Objective E: El Nino, La Nina sets
how often does El Nino/La Nina occur?
2-7 years or 3-5 years depending on who you ask :)
El Nino recovery=
6 months-2 years
El Nino: What happens in Northeastern U.S depends on the location of....
Bermuda High
ENSO stands for...
El Nino/La Nina and Southern Oscillation
1888-1889 La Nina
Temperatures fell to as much as 4 degrees C (7 degrees F) below normal
What is the name of the current that flows northward along the west coast of South America?
the Peruvian/Humboldt Current
Recorded El Ninos/La Ninas in this century
there are 23 El Ninos and 15 La Ninas in the 20th Century
Differences between El Nino and La Nina
there is a warm pool located in the Central and Western Pacific. During El Nino, the warm pool expands to cover the tropics. During La Ninoa, the warm pool shrinks. During El Nino, the trade winds strengthen.
Similarities between El Nino and La Nina
they are both extreme phases of a naturally occurring climate cycle. Both terms refer to large scale changes in sea surface temps along eastern tropical Pacific.
What happens to anchovies in South America during the El Nino season?
they disappear in El Nino events and thrive during the La Nina
Effects of La Nina
this cooling of the waters drops temperatures and brings cold winters to the Pacific Northwest, northern Plains states, Great Lakes states, Canada and warmer than usual winters to the southeastern states. Brings drier than usual conditions to California the Southwest, the Gulf of Mexico and Florida as well as drought for the South Anmerican coast and flooding for the western Pacific region.
During normal atmospheric circulation trade winds move surface water...
westward
La Nina
After the buildup of cooler waters in tropical Pacific, the easterly trade winds strengthen, cold upwelling off Peru and Ecuador intensify and sea-surface temps drop below normal.This causes cooler than normal sea-surface temps in the central and eastern tropical Pacific ocean. Conditions recur every few years and can persist for as long as two years.
Southern Oscillation is an..
Atmospheric disturbance
Is El Nino a small scale atmospheric occurrence
Even though it takes place in a small place in the Pacific, it can affect the weather in large parts of Asia, Africa, Indonesia and North/South America.
During ENSO: Surface water is pushed westward. True or False
False
Thermocline
In water, a distinctive temperature transition zone that separates an upper layer that is mixed by wind (the epilimnion) and a colder, deep layer that is not mixed (the hypolimnion)
ENSO neutral=
La Nada
Are the Brisbane Floods associated with El Nino or La Nina?
La Nina
Do fishermen in South American want La nina or El Nino?
La Nina
El Nino 1997
Most catastrophic in 20th century. Heavy Rain and flooding overwhelmed Pacific coast of South American, California and areas of Gulf Coast. Eastern Europe and East Africa also affected. Hurricanes swept through eastern and western Pacific , South east Asia suffered worse drought in history. Jusgle fires raged out of control and smoke produced pollution crisis. Ended 9 months later in 1998. Killed 2100 people and 33 billion in property damage.
Does El Nino bring floods or drought to Australia?
Nine of the ten driest winter-spring periods on record for eastern Australia occurred during this occurrence. The severe droughts of 1982, 1994, 2002 and 2006 all associated with this occurrence.
Pre La Nina occurrences
Preceded by buildup of cooler than normal subsurface waters in the tropical Pacific. Eastward moving atmospheric and oceanic waves help bring the cold water to the surface through a complex series of events still being studied.
Bermuda High steers the storms in Northeastern U.S. True or False
True
Upwelling replaces surface water from below True or False
True
El Nino
a name given to a change in the flow of water currents in the Pacific Ocean near the equator. El Nino means boy child in Spanish and it occurs around Christmas (refers to Jesus). Temps can rise to over 80 degrees
During ENSO: ENSO changes and alters weather patterns globally by ____________________
altering positions of jet streams
Monsoons
annual shift in the direction of the prevailing wind that brings on a rainy season and affects large parts of Asia and Africa
When does El Nino and La Nina peak
both of these occurrences peak during the Northern Hemisphere winter
El Nino: Polar jet stream occurs above convergence between polar ___ and ____
easterlies and westerlies
Effects of El Nino
kills marine life, upsets the food chain, moist war air slams into South American coast bringing heavy rains and storms yet countries at western of the Pacific (Australia, Indonesia and the Philippines have unusually dry weather that sometimes causes droughts and wildfire.
El niño alters ___,___,and____.
ocean temp,circulation,upwelling
El Nino is what kind of response
oceanic response
El Nino Changes in Flora & Fauna: Reduced _____ and _____
phytoplankton and kelp
Regular temps off South America's west coast
range from 60s to 70s
El Nino 1982-83
second of the most destructive El Ninos of the twentieth century. Caused Catasrophic weather patterns around the world. Devastating droughts hit Africa and Australia while torrential rains plagued Peru and Ecuador. In United States, record snow fell in Rocky mountains, floods in Florida and Gulf of Mexico. Intense storms and mudslides in Southern California. skilled 2,000 people and caused 13 billion property damage.
During ENSO: Trade winds are _____ from ____ atmospheric pressure gradient.
slow and reduced