El Nino and La Nina What weather phenomena

El Nino and La Nina

What weather phenomena has the largest impact on weather in the western US ?

El Niño and La Niña

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

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

El Niño and La Niña simplified… z El Nino is the abnormal heating of Earth’s ocean surface in the Pacific. z La Nina is the abnormal cooling of Earth’s ocean surface in the Pacific.

Did You Know… z El Nino means “The Christ Child” z La Nina means “Little Girl” z They were discovered hundreds of years ago z They occur half as often as El Nino’s z They can be caused by underwater volcanoes

Time Pattern z El Nino usually lasts from a year to two years. z The longest El Nino ever recorded lasted six years. z La Nina usually lasts nine to twelve months. z The longest ever recorded lasted three years. El Nino La Nina. Oracle Think Quest. Retrieved May 14 th, 2012. http: //library. thinkquest. org/5818/elnino. html

Causes: z El Nino is caused when trade winds allow warm water from the Pacific to flow east. z La Nina is caused when the temperatures drop in the pacific, also being blown east. z This builds up warm z This builds up at the surface water that will coasts and will cause soon cause the El a La Nina. Nino.

What causes an El Niño? Weak trade winds and weak upwelling cause warm water off the coast of S. America

What causes a La Niña? Strong trade winds blow surface water towards east, creating colder surface temperatures off South American coast. We get strong upwelling.

What causes the patterns? z. Normal

Movement of Ocean Water z. Surface currents z. Deep ocean currents z. Upwelling

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

Deep Ocean Currents z. Currents controlled by water density: temperature and salinity 90% of the ocean water moves in deep ocean currents

Upwelling zupwelling brings up cold, nutrient-rich waters to the surface, which encourage seaweed growth and support blooms of phytoplankton.

Upwelling z This happens along the coast, and when this happens it creates animal diversity. z Phytoplankton use these nutrients to grow and reproduce at rapid rates. z This attracts organisms to areas of upwelling that rely on phytoplankton as food and, in turn, attracts their consumers. z This areas is rich in biological activity and diversity. z Approximately half of the fish caught in the world come from areas of upwelling.

El Nino’s Damage Done z Floods in the Pacific states z Cause tornadoes in the mid-west states z Causes severe thunderstorms in the south z Northeast typically has stormy winters, "Snowmageddon”

La Nina’s Damage Done z Drier and Milder conditions in the south. z Cause severe droughts in the southeast. z Cause unusual cold temperature changes along the Pacific coast. z Causes wetter conditions for the Pacific states. z Northeast will have cold periods

Strange phenomenon occur during an El Niño and La Niña like. . .

Brush fires caused by drought in Texas (La Niña)

Increased Tropical Storms (La Niña)

Hurricane Floyd was HUGE! (1999 - La Niña)

Causing devastating floods in Australia (2010 -2011 La Niña)

Peruvian anchovy populations declined (El Niño)

Star Tribune Aug 2 1993 Minneapolis, MN FLOODS Upper Mississippi Basin Source: Trenberth

More tornadoes through tornado alley? NO!!! Scientists have found no significant correlation between El Niño and La Niña weather patterns and increased tornadoes.

The drought of 1988: cost about $40 billion

Watch Videos (3 minutes each) z Science Cheat Sheet http: //science. discovery. com/tv-shows/cheatsheet/videos/el-nino-and-la-nina. htm z National Geographic Video http: //video. nationalgeographic. com/video/environment-natural-disasters/landslides-and-more/elnino v La Nina water movement explained v https: //www. youtube. com/watch? v=8 q. JYCHBEj 2 g

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

Were you’re predictions correct?

Videos : If time z http: //www. youtube. com/watch? v=SR 5 VPAq. VQBw El Nino explanation video 3 min z z http: //www. youtube. com/watch? v=j. EAv-9 TZkt. Y La Nina explanation video 3. 5 min z z http: //www. youtube. com/watch? v=i. WTucps. Cl. Lc Austin newscast in January talking about Australia flooding 2 min z z http: //www. youtube. com/watch? v=l 5 x 8 d. J 57 xkk Texas weatherman predictions for this year from July 2010. about 3 min z z http: //esminfo. prenhall. com/science/geoanimations/26_Nino. Nin a. html All three animations