Atmosphere Composition

• Nitrogen 78% • Oxygen 21% • Other about

1%

Hurricanes vs. Tornadoes

Hurricanes

HurricaneDefinition:Severe tropical storm with

heavy rain that has wind speeds that exceed 74 mph

How do hurricanes form?

Step 1:

Water evaporates, into the

atmosphere, from ocean water

that is close to the equator and

is at least 80°F.

Step 2: Storm clouds form in the atmosphere out of the

evaporated water

Step 3:

Winds close to the oceans surface draw up

more and more water vapor into the center of

the storm clouds making them larger and larger

• \

Step 4:

The rotation of the Earth causes the storm clouds

to spin and wind pushes the storm clouds along

the ocean.

Clip on How Hurricanes Form

http://www.youtube.com/watch?v=k35Gwb0FFU0

Weather Conditions Associated with Hurricanes

1. Heavy rain2. Strong winds3. Storm surge

Storm SurgeDefinition:Ocean water that is

pushed towards shore by the force of winds moving cyclonically

* Causes an abnormal rise in water levels on

shore *

Animation of Storm Surge

http://www.nhc.noaa.gov/surge/animations/hurricane_stormsurge.swf

How Scientists Track Hurricanes1) Weather satellites2) Radar

3) Specialized Planes “Hurricane Hunters”

Hurricane Sandy taken by radar scatterometer on the Indian Space Research Organization’s (ISRO) Oceansat-2

Clip – Hurricane Hunters

http://www.youtube.com/watch?v=Z96uu4GZNwQ

Several days in advance

Hurricane Warnings Can Be Given…

Scale Used to Measure a Hurricane’s Severity

Scale based on the wind speed of the

hurricane

Scale Used:

Saffir-Simpson Hurricane Wind Scale

Saffir-Simpson Scale

Examples of Damage Hurricanes Can Cause

1) Beach erosion2) Flooding3) Destruction of docks,

houses, buildings, roads etc.

4) Uprooting plants

Tornadoes

Supercell Thunderstorm

Definition:An extremely intense

thunderstorm that grows very quickly due a strong updraft of moist surface air

Characteristics:• Rotates • Hail • Torrential rain• Strong winds

Supercell Thunderstorm

Clip CLIP- Supercell Thunderstorms and Tornadoes

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

TornadoDefinition:a small rotating column of air that

has high wind speeds and touches the ground

How Tornadoes Form

The horizontally rotating supercell thunderstorm is flipped vertically by the thunderstorm’s

updraft

Clip – How Tornadoes Form

http://www.youtube.com/watch?v=GM-abtIT6Is

Weather Condition Associated With Tornadoes

High winds

** As well as the same condition associated with supercell thunderstorms **

How Scientists Track Tornadoes

Doppler Radar

a radar tracking system using the Doppler effect to determine the location and velocity of the storm. of a storm, clouds, precipitation, etc.

Clip – Doppler Radar

http://www.climatecentral.org/videos/how-do-we-know/how-do-we-know-tracking-tornados/

In roughly 13 minutes or less

Tornado Warnings Can Be Given…

Why Scientists Can’t Accurately Predict Tornadoes

http://www.livescience.com/12417-killer-tornados-spin-supercell-thunderstorms.html

Scale Used to Measure a Tornado’s Severity

Enhanced Fujita Scale

Enhanced Fujita Scale

Examples of Damage Tornadoes Can Cause

1) Destruction of houses, buildings, roads, bridges etc.

2) Uprooting plants