The process of a substance going directly from a vapor form (water vapor) to a solid (ice) at the same temperature, without going through the liquid phase (water). The opposite of sublimation.

A type of humidity that considers the mass of water vapor present per unit volume of space. Also considered as the density of the water vapor. It is usually expressed in grams per cubic meter.

This is considered the mixture of gases that make up the earth's atmosphere. The principal gases that compose dry air are nitrogen (N2) at 78.09%, oxygen (O2) at 20.946%, argon (A) at 0.93%, and [..]

An extensive body of air throughout which the horizontal temperature and moisture characteristics are similar.

The soiling of the atmosphere by contaminants to the point that may cause injury to health, property, plant, or animal life, or prevent the use and enjoyment of the outdoors.

An instrument used to determine the altitude of an object with respect to a fixed level. The type normally used by meteorologists measures the altitude with respect to sea level pressure.

In meteorology, the measure of a height of an airborne object in respect to a constant pressure surface or above mean sea level.

An instrument that measures wind speed.

Of or related to the area around the geographic South Pole, from 90 degrees South to the Antarctic Circle at approximately 66 1/2 degrees South latitude, including the continent of Antarctica. Along t [..]

Although not officially recognized as a separate ocean body, it is commonly applied to those portions of the Atlantic, Pacific, and Indian Oceans that reach the Antarctic continent on their southern e [..]