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Air1 is a contemporary hit radio (CHR) radio network in the United States, playing Contemporary Christian music, especially the Top 40 hits. It is operated by the non-profit Educational Media Foundation.

History[link]

In 1986, KLRD began broadcasting Christian music from Yucaipa, California, and went by the on-air moniker K-LORD. In 1994, KXRD was started as a sister station to KLRD.^[1] In 1995, K-LORD changed their name to "Air 1" and began broadcasting via satellite from St. Helens, Oregon. In 1999, Air 1 joined with EMF Broadcasting, and finally in 2002, it moved its headquarters to Rocklin, California. Air 1 makes use of broadcast translators to spread the signal across much of the country. As of November 2011, the network lists 90 full powered radio stations and 125 translators of various power levels reaching 40 states.

Staff[link]

Current staff[link]

Air1’s on-air staff each have their own dedicated time slot. Here is the schedule for weekdays:

Times listed in this table are in the Eastern Time Zone.

The network's program director is Paul Goldsmith.

Nikki used to have Ashton's time slot during weekdays. However, she is now the producer for Brant Hansen's show, during which she can sometimes be heard on air as a cameo. She is also on air during weekend evenings. For this reason, she is nicknamed "Nikki at night".^[5]

Former staff[link]

• Sean - formerly was part of the "Sean and Mandy" show, which was discontinued on September 29, 2011. There is a recording of the last Sean and Mandy show available for download.^[6] Mandy temporarily hosted a solo morning show before finally working with Eric.
• Coppelia - formerly occupied the time slot which now belongs to Lori. She left Air 1 at roughly the same time that Sean did. Her Facebook page has been removed, but she continues to maintain a personal Twitter account. Sean and Mandy said that "Coppelia took a job with another ministry in Houston - […] we miss her :( we wish her well! :)"^[2]

Board & Financial Information[link]

It has been suggested that this article or section be merged into Educational Media Foundation. (Discuss) Proposed since November 2011.

Air1 is governed by the Educational Media Foundation, a 501(c)3 not-for-profit ministry. No individual owns any stock in the corporation, which is held for charitable purposes. The Board of Directors at large serve without compensation for rotating four-year terms, and a person with supervisory accounting experience holds one of the board positions.[18]

In addition, EMF is a member of the Evangelical Council for Financial Accountability (ECFA). Founded by Billy Graham, the ECFA oversees EMF's financial affairs, ethics and reporting standards.^{[citation needed]}

EMF is recognized by Charity Navigator with a Four Star rating, the highest given to charities. In addition, EMF is audited yearly by an independent accounting firm, ensuring accuracy and completeness of its books and records.

Charity Navigator also reports K-LOVE's CEO Mike Novak's compensation was $463,420, including bonuses, in 2010.

Air 1 stations are licensed as NCE (non-commercial educational license) radio stations. Therefore, most of Air 1's funding is provided by donations. The majority of donations are made during seasonal pledge drives (usually in the spring and in the fall).

Programming[link]

Mixology[link]

Since 2003, Air 1 listeners can vote on their favorite songs in a process called Mixology.^[7] The program was formerly known as the Air 1 Music Lab.^[8] Listeners register at www.air1.com/mix and receive periodic e-mails surveying their opinions of current songs. Each song is rated from a scale of 1 to 5 and listeners indicate how often they would like to hear the song played. Air 1 then compiles the data collected and produces a weekly top song chart where listeners can hear a sample of the song, obtain its lyrics, or click a link to buy it online.

Mixology Live ^[9] is an interactive media space where Air 1 listeners tune-in and log-on every week night to Air 1.com ^[10] (10pm-Midnight Eastern and 7-9pm Pacific) to vote for the next song to be played on the radio, recommend new songs to be added to the potential play list, and chat with other Air 1 listeners. Most listeners who interact on the media page login with their Facebook accounts. Logging-in with a Facebook account gives the user greater value for their activity on the media page when they vote for the next song to be played on the radio.

To vote for a song on Mixology Live ^[11], one simply has to click on the red or green arrows beside a song title. The green arrow facing upward indicates the ascension of a song up the play list. The red arrow facing downward indicates the descension of a song down the play list. The song at the top of the play list is the next song to be played on the radio. All those who voted for the song appear as a string of Facebook pictures at the top of the media page. On the right side of the page is a search bar that allows listeners to search for songs that they would like to recommend to be added to the play list. If a song cannot be found with the search bar, an option is given to the user to message the DJ. The regular host for Mixology Live ^[12] is Ashton. From 10pm-Midnight Eastern and 7-9pm Pacific, Mixology Live can be streamed from Air 1.com ^[13].

Air 1 yearly produces a top countdown from all of the top songs from that year. Past top songs have been:

• "Dear X (You Don't Own Me)" by Disciple in 2010
• "Give Me Your Eyes" by Brandon Heath in 2008
• "East To West" by Casting Crowns in 2007
• "My Savior My God" by Aaron Shust in 2006
• "Take Me" by Hawk Nelson in 2005
• "Blessed Be Your Name" by Tree63 in 2004
• "Run" by Kutless in 2003.

