Water cycle

Water Cycle

Dominican American Cultural Institute

The Water Cycle

Name:Dansel Urbaez Mendez

Code:2008-01-1-2107

Teacher:Sean Legere

Date:February 15, 2011

Index

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Water Cycle

Page Cover Page 1

Introduction 3

Water Cycle 4Water 5 States of Water 6 Changes in State 7The Cycle 8Concepts of Water Cycle 10

Evaporation 10Condensation 11Precipitation 11Surface Runoff  12Infiltration 12Transpiration 13

Cloud Formation14Cumulonimbus 15Nimbostartus 15Cirrocumulus 16Altostratus 16

Conclusion18

Reference Page19

Introduction

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Water Cycle

Nowadays few people know what the water cycle is, it process has a principal objective wich is to keep the planet with enough water in everywhere.

I choose this topyc becouse is one of the processes that our planet has and without it can’t work. In the following pages I expect you to learn and understand how the water cycle process works.

In this project I intend to show the differents parts of the water cycle and every one knows the importance of it.

Also I will explain how important are the clouds and how it works together with the process of water cycle.

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Water Cycle

Water Cycle.

The water cycle, also known as the hydrologic cycle or H2O cycle, describes the continuous movement of water on, above and below the surface of the Earth. Water can change states among liquid, vapour, and ice at various places in the water cycle. Although the balance of water on Earth remains fairly constant over time, individual water molecules can come and go, in and out of the atmosphere. The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, condensation, precipitation, infiltration, runoff, and transpiration. In so doing, the water goes through different phases: liquid, solid, and gas.

The water cycle also involves the exchange of heat energy, which leads to temperature changes. For instance, in the process of evaporation, water takes up energy from the surroundings and cools the environment. Conversely, in the process of condensation, water releases energy to its surroundings, warming the environment.

The water cycle figures significantly in the maintenance of life and ecosystems on Earth. Even as water in each reservoir plays an important role, the water cycle brings added significance to the presence of water on our planet. By transferring water from one reservoir to another, the water cycle purifies water, replenishes the land with freshwater, and transports minerals to different parts of the globe. It is also involved in reshaping the geological features of the Earth, through such processes as erosion and sedimentation. In addition, as the water cycle involves heat exchange, it exerts an influence on climate as well.

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Water Cycle

Water

Water is an integral part of life on this planet. It is an odorless, tasteless, substance that covers more than three-fourths of the Earth's surface. Most of the water on Earth, 97% to be exact, is salt water found in the oceans. We can not drink salt water or use it for crops because of the salt content. We can remove salt from ocean water, but the process is very expensive.

 Only about 3% of Earth's water is fresh. Two percent of the Earth's water (about 66% of all fresh water) is in solid form, found in ice caps and glaciers. Because it is frozen and so far away, the fresh water in ice caps is not available for use by people or plants. That leaves about 1% of all the Earth's water in a form useable to humans and land animals. This fresh water is found in lakes, rivers, streams, ponds, and in the ground. (A small amount of water is found as vapor in the atmosphere.) 

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Water Cycle

States of Water

Water exists in three states- solid, liquid, and gaseous.

Liquid Water

Liquid water is found in many places. You see liquid water coming out of the faucet, when it rains, and running in a river. Pure liquid water is free of salt, rocks, soil, and garbage.

Solid Water

Ice, snow, and frost are examples of water in the solid state. Liquid water freezes at 0 degrees Celsius. Celsius is scale that measures temperature. Winter is a season that you see a lot of solid water. Other examples of solid water are ice cubes, icicles, ice on a skating rink.

Water as a Gas

Gas is invisible. Water in the liquid state may change to water in the gaseous state. Waterevaporates to turn into a gas. Gases are colorless and odorless. You cannot see gas ,but sometimes you can hear it and smell it.

Water can evaporate or disappear with the help of heat. Changes in temperature can increase the rate or how long it takes water to evaporate. Evaporate means to disappear. It evaporates off wet clothes hanging on a clothesline. Plants release water vapor into the air. We breathe out water vapor.

