Essentials of Meteorology by Ahrens Chapter 1

Thunderstorm

A convective storm ( cumulonimbus cloud) with lightening and thunder. Thunderstroms can be composed of an ordinary cell, multicells, or a rapidly rotating supercell.

Middle-Latitude Cyclonic Storm

A cyclonic storm that most often forms along a front in middle and high latitudes. Also called a middle-latitude cyclonic storm, a depression, and a low. It is not a tropical storm or hurricane.

Hurricane

A tropical cyclone having winds in excess 64 knots (74 mi/hr)

Wind

Air in motion relative to the earth's surface.

Ionosphere

An electrrified region of the upper atmosphere where fairly large concentrations of ions and free electrons exist.

Temperature Inversion

An increase in air temperature with height, often simply called inversion.

Tornadoes

An intense, rotating column ofair that often protrudes from a cumuliform cloud in the shape of a funnel or a rope whose circulation is present on the ground.

Ozone

And almost colorless gaseous form of oxygen with an odor similar tooweak chlorine. The highest natural concentration is found in the stratosphere where it is known as stratospheric ozone. It also forms in polluted air near the surface where it is in the main ingredient of photochemical smog. Here, it is called from tropospheric ozone.

Pollutants

Any gaseous, chemical, organic matter that contaminates the atmosphere, soil or water.

Carbon Dioxide

Colorless, odorless gas concentration is about 0.039% in a volume of air near sea level. It is a selective absorber of infrared radiation and, consequently, it is important in the Earth's atmospheric greenhouse effect.

Climate

The accumulation of daily and seasonal weather events over a long period of time.

Mesosphere

The atmosphereic layer between the stratosphere and the thermosphere. Located at an average elevation between 50 and 80 km above the earth's surface.

Thermosphere

The atmospheric layer above the mesosphere (above about 85 km) where the temperature increases rapidly with height.

Tropopause

The boundary between the troposphere and the stratosphere.

Weather

The condition of the atmosphere at any particular time and place.

Wind Direction

The direction from which the wind is blowing.

Weather Elements

The elements of air temperature, air pressure, humidity, clouds, precipitation, visibility, and wind that determine the present state of the atmosphere, the weather.

Atmosphere

The evelope of gases that surround a planet and are held to it by the planet's gravitational attraction. The earth's atmosphere is mainly Nitrogen and Oxygen.

Stratosphere

The layer of the atmosphere above the troposphere and below the mesosphere (between 10 km and 50 km), generally characterized by an increase in temperature with height.

Troposphere

The layer of the atmosphere extending from the earth's surface to the tropospause ( about 10 km above the ground)

Air Pressure

The pressure exerted by the mass of air above a given point, usually expressed in millibars inches of mercury or in hectopascals.

Wind Speed

The rate at which air moves by a stationary object, usually measured in statute miles per hour, nautical miles per hour, or meters per second.

Lapse Rate

The rate at which an atmospheric variable decreases with height.

Air Density

The ratio of the mass of a substance to the volume occupied by it.

Middle Latitudes

The region of the world typically described between 30 degrees and 50 degrees latitude.

Outgassing

The release of gases dissolved in hot, molten rock.

Meteorology

The study of the atmosphere and atmospoheric phenomena as well as the atmosphere's interaction with the earth's surface, oceans, and life in general.

Front

The transition zone between two distinct air masses.

Aerosols

Tiny suspended solid particles or liquid droplets that enter the atmosphere from either natural or human sources, such as the burning of fossil fuels. Sulfur-containing fossil fuels, such as coal, produce sulfate aerosols.

Water Vapor

Water in vapor (gaseous) form. Also called moisture.

Radiosonde

A balloon-borne instrument that measures and transmits pressure, temperature, and humidity to a ground-based receiving station.

Oxygen

A colorless and odorless gas that occupies about 21 percent of dry air in the lower atmosphere

Nitrogen

A colorless and odorless gas that occupies about 78 percent of dry air in the lower atmosphere