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
   • A winter storm that comes each year
   • Warmer-than-normal surface water in the eastern tropical Pacific
   • 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 permanent current
   • A drop in sea level worldwide
   • 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?

   • Up to about 3 °C (6 °F), and usually less
   • About 30 °C
   • About 10 to 15 °C in each event across the Pacific
   • About 0.003 °C
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 stay the same
   • They grow stronger
   • They turn north
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 brings up warm water
   • It moves to the Arctic
   • It grows stronger

7. Read this first

   Use this

   A timeline with irregularly spaced warm and cool episodes.

8. 6.

   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
   • Every year, like the seasons
   • Once a century
   • Every month
9. 7.

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

   • About one week
   • One day
   • About 50 years
   • About 9 to 12 months
10. 8.

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

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

11. Use this

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

12. 9.

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

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

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

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