What weather phenomena has the largest impact on

our weather in Texas?

Definitions:

El Niño - Unusually warm surface water temperatures in the Pacific ocean caused by weak or reversed direction trade winds.

La Niña - Unusually cold surface water temperatures in the Pacific ocean caused by strong easterly trade winds.

Shared Characteristics:

El Niño and La Niña are

•Pacific Ocean-Atmospheric systems

•The most powerful phenomenon on earth

•Alters more than half the planet’s climate

Strange phenomenon occur during an El Niño and

La Niña like...

Strange phenomenon occur during an El Niño and

La Niña like...

• Cooling of the water in the Pacific Ocean

• Less Snow and rain on the west coast• Decreased Humidity • Unusually cold weather in Alaska• Unusually warm weather in the rest

of the USA (add to your notes)• Drought in the southwest: often

triggering forest fires• Higher than normal number of

hurricanes in the Atlantic• Flooding in Australia

La Nina Weather Characteristics

• Warming of water in the Pacific Ocean

• Rain and Flooding on the Pacific coast

• Increased Humidity • Warm weather disrupts food

chains of fish, birds and sea mammals

• Increase of thunderstorms in the southern United States.

• Fewer than normal number of hurricanes in the Atlantic

• Occurs more often than La Nina

El Nino Weather Characteristics

Brush fires caused by drought in Texas (La Niña)

Increased number of Hurricanes (La Niña)

Strong trade winds!

Hurricane Floyd was HUGE! (1999 - La Niña)

Causing devastating floods in Australia (2010-2011 La

Niña)

Australia has the opposite weather of Texas!!

Fish populations decline off the coast of S. America (El Niño)

Fish do not like warm water! (El Nino = bad fishing)

NO!!!

Scientists have found no significant correlation between El Niño and La Niña weather patterns and increased tornadoes.

More tornadoes through tornado alley?

Movement of Ocean WaterSurface Ocean Currents

Currents that are controlled by the wind. ~¼ mile depth, 10%

Deep Ocean Currents

Currents controlled by water density: temperature and salinity

90% of the ocean water moves in deep ocean currents

Upwelling

Upwelling brings up cold, nutrient rich water from the bottom of the ocean.

Fish like cold water! More food (La Nina = good fishing)

What causes the patterns?

Wind and normal trade wind pattern.

Normal trade wind speeds

What causes an El Niño?

Weak trade winds and weak upwelling cause warm water off the coast of S. America Trade winds very weak or blow in

opposite direction.

WARM!

What causes a La Niña?

Strong trade winds blow surface water towards east, creating colder surface temperatures off South American coast. STRONG trade wind speeds!

COLD!

Sea surface anomalies associated with El Niño

SST differences between El Niño and La Niña

A

B

C

QUIZ! Which is which…Normal, El Niño, La Niña?

Were your predictions correct?

How can we predict an El Niño or La Niña

event?

Need measurements to make predictions

NOAA drifting buoys #1

Measure...temperaturecurrentswinds

NOAA drifting buoys #2

Observations of conditions in the tropical Pacific are considered essential for the prediction of short term (a few months to 1 year) climate variations. To provide necessary data,

NOAA operates a network of buoys which measure temperature, currents and winds in the equatorial band. These buoys daily transmit data which are available to researchers and forecasters around the world in real time.

But What About the Rest of the Ocean outside of

the Equatorial Band?Since oceans cover about 70% of the earth’s surface, our ships, buoys and other in situ (at the collection site) instruments can’t possible cover that much space. Thanks to advanced space technology, we can now use satellites to help us collect large amounts of ocean data. 

Satellites

Contain instruments to measure wind, waves, temperature of the sea surface, ocean color, ocean surface currents, and tides.

Satellites

.Satellites have revolutionized the ocean sciences. They have advanced our knowledge about the weather and ocean processes more than any other tool. Oceanographers can use these satellite measurements for numerical modeling to predict what is happening in the deep ocean.

TOPEX/Poseidon

.TOPEX/Poseidon (T/P) was launched in 1992 and has since mapped the ocean's surface topography. T/P covers the entire planet every 10 days--an impossibility for a ship. Radar altimeters on (T/P) accurately measures the satellite's distance from the ocean's surface and tells us about the ocean's surface currents, winds, and wave heights. TOPEX/Poseidon data are used to predict the position of swift currents that appear to be connected with eddies. Eddies are spinning water currents--like giant whirlpools and are considered to be the "weather of the oceans." Knowing the locations of eddies can increase the safety of workers on oil production platforms and other ocean going vessels. It is helpful in ship routing, commercial fishing, sailing, hurricane prediction,

studying ocean circulation, and climate forecasting.

January of 2006 was the official end of the mission.

REVIEW

El Nino = The Boy = Warm = We likeLa Nina = The Girl = Cold = We don’t like

Videos

http://www.youtube.com/watch?v=SR5VPAqVQBw    El Nino explanation video  3min

  http://www.youtube.com/watch?v=jEAv-9TZktY   La Nina

explanation video  3.5min   http://www.youtube.com/watch?v=iWTucpsClLc  Austin newscast in

January talking about Australia flooding  2min   http://www.youtube.com/watch?v=l5x8dJ57xkk  Texas weatherman

predictions for this year from July 2010.   about 3min   http://esminfo.prenhall.com/science/geoanimations/animations/

26_NinoNina.html    All three animations