Chapter 13 The Nature of Storms. Lesson 7 Thunderstorms.

transcript

Chapter 13

The Nature of Storms

Lesson 7

Thunderstorms

Think About It…

During which months do we get the most

damaging thunderstorms here in the Piedmont?

Focus Question…

How do the major types of thunderstorms form?

Average Number of Thunderstorm Days Annually…

Types of Thunderstorms… Air Mass - Mountain

Where… within one air mass over a mountain Why… warm air rises over a mountain, forming storm

clouds! When… midafternoon

http://web.mst.edu/~rogersda/umrcourses/ge301/press&siever12.3.png

Types of Thunderstorms… Air Mass - Sea-Breeze

Where… coastal areas, esp. tropics/subtropics Why… temperature differences between land

and sea create convection cells and updrafts When… summer

http://apollo.lsc.vsc.edu/~wintelsw/MET1010LOL/web/notes/chapter11/ts_ingredients4summary.html

Types of Thunderstorms… Frontal - Cold

Where… at the leading edge of a cold front Why… cold air pushes warm air rapidly up at the

steep cold-front boundary When… anytime a cold front moves in!

http://apollo.lsc.vsc.edu/classes/met130/notes/chapter11/graphics/cf_xsect.jpg

Types of Thunderstorms…

Frontal – Warm Where… at the

leading edge of a warm front

Why… warm air mass slides up over a cold air mass creating clouds

When… if a warm front moves in with enough moisture and instability

http://www.atmoz.org/img/warm-front.png

Thunderstorms in the Piedmont…

Which types of thunderstorms do we experience here in the Piedmont?Frontal (warm and

cold)Local Air Mass (in the

summer)

http://www2.journalnow.com/mgmedia/image/0/354/118602/severe-storms-cause-damage-across-region/

Stages of Development of a Thunderstorm…

http://chiefio.wordpress.com/2010/12/28/ignore-the-day-at-your-peril/

NSSL – Q&A Thunderstorms…

The National Severe Storm Laboratory is in Norman, OK.

http://www.nssl.noaa.gov/primer/tstorm/tst_detecting.html

Severe Thunderstorms

Precipitation

Rain Free Base

http://ed101.bu.edu/StudentDoc/Archives/ED101fa06/mattwall/Extreme%20Weather.htm

How Lightning Forms …

http://www.erh.noaa.gov/bgm/preparedness/swaw/ny/images/Light1.gif

Lightning…

1. What is lightning? A giant spark of static

electricity

2. When does a lightning bolt form?

When there is an electrical imbalance between clouds (-) and the ground (+)

2a. What is a stepped leader? An invisible channel of

negatively charged air from a cloud

http://i.imwx.com/web/multimedia/images/blog/stepped_lightning2.jpg

Lightning…

2b. What is return stroke (positive streamer)?

A channel of positively-charged ions from the ground

3. What causes thunder? Super-heated air expanding

and contracting

How hot is lightning? 30,000 degrees Celsius

http://www.srh.noaa.gov/jetstream/lightning/images/lightning8.jpg

http://www.eoearth.org/files/119701_119800/119773/Step5.jpg

Lightning Damage…

The damage that lightning can do… 7500 forest fires/year 300 injuries/ 93 deaths/year Property damage

Lightning-struck trees on the Blue Ridge Parkwayhttp://www.sciencephoto.com/images/download_lo_res.html?id=670034119

http://www.barransclass.com/phys1090/circus/JenkinsD/JenkinsD.html

Lightning Q&A and Safety…

http://www.srh.noaa.gov/jetstream/lightning/lightning_faq.htm#10

Lesson 8

Severe Weather

Think About It…

Where is the safest place to be during a tornado?

Focus Question…

How do tornados form and how are they classified?

The Fury of the Wind… 1. A downburst is a violent downdraft concentrated in a local

areaa. Two types of downbursts are

a. macrobursts (more than 2 ½ miles wide / 130 mph winds / 5 - 20 min)

b. microbursts (2 ½ miles wide / 168 mph winds / less than 10 min).

http://www.srh.noaa.gov/jetstream/tstorms/wind.htm

b. Microbursts are deadlier b/c they are hard to detect and plan for.

Hail…

2. What is hail?Precipitation in the form of balls or lumps of ice

Floods…(The main cause of thunderstorm-related deaths)

3. What are 3 conditions that cause floods to occur?a. Wind currents in the upper atmosphere are weak

so that weather systems move slowly.

b. Abundant moisture over a limited area

c. Rain falls faster than the ground can absorb it.

d. ADD THIS Groundwater levels are high and water can not infiltrate the ground.

Slide show May 17, 2011… The Flooding Mississippi River

http://www.huffingtonpost.com/2011/05/12/mississippi-river-flooding-photos-2011_n_861204.html#s279672&title=Mississippi_River_Flooding

Tornadoes (Formation of…)

A. A change in wind direction and speed creates a horizontal rotation.

B. Strong updrafts tilt the rotating air to a vertical position.

C. A tornado forms within the rotating winds.

http://www.weatherwizkids.com/tornado_formation.jpg

Tornado Alley - The Midwest!

http://midwestweather.net/archives/tornadoclimatology.htm

A cP air mass from Canada meets a mT air mass from the Gulf of Mexico forming a supercell.