These songs stay in rotation for occasional airplay on Air 1.

News[link]

Dan Dillard is the news anchor during the Air1 Morning Show from 6:00 – 11:00 EST^[2. News reporters include Jennifer James, Rebecca Bennett and Joel Roberts.

Air 1 also airs a 30-minute, in-depth news report called Closer Look, once a week at 6:00pm PT, followed by local public affairs programming specific to each individual station. The Closer Look segment are made available as "click-able" reports on the news ^[14] portion of the www.air1.com website. Many of their daily news reports are available online the network's news page.

See also[link]

• Educational Media Foundation
• K-LOVE

References[link]

1. ^ http://air1.com/About/Story.aspx
2. ^ ^{a b c d} "Sean and Mandy - Facebook". http://www.facebook.com/SeanandMandy/posts/10150263175019017. 
3. ^ "Sterling - Facebook". http://www.facebook.com/air1sterling. 
4. ^ "Nikki - Facebook". http://www.facebook.com/Air1Nikki/posts/296611087024391. 
5. ^ "@Air1Nikki - Twitter". Twitter. http://mobile.twitter.com/air1nikki/status/134458218427584512. Retrieved 2011-11-10]. 
6. ^ "Sean and Mandy last show MP3". http://files.emfcdn.com/downloads/audio/podcasts/air1msmoments_podcast8127_20110928.mp3. 
7. ^ Air 1 Music Lab
8. ^ Air 1 Music Lab
9. ^ http://www.air1.com/music/vote.aspx
10. ^ http://www.air1.com/
11. ^ http://www.air1.com/music/vote.aspx
12. ^ http://www.air1.com/music/vote.aspx
13. ^ http://www.air1.com/listen/
14. ^ http://www.air1.com/NewsWeather/CloserLook.aspx

External links[link]

• Air 1
• Air 1 Listen On-Line
• Air 1 Top Songs
• Air 1 Station list
• Air 1 INsider

Blue light is scattered more than other wavelengths by the gases in the atmosphere, giving the Earth a blue halo when seen from space.

Limb view, of the Earth's atmosphere. Colours roughly denote the layers of the atmosphere.

This image shows the moon at centre, with the limb of Earth near the bottom transitioning into the orange-coloured troposphere, the lowest and most dense portion of the Earth's atmosphere. The troposphere ends abruptly at the tropopause, which appears in the image as the sharp boundary between the orange- and blue- coloured atmosphere. The silvery-blue noctilucent clouds extend far above the Earth's troposphere.

The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation).

Atmospheric stratification describes the structure of the atmosphere, dividing it into distinct layers, each with specific characteristics such as temperature or composition. The atmosphere has a mass of about 5×10¹⁸ kg, three quarters of which is within about 11 km (6.8 mi; 36,000 ft) of the surface. The atmosphere becomes thinner and thinner with increasing altitude, with no definite boundary between the atmosphere and outer space. An altitude of 120 km (75 mi) is where atmospheric effects become noticeable during atmospheric reentry of spacecraft. The Kármán line, at 100 km (62 mi), also is often regarded as the boundary between atmosphere and outer space.

Air is the name given to atmosphere used in breathing and photosynthesis. Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1%. While air content and atmospheric pressure vary at different layers, air suitable for the survival of terrestrial plants and terrestrial animals is currently only known to be found in Earth's troposphere and artificial atmospheres.

Composition[link]

Composition of Earth's atmosphere. The lower pie represents the trace gases which together compose 0.039% of the atmosphere. Values normalized for illustration. The numbers are from a variety of years (mainly 1987, with CO₂ and methane from 2009) and do not represent any single source.

Mean atmospheric water vapor

Air is mainly composed of nitrogen, oxygen, and argon, which together constitute the major gases of the atmosphere. The remaining gases are often referred to as trace gases,^[1] among which are the greenhouse gases such as water vapor, carbon dioxide, methane, nitrous oxide, and ozone. Filtered air includes trace amounts of many other chemical compounds. Many natural substances may be present in tiny amounts in an unfiltered air sample, including dust, pollen and spores, sea spray, and volcanic ash. Various industrial pollutants also may be present, such as chlorine (elementary or in compounds), fluorine compounds, elemental mercury, and sulfur compounds such as sulfur dioxide [SO₂].

Structure of the atmosphere[link]

Principal layers[link]

In general, air pressure and density decrease in the atmosphere as height increases. However, temperature has a more complicated profile with altitude. Because the general pattern of this profile is constant and recognizable through means such as balloon soundings, temperature provides a useful metric to distinguish between atmospheric layers. In this way, Earth's atmosphere can be divided into five main layers. From highest to lowest, these layers are:

Exosphere[link]

The outermost layer of Earth's atmosphere extends from the exobase upward. It is mainly composed of hydrogen and helium. The particles are so far apart that they can travel hundreds of kilometers without colliding with one another. Since the particles rarely collide, the atmosphere no longer behaves like a fluid. These free-moving particles follow ballistic trajectories and may migrate into and out of the magnetosphere or the solar wind.

