what happens to the hot air in our atmosphere
Earth's atmosphere is a thin blanket of gases and tiny particles — together called air. We are most enlightened of air when it moves and creates wind. All living things need some of the gases in air for life support. Without an atmosphere, Earth would likely be just another lifeless rock.
Earth's atmosphere, along with the abundant liquid water at World'southward surface, are the keys to our planet's unique identify in the solar organisation. Much of what makes Earth exceptional depends on the atmosphere. Allow's consider some of the reasons we are lucky to have an atmosphere.
INDISPENSABLE FOR LIFE ON EARTH
Without the atmosphere, Earth would look a lot more similar the Moon. Atmospheric gases, especially carbon dioxide (CO2) and oxygen (O2), are extremely important for living organisms. How does the atmosphere make life possible? How does life alter the atmosphere?
Inphotosynthesis plants use COii and create O2. Photosynthesis is responsible for almost all of the oxygen currently found in the atmosphere. By creating oxygen and food, plants have made an surround that is favorable for animals. In respiration, animals use oxygen to convert sugar into nutrient energy they can use. Plants also go through respiration and swallow some of the sugars they produce.
CRUCIAL Office OF THE Water CYCLE
As role of the hydrologic cycle, which was detailed in the World's Fresh Water chapter, h2o spends a lot of fourth dimension in the temper, mostly every bit water vapor.Allweather takes place in the atmosphere, near all of it in the lower temper. Weather describes what the atmosphere is similar at a specific fourth dimension and identify, and may include temperature, air current, and precipitation. Weather is the change we experience from 24-hour interval to solar day. Climate is the long-term boilerplate of weather in a particular spot. Although the weather for a detail winter twenty-four hours in Tucson, Arizona, may include snowfall, the climate of Tucson is generally warm and dry.
OZONE LAYER MAKES LIFE POSSIBLE
Ozone is a molecule composed of three oxygen atoms, (O3). Ozone in the upper temper absorbs high-energyultraviolet (UV) radiation coming from the Sun. This protects living things on Earth's surface from the Sun'due south most harmful rays. Without ozone for protection, simply the simplest life forms would be able to live on Earth.MODERATES EARTH'S TEMPERATURE
Along with the oceans, thetemper keeps Earth'south temperatures within an acceptable range.Greenhouse gases trap heat in the atmosphere and then they help to moderate global temperatures. Without an atmosphere with greenhouse gases, Earth'south temperatures would be frigid at night and scorching during the solar day. Important greenhouse gases include carbon dioxide, marsh gas, water vapor, and ozone.
Atmospheric Gasses
COMPOSITION OF THE Atmosphere
Nitrogen and oxygen together make up 99 percent of the planet's atmosphere. The rest of the gases are minor components simply sometimes are very important. Humidity is the amount of water vapor in the air. Humidity varies from place to place and season to season. This fact is obvious if y'all compare a summer day in Atlanta, Georgia, where humidity is high, with a wintertime twenty-four hours in Phoenix, Arizona, where humidity is depression. When the air is very humid, it feels heavy or gummy. Dry air unremarkably feels more comfortable.Where effectually the globe is hateful atmospheric water vapor higher and where is it lower and why? College humidity is establish around the equatorial regions considering air temperatures are higher and warm air can agree more moisture than libation air. Of course, humidity is lower virtually the polar regions because air temperature is lower.
Some of what is in the atmosphere is not gas. Particles of dust, soil, fecal affair, metals, common salt, fume, ash, and other solids brand upwards a small per centum of the temper. Particles provide starting points (or nuclei) for water vapor to condense on and grade raindrops. Some particles are pollutants, which are discussed in the Human Deportment and the Temper affiliate.
ATMOSPHERIC Pressure AND DENSITY
The temper has different properties at dissimilar elevations above body of water level, or altitudes. The air density (the number of molecules in a given volume) decreases with increasing distance. This is why people who climb tall mountains, such as Mt. Everest, take to prepare camp at dissimilar elevations to let their bodies get used to the decreased air.Why does air density decrease with altitude? Gravity pulls the gas molecules towards Earth'due south eye. The pull of gravity is stronger closer to the center at bounding main level. Air is denser at sea level where the gravitational pull is greater.Gases at sea level are also compressed past the weight of the atmosphere above them. The strength of the air weighing downwardly over a unit of surface area is known as its atmospheric force per unit area. The reason why we are not crushed by this weight is because the molecules inside our bodies are pushing outward to compensate. Atmospheric force per unit area is felt from all directions, not just from to a higher place.