A supercell is a giant, self-sustaining storm that can spawn tornados.

Most tornadoes occur in May.

The Enhanced Fujita Scale…

This scale is used to classify a tornado AFTER the tornado has passed by looking at the damage and effects of the tornado.

The Enhanced Fujita Scale…EF0 or EF1

- % of all tornados… 80

- Path… up to 3 miles

- Wind Speed… 60-115 mph

- Duration… 1 – 10 minutes

http://0.tqn.com/d/weather/1/0/i/C/-/-/fujita2s_600.jpg

Dr. Theodore Fujita

- % of all tornados… 19

- Path… 15+ miles

- Wind Speed… 110 - 165 mph

- Duration… 20+ minutes

- % of all tornados… 1 (Thankfully!)

- Path… 50+ miles

- Wind Speed… 200+ mph

- Duration… 1+ hours

http://thedailycap.com/alabama-tornado-2011

Tornado Safety…

1. Move to a pre-designated shelter – to a basement if possible.

2. Move to an interior room/hall, lowest floor, under sturdy furniture. (A bath tub is safest!)

3. Stay away from windows.

4. Get out of vehicles!

5. Don’t try to outrun a tornado.

6. If outside, lie flat in a ditch or depression.

7. Abandon a mobile home for a shelter.

Lesson 9

Tropical Storms

Think About It…

From which direction do the hurricanes which hit our east coast come?

Focus Question…

How does a hurricane form?

Tropical Cyclones…

1. A tropical cyclone can be described as a…

Large, rotating, low pressure storm

2. We call these storms… hurricanes

3. Tropical cyclones derive a tremendous amount of energy from…

Warm, tropical oceans

http://www.nhc.noaa.gov/HAW2/english/history.shtml

4. Which direction do tropical cyclones turn in the northern hemisphere? Counterclockwise It is a low

pressure system!

Fran, 1996, Cape Fear, NC Name was retired!

5. As a hurricane strengthens, what do the following components do?

a. Air pressure in eyewall– decreasesb. Surface wind speeds – increase

6. What are two basic conditions that tropical cyclones require to form?

a. Lots of warm ocean waterb. Disturbance to lift the air

7. Tropical cyclones in the N. Hemisphere move steadily towards… the west!

8. Which wind system moves across the USA and usually guides hurricanes out into the Atlantic Ocean?

the prevailing westerlies

Hurricane Rita – 2005, 3rd lowest pressure in Atlantic (897 mb), hit as cat. 3

http://www.srh.noaa.gov/shv/?n=hurricane_rita

Development of a Tropical Cyclone…

Tropical Disturbance – a weak, low-pressure system – group of thunderstorms collect

Tropical Depression – a disturbance begins to rotate around the center of low pressure

Katrina as a tropical depression

http://www.uvs-model.com/WFE%20on%20tropical%20cyclone%20(Hurricane).htm

Tropical Storm – a depression is labeled a storm when the wind speeds reach 39 mph.

Tropical Storm Dalila, July 2007

http://www.weatherstockphotography.com/

Tropical Hurricane – pressure drops and the wind speeds reach 74 mph

http://www.weatherstockphotography.com/

Ivan2006

Dean 2007

Katrina 2005

Hurricane History…

http://www.nhc.noaa.gov/HAW2/english/history.shtml#galveston

Anatomy of a Hurricane…

http://apollo.lsc.vsc.edu/classes/met130/notes/chapter15/vertical_circ.html

Classifying Hurricanes…

1. What scale is used to classify hurricanes?

Saffir-Simpson

2. What are the four characteristics of a hurricane described by the scale?

a. Wind speed – how high?

b. Air pressure – how low?

c. Potential for damage – how much?!

d. Storm surge http://www.nhc.noaa.gov/sshws_table.shtml?large

Weds. 12/12/12…

2:10 pm OVC St 46 degrees 30.26 54% 0 No fronts!

3. The Saffir-Simpson Scale…

a. Categories 1 – 5

b. Category that does the most damage – 5

c. Wind speed of a cat 5? > 155 mph

d. Three most powerful storms to hit USA?a. Florida Keys, 1935

b. Camille, 1969

c. Andrew, 1992http://www.nhc.noaa.gov/pastint.shtml

4. A hurricane runs out of energy

a. When it moves over land

b. When it moves over cold water

http://backyard.weatherbug.com/profiles/blogs/the-south-central-texas-445

Hurricane Hazards…

1. The strongest winds in a hurricane are in the…

… eye wall

http://www.med.navy.mil/sites/nmcp/localarea/Weather/PublishingImages/def1.gif

2. What is a storm surge?

1. When hurricane force winds drive a mound of ocean water towards coastal areas

http://www.chathamemergency.org/images/storm%20surge%202.png

3. What hurricane hazard is caused by great amounts of rain?

floods

Flooding from Hurricane Fran

http://pubs.usgs.gov/of/1996/of96-499/text/PHOTOS.html

5. Which agency is responsible for tracking and forecasting hurricanes?

The National Hurricane Center in Miami, FL at the FIU Campus (NOAA)

The World’s Best Hurricane Safety Tip…

EVACUATE!!