Thermosphere[link]

Temperature increases with height in the thermosphere from the mesopause up to the thermopause, then is constant with height. Unlike in the stratosphere, where the inversion is caused by absorption of radiation by ozone, in the thermosphere the inversion is a result of the extremely low density of molecules. The temperature of this layer can rise to 1,500 °C (2,700 °F), though the gas molecules are so far apart that temperature in the usual sense is not well defined. The air is so rarefied that an individual molecule (of oxygen, for example) travels an average of 1 kilometer between collisions with other molecules.^[3] The International Space Station orbits in this layer, between 320 and 380 km (200 and 240 mi). Because of the relative infrequency of molecular collisions, air above the mesopause is poorly mixed compared to air below. While the composition from the troposphere to the mesosphere is fairly constant, above a certain point, air is poorly mixed and becomes compositionally stratified. The point dividing these two regions is known as the turbopause. The region below is the homosphere, and the region above is the heterosphere. The top of the thermosphere is the bottom of the exosphere, called the exobase. Its height varies with solar activity and ranges from about 350–800 km (220–500 mi; 1,100,000–2,600,000 ft).^{[citation needed]}

Mesosphere[link]

The mesosphere extends from the stratopause to 80–85 km (50–53 mi; 260,000–280,000 ft). It is the layer where most meteors burn up upon entering the atmosphere. Temperature decreases with height in the mesosphere. The mesopause, the temperature minimum that marks the top of the mesosphere, is the coldest place on Earth and has an average temperature around −85 °C (−120 °F; 190 K).^[4] At the mesopause, temperatures may drop to −100 °C (−150 °F; 170 K).^[5] Due to the cold temperature of the mesosphere, water vapor is frozen, forming ice clouds (or Noctilucent clouds). A type of lightning referred to as either sprites or ELVES, form many miles above thunderclouds in the troposphere.

Stratosphere[link]

The stratosphere extends from the tropopause to about 51 km (32 mi; 170,000 ft). Temperature increases with height due to increased absorption of ultraviolet radiation by the ozone layer, which restricts turbulence and mixing. While the temperature may be −60 °C (−76 °F; 210 K) at the tropopause, the top of the stratosphere is much warmer, and may be near freezing^{[citation needed]}. The stratopause, which is the boundary between the stratosphere and mesosphere, typically is at 50 to 55 km (31 to 34 mi; 160,000 to 180,000 ft). The pressure here is 1/1000 sea level.

Troposphere[link]

The troposphere begins at the surface and extends to between 9 km (30,000 ft) at the poles and 17 km (56,000 ft) at the equator,^[6] with some variation due to weather. The troposphere is mostly heated by transfer of energy from the surface, so on average the lowest part of the troposphere is warmest and temperature decreases with altitude. This promotes vertical mixing (hence the origin of its name in the Greek word "τροπή", trope, meaning turn or overturn). The troposphere contains roughly 80% of the mass of the atmosphere.^[7] The tropopause is the boundary between the troposphere and stratosphere.

Other layers[link]

Within the five principal layers determined by temperature are several layers determined by other properties:

• The ozone layer is contained within the stratosphere. In this layer ozone concentrations are about 2 to 8 parts per million, which is much higher than in the lower atmosphere but still very small compared to the main components of the atmosphere. It is mainly located in the lower portion of the stratosphere from about 15–35 km (9.3–22 mi; 49,000–110,000 ft), though the thickness varies seasonally and geographically. About 90% of the ozone in our atmosphere is contained in the stratosphere.
• The ionosphere, the part of the atmosphere that is ionized by solar radiation, stretches from 50 to 1,000 km (31 to 620 mi; 160,000 to 3,300,000 ft) and typically overlaps both the exosphere and the thermosphere. It forms the inner edge of the magnetosphere. It has practical importance because it influences, for example, radio propagation on the Earth. It is responsible for auroras.
• The homosphere and heterosphere are defined by whether the atmospheric gases are well mixed. In the homosphere the chemical composition of the atmosphere does not depend on molecular weight because the gases are mixed by turbulence.^[8] The homosphere includes the troposphere, stratosphere, and mesosphere. Above the turbopause at about 100 km (62 mi; 330,000 ft) (essentially corresponding to the mesopause), the composition varies with altitude. This is because the distance that particles can move without colliding with one another is large compared with the size of motions that cause mixing. This allows the gases to stratify by molecular weight, with the heavier ones such as oxygen and nitrogen present only near the bottom of the heterosphere. The upper part of the heterosphere is composed almost completely of hydrogen, the lightest element.
• The planetary boundary layer is the part of the troposphere that is nearest the Earth's surface and is directly affected by it, mainly through turbulent diffusion. During the day the planetary boundary layer usually is well-mixed, while at night it becomes stably stratified with weak or intermittent mixing. The depth of the planetary boundary layer ranges from as little as about 100 m on clear, calm nights to 3000 m or more during the afternoon in dry regions.

