El Niño and La Niña

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

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

   • A drop in sea level worldwide
   • Cooler-than-normal surface water in the eastern tropical Pacific
   • A permanent current
   • Warmer-than-normal surface water in the eastern tropical Pacific Ocean
2. 2.

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

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

   Trade-wind arrows of different lengths across the Pacific. 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
4. 4.

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

5. Read this first

   Use this

   A timeline with irregularly spaced warm and cool episodes.

6. 5.

   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
7. 6.

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

   • About 9 to 12 months
   • About 50 years
   • About one week
   • One day
8. 7.

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

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

9. Use this

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

10. 8.

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

    • Much colder, drier air
    • Wetter conditions than usual
    • Drier conditions than usual
    • No change
11. 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
12. 10.

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

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