The Water Cycle: A Scientific Explanation

One of the most basic and powerful systems on the planet, the water cycle is the fundamental process that keeps plants and animals alive by constantly replenishing the water supply. But what exactly is the water cycle? This article will cover some of the basic notions and descriptions of the process.


The first stage of this cycle begins with the sun. The heat from the rays of the sun hits the oceans and warms the water at the surface to the point that it evaporates slowly. This process is essentially invisible to the naked eye, as water vapor disperses into the atmosphere. However, evaporation from the world’s oceans is not the only component to this step. In addition a process called evapotranspiration occurs. This is when the rays from the sun heat water that is present in the surface of the ground or collected in places like the leaves of plants. This also creates water vapor which rises unseen into the atmosphere.


Differences in heat and pressure between the surface of the planet and the upper atmosphere creates an uplift of air, a current that carries the evaporated water vapor high into the atmosphere. Here, as it cools, the vapor condenses to form clouds.


After the water vapor has risen and condensed, it is eventually gathered in such large quantities that the tiny water particles collect together and fall from the sky in the form of precipitation, which can be anything from rain to snow to hail. The process from condensation to precipitation is the fastest step in the cycle, and a molecule of water stays in the atmosphere for an average of only 9 days, as compared to the average of 3,200 years it takes to be recycled in the ocean.

Final Piece of the Puzzle

When the rain has fallen, one of two things happens. Either the rain has fallen directly into a body of water, where the heating process of the water cycle can begin once again, or a process known as infiltration occurs. Infiltration is a progression in which water enters the ground and flows naturally towards a body of water. Then, due to ground water discharge, the water is eventually brought back up to the surface, where it is eventually evaporated and begins the journey once again.

To conclude, the water cycle is a very precise process without which the life on the planet as we know it would not be possible.