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Quickie Questions - Earth - Atmosphere/Weather

Date Answered Questioner (age, location) Question Answer
February 9, 2011Anthony (New York)How far is outer space from the ground, like where we sit and walk on and all of that, if we went straight up?There is no sharp boundary between our atmosphere and outer space. The atmosphere just gradually gets thinner and thinner. One definition of space is called the Karman line. The Karman line is 100 km up (about 62 miles). NASA uses 122 km (76 miles) as their re-entry altitude, where space shuttles switch over from using thruster rockets to using wing and tail surfaces for steering.
March 24, 2010rawaa (Illinoi)how does altitude affect air pressure?Air pressure at sea level is the force due to the the weight of the atmospheric mass per area unit. With increasing altitude, there is less atmospheric mass, and therefore, a decreasing atmospheric pressure.
March 23, 2010R.J. (CA)I teach high school earth science and have not been able to find a good answer for why the temperature changes [or stops changing] in the atmosphere [or why ozone is mostly in the stratosphere], and the page titled "Why does the temperature of the atmosphere vary?" completely ignored the question. Where can I find a thorough explanation? My college books are just as vague!
Thanks!
The troposphere is heated from below; sunlight warms the ground or ocean, which in turn radiates the heat into the air immediately above it. Temperature drops off at a rate of about 6.5° C per km (about 3.6° F per thousand feet) of increased altitude within the troposphere. The stratosphere (above the troposphere) is thinner. Ozone heats this layer as it absorbs energy from incoming ultraviolet radiation from the Sun, causing the temperature to rise as one moves upward through the stratosphere. The mesosphere does not absorb solar radiation due to the lack of ozone, so the temperature decreases with altitude. Much of the X-ray and UV radiation from the Sun is absorbed in the thermosphere. Temperatures climb sharply in the lower thermosphere (below 200 to 300 km altitude), then level off and hold fairly steady with increasing altitude above that height. Very high up, the Earth's atmosphere becomes very thin. The region where atoms and molecules escape into space is referred to as the exosphere. It is important to keep in mind that temperature at the thermosphere and exosphere are a measure of the kinetic energy of the air molecules rather than the total energy stored by the air. Additional information could be found at our Resources for Teaching About the Atmosphere.
March 19, 2010Liz (massachusetts)When did the modern atmosphere form?Free oxygen, which signifies a shift from a reducing atmosphere to an oxidising atmosphere, did not exist until about 1.7 billion years.
March 5, 2010rossan (philippines)what is heterosphere and homosphere?The homosphere and heterosphere are defined by whether the atmospheric gases are well mixed. The homosphere includes the troposphere, stratosphere, and mesosphere, where the gases are mixed by turbulence. Above the turbopause (about 100 km), the composition varies with altitude.
February 16, 2010mary (New Bedford,Ma.)How does the atmospheres layers move?The atmosphere layers move in many different ways due to many different factors. For instance, the rotation of our planet is the reason for the Coriolis Effect - an apparent deflection of air and water to the right in the North Hemisphere and to the left in the South Hemisphere. Other forces that produce atmospheric motions are: Pressure Gradient Force. The difference in atmospheric pressure will cause air to move from high pressure to low pressure. Gravity. The principal effect of gravity can be seen in cold air drainage. As the earth’s surface cools at night, cold air will flow down hill. Friction. Important for air in contact with the earth’s surface.
February 10, 2010Mindy (Pa USA)what is the mesosphereThe mesosphere is above the stratosphere layer. The layer above the mesosphere is called the thermosphere. The mesosphere starts at 50 km (31 miles) above Earth's surface and goes up to 85 km (53 miles) high. Meteors or rock fragments burn up in the mesosphere.
February 10, 2010Mang (Syracuse NY)how can the sown fell down from the sky?Snowflakes form in clouds where the temperature is below freezing (0ºC, or 32ºF). The ice crystals form around tiny bits of dirt that have been carried up into the atmosphere by the wind. As the snow crystals grow, they become heavier and fall toward Earth. More information in our website SNOW.
February 5, 2010Al (FL)Is there a place to find a clear explanation of the Coriolis Effect? I understand why pressure systems rotate, but I don't understand why low pressure systems spin counter-clockwise and high pressure systems clockwise (NH). Thank you.For this topic I like the webpage Consequences of Rotation for Weather , developed by the Dept. of Physics & Astronomy of the University of Tennessee.
February 1, 2010Nathalie (Makati City, Phlippines)Why do large jet airplanes fly in the stratosphere?Air is roughly a thousand times thinner at the top of the stratosphere than it is at sea level. Because of this, jet aircraft and weather balloons reach their maximum operational altitudes within the stratosphere.
