Water Cycle Steps: Earth’s Natural System of Viability
Look at the world around you. Everything on Earth has a natural cycle. Plants have photosynthesis, the soil has the nitrogen cycle, animals have the food chain, even cells have a cycle involving mitosis. Life itself has a natural cycle. These cycles are what keeps the world balanced and working properly. What happens when one of these cycles is interrupted or has a new factor thrown into the mix? Bad things. Ecosystems start to fail, animals get sick and often die, and normal life changes just a little bit. Same goes for a very crucial cycle of the Earth. The water cycle. So what are the water cycle steps, why are they so important and how are they being affected by climate change?
Water Cycle Steps
The water cycle is one of the most important cycles on Earth, but what is it? Basically, the water cycle describes the continuous movement of the water on, above, and below the surface of the Earth. The water cycle steps are important because without them, the water would stay stationary and the Earth would not be able to thrive as it is now. The water cycle steps make it so the atmosphere can bring water from bodies of water like oceans and lakes, and deliver it in the form of rain to anywhere on Earth. Well, except deserts but that is beside the point.
The super simple version of the water cycle steps are water moves from one reservoir to another, like a river to an ocean, from ocean to atmosphere, and from the atmosphere back to Earth. Wash, rinse, repeat. During this cycle, the water also goes through certain states, depending on the nature of the water itself. These water cycle steps ensure that the mass of water on Earth remains fairly constant. But there is one slight problem. While the total amount of water remains the same, the type of water does not.
However, this cycle is subject to change due to a not so little thing called climate change. Yup, the big bad of this movie we call life is back. Fresh water basins are becoming increasingly rare and the sea level is also rising at a slow but constant rate. Because of these factors and others, storms are becoming stronger, we are seeing more droughts and floods which leads to erosion and a lot more.
Steps of the Water Cycle
The water cycle shows how water is exchanged through the Earth’s land, ocean, and atmosphere. Because of this cycle, water always exists in all three of those places, as well in many forms. This cycle consists of three major steps, along with a few additional steps. The three major water cycle steps are evaporation, condensation, and precipitation. However, we are going to go through every step of the water cycle, just so we do not miss anything.
The first water cycle step starts with the atmosphere pulling water out of the big bodies of water. During this process, surface water turns into water vapor. This is done by the transfer of heat energy. Water absorbs this heat energy and turns into its gaseous state. The one your Uncle is always in. The atmosphere gets this water from large bodies of water like oceans, seas, lakes, and rivers.
Water vapor is always surrounding us and is actually part of the air we breathe. It is also a very important greenhouse gas. Yup, those evil greenhouse gases that are actually not inherently evil. Greenhouse gases such as water vapor and carbon dioxide insulate the Earth and keep the planet warm enough to maintain the life we know and love. The problems arises when the atmosphere collects too much concentrations of greenhouse gases. Our saving grace turns into our downfall. Natural levels of greenhouse gases maintain the heat needed for life to thrive. Excess levels of the gases cause the Earth to heat more than it needs and that causes problems.
The evaporation process of the water cycle steps is made so by the sun. As the sun heats the water on the surface of the ocean, the water turns into vapor. However, evaporation is also influenced by wind, temperature and the density of the specific body of water. Quick fact, 86% of global evaporation happens over the ocean.
Next up in the water cycle steps is condensation. This happens when the water vapor rises into the atmosphere and is changed into water droplets. This happens due to the temperature change from low to high altitudes. When gas is chilled, it turns back into a solid state. This is what happens here. These water particles that form in the atmosphere then come together to form clouds.
Condensation can actually happen at any altitude. Clouds form as water vapor “condenses”, or becomes concentrated. This happens by the water vapor coming together as a liquid around particles called cloud condensation nuclei (CCN). CCN can take many forms including dust, salt, or even pollutants. When clouds form at a lower elevation like ground level, it is called fog or mist. Fog is not a form of precipitation because no water is being released.
Like the first of the water cycle steps, condensation is also affected by the sun. As the vapor cools, it reaches its saturation point, often called dew point. In addition, air pressure also plays an important part on the dew point of an area. You are probably most familiar with dew points from waking up in the morning to find your grass full of dew.
Here is one of the additional and smaller steps I mentioned before. While not a major part of the water cycle steps, sublimation still contributed to the water vapor in the air. This happens when ice directly converts into water vapor without first converting into a liquid. This process accelerates when the temperature is low or pressure is high. The main sources of sublimation are the ice sheets of the North and South Pole, as well as the ice caps on mountains. It is a rather slower process than standard evaporation, but still has a part to play.
