El Niño and La Niña

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

2. 1.

   What is El Niño, by Ari's reading (NOAA)?

   • Cooler-than-normal surface water in the eastern tropical Pacific Ocean
   • Warmer-than-normal surface water in the eastern tropical Pacific
   • A winter storm that comes each year
   • Stronger upwelling of cold water off South America
3. 2.

   What is La Niña, by Bo's reading (NOAA)?

   Use the picture in question 1.

   • A drop in sea level worldwide
   • A permanent current
   • Warmer-than-normal surface water in the eastern tropical Pacific Ocean
   • Cooler-than-normal surface water in the eastern tropical Pacific
4. 3.

   A number line of anomalies above and below zero. NOAA: about how large are these sea-surface temperature changes, by Kira's reading?

   • About 0.003 °C
   • About 30 °C
   • Up to about 3 °C (6 °F), and usually less
   • About 10 to 15 °C in each event across the Pacific

5. Read this first

   Use this

   Trade-wind arrows of different lengths across the Pacific.

6. 4.

   Normally, which way do the tropical Pacific trade winds blow, by Jun's reading (NOAA)?

   • From north to south
   • From west to east, toward South America
   • They do not blow
   • From east to west, toward Asia
7. 5.

   What happens to the trade winds during El Niño, by Luz's reading (NOAA)?

   • They stay the same
   • They grow stronger
   • They weaken, and can even reverse
   • They turn north
8. 6.

   Cold water rising off South America, with arrows of different sizes. What happens to upwelling off South America during El Niño, by Milo's reading (NOAA)?

   • It grows stronger
   • It weakens or stops
   • It brings up warm water
   • It moves to the Arctic

9. Use this

   A timeline with irregularly spaced warm and cool episodes.

10. 7.

    How often do El Niño and La Niña events occur, by Noah's reading (NOAA)?

    • Every 2 to 7 years on average, not on a set schedule
    • Once a century
    • Every year, like the seasons
    • Every month
11. 8.

    Which happens more often, by Ren's reading (NOAA)?

    • Neither has ever occurred
    • El Niño
    • La Niña
    • They alternate exactly, year by year

12. Use this

    Map of the U.S. with the jet stream dipping south or north.

13. 9.

    During an El Niño winter, what usually happens in the southern United States, by Tala's reading (NOAA)?

    • Much colder, drier air
    • No change
    • Wetter conditions than usual
    • Drier conditions than usual
14. 10.

    Where does El Niño push the Pacific jet stream, by Esme's reading (NOAA)?

    • Up into space
    • North of its usual position
    • South of its usual position
    • It stops the jet stream