The average temperature of the atmosphere at the surface of Earth is 14 °C (57 °F; 287 K)^[9] or 15 °C (59 °F; 288 K),^[10] depending on the reference.^{[11] [12][13]}

Physical properties[link]

Comparison of the 1962 US Standard Atmosphere graph of geometric altitude against air density, pressure, the speed of sound and temperature with approximate altitudes of various objects.^[14]

Pressure and thickness[link]

The average atmospheric pressure at sea level is about 1 atmosphere (atm) = 101.3 kPa (kilopascals) = 14.7 psi (pounds per square inch) = 760 torr = 29.92 inches of mercury (symbol Hg). Total atmospheric mass is 5.1480×10¹⁸ kg (1.135×10¹⁹ lb),^[15] about 2.5% less than would be inferred from the average sea level pressure and the Earth's area of 51007.2 megahectares, this portion being displaced by the Earth's mountainous terrain. Atmospheric pressure is the total weight of the air above unit area at the point where the pressure is measured. Thus air pressure varies with location and weather.

If the atmosphere had a uniform density, it would terminate abruptly at an altitude of 8.50 km (27,900 ft). It actually decreases exponentially with altitude, dropping by half every 5.6 km (18,000 ft) or by a factor of 1/e every 7.64 km (25,100 ft), the average scale height of the atmosphere below 70 km (43 mi; 230,000 ft). However, the atmosphere is more accurately modeled with a customized equation for each layer that takes gradients of temperature, molecular composition, solar radiation and gravity into account.

In summary, the mass of the earth's atmosphere is distributed approximately as follows:^[16]

• 50% is below 5.6 km (18,000 ft).
• 90% is below 16 km (52,000 ft).
• 99.99997% is below 100 km (62 mi; 330,000 ft), the Kármán line. By international convention, this marks the beginning of space where human travelers are considered astronauts.

By comparison, the summit of Mt. Everest is at 8,848 m (29,029 ft); commercial airliners typically cruise between 10 km (33,000 ft) and 13 km (43,000 ft) where the thinner air improves fuel economy; weather balloons reach 30.4 km (100,000 ft) and above; and the highest X-15 flight in 1963 reached 108.0 km (354,300 ft).

Even above the Kármán line, significant atmospheric effects such as auroras still occur. Meteors begin to glow in this region though the larger ones may not burn up until they penetrate more deeply. The various layers of the earth's ionosphere, important to HF radio propagation, begin below 100 km and extend beyond 500 km. By comparison, the International Space Station and Space Shuttle typically orbit at 350–400 km, within the F-layer of the ionosphere where they encounter enough atmospheric drag to require reboosts every few months. Depending on solar activity, satellites can still experience noticeable atmospheric drag at altitudes as high as 700–800 km.

Density and mass[link]

Temperature and mass density against altitude from the NRLMSISE-00 standard atmosphere model (the eight dotted lines in each "decade" are at the eight cubes 8, 27, 64, ..., 729)

The density of air at sea level is about 1.2  kg/m³ (1.2 g/L). Density is not measured directly but is calculated from measurements of temperature, pressure and humidity using the equation of state for air (a form of the ideal gas law). Atmospheric density decreases as the altitude increases. This variation can be approximately modeled using the barometric formula. More sophisticated models are used to predict orbital decay of satellites.

The average mass of the atmosphere is about 5 quadrillion (5×10¹⁵) tonnes or 1/1,200,000 the mass of Earth. According to the American National Center for Atmospheric Research, "The total mean mass of the atmosphere is 5.1480×10¹⁸ kg with an annual range due to water vapor of 1.2 or 1.5×10¹⁵ kg depending on whether surface pressure or water vapor data are used; somewhat smaller than the previous estimate. The mean mass of water vapor is estimated as 1.27×10¹⁶ kg and the dry air mass as 5.1352 ±0.0003×10¹⁸ kg."

Optical properties[link]

Solar radiation (or sunlight) is the energy the Earth receives from the Sun. The Earth also emits radiation back into space, but at longer wavelengths that we cannot see. Part of the incoming and emitted radiation is absorbed or reflected by the atmosphere.

Scattering[link]

When light passes through our atmosphere, photons interact with it through scattering. If the light does not interact with the atmosphere, it is called direct radiation and is what you see if you were to look directly at the Sun. Indirect radiation is light that has been scattered in the atmosphere. For example, on an overcast day when you cannot see your shadow there is no direct radiation reaching you, it has all been scattered. As another example, due to a phenomenon called Rayleigh scattering, shorter (blue) wavelengths scatter more easily than longer (red) wavelengths. This is why the sky looks blue; you are seeing scattered blue light. This is also why sunsets are red. Because the Sun is close to the horizon, the Sun's rays pass through more atmosphere than normal to reach your eye. Much of the blue light has been scattered out, leaving the red light in a sunset.