At higher altitudes the atmospheric pressure is lower and the air is less dense than at college altitudes. If your ears have ever "popped", you have experienced a modify in air pressure. Gas molecules are found inside and outside your ears. When you modify altitude speedily, like when an airplane is descending, your inner ear keeps the density of molecules at the original altitude. Somewhen the air molecules inside your ear suddenly motility through a small tube in your ear to equalize the pressure. This sudden rush of air is felt as a popping sensation.
Although the density of the atmosphere changes with altitude, the composition stays the same with altitude, with one exception. In the ozone layer, at well-nigh 20 km to 40 km to a higher place the surface, in that location is a greater concentration of ozone molecules than in other portions of the temper.
Layers of the Temper
The atmosphere is layered, respective with how the atmosphere's temperature changes with altitude. By understanding the way temperature changes with altitude, we can learn a lot about how the atmosphere works. While weather takes place in the lower temper, interesting things, such equally the beautiful aurora, happen higher in the temper.
Why does warm air rise? Gas molecules are able to move freely and if they are uncontained, as they are in the atmosphere, they can take up more or less space.
- When gas molecules are absurd, they are sluggish and exercise not take up as much space. With the same number of molecules in less space, both air density and air pressure are higher.
- When gas molecules are warm, they move vigorously and take upwardly more space. Air density and air pressure level are lower.
Warmer, lighter air is more buoyant than the cooler air above it, so it rises. The cooler air so sinks down, because it is denser than the air below information technology. This is convection, which was described in the Plate Tectonics chapter.
The property that changes most strikingly with distance is air temperature. Dissimilar the change in pressure and density, which decrease with distance, changes in air temperature are not regular. A change in temperature with distance is called a temperature gradient.
The atmosphere is divided into layers based on how the temperature in that layer changes with altitude, the layer'southward temperature gradient. The temperature gradient of each layer is different. In some layers, temperature increases with altitude and in others it decreases. The temperature gradient in each layer is adamant past the oestrus source of the layer. Most of the of import processes of the atmosphere take place in the lowest two layers: the troposphere and the stratosphere.
TROPOSPHERE
The temperature of thetroposphere is highest about the surface of the Globe and decreases with altitude. On average, the temperature slope of the troposphere is half-dozen.5oC per 1,000 m (iii.sixoF per one,000 ft.) of altitude. What is the source of heat for the troposphere? Earth's surface is a major source of estrus for the troposphere, although virtually all of that heat comes from the Sun. Rock, soil, and water on Earth absorb the Sun's light and radiate it back into the atmosphere equally heat. The temperature is too higher almost the surface considering of the greater density of gases.
Detect that in the troposphere warmer air is below cooler air. What exercise you lot think the outcome of this is? This condition is unstable. The warm air near the surface rises and cool air higher in the troposphere sinks. So air in the troposphere does a lot of mixing. This mixing causes the temperature gradient to vary with time and place. The ascent and sinking of air in the troposphere means that all of the planet'southward conditions takes place in the troposphere.
Sometimes at that place is a temperatureinversion, air temperature in the troposphere increases with distance and warm air sits over common cold air. Inversions are very stable and may last for several days or even weeks. They class:
- Over land at night or in wintertime when the ground is cold. The cold ground cools the air that sits above it, making this depression layer of air denser than the air in a higher place it.
- Near the coast where cold seawater cools the air above it. When that denser air moves inland, it slides below the warmer air over the state.
| Since temperature inversions are stable, they often trap pollutants and produce unhealthy air conditions in cities. At the top of the troposphere is a thin layer in which the temperature does not change with height. This means that the cooler, denser air of the troposphere is trapped beneath the warmer, less dense air of the stratosphere. Air from the troposphere and stratosphere rarely mix. |
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STRATOSPHERE
Ash and gas from a large volcanic eruption may flare-up into thestratosphere, the layer higher up the troposphere. In one case in the stratosphere, it remains suspended there for many years because there is and so little mixing between the two layers. Pilots like to fly in the lower portions of the stratosphere because there is fiddling air turbulence.In the stratosphere, temperature increases with altitude. What is the heat source for the stratosphere? The direct heat source for the stratosphere is the Sunday. Air in the stratosphere is stable considering warmer, less dumbo air sits over cooler, denser air. As a result, in that location is little mixing of air within the layer.Theozone layer is found inside the stratosphere betwixt 15 to 30 km (9 to 19 miles) distance. The thickness of the ozone layer varies past the season and also by breadth.
