Model experiment of ocean currents

 In this small experiment we want to show how cold dense water sinks below hot and less dense water

we use:

A large tank 

Hot water

cold saline water with fruit dye

as we see, the cold saline water sinke below the hot fresh water,

This can be used as a model for down welling or to explain how differences in density cause deep ocean currents

A few fast points for revision:

1. Density depends on temperature and salinity

   • Cold water is denser than warm water.

   • Salty water is denser than fresher water.

2. Dense water sinks

   • In polar regions, water cools and becomes saltier (because ice formation leaves salt behind).

   • This dense water sinks deep into the ocean.

3. Lighter water rises

   • Warmer, less salty water stays near the surface and replaces sinking water.

4. This creates movement

   • The sinking and rising of water sets up a global "conveyor belt" of circulation (called the thermohaline circulation).