Wind, Clouds, and Precipitation

WINDS

DIFFERENCES IN AIR PRESSURE

UNEQUAL HEATING OF AIR

Responsible for triggering the initial movement of air.

CORIOLIS EFFECT

SHIFT IN WIND DIRECTION

DUE TO EARTH’S

ROTATION

http://upload.wikimedia.org/wikipedia/commons/b/b6/Corioliskraftanimation.gif

As air moves from high to low pressure in the northern hemisphere, it is deflected to the right by the Coriolis force. In the southern hemisphere, air moving from high to low pressure is deflected to the left by the Coriolis force.

Flushing Toilets on the Equator

Myth or Real:

Toilets flushed in the northern hemisphere apparently spin to the right, in the southern hemisphere the water spins left -- this is supposedly caused by the Coriolis effect. And on the equator? It's a straight shot down.

http://www.phschool.com/atschool/phsciexp/active_art/global_winds/index.html

The global wind belts are formed by two main factors: the unequal heating of the earth by sunlight and the earth's spin.

The unequal heating makes the tropical regions warmer than the polar regions. As a result, there is generally higher pressure at the poles and lower at the equator.

The atmosphere tries to send the cold air toward the equator at the surface and sends warm air northward toward the pole at higher levels.

Source: http://www.islandnet.com/~see/weather/whys/globalwinds.htm

Click on the link to watch an animation:

http://www.mhhe.com/biosci/genbio/tlw3/eBridge/Chp29/animations/ch29/global_wind_circulation.swf

http://www.geography.hunter.cuny.edu/~tbw/wc.notes/7.circ.atm/animations/GlobalWind.html

Animation 1 Animation 2

Earth’s Winds

GLOBAL WINDS UNEQUAL HEATING EQUALS GLOBAL PATTERN OF AIR CIRCULATION

LOCAL WINDS

LAND BREEZE

SEA BREEZE

MONSOON

MONSOONS

CARRIES WARM MOIST AIR

SEASONAL WINDS

Philippines

Northeast Monsoon (cold and wet)

Southwest Monsoon (dry)

DOLDRUMS

CALM SURFACE WINDS AT

EQUATOR (0 degrees latitude)

TRADE WINDSAIR MOVING BACK TO THE

EQUATOR FORMING A BELT

OF WARM, STEADY WINDS

HORSE LATITUDES

30 degrees North and South of Equator

Warm air cools and sink; clear skies; winds are calm

PREVAILING WESTERLIES

40-60 degrees Latitude (West to East)

Strong Winds

POLAR EASTERLIES

COLD BUT WEAK WINDS EAST

TO WEST

http://www.phschool.com/atschool/phsciexp/active_art/global_winds/index.html

JET STREAMS

ABOVE 12 KMS

180-350 Km/Hr

(speed)

“rivers of air"

CLOUDS

http://www.youtube.com/watch?v=ODImMpGFUa4&feature=related

http://video.about.com/weather/How-Do-Clouds-Form-.htm

MOISTURE CONDENSES ON

SMALL PARTICLES OF

DUST/ SOLIDS IN THE AIR

DEW POINTTEMPERATURE AT WHICH AIR

CONDENSES

WHY RISING AIR COOLS

MOLECULES COLLIDE AND REBOUND SPEED

DECREASES

CONDENSATIONWATER VAPOR

CHANGES INTO LIQUID

CLOUD FORMATION

WATER VAPORCONDENSATION NUCLEILOW TEMPERATURE

Source: http://www.vivoscuola.it/US/RSIGPP3202/umidita/lezioni/form.htm

Why do clouds have flat bottoms?

Dew point

Cloud droplets

Snow

Ice

TYPES OF CLOUDS

When warm air rises, other cooler air rushes in to take its place. The air that rushes in moves parallel to the ground. It is this moving air that we call “wind”.

Wind is caused by the uneven heating of the earth’s surface. Air that moves up and down is important in making winds. This is called a current.

Warm air near the surface of the Earth can hold more moisture than cool air above the Earth’s surface.

Water from the Earth’s lakes, oceans, land surfaces, and plants evaporates into this warmer air. Eventually, the warm moisture-filled air rises and becomes cool. Now the air can no longer hold all the moisture it had acquired when it was near the surface of the Earth. As a result, much of the water vapor in the air condenses.

Water vapor that condenses and forms clouds can fall to the Earth as rain, sleet, snow, or hail. Water that falls from the atmosphere to the Earth is called precipitation.

Hurricanes/Typhoons/ Cyclones & Tornadoes

http://www.youtube.com/watch?v=zP4rgvu4xDE

A hurricane begins over warm water as a low-pressure area, or tropical disturbance.

If the tropical disturbance grows in size and strength, it becomes a tropical storm, which may then become a hurricane.

A hurricane is a tropical storm that has winds of 119 kilometers per hour or higher.

http://www.youtube.com/watch?v=5iN352idLks&feature=fvwrel How Hurricanes Form

http://www.youtube.com/watch?v=5iN352idLks&feature=fvwrel How Hurricanes Form

Hurricanes/typhoons/cyclones-what’s in a name?

http://spaceplace.nasa.gov/hurricanes/

LOCATION, LOCATION, LOCATION

HOW?

hurricanes/typhoons and tornadoes spin COUNTER-CLOCKWISE in NORTH

H

H

H

H

http://edition.cnn.com/2011/US/04/28/severe.weather/index.html?hpt=T2

http://edition.cnn.com/2011/US/04/27/tornado.outbreak/index.html?hpt=T1

Experts: Severe weather across South could set tornado record

http://news.yahoo.com/s/yblog_thelookout/20110428/ts_yblog_thelookout/watch-tuscaloosas-terrifying-tornado

Yahoo video clips

Tornado Outbreak of 2011

The jet stream is the main reason for all the severe weather. The warm humid air from the south is clashing with the cool dry air coming down from Canada and where the two meet is where we find severe thunderstorms and tornadoes.

http://www.nytimes.com/interactive/2011/04/28/us/map-of-the-tornadoes-across-the-south.html

Including yesterday's storm, there have been a whopping 800 reports of tornadoes in April, easily surpassing April 2003's all-time record of 543 twisters.

Tornadoes Song: http://www.youtube.com/watch?v=iOw6ONcKk4g

http://www.youtube.com/watch?v=cvOut9VUqKY&feature=fvwrel

http://news.yahoo.com/s/yblog_thelookout/20110428/ts_yblog_thelookout/watch-tuscaloosas-terrifying-tornado

Yahoo video clips

Tornadoes

A tornado is a rapidly whirling, funnel-shaped cloud that reaches down from a storm cloud to touch Earth’s surface.

Tornadoes develop in low,heavy cumulonimbus clouds—the same clouds that bring thunderstorms.

http://www.youtube.com/watch?v=3Qu9wR03GVA&feature=related

http://www.youtube.com/watch?v=VQDkmziz1n8&feature=fvwrel

http://www.youtube.com/watch?v=NTjR91JC850