Polar Oceans and World Climate

Question 1

On a bright summer day, two identical research huts are set up side by by: one sits on a thick sheet of sea ice and the other sits on open ocean water. Which statement best explains why the hut on the ice stays cooler than the hut on the water?

Accepted Answer

The bright ice surface bounces most of the Sun’s rays away, so little solar energy reaches the hut, keeping it cooler.

Answer

The ice is very cold, so it pulls heat from the air and makes the hut on it warmer.

Answer

Dark water soaks up the Sun’s rays and turns them into heat, so the hut above it gets hotter.

Answer

Both huts get the same amount of sunlight, so their temperatures are the same.

Question 2

Scientists in the Southern Ocean find that the water just below the surface (about 150 m deep) is colder (‑1.8 °C) and slightly saltier (35.2 ppt) than the water at the very top (0 °C, 34 ppt). Which statement best explains how this cold, salty water helps move water around the whole planet?

Accepted Answer

Being both colder and saltier makes the water denser, so it sinks, pulling water from other regions down with it and starting a deep‑water current that joins the global conveyor belt.

Answer

Because it is colder, the water stays on the surface and the wind pushes it around the world.

Answer

The cold water is lighter than warm water, so it rises and pulls surface water with it toward the equator.

Answer

The sunlight that reaches this depth heats the water, causing it to expand and flow outward across the ocean.

Question 3

Which of the following best describes how water from the far‑north ocean helps start a worldwide movement of ocean water?

Accepted Answer

Very cold, salty water becomes heavy, sinks down, and pulls other water with it, beginning a global flow of water through the deep ocean.

Answer

Cold water stays at the surface and spreads outward, while warm water sinks, creating the global water movement.

Answer

Strong winds push surface water toward the poles where it freezes and then melts, forming a worldwide loop.

Answer

Sunlight warms polar water, causing it to rise and push other water down, driving the global circulation.

Try three questions

On a bright summer day, two identical research huts are set up side by by: one sits on a thick sheet of sea ice and the other sits on open ocean water. Which statement best explains why the hut on the ice stays cooler than the hut on the water?

Scientists in the Southern Ocean find that the water just below the surface (about 150 m deep) is colder (‑1.8 °C) and slightly saltier (35.2 ppt) than the water at the very top (0 °C, 34 ppt). Which statement best explains how this cold, salty water helps move water around the whole planet?

Which of the following best describes how water from the far‑north ocean helps start a worldwide movement of ocean water?

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