Changes in State

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Water Cycle

Gas to Liquid

When a gas changes to a liquid, it goes through the process of condensation. This is when the gas cools and loses energy. Then the particles are forced to change state, from a gas to a liquid.

Liquid to Solid

When a liquid changes to a solid, it goes through the process of Freezing. This is when a liquid cools below the freezing point and loses energy. Then the particles are forced to change state, from a liquid to a solid.

Solid to Gas

When a solid changes directly to a gas, it goes through the process of sublimation. The particles are forced to change state.

Liquid to Gas

The process in which a liquid changes into a gas is called Evaporation. When a liquid gains enough energy, it can overcome all of the attracting forces. Then it changes state, from a liquid to a gas.

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Water Cycle

The Cycle

Water is constantly being cycled between the atmosphere, the ocean and land. This cycling is a very important process that helps sustain life on Earth. 

As the water evaporates, vapors rise and condense into clouds. The clouds move over the land, and precipitation falls in the form of rain, ice or snow. The water fills streams and rivers, and eventually flows back into the oceans where evaporation starts the process anew.     

Water's state (solid, liquid or gas) is determined mostly by temperature. Although water continuously changes states from solid to liquid to gas, the amount of water on

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Earth remains constant. There is as much water now as there was hundreds of millions of years ago. 

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Water Cycle

Concepts of Water Cycle.

There are six important processes that make up the water cycle. These are: 

Evaporation

Evaporation is the process where a liquid, in this case water, changes from its liquid state to a gaseous state. Liquid water becomes water vapor. Although lower air pressure helps promote evaporation, temperature is the primary factor. For example, all of the water in a pot left on a table will eventually evaporate. It may take several weeks. But, if that same pot of water is put on a stove and brought to a boiling temperature, the water will evaporate more quickly. 

During the water cycle some of the water in the oceans and freshwater bodies, such as lakes and rivers, is warmed by the sun and evaporates. During the process of evaporation, impurities in the water are left behind. As a result, the water that goes into the atmosphere is cleaner than it was on Earth.     

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Water Cycle

Condensation

Condensation is the opposite of evaporation. Condensation occurs when a gas is changed into a liquid. Condensation occurs when the temperature of the vapor decreases. 

When the water droplets formed from condensation are very small, they remain suspended in the atmosphere. These millions of droplets of suspended water form clouds in the sky or fog at ground level. Water condenses into droplets only when there are small dust particles present around which the droplet can form.    

Precipitation

When the temperature and atmospheric pressure are right, the small droplets of water in clouds form larger droplets and precipitation occurs. The raindrops fall to Earth. 

As a result of evaporation, condensation and precipitation, water travels from the surface of the Earth goes into the atmosphere, and returns to Earth again.     

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Water Cycle

Surface Runoff 

Much of the water that returns to Earth as precipitation runs off the surface of the land, and flows down hill into streams, rivers, ponds and lakes. Small streams flow into larger streams, then into rivers, and eventually the water flows into the ocean. 

Surface runoff is an important part of the water cycle because, through surface runoff, much of the water returns again to the oceans, where a great deal of evaporation occurs.     

Infiltration 

Infiltration is an important process where rain water soaks into the ground, through the soil and underlying rock layers. Some of this water ultimately returns to the surface at springs or in low spots downhill. Some of the water remains underground and is called groundwater. 

As the water infiltrates through the soil and rock layers, many of the impurities in the water are filtered out. This filtering process helps clean the water.    

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Water Cycle

Transpiration

One final process is important in the water cycle. As plants absorb water from the soil, the water moves from the roots through the stems to the leaves. Once the water reaches the leaves, some of it evaporates from the leaves, adding to the amount of water vapor in the air. This process of evaporation through plant leaves is called transpiration. In large forests, an enormous amount of water will transpire through leaves.  

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Water Cycle

Cloud Formation

Precipitation is one key to the water cycle. Rain comes from clouds, but where do clouds come from? 

Through the process of evaporation and transpiration, water moves into the atmosphere. Water vapors then join with dust particles to create clouds. Eventually, water returns to Earth as precipitation in the form of rain, snow, sleet, and hail. 

