Chapter 12 Earth Science

Coriolis effect

Results in fluids and objects moving in an apparent curved path rather than a straight line

Polar easterlies

Wind zones between 60° North latitude and the north pole and 60° south latitude and the south pole

Prevailing westerlies

The wind systems on earth located between latitudes 30° north and 60°, and 30° and 60° south

Trade winds

Between latitudes 30° north and 30° south are two circulation belts of wind

Jet stream

A narrow bond of fast high altitude westerly wind

Front

A narrow region between two air masses of different densities

Air mass

A large volume of air that has the same characteristics, such as humidity and temperature, as it’s source region

Source region

Area over which an air mass forms

Weather

Short term variations in atmospheric phenomena that interact and effect the environment and life on earth

Climate

Long term average of variations of weather for a particular area

Heat

The transfer of thermal energy through the difference in temperature

Cold front

When cold dense air displacement warm air, which is less dense, up along a steep slope

Warm front

Advancing warm air displaces cold air along a warm front. A warm front develops a gradual boundary slope

Stationary front

When two air masses meet but neither advances, the boundary between the stalls. This stationary front frequently occurs between two modified air masses that have small temperature and pressure gradients gradients between them.

Occluded Fronts

Sometimes, a cold air mass moves so rapidly that it overtakes a warm front and forces the warm air upward. As the warm air is lifted, the advancing cold air mass collides with another cold air mass.

Thermometer

Measures the temperature using either Fahrenheit or the Celsius scale.

Barometer

Measures air pressure.

Anemometer

Measures wind speed.

Hygrometer

Measures relative humidity.

Radiosonde

Instrument used for gathering upper-atmosphere data.

Station Model

A record of weather data for a particular site at a particular time.

Isobar

Lines of equal pressure.

Isotherm

Lines of equal temperature.

Digital Forecast

Created by applying physical principles and mathematics to atmospheric variables and then making predictions about how these variables will change overtime.

Analog Forecast

Based on a comparison of current weather patterns to similar weather patterns from the past.

Short-Term Forecasts

The most accurate and detailed forecasts are short-term because weather systems change directions, speed, and intensities overtime.

Long-Term Forecasts

Because it is impossible for computers to model every variable that affects weather at a given time and place, all long-term forecasts are less reliable than short-term forecasts.