Post on 18-Jan-2016
End of Year – Science Study Guide
Earth Systems and Structures
Earth Systems
• Weather – daily temperature and precipitation
• Climate – average temperature and precipitation over time
Weather Tools
• Thermometer – used to tell the temperature• Barometer – used to tell the amount of air
pressure• Rain Gauge – collects the amount of rainfall that
has fallen• Hygrometer – tells how much moisture is in the
air (humidity)• Anemometer – indicates wind speed• Wind Vane – indicates wind direction
Types of Clouds
Cirrus• Wispy clouds that are the
highest clouds in the atmosphere; made of ice crystals
• Change in weather is coming
Stratus• These clouds form in layers,
blanket the sky, and bring gray/dull weather (fog) but they don’t bring rain
Types of Clouds
Cumulus• Large white puffy
clouds that may bring light rain
Cumulonimbus• Large dark clouds
that bring severe storms. Can expect heavy rains.
Air Pressure
Low Pressure (lousy)• Air rises and forms water droplets• Strong winds and dropping temperatures• Usually results in rain and storms
High Pressure (happy)• Several days of clear, sunny skies• Causes air to sink• Mild winds and stable temperatures
Air Masses and Fronts
• Air Mass – a large body of air with about the same temperature and humidity throughout
• Polar Air Mass – Cold air• Tropical Air Mass – Warm air
• Front – the boundary where two different air masses meet
Front Symbols
Types of Fronts
Warm Front• Laid back – rises over the cold front• Rain showers• Warmer air follows the front
Cold Front• Rude – takes over and pushes warm front up• Stormy/Windy weather• Cooler air follows the front
Types of Fronts
Stationary Front• Cold and warm front meet and neither moves• Overcast and rainy weather
Occluded Front• Two cold air masses meet and the warm air
between them is pushed upward.• Rain and Snow• Cool Temperatures
Types of StormsType of Storm Where it Forms Time of Year
Thunderstorm Within large cumulonimbus clouds
Spring or Summer
Tornado Cumulonimbus Clouds Spring or Summer
Hurricane Over warm ocean water Late Summer and early Autumn/Fall
Weather Patterns
Local Weather Patterns:• Moderate temperature and moderate rainfall
with hot Summers and cold Winters
• Thunderstorms, Tornadoes, and Hurricanes possible between Spring and Fall
What Affects Weather Patterns?
• Equator – an imaginary line that divides the Earth into the Northern and Southern Hemispheres
• Latitude – distance north or south of the equator
Climate Zones
Tropical Zones• Located closest to equator so it gets most energy from the sun;
warm and hot all year
Polar Zones• Located farthest from the equator near North and South Poles;
get least amount of energy from sun; cool and cold all year
Temperate Zones• Between Polar and Tropical Zones; amount of energy from the
sun changes throughout the year; seasons with very different temperatures
Two HemispheresNorthern Hemisphere Southern Hemisphere
Located above the equator Located below the equator
Opposite weather of Southern Hemisphere
Opposite weather of Northern Hemisphere
In Temperate Zone: In Temperate Zone:
Summer is June, July, August Summer is Dec., Jan., Feb.
Winter is Dec., Jan., Feb. Winter is June, July, August
Fall here Spring there
Spring here Fall there
Also Affecting Weather Patterns
Mountains • higher places have cooler temperatures than low places • Warm air moving toward mountains will rise and cool
(causing rainfall)Bodies of Water• tend to have milder weather• In Winter – warmer ocean water keeps nearby land
warm• In Summer – cooler ocean water keeps nearby land cool
Currents
• Current – a flow of air or water in a certain direction
• Two Types:• Global wind currents – in the air (includes Jet
Streams)• Ocean Currents – in the water (includes Gulf
Stream, El Nino, La Nina)
Global Winds
• Polar Easterlies – Travel from the Poles (east to west)
• Westerlies - Between the Poles and Tropics (travel west to east); where we live
• Trade Winds- Travel toward the Equator (east to west)
• The paths of global winds curve because…Earth spins on its axis.
Jet Stream
• An air current in the upper atmosphere that flows from East to West.
• Dip, bend and change position to affect North America’s weather
• Affect the paths of storms.
• From the North (dips South) – Polar Jet Stream lets cold air from Canada flow down into the US
• From the South (bends North) – Subtropical Jet Stream lets warm air flow in from the South
Ocean Currents
• Warm Currents (Tropical) – ocean currents that flow away from the equator; carry warm water near coastlines to cooler areas
• Cold Currents (Polar) – ocean currents that flow away from the poles; bring cooler temperatures to hotter coastlines
Ocean Currents
• The Gulf Stream – a warm ocean current in the Atlantic Ocean that moves warm waters toward the north. Helps keep weather mild during cooler months by warming the air and land.
• El Nino – unusual warming of surface temperatures in the Pacific Ocean, drought in Western US, Flooding in S. America
• La Nina – unusual cooling of the surface temperatures in the Pacific Ocean, flooding in Western US, drought in S. America