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

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

   Use the picture in question 1.

   • Cooler-than-normal surface water in the eastern tropical Pacific
   • A permanent current
   • A drop in sea level worldwide
   • Warmer-than-normal surface water in the eastern tropical Pacific Ocean
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
   • About 10 to 15 °C in each event across the Pacific
   • Up to about 3 °C (6 °F), and usually less
5. 4.

   Trade-wind arrows of different lengths across the Pacific. What happens to the trade winds during El Niño, by Luz's reading (NOAA)?

   • They weaken, and can even reverse
   • They turn north
   • They grow stronger
   • They stay the same
6. 5.

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

7. Read this first

   Use this

   A timeline with irregularly spaced warm and cool episodes.

8. 6.

   How long does an El Niño or La Niña episode typically last, by Pia's reading (NOAA)?

   • About 50 years
   • One day
   • About 9 to 12 months
   • About one week
9. 7.

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

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

10. Use this

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

11. 8.

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

    • Wetter conditions than usual
    • Drier conditions than usual
    • No change
    • Much colder, drier air
12. 9.

    During La Niña winters, what usually happens in the southern United States, by Zee's reading (NOAA)?

    • Wetter and cooler than normal
    • Drier and warmer than normal
    • No change
    • Steady snow
13. 10.

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

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