Absorption[link]

Different molecules absorb different wavelengths of radiation. For example, O₂ and O₃ absorb almost all wavelengths shorter than 300 nanometers. Water (H₂O) absorbs many wavelengths above 700 nm. When a molecule absorbs a photon, it increases the energy of the molecule. We can think of this as heating the atmosphere, but the atmosphere also cools by emitting radiation, as discussed below.

Rough plot of Earth's atmospheric transmittance (or opacity) to various wavelengths of electromagnetic radiation, including visible light.

The combined absorption spectra of the gases in the atmosphere leave "windows" of low opacity, allowing the transmission of only certain bands of light. The optical window runs from around 300 nm (ultraviolet-C) up into the range humans can see, the visible spectrum (commonly called light), at roughly 400–700 nm and continues to the infrared to around 1100 nm. There are also infrared and radio windows that transmit some infrared and radio waves at longer wavelengths. For example, the radio window runs from about one centimeter to about eleven-meter waves.

Emission[link]

Emission is the opposite of absorption, it is when an object emits radiation. Objects tend to emit amounts and wavelengths of radiation depending on their "black body" emission curves, therefore hotter objects tend to emit more radiation, with shorter wavelengths. Colder objects emit less radiation, with longer wavelengths. For example, the Sun is approximately 6,000 K (5,730 °C; 10,340 °F), its radiation peaks near 500 nm, and is visible to the human eye. The Earth is approximately 290 K (17 °C; 62 °F), so its radiation peaks near 10,000 nm, and is much too long to be visible to humans.

Because of its temperature, the atmosphere emits infrared radiation. For example, on clear nights the Earth's surface cools down faster than on cloudy nights. This is because clouds (H₂O) are strong absorbers and emitters of infrared radiation. This is also why it becomes colder at night at higher elevations. The atmosphere acts as a "blanket" to limit the amount of radiation the Earth loses into space.

The greenhouse effect is directly related to this absorption and emission (or "blanket") effect. Some chemicals in the atmosphere absorb and emit infrared radiation, but do not interact with sunlight in the visible spectrum. Common examples of these chemicals are CO₂ and H₂O. If there are too much of these greenhouse gases, sunlight heats the Earth's surface, but the gases block the infrared radiation from exiting back to space. This imbalance causes the Earth to warm, and thus climate change.

Refractive index[link]

The refractive index of air is close to, but just greater than 1. Systematic variations in refractive index can lead to the bending of light rays over long optical paths. One example is that, under some circumstances, observers onboard ships can see other vessels just over the horizon because light is refracted in the same direction as the curvature of the Earth's surface.

The refractive index of air depends on temperature, giving rise to refraction effects when the temperature gradient is large. An example of such effects is the mirage.

Circulation[link]

An idealised view of three large circulation cells.

Atmospheric circulation is the large-scale movement of air through the troposphere, and the means (with ocean circulation) by which heat is distributed around the Earth. The large-scale structure of the atmospheric circulation varies from year to year, but the basic structure remains fairly constant as it is determined by the Earth's rotation rate and the difference in solar radiation between the equator and poles.

Evolution of Earth's atmosphere[link]

Earliest atmosphere[link]

The outgassings of the Earth were stripped away by solar winds early in the history of the planet until a steady state was established, the first atmosphere. Based on today's volcanic evidence, this atmosphere would have contained 60% hydrogen, 20% oxygen (mostly in the form of water vapor), 10% carbon dioxide, 5 to 7% hydrogen sulfide, and smaller amounts of nitrogen, carbon monoxide, free hydrogen, methane and inert gases.^{[citation needed]}

A major rainfall led to the buildup of a vast ocean, enriching the other agents, first carbon dioxide and later nitrogen and inert gases. A major part of carbon dioxide exhalations were soon dissolved in water and built up carbonate sediments.

Second atmosphere[link]

Water-related sediments have been found dating from as early as 3.8 billion years ago.^[17] About 3.4 billion years ago, nitrogen was the major part of the then stable "second atmosphere". An influence of life has to be taken into account rather soon in the history of the atmosphere, since hints of early life forms are to be found as early as 3.5 billion years ago.^[18] The fact that this is not perfectly in line with the 30% lower solar radiance (compared to today) of the early Sun has been described as the "faint young Sun paradox".

The geological record however shows a continually relatively warm surface during the complete early temperature record of the Earth with the exception of one cold glacial phase about 2.4 billion years ago. In the late Archaean eon an oxygen-containing atmosphere began to develop, apparently from photosynthesizing algae which have been found as stromatolite fossils from 2.7 billion years ago. The early basic carbon isotopy (isotope ratio proportions) is very much in line with what is found today,^[19] suggesting that the fundamental features of the carbon cycle were established as early as 4 billion years ago.

