Intro to Weather Clip
Weather Temporary behavior of atmosphere (what s going on at any certain time) Small geographic area 1.) Can change rapidly
Weather --The study of weather is 2.) meteorology --Someone who studies weather is called a meteorologist
Climate 3.) Long-term behavior of atmosphere (100+ years) Large geographic area 4.) Very slow to change
POLAR CLIMATE 90 o -60 o latitude Cool summers, cold year-round 5.) Dry
TEMPERATE CLIMATE 60 o -30 o latitude 6.) True Seasons Variety of climate patterns Moderate precipitation (rain/snow)
TROPICAL CLIMATE 30 o - equator 7.) No winter, warm year-round High temp, rainfall, humidity
What Factors Affect Weather & Climate? 8.) The Sun The Water Cycle 9.) The Atmosphere The Ocean
Cloud Formation
Cloud Formation 10.) Warm air rises (less dense) Air will gradually cool. The air will begin condensing. These nuclei will collide with other nuclei, eventually forming a cloud.
Types of Clouds Low clouds- lying on or just above the surface (up to ~10,000 ft). Consist of stratoform (flat) clouds cumuloform (puffy) clouds,
Types of Clouds Stratus: Cumulus:
Types of Clouds (Cont d) Middle Clouds - extending from 10,000 20,000 feet above the surface : - Consist of altoform (meaning a middle cloud) type clouds. Altostratus: Altocumulus:
Types of Clouds (Cont d) : High Clouds - These clouds are wispy/crisp/featherlike in appearance, and do not produce precipitation. - Consists of mainly ice crystals suspended above 20,000 feet from the surface. These clouds are wispy/crisp/featherlike in appearance, and do not produce precipitation.
Types of Clouds (Cont d) Cirrus: Cirrostratus: Cirrocumulus:
How Does the Sun Affect Weather? It warms the atmosphere & oceans It creates climate zones It keeps the water cycle going It affects weather patterns
The Water Cycle All the water on the planet is recycled in this manner!
Parts of the Cycle Evaporation Water going from a liquid to a gas (gains energy from the sun)
Parts of the Cycle *Transpiration evaporation of water from/out of plants. Locate this on the diagram! transpiration
Parts of the Cycle Condensation Water going from a gas to a liquid (cools or loses energy) When this happens in the atmosphere, CLOUDS form.
Clouds by Brainpop
Parts of the Cycle Precipitation when water falls out the atmosphere. Forms when the water droplets in clouds become too heavy to stay up.
Precipitation Liquid water = rain Rain Clip Frozen water = snow or sleet or hail
The Water Cycle Water Cycle by Brainpop
Water Cycle Advanced by Brainpop
The Water Cycle by Brainpop 1) What process must happen for clouds to form? 2) What is collection? 3) Name one way to conserve water.
How does the atmosphere affect weather? The atmosphere is a mixture of gases that surrounds the Earth Has five different layers; each has different properties We ll label them in just a minute Air Temperature and Pressure change with altitude Weather occurs in the layer closest to Earth (troposphere)
Write in the labels! Exosphere Thermosphere Ionosphere Mesosphere Stratosphere Troposphere Ozone layer
1. What is ozone? Earth s Atmsophere by Brainpop 2. What layer of the atmosphere does weather occur in? 3. What 2 gases compose the most of Earth s Atmosphere?
Air Masses = body of air with a certain temperature and moisture level Can be warm or cold Can contain a lot of moisture or not a lot of moisture
Fronts = places where air masses meet 4 Types: Warm, Cold, Occluded, Stationary Each kind can bring different kinds of weather
Occluded Front: Stationary Front:
Science Saurus 221/222 & Reading a Weather Map Worksheet
How does Air Pressure affect weather? How much the earth s atmosphere is pressing down on us Measured with a BAROMETER If it CHANGES, then new weather is on the way: Falling Air Pressure = stormy weather coming Rising Air Pressure = fair weather coming Steady Air Pressure = no change is coming
Pressure Systems
Winds = created from differences in air pressure Moves from areas of HIGH to LOW pressure Greater the difference in pressure, the FASTER the wind blows Measured with wind vanes and anemometers or you can estimate with the Beaufort Wind Scale ScienceSaurus 224/225
Beaufort Wind Scale
Global Winds Thousands of kilometers long; can cause weather to move in different directions Jet stream, prevailing westerlies, doldrums, horse latitudes, trade winds Big Winds Blowin Worksheet & Science Saurus Section 217
Global Winds Caused by the temperature difference in different regions Hot Tropical Regions causes air to rise Cold polar Regions causes air to sink
Global Winds Also affected by Earth s Spin Coriolis Effect = causes winds to curve to the right in the N. Hemisphere; to the left in the S. Hemisphere
Big Winds Blowin Worksheet
Winds by Brainpop 1. What does warm air do? 2. What do you call winds that blow all the time in the same part of the world? 3. What are jet streams?
