engines on display.

The penetration of any planetary atmosphere by any object from outer space: An atmospheric entry specifically applies to the penetration of the Earth's atmosphere by a crewed, or uncrewed, capsule or spacecraft.

The atmospheric entry is the penetration of human-made or natural objects from a planetary atmosphere by an object approaching from space, especially of the Earth's atmosphere by a re-entering spacecraft.

The reduction in intensity of light from an astronomical object by absorption and scattering in the Earth's atmosphere: Atmospheric extinction increases when the object is closer to the horizon because of the greater thickness of atmosphere through which its light must travel.

One of the constituents of air that consists of a gaseous mixture: Atmospheric gases primarily include nitrogen, oxygen, argon, carbon dioxide, water vapor, ozone, neon, helium, krypton, methane, hydrogen, and nitrous oxide, plus small amounts of other gases.

The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night.

Any atmospheric flow used to refer to the general circulation of the Earth and regional movements of air around areas of high and low pressure: On average, the atmospheric general circulation corresponds to large-scale wind systems arranged in several east–west belts that encircle the Earth.

Any foreign material that mixes with and contaminates the air in the atmosphere: One well-known atmospheric impurity is smog, which is comprised of fog and chemical fumes and causes a yellowish atmosphere.

Electromagnetic radiation, caused by natural electrical disturbances in the atmosphere; atmospherics; sferics; strays: Atmospheric interferences interfere with radio systems.

The radio frequency electromagnetic radiation originated principally in the irregular surges of charge in thunderstorm lightning discharges.

Atmospherics are heard as a quasi-steady background of crackling noise (static) on certain radio frequencies, such as those used to broadcast AM radio signals.

Since any acceleration of electric charge leads to emission of electromagnetic radiation, and since the several processes involved in propagation of lightning lead to very large charge accelerations, the lightning channel acts like a huge transmitter, sending out radiation with frequencies of the order of 10 kHz.

An atmospheric condition in which the air temperature rises with increasing altitude, holding surface air down and preventing dispersion of pollutants: Atmospheric inversion is a departure from the usual increase or decrease of an atmospheric property with altitude.

Atmospheric inversion usually refers to an increase in temperature with increasing altitude, which is a departure from the usual decrease of temperature with height.

In other words, atmospheric inversion is a reversal in the normal temperature lapse rate, the temperature rising with increased elevation instead of falling.

Usually within the lower atmosphere (the troposphere), the air near the surface of the Earth is warmer than the air above it, largely because the atmosphere is heated from below as solar radiation warms the Earth's surface, which in turn then warms the layer of the atmosphere directly above it.

The process by which neutral atmospheric molecules or atoms are rendered electrically charged chiefly by collisions with high-energy particles: Atmospheric ionization is the charging of neutral particles in the atmosphere through violent contact with charged particles.

Atmospheric ionization is the production of ions in the atmosphere by the loss of an electron from a molecule, typically, for example, by cosmic rays or cosmic radiation.

Cosmic rays and radioactive decay are the main sources of atmospheric ionization.

Radioactivity at the surface can also produce ions in the lowest layer of the atmosphere.

The environmental rate of decrease with height for an atmospheric variable or temperature: The atmospheric lapse rate is the rate of decrease with height and not simply the rate of change.

While most often applied to the Earth's atmosphere, the concept can be extended to any gravitationally supported ball of gas.

In other words, the atmospheric lapse rate involves the decrease of temperature with elevation in the atmosphere.

The "environmental lapse rate" is determined by the distribution of temperature in the vertical at a given time and place and should be carefully distinguished from the process lapse rate, which applies to an individual air parcel.

Any one of a number of layers of the atmosphere, most commonly distinguished by temperature distribution: The atmospheric layer is also known as the "atmospheric shell" or "atmospheric region".

The atmospheric layer is one of several strata or layers of the Earth's atmosphere.

Temperature distribution is the most common criterion used for denoting the various shells.

Loud sounds heard during radio reception interferences in the air: Sally found out that atmospheric noise was caused by natural processes in the atmosphere, mainly by lightning discharges during thunderstorms!

A branch of meteorological physics or physical meteorology in which phenomena are seen occurring in the sky and are described and explained: Atmospheric optics is the study of the optical characteristics of the atmosphere or products of atmospheric processes.

The term atmospheric optics is usually confined to visible and near visible radiation, however, unlike meteorological optics, it routinely includes temporal and spatial resolutions beyond those discernible with the naked eye.

"Meteorological optics" is that part of atmospheric optics concerned with the study of patterns observable with the naked eye.

This restriction is often relaxed slightly to allow the use of simple aids, such as binoculars or a polarizing filter.

Topics included in meteorological optics are sky color, mirages, rainbows, halos, glories, coronas, and shines.

A branch of science dealing with the investigation and study of the physical phenomena of the atmosphere: Judy was very interested in geophysics and decided to take some courses in atmospheric physics to learn more about the observable occurrences or facts of the atmosphere.

A unit of barometric pressure that is taken to be the standard pressure of the Earth's atmosphere at sea level: The average atmospheric pressure at sea level is approximately 14.7 pounds per square inch.

With an increasing altitude, the atmospheric pressure decreases. For example, at 30,000 feet, approximately the height of Mt. Everest, the air pressure is 4.3 pounds per square inch.

The atmospheric pressure at any point in an atmosphere is due solely to the weight of the atmospheric gases above the point concerned.