Wind picks up dust and other particles which, when they collide with the terrain, erode the relief and leave deposits ( eolian processes). Historical outline on the discovery of atmospheric structure.
atmosphere layers miles – Energy Program
The atmosphere is comprised of layers based on temperature. 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 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 experience noticeable atmospheric drag at altitudes as high as 700-800 km.
The idea here is straightforward: When you dig a hole in the ground, the hole fills up with air.1The dirt you pile up outside the hole displaces air, so at first you won’t have much effect on the surrounding atmosphere, but the effect grows as the hole gets deeper and the pile gets higher. So keep at it! If you dig a big enough hole, most of the atmosphere will flow in, and there won’t be enough left outside the hole to breathe.2You need to remove about 65% of the atmosphere before sea level air becomes too thin to support human life.3As this paper points out, it’s odd—and likely coincidental—that the highest point on Earth happens to be just about exactly as high as the human high-altitude survival limit.
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 (9.3-21.7 mi; 49,000-115,000 ft), though the thickness varies seasonally and geographically. About 90% of the ozone in Earth’s atmosphere is contained in the stratosphere.
Thermosphere: The thermosphere is a thermal classification of the atmosphere. In the thermosphere, temperature increases with altitude. The thermosphere includes the exosphere and part of the ionosphere.
Stratosphere – The stratosphere extends for the next 32 miles after the troposphere. Unlike the troposphere the stratosphere gets its heat by the Ozone Layer absorbing radiation from the sun. As a result, it gets warmer the further away you get from the Earth. Weather balloons go as high as the stratosphere.
Earth’s atmosphere is divided into five main layers: the exosphere, the thermosphere, the mesosphere, the stratosphere and the troposphere. The atmosphere thins out in each higher layer until the gases dissipate in space. There is no distinct boundary between the atmosphere and space, but an imaginary line about 62 miles (100 kilometers) from the surface, called the Karman line, is usually where scientists say atmosphere meets outer space.
The stratospheric temperature profile creates very stable atmospheric conditions, so the stratosphere lacks the weather-producing air turbulence that is so prevalent in the troposphere. Consequently, the stratosphere is almost completely free of clouds and other forms of weather. However, polar stratospheric or nacreous clouds are occasionally seen in the lower part of this layer of the atmosphere where the air is coldest. The stratosphere is the highest layer that can be accessed by jet-powered aircraft.
At sea level, the air pressure is about 14.7 pounds per square inch. As your altitude increases (for example, if you climb a mountain), the air pressure decreases. At an altitude of 10,000 feet, the air pressure is 10 pound per square inch (and there is less oxygen to breathe).
Although variations do occur, the temperature usually declines with increasing altitude in the troposphere because the troposphere is mostly heated through energy transfer from the surface. Thus, the lowest part of the troposphere (i.e. Earth’s surface) is typically the warmest section of the troposphere. This promotes vertical mixing (hence, the origin of its name in the Greek word τρόπος, tropos, meaning “turn”). The troposphere contains roughly 80% of the mass of Earth’s atmosphere. 23 The troposphere is denser than all its overlying atmospheric layers because a larger atmospheric weight sits on top of the troposphere and causes it to be most severely compressed. Fifty percent of the total mass of the atmosphere is located in the lower 5.6 km (3.5 mi; 18,000 ft) of the troposphere.
To better understand the formation and composition of Earth, scientists sometimes compare our planet with Venus and Mars. All three of these planets are rocky in nature and are part of the inner solar system, meaning that they are in between the sun and the asteroid belt.
The troposphere is the layer closest to Earth’s surface. It is 4 to 12 miles (7 to 20 km) thick and contains half of Earth’s atmosphere. Air is warmer near the ground and gets colder higher up. Nearly all of the water vapor and dust in the atmosphere are in this layer and that is why clouds are found here.
The exosphere is the most distant atmospheric region from Earth’s surface. In the exosphere, an upward travelling molecule can escape to space (if it is moving fast enough) or be pulled back to Earth by gravity (if it isn’t) with little probability of colliding with another molecule. The altitude of its lower boundary, known as the thermopause or exobase, ranges from about 150 to 300 miles (250-500 km) depending on solar activity. The upper boundary can be defined theoretically by the altitude (about 120,000 miles, half the distance to the Moon) at which the influence of solar radiation pressure on atomic hydrogen velocities exceeds that of the Earth’s gravitational pull. The exosphere observable from space as the geocorona is seen to extend to at least 60,000 miles from the surface of the Earth. The exosphere is a transitional zone between Earth’s atmosphere and interplanetary space.
