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)?

   • 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
   • Cooler-than-normal surface water in the eastern tropical Pacific Ocean
3. 2.

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

   Use the picture in question 1.

   • Warmer-than-normal surface water in the eastern tropical Pacific Ocean
   • A drop in sea level worldwide
   • A permanent current
   • 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 10 to 15 °C in each event across the Pacific
   • About 30 °C
   • 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 turn north
   • They stay the same
   • They grow stronger
   • They weaken, and can even reverse

6. Read this first

   Use this

   A timeline with irregularly spaced warm and cool episodes.

7. 5.

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

   • Every month
   • Every 2 to 7 years on average, not on a set schedule
   • Once a century
   • Every year, like the seasons
8. 6.

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

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

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

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

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)?

    • Drier conditions than usual
    • Wetter conditions than usual
    • Much colder, drier air
    • No change
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)?

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