jason-1jason-2/ostmaquariusgracejason-3gravity-recovery-and-climate-experiment

Go With the Flow!

Play Go With the Flow to learn about ocean currents—and to find the hidden treasure!

In this game, you are in a submarine and you need to fix the currents to take you where you want to go. Where do you want to go? You want to get the key to the treasure chest full of gold!

Here are the two rules to remember:

  • Salt makes water heavier, so it sinks.

  • Heat makes water lighter, so it rises.

In your current management toolbox, you have these tools:

Game icon for salt. Blue background with sprinkling of salt crystals. Salt to make the current go down.
Icon for heat tool. Orange block. Heat to make the current go up.
Icon for current tool. Blue background with arrow pointing to right or left. A sideways current tool that you can use to send, or bend, the current to the right or left.
Icon for wall tool. Brown block with rocky texture. Walls that you can use to block currents.
Icon for submarine. With these tools, you can make your little submarine go anywhere to get the key to the treasure chest.
Icon for key to treasure chest. Key is hanging from a buoy under water. Keep your eye out for the key to unlock the treasure!
Treasure chest full of gold.

It's all yours! Just go with the flow!

How Currents Work in the Ocean

The rules of the game are how ocean currents work in real life, too. Salt makes water heavier, so it sinks. Heat makes water lighter, so it rises.

If you have tasted the ocean, you know it is very salty. Salty water is "thicker" or denser than fresh water. That is why it is easier to float in the ocean than in a fresh-water swimming pool or lake.

Does that mean that fresh river water would float on top of salty ocean water? It all depends on the temperature. Heat makes water lighter, or less dense. So, warm salt water might float on colder fresh water.

Drawing shows cross-section of saltwater layered below fresh water.

Image credit: NASA/JPL-Caltech

In the ocean, things get even more complicated. The ocean is salty, but some parts are saltier than others. For example, every summer, some of the sea ice in the Arctic Ocean (near the North Pole) melts. Then in winter, it freezes again. The salt doesn't freeze; only the water freezes.

The salt from the ice mixes into the water below, making it even saltier. When the salt-free ice melts the next summer, the melted fresh water tends to make the nearby upper ocean less salty. But the melt water is also colder, which makes it sink.

All this heating and cooling and melting and thawing creates big ocean currents. Cold water sinks near the North and South Poles. Cold water also flows toward the equator, getting warmer as it goes. As the cold water warms, it starts to rise to the top and sends the warmer surface water back toward the poles. The warm water flowing from the equator toward the poles helps warm the climate in North America and Europe.


Play this video to see the major ocean currents flow around the globe. Image credit: NASA/Goddard Space Flight Center Scientific Visualization Studio

This ocean motion is called the "great ocean conveyor belt." The movement of water on this conveyor belt makes Earth a nice place to live. Without it, the equator would be way too hot and the northern and southern parts of the planet might be frozen all the time.

What would happen if the ocean became too warm and the ice did not form?

As Earth gets warmer, less ice forms in the Arctic each winter and more ice melts in the summer. How are these changes in the ocean's surface temperature and saltiness—or salinity—affecting the ocean currents? How is the melting and heating affecting the average sea level?

NASA spacecraft are collecting information about ocean temperature and salinity all the time. The information they collect will help scientists find the answers to these questions—and more!

For example, the NASA mission SMAP—short for Soil Moisture Active Passive—has an instrument that measures the salinity on the surface of the sea. This information can help us better understand when and how the ocean currents are changing.

Artist’s conception of SMAP taking data from orbit.

An artist's illustration of the SMAP satellite collecting data while orbiting Earth. Image credit: NASA/JPL-Caltech

article last updated September 27, 2018
Lo sentimos, este artículo no está disponible en Español.
close
More Less
More Less