Third atmosphere[link]

Oxygen content of the atmosphere over the last billion years. This diagram in more detail

The accretion of continents about 3.5 billion years ago^[20] added plate tectonics, constantly rearranging the continents and also shaping long-term climate evolution by allowing the transfer of carbon dioxide to large land-based carbonate storages. Free oxygen did not exist until about 1.7 billion years ago and this can be seen with the development of the red beds and the end of the banded iron formations. The Earth had a lot of iron in the beginning, and higher amounts of oxygen was not available in the atmosphere until all the iron had ben oxidized. This signifies a shift from a reducing atmosphere to an oxidising atmosphere. O₂ showed major ups and downs until reaching a steady state of more than 15%.^[21] The following time span was the Phanerozoic eon, during which oxygen-breathing metazoan life forms began to appear.

The amount of oxygen in the atmosphere has gone up and down during the last 600 million years. There was a peak 280 million years ago, when the amount of oxygen was about 30 %, much higher than today. The cause of changes in the atmosphere is two main processes: Plants converts carbon dioxide into the bodies of the plants, which emits oxygen into the atmosphere, and break down of pyrite rocks cause sulphur to be added to the oceans. Volcanos cause this sulphur to be oxidized, reducing the amount of oxygen in the atmosphere. But volcanos also emit carbon dioxide, so that plants can convert this to oxygen. The exact cause of the variation of oxygen in the atmosphere is not known. Periods with much oxygen in the atmosphere are believed to cause rapid development of animals. Even if the atmosphere today has only 21 percent oxygen, today is still regarded as a period with rapid development of animals because of a high amount of oxygen in the atmosphere.^[22]

Currently, anthropogenic greenhouse gases are increasing in the atmosphere. According to the Intergovernmental Panel on Climate Change, this increase is the main cause of global warming.^[23]

Air pollution[link]

Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to organisms into the atmosphere.^[24] Stratospheric ozone depletion is believed to be caused by air pollution (chiefly from chlorofluorocarbons).^{[citation needed]}

See also[link]

	Atmosphere portal
	Environment portal

References[link]

External links[link]

Wikimedia Commons has media related to: Earth's atmosphere

• NASA atmosphere models
• NASA's Earth Fact Sheet
• American Geophysical Union: Atmospheric Sciences
• Outreach of the GEOmon project See how Earth atmosphere is observed and monitored by a European project that combines many approaches.
• Stuff in the Air Find out what the atmosphere contains.
• Layers of the Atmosphere
• Answers to several questions of curious kids related to Air and Atmosphere
• The AMS Glossary of Meteorology
• Paul Crutzen Interview Free video of Paul Crutzen Nobel Laureate for his work on decomposition of ozone talking to Harry Kroto Nobel Laureate by the Vega Science Trust.
• Slides describing the Earth's modern atmosphere

v t e Atmospheres Major Sun Venus Earth Mars Jupiter Saturn Titan Uranus Neptune Triton Pluto HD 209458 b Tenuous Mercury Moon Io Europa Ganymede Callisto Enceladus Dione Rhea See also Stellar atmosphere Coma (cometary) Extraterrestrial atmospheres

Matthew West
Matthew West playing a concert on the History 101 tour in September 2005
Background information
Birth name	Matthew Joseph West
Born	(1977-04-25) April 25, 1977 (age 35)
Origin	Downers Grove, IL, U.S.[1]
Genres	CCM, pop/rock, Adult contemporary, Indie pop[2]
Occupations	Singer/songwriter
Years active	1997–present
Labels	Universal South, Sparrow
Website	matthewwest.com

Matthew Joseph West^[3] (born April 25, 1977) is a Contemporary Christian musician from Nashville, Tennessee. He has released four studio albums and is known for his No. 1 hits "More", "You Are Everything", and "The Motions". He was nominated for five Dove Awards in 2005, two of which were for his major label debut album Happy.

First starting out as an independent musician in the late 1990s, he released three independent albums before signing with Universal South Records. With the release of his Dove Award-winning debut album Happy (2003) came the success of his first radio single "More", which stayed at No. 1 on Christian AC charts for nine weeks and received two Dove Award nominations. His second record History (2005) was followed by a 2006 re-release of the originally independent album Sellout. In 2007 he faced vocal issues which threatened his career with two months of prescribed vocal rest. His third studio album Something to Say (2008) also enjoyed chart success with No. 1 hits "You Are Everything" and "The Motions".

In addition to his main solo career, West has worked as a songwriter for many Christian musicians and groups such as Point of Grace, Mandisa, and Natalie Grant, as well as mainstream country acts Rascal Flatts and Billy Ray Cyrus.