Relative Humidity Measure of the amount of moisture in the air compared to what the air could hold How full of water the air is Expressed as % 100% relative humidity = saturated air Relative Humidity Test Applet http://itg1.meteor.wisc.edu/wxwise/relhum/rhac.html
Relative Humidity Controlled by temperature 1. Warm air holds more moisture than cool air (more space for water vapor between air molecules) 2. As air warms, relative humidity decreases 3. As air cools, relative humidity increases
Dew Point =Temperature at which the air is saturated (100% relative humidity) Several events can occur when the dew point temp. is reached: 1. If dew point temp. is above freezing: a. water vapor condenses as liquid b. dew will form on surfaces
Dew Point c. cloud droplets will form in air 2. If dew point temp. is below freezing: a. water vapor condenses as a solid b. frost on surfaces c. snow (or hail) in the air
Humidity by Brainpop 1. What single factor controls humidity? 2. What temperature air can hold the most water molecules? 3. What causes water to evaporate into the atmosphere?
Rainbows Caused by sunshine on raindrops White light (all colors) is refracted (bent) into colors as it enters and exits the drop To see a rainbow you must have the sun behind you and raindrops in the air Diagram:
Rainbow by Brainpop
How does the Ocean affect weather? Ocean currents affect the temperature of the land they pass by Cold ocean currents = cooling effect Warm ocean currents = warming effect Temperature changes affect pressure which then creates WINDS Winds blow this cooling or warming effect over the land http://earth.rice.edu/mtpe/hydro/hydrosphere/topics/ocean_atm_circ_elnino.mov
http://www.wunderground.com/mar/
Science Saurus Sections 203-204-205-206
Advanced Weather by Brainpop Violent Weather
Thunderstorms Requires a mature cumulonimbus cloud Signs a. Sudden reversal of wind direction b. Noticeable increase in wind speed c. Sudden drop in temperature
Thunderstorms Possible weather: a. heavy rains (flash floods) b. lightning (forest fires) c. thunder (frightens animals) d. hail (crop damage) e. tornadoes f. strong, gusty winds Thunderstorm by Brainpop
Safety Rules Stay indoors Prepare for lightning, strong winds Listen on radio/tv for tornado watch/warning Thunderstorms don t last long
Lightning Storm Cumulonimbus cloud becomes electrically charged and ground below has opposite charge
Lightning stroke: flow of current thru air (a poor conductor) from the to the + Lightning can flow from cloud to ground, cloud to cloud, and from ground to cloud Bright light is caused by glowing air molecules heated by the current Lightning follows the path of least resistance (easiest way to positive) Lightning rod offers lightning an easy, safe path to the ground (+)
Thunder is the shock wave caused by the explosive expansion of heated air Sound travels @ about 1100 ft/sec in air 5,280 ft in one mile Distance from you to lightning = number of seconds between seeing the flash and hearing the thunder divided by 5. (5,280 ft / 1100 ft/sec = 5 seconds)
Types of Lightning Streak or bolt a. Single or branched lines of light b. Common in Puget Sound area
Sheet a. shapeless flash over wide area b. is cloud-to-cloud bolt hidden by the clouds c. common in Puget Sound area
Other types of lightning a. heat, ribbon, beaded (types of bolt) b. ball (only other shape lightning can have)
Safety rules for lightning storms Stay indoors Stay away from anything that conducts electricity (stove, sink, telephone, TV) Get out of the water and off of small boats Stay away from open doors, windows, fireplaces Stay in your car (very safe place to be) Don t stand under lone trees or in open places Avoid hilltops If your hair stands on end, or your skin tingles, drop to the ground but try to keep as little contact with the ground as possible
Lightning Strikes (17 minutes) Stories of people hit by lightning
Tornado (a.k.a twister, cyclone) Counterclockwise column of rotating air extending from cumulonimbus cloud Per square foot, is the most destructive atmospheric event Rated by wind speed (F1 to F5) Tornado season = April, May, June Tornadoes that form over water are called waterspouts
Behavior of a tornado is unpredictable Typical tornado will: 1. Occur between 3-7 pm 2. Travel 4 miles 3. Be 300-400 m wide 4. Travel 25-40 mi/hour 5. Have wind speeds up to 300 mi/hr 6. Produce extremely low pressure 7. Be dark due to debris picked up Tornado by Brainpop
Safety Rules Rule #1: Take immediate action! Move away from tornado s path Tornado s path Move away at a right angle
Lie flat in nearest ditch, etc. At home a. open windows, doors b. seek shelter in basement or under heavy table in middle of house On the trail of a tornado
Tropical Cyclone Nicknames 1. Atlantic: hurricane 2. SE Asia, Japan: typhoon 3. Australia: willy-willy 4. Indian Ocean: cyclone
Tropical Cyclone Rated by wind speed (category 1 to 5) Starts and grows over warm ocean water Composed of bands of thunderstorms spiraling counterclockwise around a low pressure center
Characteristics Several hundred miles wide Last many days (even weeks) Winds from 74-200 mi/hr Contains an eye a. Small region of low pressure b. Surrounded by highest winds c. Calm, peaceful, sunny weather d. Last for about 1 hour as hurricane passes by Hurricances by Brainpop
Safety Rules Prepare for high winds Prepare for flooding (greatest source of damage) a. Up to 20 in. of rain b. Flooding by coastal water 3. Prepare for thunderstorms 4. Have on hand stored food, water, blankets, candles, matches, radio, etc. 5. Seek shelter Hurricanes Clip