The Earth's atmosphere


Earth - our home - is a unique planet in the solar system because it is the only planet in the solar family that supports life. In this project you will come to know about the atmosphere of the Earth which is one of the important spheres of the Earth that helps in supporting life on this planet.

Introduction


Daily we all take in or inhale Earth's atmosphere through an important life process called the respiration. We take in or inhale air and also we leave out or exhale air through respiration. And because of this important process called respiration all the living things on the Earth are able to survive or live a life. We cannot see, smell or taste the Earth's atmosphere which is a mixture of various gases that are present in different proportions. In true sense, atmosphere is an envelop or a blanket of gases round a planet. Other planets too have atmosphere around them, but they lack the important life-giving gas which is known as the oxygen.

About Earth's atmosphere


Earth's atmosphere is made up of a mixture of gases which is generally called the air. Nearly 78 % of the air is occupied by Nitrogen gas and about 21 % of the air is occupied by Oxygen which is the most important gas and supports life on Earth. There are very small percentage of other gases like Carbon dioxide, Argon, Carbon monoxide, Oxides of Nitrogen, Krypton and Methane including water vapour in the air. All these together make the atmosphere of the Earth. The atmosphere is held in its place due to the pulling force of the Earth called the gravity. We cannot see the air around us but we can feel it when it moves from one place to the other. And such a moving air is called wind.

Air has weight and it occupies the entire volume in an given area. The air in the atmosphere exerts pressure which is called the atmospheric pressure. This atmospheric pressure depends on how much air is present in the atmosphere and it the highest near the Earth's surface. As you go to higher altitudes, there density of air becomes lesser and lesser and hence the atmospheric pressure goes on decreasing as you go higher and higher.

There is a variation in the temperature of the air as well which is close to the Earth and this difference in temperature causes low and high pressure areas on the Earth. The air close to the Earth's surface becomes warmer due to the radiation of heat from the Earth's surface and thus it becomes lighter in weight. This light moves upward and thus causes low pressure areas. While in higher altitudes where it is very cold, the air becomes heavier and thus sinks or comes downward and this causes high-pressure areas.

Atmosphere and the weather


The air in the atmosphere always moves and such a moving air is called wind. The hot or warm air being lighter in weight rises up and the cold air rushes in to take its place. The wind blows in the areas where the high and low pressures meet.

Layers of the atmosphere


The Earth's atmosphere extends up to a height of 6,000 miles (9,600 Kilometers) above the Earth's surface. There are different layers of the atmosphere.

Troposphere: This layer is above the surface of the Earth and we see the clouds floating in the air is in the layer.

Stratosphere: This layer is above the Troposphere and the Jet planes fly in this layer of the atmosphere. The Earth's Ozone layer is in the Stratosphere. The Ozone layer absorbs the harmful ultra violet rays that come from the Sun and thus protect the Earth from the harmful rays.

Other spheres: The atmosphere gets thinner and thinner as we go higher up. Next to Stratosphere is the Mesosphere and then the Thermosphere. The top most layer of the Earth's atmosphere is the Exosphere where the atmosphere ends and the thin air in this layer gradually merges or mixes with the outer space.


Comments

Author: Kishan Kumar Thakur07 Oct 2013 Member Level: Silver   Points : 10

I.am kishan kumar thakur . From Harari Dularpur Sursand Science: Ozone Basics
Ozone is very rare in our atmosphere, averaging about three molecules of ozone for every 10 million air molecules. In spite of this small amount, ozone plays a vital role in the atmosphere. In the information below, we present "the basics" about this important component of the Earth's atmosphere.
Click here for larger image
Where is ozone found in the atmosphere?
Ozone is mainly found in two regions of the Earth's atmosphere. Most ozone (about 90%) resides in a layer that begins between 6 and 10 miles (10 and 17 kilometers) above the Earth's surface and extends up to about 30 miles (50 kilometers). This region of the atmosphere is called the stratosphere. The ozone in this region is commonly known as the ozone layer. The remaining ozone is in the lower region of the atmosphere, which is commonly called the troposphere. The figure (above) shows an example of how ozone is distributed in the atmosphere.
What roles does ozone play in the atmosphere and how are humans affected?
The ozone molecules in the upper atmosphere (stratosphere) and the lower atmosphere (troposphere) are chemically identical, because they all consist of three oxygen atoms and have the chemical formula O3. However, they have very different roles in the atmosphere and very different effects on humans and other living beings. Stratospheric ozone (sometimes referred to as "good ozone") plays a beneficial role by absorbing most of the biologically damaging ultraviolet sunlight (called UV-B), allowing only a small amount to reach the Earth's surface. The absorption of ultraviolet radiation by ozone creates a source of heat, which actually forms the stratosphere itself (a region in which the temperature rises as one goes to higher altitudes). Ozone thus plays a key role in the temperature structure of the Earth's atmosphere. Without the filtering action of the ozone layer, more of the Sun's UV-B radiation would penetrate the atmosphere and would reach the Earth's surface. Many experimental studies of plants and animals and clinical studies of humans have shown the harmful effects of excessive exposure to UV-B radiation.
At the Earth's surface, ozone comes into direct contact with life-forms and displays its destructive side (hence, it is often called "bad ozone"). Because ozone reacts strongly with other molecules, high levels of ozone are toxic to living systems. Several studies have documented the harmful effects of ozone on crop production, forest growth, and human health. The substantial negative effects of surface-level tropospheric ozone from this direct toxicity contrast with the benefits of the additional filtering of UV-B radiation that it provides.

Author: Adesola Adeyeye17 Oct 2013 Member Level: Gold   Points : 2

This is a very concise and precise information about the earth. The today students are really finding studying easy of the advent of the internet. Every subject can be viewed online and properly understood with proper illustrations.

Author: Kishan Kumar Thakur25 Oct 2013 Member Level: Silver   Points : 10

Hai. I'm kishan kumar thakur from sweet village Harari Dularpur Sursand write about own earth
Earth, our home planet, is the only planet in our solar system known to harbor life. All of the things we need to survive are provided under a thin layer of atmosphere that separates us from the uninhabitable void of space. Earth is made up of complex, interactive systems that are often unpredictable. Air, water, land, and life—including humans—combine forces to create a constantly changing world that we are striving to understand.
Viewing Earth from the unique perspective of space provides the opportunity to see Earth as a whole. Scientists around the world have discovered many things about our planet by working together and sharing their findings.
Some facts are well known. For instance, Earth is the third planet from the sun and the fifth largest in the solar system. Earth's diameter is just a few hundred kilometers larger than that of Venus. The four seasons are a result of Earth's axis of rotation being tilted more than 23 degrees.
Oceans at least 2.5 miles (4 kilometers) deep cover nearly 70 percent of Earth's surface. Fresh water exists in the liquid phase only within a narrow temperature span (32 to 212 degrees Fahrenheit/ 0 to 100 degrees Celsius). This temperature span is especially narrow when contrasted with the full range of temperatures found within the solar system. The presence and distribution ofwater vaporin the atmosphere is responsible for much of Earth's weather.
Protective Atmosphere
Near the surface, an ocean of air that consists of 78 percent nitrogen, 21 percent oxygen, and 1 percent other ingredients envelops us. Thisatmosphereaffects Earth's long-term climate and short-term local weather; shields us from nearly all harmful radiation coming from the sun; and protects us from meteors as well. Satellites have revealed that the upper atmosphere actually swells by day and contracts by night due to solar activity.
Our planet's rapid spin and molten nickel-iron core give rise to amagnetic field, which the solar wind distorts into a teardrop shape. The solar wind is a stream of charged particles continuously ejected from the sun



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