Early life[link]

Matthew West was born on April 25, 1977 in Downers Grove, IL.^[4] As a child he was a fan of his hometown baseball team, the Chicago Cubs, and wanted to eventually have a career in baseball.^[5] He played baseball throughout high school, becoming team captain as a senior. He was hoping for a college baseball scholarship but instead ended up receiving a four-year music scholarship at Millikin University in Illinois. He graduated from Millikin in 1999.^[5]

Musical career[link]

West wrote most of his first songs in the sanctuary of his father's church while he was at home during college breaks.^[5] He was a songwriter and independent musician from 1997–2002, releasing three albums: September Sun (1997), Every Step of the Way (1998), and Sellout (2002).^[6][7] In October 1997, he went on a three-city tour to support of the release of September Sun.^[6]

Just before graduating from Millikin University in 1999, someone from the college recommended that West attend the GMA Music in the Rockies event for aspiring musicians. Although West was not interested at first, he attended after learning that other people signed him up and paid his entrance fee.^[5] He met a representative from Word Publishing at the event who took interest in him and kept in contact until he graduated. West landed in the finals of a songwriting competition and was offered a songwriting deal in July 1999, five weeks after graduating.^[5][6] After penning songs for well-known musicians like Billy Ray Cyrus and Rachael Lampa, he began touring the United States as an independent artist in 2000 and 2001.^[5][6]

On July 26, 2002,^[6] only a week or two before signing a record contract with Universal South Records, West had an injury to his left arm which threatened his musical career and guitar playing. He says, "I locked myself out of my house. But I'd done that before, and I had a way of breaking in through a window. But this time, I had a really hard time getting the window open. I started pushing up on the window really hard and my hand broke through the glass. Blood starting spewing out of my left arm everywhere and I ran down my street screaming for help. After seeing so much blood, I went into shock and just blacked out in the middle of the street. The next thing I can remember is some construction workers praying over me in Spanish and then being taken to the hospital."^[5] West was told that the chances were low of regaining the full use of his left arm, having come very close to severing a major artery.^[5] He recovered after the accident, however, and was able to continue playing guitar and record for his first studio album.^[8]

[edit] Happy (2003)

After signing with Universal South Records on August 23, 2002,^[6] West released his first non-independent studio album, Happy on December 26, 2003.^[9] The album's producers Kenny Greenberg and Jason Houser co-wrote the song "More" with West.^[10][11] The track was his first and most successful radio single to date, staying at No. 1 on R&R's Christian Adult Contemporary chart for a record-breaking nine weeks.^[12] It was the most played Christian AC song of 2004^[13] and went on to be labelled as the Christian Song of the Year by ASCAP.^[14] Two additional songs, "The End" and "You Know Where to Find Me", were also released as singles off the album.^[15] Beginning in late September 2004, West joined Avalon and Mark Schultz on a 40-city fall tour, which concluded at the end of November.^[16] In 2005, he was nominated for five Dove Awards, including "New Artist of the Year" and "Song of the Year".^[17] He won the "Recorded Music Packaging of the Year" Dove Award for his debut album Happy.^[18]

In early 2005, he was on the WinterJam 2005 tour, hosted by NewSong, with tobyMac, Building 429, Tait, and Rachael Lampa.^[19]

[edit] History (2005)

Matthew West at a concert on tobyMac's Winter Wonder Slam tour in December 2005

With Kenny Greenberg and Jason Houser once again as producers,^[20] Matthew West began recording for his second studio album in early 2005.^[15] History, co-produced by West, was released on June 21, 2005 on Universal South Records.^[21] The first single off the album, "Next Thing You Know", was released June 20, a day before the album's release.^[22] The theme of the title track "History" was inspired by a R&R music news headline "Matthew West Makes History", in reference to his first album, Happy. "It's not every day you read a headline like that with your name in it that calls you a history maker," he said.^[23] Beginning on September 14, 2005, he kicked off the 30-city History 101 tour, his first headlining tour, which included guest musicians Shawn McDonald and Paul Wright.^[24] He then joined tobyMac's Winter Wonder Slam tour, beginning on December 1, 2005, along with John Reuben, BarlowGirl, GRITS, and DJ Maj.^[25] Two additional songs were released off History as singles: "Only Grace" and the title track "History".^[26][27]

His independent album Sellout was re-released in 2006 on Universal South Records.^[28]

Vocal problems[link]

West said that he began to experience "some vocal fatigue" in April 2007. He said "I had lost some of my vocal range, staying on higher notes and lower notes. I even began having a hard time speaking."^[29] At a vocal check-up in response to the issue, West's doctors at the Nashville Vanderbilt Voice Center discovered "hemorrhaging caused by some polyps".^[29] He was told by his doctors that vocal surgery was the only option, since a few weeks had passed.^[29] The surgery took place on May 17, 2007, a process that he said was "career threatening."^[30] Afterward, he was prescribed a two-month period of silence for vocal rest.^[29]

A video documentary titled Nothing to Say, directed and produced by Benjamin Eisner, was released in early 2008, highlighting Matthew West's time of silence and vocal recovery in 2007.^[31] In February 2008, the documentary was available exclusively in Family Christian Stores as a CD/DVD combo pack with West's album Something to Say.^[31]

[edit] Something to Say (2008–2010)

His next single "You Are Everything" was released in late 2007. The song was available as a free download from West's website.^[32] He also recorded a duet("Christmas Makes Me Cry") with American Idol finalist Mandisa which was released as a Christmas radio single in November 2007, from Mandisa's Christmas Joy EP.^[32]

