What makes the sea water cold?

Sea water is not always cold. In fact, the temperature of sea water can vary greatly depending on the location and the time of year. For example, the water in the tropics is typically much warmer than the water in the polar regions. And, the water in the summer is typically much warmer than the water in the winter.

There are a number of factors that can affect the temperature of sea water, including:

* The amount of sunlight that the water receives. The sun is the primary source of heat for the Earth, and so the amount of sunlight that a body of water receives will have a big impact on its temperature. The more sunlight that the water receives, the warmer it will be.

* The depth of the water. The deeper the water, the colder it will be. This is because the sun's rays cannot penetrate as deeply into the water, and so the water at the bottom of the ocean is not heated as much as the water at the surface.

* The amount of salt in the water. Salt water is denser than fresh water, and so it takes more energy to heat salt water than it does to heat fresh water. This means that the more salt there is in the water, the colder it will be.

* The currents in the water. Currents can transport warm water from one place to another, and cold water from one place to another. This can have a big impact on the temperature of the water in a particular location.

All of these factors can work together to create a wide range of temperatures in sea water. The coldest sea water is found in the Arctic and Antarctic Oceans, where the water temperature can be as low as -2°C (28°F). The warmest sea water is found in the tropics, where the water temperature can be as high as 30°C (86°F).