The ozone layer is extremely important because ozone gas in the stratosphere absorbs virtually of the Sun'due south harmful ultraviolet (UV) radiation. Because of this, the ozone layer protects life on Earth. High-energy UV light penetrates cells and damages DNA, leading to cell death (which we know as a bad sunburn). Organisms on World are not adapted to heavy UV exposure, which kills or amercement them. Without the ozone layer to reflect UVC and UVB radiations, nearly circuitous life on Earth would not survive long.
MESOSPHERE
Temperatures in themesosphere subtract with altitude. Because at that place are few gas molecules in the mesosphere to absorb the Sun's radiation, the estrus source is the stratosphere below. The mesosphere is extremely common cold, especially at its summit, nearly -ninety degrees C (-130 degrees F).
The air in the mesosphere has extremely depression density: 99.9 percent of the mass of the atmosphere is beneath the mesosphere. As a result, air pressure is very low. A person traveling through the mesosphere would experience astringent burns from ultraviolet light since the ozone layer which provides UV protection is in the stratosphere below. There would be nearly no oxygen for breathing. Stranger nonetheless, an unprotected traveler's blood would eddy at normal body temperature because the pressure is so low.
THERMOSPHERE
The density of molecules is so low in thethermosphere that one gas molecule can go well-nigh 1 km before information technology collides with another molecule. Since so fiddling free energy is transferred, the air feels very common cold. Within the thermosphere is theionosphere. The ionosphere gets its proper noun from the solar radiation that ionizes gas molecules to create a positively charged ion and 1 or more negatively charged electrons. The freed electrons travel within the ionosphere equally electric currents. Because of the gratuitous ions, the ionosphere has many interesting characteristics. At night, radio waves bounce off the ionosphere and back to Earth. This is why y'all tin can oftentimes choice up an AM radio station far from its source at nighttime.The Van Allen radiation belts are two doughnut-shaped zones of highly charged particles that are located beyond the atmosphere in the magnetosphere. The particles originate in solar flares and fly to World on the solar current of air. Once trapped past Earth's magnetic field, they follow forth the field's magnetic lines of forcefulness. These lines extend from above the equator to the N Pole and also to the Due south Pole then return to the equator.
When massive solar storms cause the Van Allen belts to become overloaded with particles, the result is the near spectacular characteristic of the ionosphere — the aurora. The particles spiral along magnetic field lines toward the poles. The charged particles energize oxygen and nitrogen gas molecules, causing them to low-cal up. Each gas emits a particular color of light.
There is no existent outer limit to theexosphere, the outermost layer of the atmosphere; the gas molecules finally become so scarce that at some point there are no more than. Beyond the temper is the solar wind. The solar wind is made of high-speed particles, by and large protons and electrons, traveling rapidly outward from the Sun.
| There is no real outer limit to theexosphere, the outermost layer of the atmosphere; the gas molecules finally get so scarce that at some point there are no more. Across the temper is the solar wind. The solar air current is made of high-speed particles, mostly protons and electrons, traveling apace outward from the Sunday. This video is very thorough in its discussion of the layers of the atmosphere. |
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Atmospheric Energy, Temperature, and Heat
ENERGY
Energy travels through space or fabric. This is obvious when you stand near a fire and experience its warmth or when you pick up the handle of a metal pot even though the handle is not sitting directly on the hot stove. Invisible energy waves tin can travel through air, glass, and even the vacuum of outer infinite. These waves have electrical and magnetic properties, and so they are called electromagnetic waves. The transfer of free energy from one object to some other through electromagnetic waves is known as radiation. Different wavelengths of energy create dissimilar types of electromagnetic waves.