Matthew West's album, Something to Say, was released on January 15, 2008.^[33] It reached No. 8 on Billboard's Top Christian albums chart, and peaked at No. 159 on the Billboard 200 chart,^[34] making it his first Billboard 200 album .^[35] It was produced by Brown Bannister, Ed Cash, and Christopher Stevens.^[36] West said in an interview that all of the album's songs had already been written and the title "Something to Say" had already been decided "months before I found out that I was going to have nothing to say."^[29][37] The first radio single released from the album was "You Are Everything". In March 2008, the song reached No. 1 on R&R's Christian AC chart.^[38] "Something to Say", the album's title track, was also released to radio, receiving airplay in June 2008.^[39]

Matthew West guested on tobyMac's 26-city "Boomin' Beyond Measure" tour along with Jeremy Camp.^[40] The tour ran from February 6 through March 21, 2008.^[41]

He was featured on the Billy Graham television special America's Dream: Chasing Happiness, which aired in the U.S. on March 1–9, 2008.^[42] The appearance included a world premiere of his music video for "Nothing Else", a song from History.^[42] On June 29, West hosted GMA's 2008 Gospel Dream, a televised Christian music talent competition.^[43] "The Motions" was released as his next single, placing at No. 1 on R&R's Christian AC chart in April 2009.^[44]

He has a song on the upcoming album of country artist Jo Dee Messina, and another under consideration by “American Idol” finalist Danny Gokey. In December 2009, "The Motions" was Grammy-nominated for Best Gospel Song, his first Grammy nomination.^[45]

[edit] Story of Your Life (2010-present)

The first single from Matthew West's new album, "My Own Little World" was released on August 23, 2010. The album, The Story of Your Life, was released October 5, 2010, and according to West, is a response to thousands of life stories his fans shared with him. "The first day, I got 1,000 stories. All of a sudden, I was like, 'holy cow, something special is about to take place'. I rented a cabin in Tennessee, about 25 minutes from my house that felt like it was out in the middle of nowhere. And I spent two months in that cabin reading 10,000 stories," the singer/songwriter reported in an interview with CBN.com.^[46] Matthew is also starring in The Heart of Christmas.^[47]

Other songwriting[link]

In addition to his main solo career, Matthew West has also written songs for other bands and musicians, including Mark Schultz, Mandisa, Jump5, Sara Groves, Joy Williams, Salvador, Natalie Grant, PureNRG, and Point of Grace, as well as mainstream country act Billy Ray Cyrus. Rascal Flatts recorded Matthew's song "The Day Before You" on their album Feels Like Today.^{[2][11][48][49]} He co-wrote "Voice of a Savior" by Mandisa and "Thank You" by 33Miles, both of which were released as singles in early 2008.^[50]

Personal life[link]

Matthew West currently lives in Nashville, Tennessee with his wife Emily.^[13][51] He married Emily on May 10, 2003 after proposing to her in September 2002.^[6] They have a daughter Luella Jane ("Lulu") and a daughter Delaney Ruth.^[52] The Wests own a pug named Earl "The Girl".^[23]

Awards[link]

GMA Dove Awards[link]

Discography[link]

Albums[link]

This biographical section of an article needs additional citations for verification. Please help by adding reliable sources. Contentious material about living persons that is unsourced or poorly sourced must be removed immediately, especially if potentially libelous or harmful. (January 2012)

• 1997 - September Sun
• 1998 - Every Step of the Way
• 2002 - Sellout
• 2003 - Happy
• 2005 - History
• 2008 - Something to Say
• 2010 - The Story of Your Life
• 2011 - The Heart of Christmas

Singles[link]

This biographical section of an article needs additional citations for verification. Please help by adding reliable sources. Contentious material about living persons that is unsourced or poorly sourced must be removed immediately, especially if potentially libelous or harmful. (January 2012)

Compilation contributions[link]

• 2003: Festival Con Dios Vol. 3 – "More", from Happy (Inpop)^[4]
• 2004: WOW Hits 2005 – "More", from Happy (Sparrow)
• 2005: WOW Christmas: Green – "Let It Snow, Let It Snow, Let It Snow" (Word)
• 2005: Night of Joy 2005 – "Get Away", from History (Disney)
• 2006: WOW Hits 2007 – "Only Grace", from History (EMI)^[54]
• 2007: Christmas Joy EP – "Christmas Makes Me Cry", a duet with Mandisa (Sparrow)^[55]
• 2007: WOW Hits 2008 – "History", from History (EMI)^[56]
• 2008: WOW Hits 1 - "You Are Everything," from Something to Say
• 2008: WOW Hits 2009 - "You Are Everything," from Something to Say
• 2009: WOW Hits 2010 - "The Motions," from Something to Say
• 2010: WOW Hits 2011 - "My Own Little World," from The Story of Your Life
• 2011: Music Inspired by the Story - "Good (Adam & Eve)," a duet with Leigh Nash (EMI Christian Music) ^[57]
• 2011: WOW Hits 2012 - "Strong Enough," from The Story of Your Life

References[link]