Surface ocean currents and the Coriolis effect

Grade 9 Science Worksheet

Circle the best answer.

1. 1.

   NOAA: trade winds near 30° N blow from the northeast toward the southwest. Why not straight toward the equator, by Bo's reading?

   • Mountains block it
   • The Coriolis effect turns it to the left
   • The Coriolis effect turns the air to the right
   • Ocean salt pushes the wind
2. 2.

   Wind pushing surface water offshore as cold water rises. NOAA: in downwelling, wind piles surface water against a coast. What does that water do, by Esme's reading?

   • It rises, bringing nutrients up
   • It freezes
   • It flows uphill onto land
   • It sinks toward the bottom
3. 3.

   Five gyres on a world map with their turning directions. Which way do Southern Hemisphere gyres turn, by Kira's reading (NOAA)?

   • Counterclockwise
   • They change direction each year
   • Clockwise
   • They do not turn
5. 4.

   NOAA: the Gulf Stream is paired with another current to flank the North Atlantic gyre. Which, by Luz's reading?

   • A gyre right on the equator
   • The Canary Current, a weak, broad eastern boundary current
   • A second strong western boundary current
   • A deep, cold, salt-driven current
6. 5.

   How does the Gulf Stream affect Florida's east coast, by Milo's reading (NOAA)?

   Use the picture in question 4.

   • Colder winters than nearby states
   • Warmer winters and cooler summers than nearby states
   • Hotter summers than nearby states
   • No effect on the coast
8. 6.

   NOAA: the Gulf Stream moves 1 to 3 knots, or 1.85 to 5.55 km/h. How far does it go in a day at 1.85 km/h, by Pia's math?

   • About 1.85 km
   • About 444 km
   • About 4.4 km
   • About 44 km
9. 7.

   At 5.55 km/h, about how many days would the Gulf Stream take to carry a drifter 1,000 km, by Ren's math?

   Use the picture in question 6.

   • About 0.75 days
   • About 180 days
   • About 5,550 days
   • About 7.5 days
11. 8.

    NOAA: in the Ekman spiral, each deeper layer moves more slowly and is deflected farther. Which way do the deeper layers turn in the Northern Hemisphere, by Tala's reading?

    • Farther to the right
    • Faster than the surface layer
    • Farther to the left
    • Straight down
12. 9.

    About how deep does the Ekman spiral reach, by Zee's reading (NOAA)?

    Use the picture in question 8.

    • Down to the sea floor
    • About 10 m
    • About 1,000 m
    • About 100 m
13. 10.

    Wind pushing surface water offshore as cold water rises. Wind blows surface water away from a coast (NOAA). What happens next, by Ari's reading?

    • Fresh river water fills the gap
    • Sea level rises at the coast
    • Cold, nutrient-rich water wells up from below
    • Warm water sinks, and the coast warms