sphero-, spher-, -sphere-

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.

In petroleum engineering, the preparation of petroleum specimens for testing purposes: Atmospheric pressure cure is achieved by aging petroleum samples at normal atmospheric pressure for a given length of time at a specific temperature and humidity.

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.

A radio wave that is propagated by reflection through the atmosphere by reflections and refractions occurring in the atmosphere: Atmospheric radio waves may include either the ionospheric wave or the tropospheric wave, or both of them.

1. The light passing through the Earth's atmosphere: Atmospheric refraction includes both astronomical refraction and terrestrial refraction.
2. An apparent upward displacement of celestial objects relative to the horizon as light from them is bent toward the vertical by the decreasing density with altitude of the Earth's atmosphere: Atmospheric refraction is greatest for objects on the horizon and negligible at elevations higher than about 45 degrees.

The angular difference between the apparent zenith distance of a celestial body and its true zenith distance is produced by refraction effects as the light from the body penetrates the atmosphere.

Any refraction caused by the atmosphere's normal decrease in density with height.

Near surfaces on the Earth, those within a few meters or so, are usually dominated by temperature gradients.

A diffusion or alteration in the direction of the propagation, frequency, or polarization of electromagnetic radiation: Atmospheric scattering occurs through contact with, or by interaction with the atoms in the atmosphere.

The twinkling of stars (fluctuation of intensity) as seen through a planet's atmosphere: Atmospheric scintillation is caused by a star's light being distorted by the Earth's atmosphere and atmospheric scintillation is greater for bright stars that are low on the horizon.

The measurement of atmospheric conditions above the effective range of surface weather observations; atmospheric profiling: Atmospheric sounding is a calculation of the vertical spread of physical properties in the atmosphere including temperature, wind velocity, wind direction, pressure, ozone concentration, pollution, and water content in a fluid form.

A process for bringing freshly placed concrete, or cement products, to a required strength and quality by maintaining the humidity and temperature at specified levels for a given period of time: Atmospheric steam curing is usually done at a maximum ambient temperature between 100 and 200°F., or 40 and 95°C.

The constituting elements that characterize the atmosphere: An atmospheric structure includes wind direction and velocity, altitude, air density, and the velocity of sound.

Particles drifting in the air: Atmospheric suspensoids can be specks of dust that are finely divided and suspended in the atmosphere.

A movement of atmospheric masses caused by the gravitational attraction of the sun and moon and by daily solar heating; amplitudes are minute except in the upper atmosphere: An atmospheric tide is a tidal movement of the atmosphere resembling an ocean tide but caused principally by diurnal temperature changes.

Both the sun and moon produce atmospheric tides, and there also exist both gravitational tides (gravitational attraction of the sun or moon) and thermal tides (differential heating of the atmosphere by the sun).

The rhythmic, periodic oscillation of the Earth's atmosphere occurs because of the gravitational effects of the Earth, sun, and moon and to the absorption of radiation by the atmosphere.