- The wavelengths humans can see are known as "visible light." These wavelengths appear to the states as the colors of the rainbow. What objects can you call back of that radiate visible lite? Ii include the Sunday and a light bulb.
- The longest wavelengths of visible calorie-free announced cherry-red. Infrared wavelengths are longer than visible crimson. Snakes tin come across infrared energy. We feel infrared energy every bit oestrus.
- Wavelengths that are shorter than violet are called ultraviolet.
Can you recall of some objects that appear to radiate visible low-cal, just actually practise not? The moon and the planets do not emit light of their own; they reflect the low-cal of the Sun.Reflection is when calorie-free (or another wave) bounces back from a surface.Albedo is a measure of how well a surface reflects calorie-free. A surface with loftier albedo reflects a big percentage of low-cal. A snow field has high albedo.
One important fact to retrieve is that free energy cannot be created or destroyed — it can merely exist changed from one class to another. This is such a fundamental fact of nature that information technology is a law: the law of conservation of free energy.
In photosynthesis, for example, plants catechumen solar energy into chemical energy that they tin use. They do not create new free energy. When energy is transformed, some about ever becomes rut. Heat transfers between materials easily, from warmer objects to libation ones. If no more estrus is added, eventually all of a material volition attain the same temperature.
TEMPERATURE
Temperature is a mensurate of how fast the atoms in a textile are vibrating. High temperature particles vibrate faster than low temperature particles. Rapidly vibrating atoms smash together, which generates heat. Every bit a material cools down, the atoms vibrate more slowly and collide less ofttimes. As a issue, they emit less oestrus. What is the difference between heat and temperature?
- Temperature measures how fast a fabric'southward atoms are vibrating.
- Heat measures the material's total energy.
Which has college heat and which has higher temperature: a candle flame or a bathtub total of hot water?
- The flame has higher temperature, but less oestrus, considering the hot region is very small.
- The bathtub has lower temperature simply contains much more rut because information technology has many more vibrating atoms. The bathtub has greater total free energy.
HEAT
Oestrus is taken in or released when an object changes country, or changes from a gas to a liquid, or a liquid to a solid. This estrus is calledlatent oestrus. When a substance changes state, latent oestrus is released or absorbed. A substance that is irresolute its state of matter does not alter temperature. All of the energy that is released or captivated goes toward changing the material'southward state.
For example, imagine a pot of boiling water on a stove burner: that water is at 100 degrees C (212 degrees F). If you lot increase the temperature of the burner, more rut enters the water. The h2o remains at its boiling temperature, but the additional energy goes into changing the h2o from liquid to gas. With more heat the water evaporates more than rapidly. When water changes from a liquid to a gas information technology takes in heat. Since evaporation takes in heat, this is chosen evaporative cooling. Evaporative cooling is an inexpensive way to cool homes in hot, dry areas.
Substances also differ in theirspecific heat, the corporeality of energy needed to enhance the temperature of 1 gram of the fabric by 1.0 degrees C (1.8 degrees F). Water has a very high specific heat, which means it takes a lot of energy to change the temperature of h2o. Permit'south compare a pool and asphalt, for example. If you are walking barefoot on a sunny day, which would you lot rather walk across, the shallow puddle or an cobblestone parking lot? Considering of its high specific heat, the water stays libation than the asphalt, even though information technology receives the same corporeality of solar radiation.
Free energy from the Sun
The earth constantly tries to maintain an energy balance with the atmosphere. Well-nigh of the energy that reaches the Earth's surface comes from the Sun. About 44% of solar radiation is in the visible light wavelengths, but the Sun likewise emits infrared, ultraviolet, and other wavelengths. When viewed together, all of the wavelengths of visible lite announced white. But a prism or water droplets tin intermission the white light into different wavelengths and then that separate colors announced.
Of the solar energy that reaches the outer atmosphere, UV wavelengths have the greatest free energy. Only almost seven percent of solar radiation is in the UV wavelengths. The three types are:
- UVC: the highest free energy ultraviolet, does not attain the planet'south surface at all.
- UVB: the second highest free energy, is also mostly stopped in the atmosphere.
- UVA: the lowest energy, travels through the atmosphere to the ground.