All clouds contain water vapors. You rarely ever see clouds in the desert because there is very little water to evaporate and form clouds. Coastal regions can receive a lot of rain because they pull up moisture from surrounding waters. 

Cloud size are influenced by many complex factors, some of which we still do not understand very well. These include: heat, seasons, mountain ranges, bodies of water, volcanic eruptions, and even global warming. 

Differents kinds of clouds are:

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Water Cycle

Cumulonimbus

Cumulonimbus (Cb) is a type of cloud that is tall, dense, and involved in thunderstorms and other intense weather. Cumulonimbus originates from Latin: Cumulus "accumulated" and nimbus "rain". It is a result of atmospheric instability. These clouds can form alone, in clusters, or along a cold front in a squall line. They create lightning through the heart of the cloud. Cumulonimbus clouds form from cumulus clouds (namely from cumulus congestus) and can further develop into a supercell, a severe thunderstorm with special features.

Nimbostartus 

A Nimbostratus cloud is characterized by a formless cloud layer that is almost uniformly dark gray. "Nimbo" is from the Latin word "nimbus", meaning rain. It is a low to middle-level (family C2) stratiform cloud that produces rain, developing cloud basesbetween the surface and 10000 ft (3000 m). This cloud typically forms from altostratus in the middle altitude range then subsides into the low altitude range during precipitation. Nimbostratus usually has a thickness of 2000 meters. In rare cases, Nimbostratus can be very thin and accompanied by a separate layer of altostratus divided by a cloudless layer. Though found worldwide, nimbostratus is found more commonly in the middle latitudes.

Cirrocumulus 

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Water Cycle

Cirrocumulus clouds are high-altitude clouds that usually occur at an altitude of 5 km to 12 km. Like other cumulus clouds, cirrocumulus clouds signify convection. Unlike other cirrus clouds, cirrocumulus include a small amount of liquid water droplets, although these are in a supercooled state. Ice crystals are the predominant component, and typically, the ice crystals cause the supercooled water drops in the cloud to rapidly freeze, transforming the cirrocumulus into cirrostratus. This process can also produce precipitation in the form of a virga consisting of ice or snow. Thus cirrocumulus clouds are usually short-lived.

Properly, the term cirrocumulus refers to each cloud, but is typically also used to refer to an entire patch of cirrocumulus. When used in this way, each cirrocumulus element is referred to as a "cloudlet".

Altostratus 

Altostratus is a cloud belonging to a class characterized by a generally uniform gray sheet or layer, lighter in color thannimbostratus and darker than cirrostratus. The sun can be seen through thin altostratus, but thicker layers can be quite opaque. They can look similar to lower altitude stratus clouds.

Altostratus is caused by a large air mass that is lifted then condensed, usually by an incoming frontal system and can be found over widespread areas. Altostratus clouds are potentially dangerous, because they can cause ice accretion on aircraft. Their altitude is

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Water Cycle

from 6,500–20,000 feet (2,400–6,100 m). They are primarily composed of water droplets.

Altostratus clouds can produce light precipitation, often in the form of virga. If the precipitation increases in persistence and/or intensity, the altostratus cloud may thicken into Nimbostratus.

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Water Cycle

Conclusion

Once we studied the proces of water cycle we know that it is indispensable for the worlds’ function since is the only way to bring water to plants and animals, from this point of view were not life in the planet if it doesn’t work well.

In this project we learned that only one percent of the worlds’ water is available for human use, it means that we need to be careful of the water.

After we know how important the water cycle is we should be part of the people who try to maintain the world clean to keep the live worlwide.

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Water Cycle

Reference page

http://en.wikipedia.org

http://www.mbgnet.net/fresh/cycle/index.htm

http://www.radford.edu/~sbisset/wqh2o.htm

http://ga.water.usgs.gov/edu/watercycle.html

http://www.nyu.edu/pages/mathmol/textbook/slg.html

http://www.elytradesign.com/ali/html/changes.htm

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