The last of the major parts in the water cycle steps is precipitation. Everyone knows about this one. It’s rain! However, precipitation technically is not a process at all. It is the result of evaporation and condensation. Precipitation describes any liquid or solid water that falls to Earth as a result of those two processes. It includes rain, hail, snow, sleet and a bunch more. Precipitation is one of many ways that water is cycled from the atmosphere to the Earth or Ocean.
Basically, this happens because the cloud gets too heavy and the atmosphere can not hold anymore water. The water droplets combine with other droplets to make bigger ones. How the water falls depends on altitude, temperature, and wind. At high altitudes, the temperature is low and the droplets will lose their heat energy. Thus they fall down as rain. If the temperature is very low, like below 0 degrees celsius, the droplets fall as snow.
Contrary to popular belief, fog or mist is not a form of precipitation. I know I mentioned this before but I felt like it needs to be said again. During fog, nothing actually falls to Earth. Fog and mist are actually part of the water cycle called suspensions. Liquid suspended in the atmosphere at a low altitude. Quick fact, 78% of global precipitation happens over the ocean.
This is sort of like respiration but involves a few more steps. Oh, and it happens in plant life. When precipitation happens, the soil absorbs some of the water. While in the soil, the roots of plants will take in the water and push it towards the leaves where it is used for photosynthesis. Any excess water, the plant releases through stomata which are very tiny openings on the leaves. Kind of like pores on your skin.
This happens as a result of precipitation, so it is again, technically not a process. As water pours down, it leads to runoff. This is the action of water running over the surface of the Earth. Another way this happens is during snowmelt. As water runs over the ground, it can displace the topsoil with it and move minerals along lakes, seas and oceans.
This last process happens when water does none of the things stated above after precipitation. Sometimes, some of the water will move deep into the soil. Avoid the plants, avoid evaporation, avoid runoff, everything. The water instead seeps down and increased the level of the groundwater table. It is called pure water and is 100% fresh and drinkable. The infiltration is measured sa inches of water-soaked by the soil per hour.
States of Water
As mentioned before, there are various states that water can continuously circulate through. They are solid, liquid, and vapor. Solid forms of water are ice which also include hail and sleet from precipitation, as well as massive solid water forms like glaciers, ice sheets, and ice caps. In fact, most of Earth’s freshwater is ice in the Poles.
Liquid is an obvious state and one that basically everyone is familiar with. Rain, oceans, lakes, rivers, streams, etc. Liquid water can also be created during snowmelt and the melting of ice like glaciers and ice sheets.
Lastly is vapor. Water vapor is actually not distributed evenly across the atmosphere and is much more concentrated in certain areas. The ocean is one of these areas. In fact, water vapor above the ocean makes up 4% of the air. Above isolated deserts, it can make up less than 1%.
Water Cycle Effects
The water cycle steps have actually affected the Earth many times and still do. The biggest way that the water cycle is affecting the Earth is through the weather. Almost all weather involves some sort of precipitation. Storms involve rain or snow, heat can involve humidity or lack thereof. Humidity is the amount of water vapor in the air. Since water vapor is not evenly distributed, certain areas will be more humid than others. Temperature is regulated by the water cycle itself. Through the water cycle, heat is exchanged and temperatures fluctuate. As water evaporates, it absorbs energy and cools the local environment. When it condenses, it releases energy, heating up the local area.
In addition, the water cycle steps have also has an effect on the geography of Earth. This mainly through the melting of glaciers and erosion. When glaciers melt, they reveal or add a whole new area and increase the amount of water in a given area. Glaciers can also carve away entire valleys as they move, create mountain peaks, leave behind incredible amounts of rubble. During erosion, the creation of canyons can happen. This is because of the amount of water that is running along the surface, which can pull with it a lot of the Earth.
Climate Change and the Water Cycle Steps
Climate change has been affecting pretty much everything on Earth, and the water cycle is one of that everything. The increase of the global temperature is causing a lot of things to happen. Mainly, it is leading to a lot more evaporation of water from the land and sea into the atmosphere. This can lead to a whole number of issues. Including: drought, intense storms, increase risk of flooding, and stronger heat waves. In addition, due to the rising temperatures, glaciers are melting at an accelerated rate. This is causing the sea level to rise, increasing the risk of flooding.
Basically if temperatures continue to rise, this will happen. Precipitation patterns will change more, meaning more (or less) rainfall over some regions, which will result in increased flooding and also drought (again in some regions); hurricanes will become more frequent and stronger all around, looking at the fact that there have been increasing since the early 1980s; sea levels will continue to rise resulting in increased flooding, stronger storm surges, and loss of land due to both erosion and waters coming further inland; Arctic is likely to become ice-free before the mid-century.