January 25, 2010isabela (Philippines)does the atmosphere of today have the same composition than it did 400 million years ago? ExplainIt has been calculatd that Earth's atmospher reached the oxygen level of 20% about 400 million years ago.
January 18, 2010jamuna (india)which gas is not a constituent of green house gas?Greenhouse gases are atmospheric gases that absorb and emit radiation within the infrared portion of the spectrum (Thermal). The main greenhouse gases in our atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone. Oxygen is not considered a greenhouse gas.
January 15, 2010antoine (alabama us)how many miles to travel until you reach the exosphereVery high up, the Earth's atmosphere becomes very thin. The region where atoms and molecules escape into space is referred to as the exosphere. The exosphere is on top of the thermosphere which extends from about 90 km (56 miles) to between 500 and 1,000 km (311 to 621 miles) above our planet.
January 11, 2010Richard (Colorado)What determines the location and magnitude of poleward energy transport?The main driver is the radiative imbalance at the top of the atmosphere, the difference between the net downward shortwave flux and the outgoing infrared flux, which is larger than 70 W m-2 near the equator when averaged over longitude and season (Hartmann, D. L., 1994: Global Physical Climatology. Academic Press, 411 pp.). For more specific details see http://www.gfdl.noaa.gov/bibliography/related_files/ih0101.pdf.
January 5, 2010Callie (Washington)Which layer of the atmosphere is currently the greatest interest to most meteoroligists?meteorologists study the troposphere, the lowest layer of Earth's atmosphere. The troposphere starts at Earth's surface and goes up to a height of 7 to 20 km (4 to 12 miles) above sea level. Most of the mass (about 75-80%) of the atmosphere is in the troposphere. Almost all weather occurs within this layer.
January 5, 2010Sanjiv Bridglal (Trinidad)What happens in the Thermosphere?Temperatures climb sharply in the lower thermosphere (below 200 to 300 km altitude), then level off and hold fairly steady with increasing altitude above that height. Solar activity strongly influences temperature in the thermosphere. The thermosphere is typically about 200° C (360° F) hotter in the daytime than at night, and roughly 500° C (900° F) hotter when the Sun is very active than at other times. Temperatures in the upper thermosphere can range from about 500° C (932° F) to 2,000° C (3,632° F) or higher. Although the thermosphere is considered part of Earth's atmosphere, the air density is so low in this layer that most of the thermosphere is what we normally think of as outer space. In fact, the most common definition says that space begins at an altitude of 100 km (62 miles), slightly above the mesopause at the bottom of the thermosphere. The space shuttle and the International Space Station both orbit Earth within the thermosphere!
January 4, 2010Matthew (North Carolina)Why do we have thunder and lightning?Lightning is the most spectacular element of a thunderstorm. In fact it is how thunderstorms got their name. Wait a minute, what does thunder have to do with lightning? Well, lightning causes thunder. Lightning is a giant spark. A single stroke of lightning can heat the air around it to 30,000 degrees Celsius (54,000 degrees Farhenheit)! This extreme heating causes the air to expand at an explosive rate. The expansion creates a shock wave that turns into a booming sound wave, better known as thunder. Thus the name thunderstorm. Don't miss our web page Lightning Formation.
December 23, 2009Shaina (New York/united states)What is the depth of each one of the layers of the atmosphere?Please, see our diagram for heights and temperatures information.
December 23, 2009alina (california)Hi. I am doing a slide show for school on hurricanes and i was wondering if u have more facts about the eye of a storm?As a hurricane strengthens and wind speeds increase, an eye begins to form at the center of the storm. Usually this happens once winds reach about 80 mph. The eye is usually circular when viewed from above, and about 20 to 40 miles is diameter. More information in our web page The Eye of a Hurricane and links therein.
December 23, 2009Keyonna (Florida)How do thunderstorms affect the biosphere, hydrosphere, geosphere, cyrosphere and atmosphere?This is too broad a topic to be discussed in this section. Please, visit our web page Thunderstorms and the links therein for a good amount of related information.
October 19, 2009rosemary (japan)do pilets like to fly there air planes in the stratosphere?The stratosphere is the is the second atmospheric layer, as one moves upward from Earth's surface. Many jet aircrafts fly there because it is very stable. Air is roughly a thousand times thinner at the top of the stratosphere than it is at sea level.
October 16, 2009Wale (London, England)Flying in a plane at a height of 38,000 feet, I understand that the temperature outside the plane is -51 degrees. Why is this?The temperature gradually drops until you get to about 38,000 feet, where it's about 75 degrees Fahrenheit below zero. At that point, you reach the stratosphere, where the temperature goes up again until you're about 30 miles up, peaking up around 20-25 degrees above zero. See a temperature perfil of the atmosphere in our web page Temperature ot the Atmosphere Throughout Different Layers.
