Question 1 of 15
What does ENSO stand for?
Why: ENSO covers the whole cycle, including El Nino, La Nina, and neutral conditions.
Question 2 of 15
El Nino is defined by what condition?
Why: Sustained warming of the tropical Pacific sea surface is the defining signature of El Nino.
Question 3 of 15
What happens to the Pacific trade winds during El Nino?
Why: Weakened trades let warm water slosh eastward instead of piling up in the western Pacific.
Question 4 of 15
How does El Nino typically affect the Atlantic hurricane season?
Why: Stronger upper-level winds over the Atlantic tear apart developing tropical systems.
Question 5 of 15
How does La Nina typically affect Atlantic hurricane seasons?
Why: Reduced Atlantic wind shear during La Nina gives tropical systems a better chance to organise.
Question 6 of 15
Where did the name El Nino originate?
Why: El Nino means 'the boy', a reference to the Christ child, because the warming often peaked around Christmas.
Question 7 of 15
What does La Nina mean?
Why: La Nina, 'the girl', is the cool counterpart to El Nino.
Question 8 of 15
Roughly how often does the ENSO cycle swing between phases?
Why: The irregular cycle typically repeats every two to seven years with no fixed schedule.
Question 9 of 15
The Southern Oscillation Index compares surface pressure between which two places?
Why: The pressure seesaw between Tahiti and Darwin, Australia was the original clue that ENSO existed.
Question 10 of 15
During El Nino, the southern United States typically sees what?
Why: A southward-shifted subtropical jet steers more storms across the southern tier.
Question 11 of 15
During El Nino, the Pacific Northwest and Ohio Valley tend to be what?
Why: The storm track shifts south, leaving the northern tier relatively dry and mild.
Question 12 of 15
What is the Walker circulation?
Why: El Nino weakens the Walker circulation, which is why rainfall patterns shift so dramatically.
Question 13 of 15
Which years featured especially strong El Nino events?
Why: Both events were among the strongest on record and produced global weather and economic impacts.
Question 14 of 15
What is the neutral phase of ENSO?
Why: Neutral conditions are common and simply mean tropical Pacific temperatures are near their long-term average.
Question 15 of 15
Does ENSO affect only the Pacific region?
Why: ENSO teleconnections reach African rainfall, Australian drought, Indian monsoons, and North American winters.