19A: Weather...Weather •Weather: the condition of Earth’s atmosphere at any given time and place •Meteorology: The study of the atmosphere •Collect data to describe and predict

19A: Weather

• Wind power: clean energy

• Wind farms: Many turbines

• Supply electricity

19.1http://www.shoener.com/waymart-wind-farm. html

View from the blade of a turbinehttp://www.viewpure.com/iwHpGw665NA?start=0&end=0

Weather

• Weather: the condition of Earth’s atmosphere at any given time and place

• Meteorology: The study of the atmosphere

• Collect data to describe and predict weather 19.2

https://graphical.weather.gov/images/conus/M axT1_conus.png

Weather• Temperature

•Amount of thermal energyin the air

-Thermometers

-Thermographs 19.2

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Weather

• Temperature scales are linked to constant physical conditions

• Fahrenheit scale

• Water freezes at 32°

• Water boils at 212°

19.2https://mywritinghome.wordpress.com/2017/0 7/27/ne ver-wa lk-awa y-from-a -boiling -pot/

Weather

• Temperature

• Celsius scale

• Water freezes at 0°

• Water boils at 100°

• A Fahrenheit degree is “smaller” 19.2

• Pressure:

• Force exerted by air on a standard area

• Changes with temperature, elevation

• hot air: less pressure

• Top of a mountain: less pressure 19.2http://www.viewpure.com/MYswNGN5Gc8?start=0&end=0

• Pressure

• Units of force per area

• Lb/in² or psi

• N/m² or Pa

• Bar, mbar

• Barometer19.2

https://www.thestar.com/autos/2015/1 2/18/w hats-the-prope r-tire-pressure-for-your-car.ht ml

Weather

• Wind is moving air

• Wind direction is the direction from which the wind is coming

• Weather vane

19.2https://www.clipartmax.com/middle/m2 i8A0m2m2d3A 0A0_y ear-five-observ ed-the-s imilarit ies-and-differe nces-car toon-tr ee-with-face/

“Okay, I see where you’re coming from”https://static.vecteezy.com/system/resources/preview s/000/0 92/465 /non_2 x/weat her-vane-vectors.jpg

Weather

•Wind is moving air

•Wind speed (knots)•Anemometer

•Wind is associated with changing weather

•Windchill effect

19.2https://en.wikipedia.org/wiki/Anemometer

Weather

• Precipitation is any form of water that falls to the earth’s surface from the sky

• Rain is most common

• Rain gauge

19.2https://www.duncraft.com/common/ima ges/pr oducts/l arge/S 30012S _zoom.j pg

https://slideplayer.com/slide/12717877/

https://archive.sswm.info/print/1527?ti d=525

Weather

• Humidity is a measure of the amount of invisible water vapor in the air• Absolute humidity (g/m^3)• Relative humidity• Hygrometers• Actually one more thing- listen for the next slide

19.2https://cdn.britannica.com/79/163379-1 38-536 A3C0C/process-water-v apour-atmosphere-video.jpg

AnemometerAn-e-mom-eter

Winds

• Pressure effects

• Pressure gradient

• From higher to lower pressure

19.3

Winds

• Coriolis effect

• Deflects winds

• Deflection depends on hemisphere and speed

19.3

Winds

• Friction effects

• Friction force

• Drag

• Opposite of the direction wind blows

• Related to wind speed

19.3

Winds

• Cyclones and anticyclones

• Surface winds

• Pressure gradient, Coriolis effect, and friction all affect the wind direction and speed

19.3

Winds

• Cyclones and anticyclones

• Cyclonic wind pattern

• Anticyclonic wind pattern

• Many other factors also affect surface winds

19.3

Winds

• Global winds

• Trade winds

• Near 30° latitudes

• Prevailing westerlies

• Polar easterlies

• Cold, dry

19.4

Winds

• Permanent highs, lows

• Doldrums

• Horse latitudes

• Subpolar lows

• Polar highs

19.4

Winds

• Local winds

• Causes

• Sea and land breezes

• Valley and mountain breezes

• Chinooks and foehns

19.5

19C

Clouds

Clouds

• Humidity

• Warmer air can hold more water vapor than cooler air

• Dew point

• Condensation

19.6

Clouds

• A cloud is a mass of extremely tiny liquid water droplets or ice crystals in the air

• Two methods of formation

19.6

Clouds

• Air must absorb enough water vapor to condense water droplets (or ice crystals) at its existing temperature

19.6

Clouds

• Air must cool to the dew point for the amount of water vapor it is holding to condense or form ice crystals

19.6

Clouds

• Air can cool simply by rising

• Condensation nuclei

• Freezing nuclei

19.6

Clouds

• Supercooled clouds

• Liquid water at temperatures below the freezing point of water

• Atmosphere must be quiet

19.6

Clouds

• Types of clouds

• Shapes

• Stratus

• Cumulus

• Cirrus

19.7

Clouds

• Types of clouds

• Altitude zones

• Strato-

• Alto-

• Cirro-

• Cumulo-

19.7

Clouds

• Types of clouds

• Fog is a stratus-like cloud that forms at ground level

• Nimbus

19.7

Clouds

• Precipitation

• Cloud water droplets are very small (about 0.02 mm)

• Coalescence

• Rain

• Drizzle19.8

Clouds

• Precipitation

• Freezing rain

• Sleet

• Updrafts

• Hail

• Snow

• Wintry mix19.8

Clouds

• Dew forms on objects that are cooler than the surrounding air

• Heavier dew forms when air is calm

19.9

Clouds

• Colder air cannot hold as much moisture as warmer air

• Frost

19.9