The remaining solar radiation is the longest wavelength, infrared. Most objects radiate infrared free energy, which we experience as heat. Some of the wavelengths of solar radiations traveling through the atmosphere may be lost because they are absorbed by various gases. Ozone completely removes UVC, most UVB and some UVA from incoming sunlight. Oxygen, carbon dioxide, and water vapor likewise filter out some wavelengths.
Heat Transfer in the Atmosphere
Heat moves in the temper the aforementioned way it moves through the solid Earth (Plate Tectonics affiliate) or another medium. What follows is a review of the way rut flows and is transferred, but applied to the atmosphere.
Radiation is the transfer of energy betwixt two objects by electromagnetic waves. Oestrus radiates from the ground into the lower temper.
Inconduction, estrus moves from areas of more rut to areas of less oestrus by straight contact. Warmer molecules vibrate rapidly and collide with other nearby molecules, transferring their free energy. In the atmosphere, conduction is more effective at lower altitudes where air density is higher; transfers heat upward to where the molecules are spread further apart or transfers estrus laterally from a warmer to a cooler spot, where the molecules are moving less vigorously.
Heat transfer past motion of heated materials is calledconvection. Estrus that radiates from the basis initiates convection cells in the atmosphere.
Rut AT World'S SURFACE
Most half of the solar radiation that strikes the peak of the atmosphere is filtered out before it reaches the ground. This energy tin be absorbed past atmospheric gases, reflected by clouds, or scattered. Scattering occurs when a calorie-free wave strikes a particle and bounces off in another direction.
Most iii% of the free energy that strikes the basis is reflected back into the atmosphere. The residuum is captivated past rocks, soil, and water so radiated dorsum into the air as heat. These infrared wavelengths tin can only be seen by infrared sensors. Considering solar free energy continually enters Earth'due south temper and basis surface, is the planet getting hotter? The answer is no (although the next department contains an exception) because energy from Earth escapes into infinite through the acme of the temper. If the corporeality that exits is equal to the corporeality that comes in, and then average global temperature stays the aforementioned. This means that the planet'south heat upkeep is in balance. What happens if more free energy comes in than goes out? If more energy goes out than comes in?
To say that the Earth's rut budget is balanced ignores an of import point. The amount of incoming solar free energy is different at different latitudes). Where practice you lot remember the well-nigh solar energy ends up and why? Where does the least solar energy end upward and why? The difference in solar energy received at different latitudes drives atmospheric circulation.
| Equatorial Regions Polar Regions | 24-hour interval Length Night 6 months | Sun Angle Depression | Solar Radiations Low | Albedo High |
THE GREENHOUSE Result
The exception to Earth'due south temperature being in balance is caused past greenhouse gases. But kickoff the role of greenhouse gases in the atmosphere must be explained. Greenhouse gases warm the atmosphere by trapping heat. Some of the heat radiation out from the ground is trapped by greenhouse gases in the troposphere. Like a blanket on a sleeping person, greenhouse gases human activity as insulation for the planet. The warming of the atmosphere because of insulation by greenhouse gases is called thegreenhouse issue. Greenhouse gases are the component of the temper that moderate Globe's temperatures.Greenhouse gases include CO2, Water, methane, O3, nitrous oxides (NO and NO2), and chlorofluorocarbons (CFCs). All are a normal part of the atmosphere except CFCs. The table below shows how each greenhouse gas naturally enters the atmosphere.
| Greenhouse Gas | Where It Comes From |
Different greenhouse gases accept different abilities to trap heat. For example, one methyl hydride molecule traps 30 times equally much oestrus every bit i COtwo molecule. I Chlorofluorocarbon-12 molecule (a type of CFC) traps 10,600 times as much rut as one COtwo. Withal, CO2 is a very important greenhouse gas because it is much more than abundant in the atmosphere.
Human being activity has significantly raised the levels of many of greenhouse gases in the atmosphere. Methane levels are about ii one/two times college every bit a result of human activity. Carbon dioxide has increased more than 35%. CFCs have only recently existed.
What practice you think happens as atmospheric greenhouse gas levels increase? More greenhouse gases trap more heat and warm the atmosphere. The increase or decrease of greenhouse gases in the atmosphere touch on climate and atmospheric condition the world over.
Source: https://courses.lumenlearning.com/earthscience/chapter/the-atmosphere/
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