PHS 1010 Earth Science Huff Chp. 18 Terms

Pressure gradient

the force that causes air to move from one pressure to another; moves perpendicular to isobars when it is the only force

Isobars

lines of equal air pressure

Pressure gradient force

pressure change over distance

Coriolis effect

apparent deflection in the wind direction due to Earth's rotation

2 multiple choice options

Geostrophic winds

blow parallel to isobars

Jet stream

"river" of air at high altitude

3 multiple choice options

Cyclone

a center of low pressure

3 multiple choice options

Anticlone

a center of high pressure; pressure increases toward the center

3 multiple choice options

Convection current

vertical current due to differences in density

Equatorial low pressure zone

air is heated from solar radiation, which causes it to be less dense and rise

3 multiple choice options

Subtropical high pressure zone

subsiding, stable dry air (moisture dumped at the low makes this air drier as it sinks to the ground

1 multiple choice option

Trade winds

produced by air traveling toward the equator from the subtropical high

Hadley cell

vertical air circulation due to convection

1 multiple choice option

Easterly winds

polar wind; air spreads toward the equator

Polar front

polar easterlies collied with the westerlies

Monsoon

abnormally high rainfall in a given area

2 multiple choice options

Valley breezes

air that flows upslope during the day (due to warmer less dense air rising up in the mountain as it is heated by the sun)

Mountain breezes

air that flows downslope at night (due to cooler more dense air sinking down the slope)

Chinook winds

winds blowing down from the land (mountains) due to high pressure centered over the mountains (results in hot, dry winds)

Santa Ana winds

chinook winds in Southern California

Land breezes

winds blowing from the land to the sea during the night

Sea breezes

winds blowing from the sea onto land during the afternoon

ITCZ

Intertropical convergence zone

2 multiple choice options

Normal equatorial Pacific conditions

strong winds push warmer surface water toward the Western Pacific (south pacific islands and northern australia)-creating a low pressure center (convective lifting here means a rainy season)

El Nino

weakened trade winds change the normal flow of water to a strong current that flow from west to east (opposite of normal conditions)

1 multiple choice option

La Nino

(opposite of El Niño) triggered by colder than average surface temperatures in the eastern pacific, which amplifies the normal flow of warm to the western pacific