Beginning at the surface of Earth, the troposphere extends to around seven miles up. This is the layer we live in and contains most of what we consider to be “the atmosphere”, including the air we breathe and nearly all of the weather and clouds we see. In the troposphere, the temperature of the air decreases the higher you go.
Shooting stars—the fiery burnout of meteors, dust, and rocks from outer space—are visible in the mesosphere. Most shooting stars are the size of a grain of sand and burn up before entering the stratosphere or troposphere. However, some meteors are the size of pebbles or even boulders. Their outer layers burn as they race through the mesosphere, but they are massive enough to fall through the lower atmosphere and crash to Earth as meteorites.
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. This heats the atmosphere, but the atmosphere also cools by emitting radiation, as discussed below.
An interactive simulation for the atmosphere model is available at this web site. With the simulation, you can change altitude and see the effects on pressure and temperature. The same atmosphere model is also used in the FoilSim and EngineSim computer simulators.
The gradual change from the troposphere to the stratosphere begins at approximately 7 miles (11km) high. The temperature in the lower stratosphere is extremely stable and cold at -70deg.F (-57deg.C). Here, strong winds occur as part of defined circulation patterns. High cirrus clouds sometimes form in the lower stratosphere, but for the most part there are no significant weather patterns in the stratosphere.
The thermosphere extends from the mesopause (the upper boundary of the mesosphere) to 690 kilometers (429 miles) above the surface of the Earth. Here, thinly scattered molecules of gas absorb x-rays and ultraviolet radiation. This absorption process propels the molecules in the thermosphere to great speeds and high temperatures. Temperatures in the thermosphere can rise to 1,500 degrees Celsius (2,732 degrees Fahrenheit, or 1,773 kelvin).
Earth’s atmosphere is 78% nitrogen, 21% oxygen, 0.9% argon, and 0.03% carbon dioxide with very small percentages of other elements. Our atmosphere also contains water vapor. In addition, Earth’s atmosphere contains traces of dust particles, pollen, plant grains and other solid particles.
The geological record however shows a continuous relatively warm surface during the complete early temperature record of Earth – with the exception of one cold glacial phase about 2.4 billion years ago. In the late Archean Eon an oxygen-containing atmosphere began to develop, apparently produced by photosynthesizing cyanobacteria (see Great Oxygenation Event ), which have been found as stromatolite fossils from 2.7 billion years ago. The early basic carbon isotopy ( isotope ratio proportions) strongly suggests conditions similar to the current, and that the fundamental features of the carbon cycle became established as early as 4 billion years ago.
Earth’s atmosphere Lower 4 layers of the atmosphere in 3 dimensions as seen diagonally from above the exobase. Layers drawn to scale, objects within the layers are not to scale. Aurorae shown here at the bottom of the thermosphere can actually form at any altitude in this atmospheric layer.
The ionosphere is a region of the atmosphere that is ionized by solar radiation. It is responsible for auroras During daytime hours, it stretches from 50 to 1,000 km (31 to 621 mi; 160,000 to 3,280,000 ft) and includes the mesosphere, thermosphere, and parts of the exosphere. However, ionization in the mesosphere largely ceases during the night, so auroras are normally seen only in the thermosphere and lower exosphere. The ionosphere forms the inner edge of the magnetosphere It has practical importance because it influences, for example, radio propagation on Earth.
The atmosphere’s principal constituents of nitrogen (78%) and oxygen (21%) have varied little for millions of years. Within the remaining 1 percent, there are trace gases such as argon and a group of gases known collectively as the greenhouse gases (GHGs), which serve the important role of trapping heat that the Earth receives from the sun and which make the planet hospitable for life.
The water cycle is all about storing water and moving water on, in, and above the Earth. Although the atmosphere may not be a great storehouse of water, it is the superhighway used to move water around the globe. Evaporation and transpiration change liquid water into vapor, which ascends into the atmosphere due to rising air currents. Cooler temperatures aloft allow the vapor to condense into clouds and strong winds move the clouds around the world until the water falls as precipitation to replenish the earthbound parts of the water cycle. About 90 percent of water in the atmosphere is produced by evaporation from water bodies, while the other 10 percent comes from transpiration from plants.