Transcript Chapter 8
Chapter 8 5th Grade Science Weather Patterns Layers of Air • ______ - made up of 8/10 nitrogen and 2/10 Air oxygen, small parts of carbon dioxide, water vapor and other gases • _______ of Earth’s atmosphere 5 layers • Most weather conditions occur in the ________ layer – troposphere bottom temperature • ___________ and ___________ change Air pressure through the layers 5 Layers • Air pressure __________ as you go ___upthrough decreases the atmosphere – Gas particles get _______ _____ air farther apart and there is less above 5 Layers: 1. ___________ - Highest layer Exosphere 2. Thermosphere ___________ Mesosphere 3. ____________ 4. _____________ Stratosphere 5. ______________ - bottom layer Troposphere Heating and Cooling Earth • Land heats up _____ faster than water in the sun • Land cools _____ faster than water • Air above land and water have different temperatures ____________. • Differences in temperatures cause: winds – _________ storms – _________ Other sorts of weather – ___________________ Convection Current • ______________ - caused by different Convection current temperatures – gases and liquids rise and sink in a circular pattern. • ______ Cool air - gas particles are closer together than in warm air heavier – Cooler air is _________ than warm air – Cool air _______ and lets the warm air ______ sinks rise above it 6 Convection Currents • __________________ 6 huge convection currents form above the Earth • Warm air from the _______ rises and then Tropics cools as it moves north and south • ______________________ - the combination Regional surface wind patterns of movement of huge convection currents and the spinning of the Earth on its axis • Winds blow from _______ to _______ West East Jet Streams • _________ Jet Streams - found high above the ground between the 6 huge convection currents winds – Band of very fast ________ formed by different temperatures between convection currents – Causes changes in ______, ___________, wind temperature and precipitation ____________ by affecting the movement of air Study Diagram on Page 232-233 Air Masses • __________ - large body of air with similar Air Masses properties (_________ temperature and ______________) Amount of Water vapor all through it • Air masses move because of ______ winds Jet Streams • Some air masses are guided by the _________ storms • At the edge of an air mass, _______ may occur • There are __ 4 kinds of air masses – the kind of weather depends on the air mass in that area. 4 Air Masses • ________________ - air mass from this area is Continental Polar Air cold and fairly dry because the land near the poles is not very moist • ________________ Maritime Tropical Air - humid air with lots of moisture because of evaporation over tropical oceans and rainforests • _________________ - air is cold and moist Maritime Polar air because cold ocean water near the poles evaporates • _________________ Continental Tropical Air - warm and fairly dry from hot desert air Fronts • ________ - a boundary between two air Front masses • Air masses and fronts move from _____ west to ____ east across the United States front • A ______ gets its name from the kind of air that moves into the area. • Example: cold front = ______, Cold air warm front =_________ Warm air Fronts Continued • _____________ - a front that does not move Stationary front very much or it moves back and forth over the same area. • Areas of rising air near fronts have Lower air pressure ______________ than areas in the middle of air masses • Rising air masses at fronts often cause ____________ Rain or snow Cold Front / Warm Front Cold Front • __________ - cooler air moves into an area and forces warmer air to move upwards quickly • The rising air forms ___________ Cumulus clouds along the steep boundary Cold Front • Heavy precipitation often falls near a _______ • ________ Warm Front - warmer air moves against cooler air. Warmer air rises above the cooler air • Clouds of a warm front often move ______ slowly and precipitation cause longer periods of __________ Severe Weather • ___________ Severe weather includes thunderstorms, tornadoes, and hurricanes Thunderstorms - caused by strong, quickly rising • __________ currents in moist air: Three stages – 1st Stage: Clouds grow as moisture _________ condenses in the rising air. The clouds have both __________ Ice crystals and ____________ Water droplets – 2nd Stage – precipitation begins to fall – storm has Moving currents both upward and downward _____________ Watch / Warnings • 3rd stage – all of the _________ are moving currents downward , the clouds get ________ as smaller precipitation falls. Severe Storm Watch - means that severe • ______________ thunderstorms with high winds and hail might form • ________________ - means that severe Severe Storm Warning thunderstorms have formed and people should prepare for them appropriately Tornadoes winds in a storm blow at different • Layers of _____ _________ or in different ________ speeds directions column of air starts • Between the layers, a ______ spinning. • The spinning column of air is called a ___________ Funnel cloud • When the funnel cloud touches the ground it is called a _______. tornado Tornado Warning kilometers • Tornados can move at hundreds of ________ per hour cars • The winds can be strong enough to move ____ and ________. buildings shelter in • After a warning people should take ______ the lowest part of a building like a __________ basement • No ________ near the center _____ of the building windows Hurricanes • Hurricanes get energy from ______________. Warm ocean waters • Water vapor from the ocean condenses ________ and energy releases ______. energy • Under the right condition, the ________ builds and drives the _____ winds of a hurricane to land. • Once the hurricane reaches land, the ______ energy is reduced. Hurricane Warning Not as fast • Winds of a hurricane are __________ as a tornado, but they can be more ________. destructive • To prepare for a hurricane, people must ________________, ___________, and Board up windows Store food water ________ • Flashlights and battery powered radios • Most important – STAY INSIDE or leave if the authorities call for an evacuation Weather Instruments barometer - shows air pressure • ________ • ___________ - measures wind speed – wind anemometer makes the cups of the instrument spin around hygrometer - measures moisture in the air • ________ • ___________ - measures how much rain has Rain gauge fallen • _______ - measures the winds and radar precipitation during a storm Weather Predictions Weather forecasters - observe patterns of • ______________ weather change and make _________ inferences inferences • _________ - conclusions of how air, land, and the steps of the water cycle affect each other systems to make Weather ___________. • Forecasters make ________ predictions about the weather in the future based on their ________ inferences Forecasts • Forecasters make predictions by assuming that _______ weather conditions will behave current past like similar weather in the _____ Weather maps to display the • Forecasters use __________ data • Triangles and circles point in the direction that the _____ front is moving • Fronts are always in places of __________ Low pressure • ___________ High pressure = clear skies Climate • _______ - the average of weather conditions Climate over a period of time • Climate includes the average amount of precipitation temperature and ___________, the average ________, how much ___________ changes over a temperature period of time. • __________ and _________ are not the same Climate weather thing – climates do not change, weather changes. Landforms affect Climate • Higher land is ________ because cooler decrease temperatures ________ with height in the troposphere. Climates • _________ on opposite sides of a mountain vary. • The ______ side of the mountain gets more west precipitation than the ____ East • ________ can affect a climate by slowing the Oceans rise and fall of the air temperature Oceans and Climate • The temperature of air on land warms and cools faster than the temperature of the air over an ocean. Ocean currents • _____________ can make climate warmer or cooler • ________________________ Gulf Stream and North Atlantic Drift are large currents that carry warm water northward • The water warms the _____ winds above it • __________ Cold Currents - make the coastal climate cooler Climate Change Climates • ________ have changed throughout history • _______ help scientists make assumptions fossils about ancient climates • Climates can change as the result of: – ______________ Volcanic Eruptions Asteriod or meteorite impacts – _______________________ Burning coal and gasoline – _____________________