WEATHER #1 flashcard answers 6th grade

What is weather? weather= the state of the atmosphere at ANY time… ~ includes=temperature, precipitation, air pressure, humidity and wind ~ both DAILY & SEASONAL changes

~ reflects what it formed over… Describe an air mass. air mass a body of air with consistent features ~ such as… temperature and relative humidity (amount of water vapor in the air) ~ reflects what it formed over…

What is air pressure? air pressure= the weight of the atmosphere (air) pressing down on Earth ~ highest at sea level & decreases as you move upwards ~ air flows from HIGH pressure to LOW pressure

Describe a high pressure system . when COOL air SINKS closer to Earth, increasing the surface air pressure ~ makes it difficult for air to rise (cool sinks down)

Describe a low pressure system . when WARM air RISES away from Earth’s surface, decreasing the air pressure at the surface ~ creates a ‘hole’ where the warm air used to be

(no clouds & blue skies) What weather type goes with a… 1) high pressure & 2) low pressure system? high pressure system= FAIR weather (no clouds & blue skies) low pressure system= CLOUDY, STORMY weather

the HORIZONTAL movement of air What is wind? wind= the HORIZONTAL movement of air

which creates CONVECTION CURRENTS What causes wind? caused by= the UNEVEN HEATING of Earth’s surface… which creates CONVECTION CURRENTS ~ Warm air is less dense & rises… denser, cool air rushes in to replace it! ~ Winds form as air moves from high to low pressure areas.

Flag blows towards land! What is a sea breeze? sea breeze= COOLER air moving from the sea towards the land ~ as warm air above the land rises, the cool air above the ocean rushes in to replace it… Flag blows towards land!

What is a land breeze? land breeze= COOLER air moving from the land towards the sea ~ At NIGHT… the land cools faster than the water. ~ as warmer air above the ocean rises, the cooler air above the land rushes in to replace it… Flag blows towards ocean!

~ Earth’s ROTATION slightly bends these winds CORIOLIS effect What are Global Winds? Global Winds= the winds that push air masses around Earth, bringing changes in the weather ~ EXCHANGE between the warm air from the Equator and the cold air from the poles ~ Earth’s ROTATION slightly bends these winds CORIOLIS effect

2) Prevailing Westerlies 3) Polar Easterlies List 3 Global Winds. Global Winds 1) Trade Winds above & below equator to 30 degrees latitude; STEADY & strong 2) Prevailing Westerlies between 30-60 degrees latitude; STRONG & gusty 3) Polar Easterlies at the very top & bottom of Earth (near the North Pole & the South Pole); WEAK

What are Local Winds? breezes covering only SHORT distances ~ Caused when land heats up AND cools down faster than water. ~ Example of convection.

LIST & DESCRIBE the 2 types of Local Winds. 1) SEA breeze= cool light winds coming from the ocean to land 2) LAND breeze= ONLY at NIGHT…cool light winds leaving the shore towards the ocean

Describe the Jet Stream. strong winds with high speed and high pressure found in the upper troposphere (where jet planes fly) ~ Moves WEST to EAST across the USA, moving storms!