Lesson 10

Human Impact on Air Quality

Smog…

1. Smog is a yellow-brown photochemical haze.

2. Smog is caused by the action of solar radiation on an atmosphere polluted with hydrocarbons and nitrogen oxides, mostly from car exhaust.

3. Smog can make it difficult to breathe!

4. The major chemical in smog is ozone.

5. Ozone irritates the eyes, nose, throat, and lungs.

Particulate Matter…

1. Four examples of particulate matter include…1. ash, dust, pollen, and asbestos fibers.

2. These are forms of SOLID pollutants in the air.

2. Particulate matter is harmful to people because they can…

1. lodge in lung tissues,

2. disrupt normal functions,

3. cause breathing difficulties and lung disease.

Global Warming…

a. Global warming is…1. an increase in Earth’s average surface

temperature.

b. Some scientists believe that the cause of global warming is...

1. … the burning of fossil fuels

2. …which releases carbon dioxide (CO2)

Remember - CO2 makes up only .04% of the atmosphere! (4 out of 10,000 molecules)

There are many scientists who believe the Sun has the major role in global warming/cooling.

The Greenhouse Effect

What is the greenhouse effect? It is heat from the sun being trapped by the gases in our atmosphere. A greenhouse effect you may

relate to is that of a closed car on a cold, sunny day in winter.

The greenhouse effect is a GOOD thing! It allows for life on our planet!

The Greenhouse Effect

http://www.uic.com.au/graphics/ueg1-1.gif

The Greenhouse Effect and Carbon Dioxide news.bbc.co.uk

Carbon dioxide is released into the atmosphere by respiration, decay, and burning of fossil fuels. It is absorbed or stored by

such carbon sinks as untapped fossil fuels, oceans, and forests.

The Ozone Issue

The ozone layer is found in the stratosphere.

It absorbs ultraviolet radiation from the sun.

www.space.gc.ca

The Ozone Issue

The ozone layer is important because…

• Ultraviolet radiation from the sun can cause cataracts (a clouding of the lens of the eye) and skin cancer.

• Ultraviolet radiation can kill the eggs of certain animals like amphibians because they lay their eggs in shallow water.

www.matthews.co.nz www.waterencyclopedia.comwww.mja.com.au

The Ozone Issue

The chemical formula for

ozone is O3

www.acd.ucar.edu

www.environment.gov.au

www.piscine-ozone.com

The Ozone Issue

Man-made chemicals called (CFCs) chlorofluorocarbons react with ozone and break it apart.

The part of the CFC molecule that reacts with the ozone molecule is the chlorine atom.

observe.arc.nasa.gov

The Ozone Issue

CFCs are used as refrigerants, coolants, propellants in aerosol cans, and Styrofoam.

tiki.oneworld.net www.ec.gc.ca

The Ozone Issue

This diagram

illustrates what a “hole” in the ozone might look like.

www.ec.gc.ca

The Ozone Issue

“The hole in the ozone layer above Antarctica is seen in a series of satellite images over a 21-year time span.

The hole may actually close within 50 years as the level of destructive ozone-depleting CFCs in the atmosphere is now declining, one of the world's leading atmospheric scientist Paul Fraser from the Australian government's Commonwealth Scientific and Industrial Research Organisation (CSIRO) said on Tuesday.

Fraser said he had measured a decline in ozone-destroying gases since 2000. — Reuters photo”

http://www.tribuneindia.com/2002/20020919/science.htm#2

The Ozone Issue

d. CFCs were banned in the late 1980’s in industrialized nations. They are still in use in some places in the world.

“Under the 1987 Montreal Protocol, developing countries committed themselves to halving consumption and production of the CFCs by 2005 and to achieving an 85 percent cut by 2007.”

http://www.tribuneindia.com/2002/20020919/science.htm#2

Acid Rain…

a. Acid Rain is precipitation with a pH of less than 5.

b. The pH of natural precipitation is 5.0 to 5.6.c. Acid precipitation forms when sulfur dioxide

and nitrogen oxides combine with atmospheric moisture to create sulfuric acid and nitric acid.

d. Six types of acid precipitation are acidic rain, snow, fog, mist, gas, and dust.

e. Nitrous oxide and sulfur dioxide come from volcanoes, marshes, and human activities

Acid Rain…

f. The source of acid precipitation that receives the most attention is caused by coal-burning power plants in the midwestern USA.

g. Three effects of acid precipitation are...a. It causes damage to aquatic ecosystems and

vegetation.b. It affects plants and soil.c. It damages stone buildings and statues.

h. Acid precipitation can be prevented by using wet scrubbers to reduce emissions of sulfur dioxide by coal-burning power plants.

World’s Tallest Buddha…

http://english.china.com/zh_cn/tourism/news/11020847/20071107/14450790.html

Buddha will get a face lift after many years of weathering and acid

rain damage.

Chapter 13 The Nature of Storms. Lesson 7 Thunderstorms.

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