October 9, 2009Bunmi (Maryland)Does the Earth's atmosphere rotate with the Earth or does it stand still?The atmosphere does rotate with the Earth, but not as a rigid body, and not always in the same direction.
October 2, 2009Vidhi (Maharashtra)What do you mean by Atmospheric Pressure?Atmospheric Pressure is defined as the weight of the atmosphere on a given point, an average of 1013.2 millibars or 29.2 inches of mercury at sea level.
September 25, 2009Thobeka (SouthAfrica)what is the composition of the troposphere that make up the air and their percentages.The troposphere starts at Earth's surface and goes up to a height of 7 to 20 km (4 to 12 miles, or 23,000 to 65,000 feet) above sea level. Most of the mass (about 75-80%) of the atmosphere is in the troposphere. Its composition is a mixture of nitrogen (78%), oxygen (21%), and other gases (1%).
September 16, 2009ameya (india)does the earth's atmosphere has sixth layer?what's its name?The Earth's atmosphere is commonly divided in 5 layers. Sometimes scientists talk about other layers as the ozone layer or the ionosphere, but they are just part of some of these 5 layers.
August 17, 2009TAJHANAE (CONNECTICUT)WHAT IS THE ALTITUDE A STRATUS CLOUD IS FORMED ATStratus clouds belong to the Low Cloud (surface-2000 m up) group. They are uniform gray in color and can cover most or all of the sky. Stratus clouds can look like a fog that doesn't reach the ground.
July 23, 2009jordog (wyoming)What is the pressure level of oxygen?Atmospheric oxygen partial pressure is approximately 21% of the atmospheric pressure of the location at which you measure. For example, the atmospheric preassure at sea level is around 1 atmosphere, and the partial pressure of oxygen is 0.21 atm.
July 20, 2009khun (Cambodia)How many percentage of rainfall does the earth absorb? And how many percentage of it turn to the atmospher?The amount of rainfall absorved by the ground varies from place to place. It depends on the vegetation cover, the kind of soil, artificial structures (roads, buildings, irrigation chanels), local topography, season, lat/lon, etc.
May 12, 2009ZachI saw a show about mars and on the show it talked about how mars had a moon that churned its core and basically created a hospitable atmosphere for the planet(I know its just a theory). However, I was wondering if the earths moon did the same sort of thing for our planet.One of the theories is: Soon after it formed, Earth's incandescent core was enveloped by an ocean of magma. Intense bombardment by meteorites combined with the mantle's heat caused outgassing of its volatile constituent rocks. Within a few million years, a thick, dense atmosphere formed, even though a large portion of it was probably expelled by the gigantic impact that created the Moon 4.4 billion years ago. See more information here.
April 17, 2009Elaine (NY)The most abundant gas in the atmoshphere is...
A) Oxegen,
B) Nitrogen
C) Argon
D) HElium
Nitrogen is the most abundant gas in the atmosphere: 78% of the Earth’s atmosphere is nitrogen, 21% oxygen, and 1% other gases like carbon dioxide, etc.
April 17, 2009tina (New Jersey)what is the temperature of the thermosphere?Temperatures climb sharply in the lower thermosphere (below 200 to 300 km altitude), then level off and hold fairly steady with increasing altitude above that height. Solar activity strongly influences temperature in the thermosphere. The thermosphere is typically about 200° C (360° F) hotter in the daytime than at night, and roughly 500° C (900° F) hotter when the Sun is very active than at other times. Temperatures in the upper thermosphere can range from about 500° C (932° F) to 2,000° C (3,632° F) or higher.
April 13, 2009Chelsea (Rocky Hill,CT)what are two things,that begin with the letter P, that have to do with the Earths Atmospere?Are you solving a crossword or similar? PRESSURE is one of the parameter that defined the state of the atmosphere, Various industrial POLLUTANTS are also now present in the air.
March 24, 2009Robert (USA)What dose Cirrus meanCirrus comes from the Latin term for "curl or wisp of hair." It is used to identify high clouds, usually above 18,000 feet, composed of ice crystals and appearing in the form of white, delicate filaments or white or mostly white patches or narrow bands.
March 24, 2009Robert (Plymouth Meeting)What dose Cirrus meanCirrus comes from the Latin term for "curl or wisp of hair." It is used to identify high clouds, usually above 18,000 feet, composed of ice crystals and appearing in the form of white, delicate filaments or white or mostly white patches or narrow bands.
March 18, 2009balraj (canada)how does the atmoshere move in spaceThe atmosphere is in continuos motion. The resultant motion is due to a combination of factors, and the 2 most importants are the rotation of our planet, and the heating/cooling due to the Sun (day-night and solar activity related). The atmosphere rotates and also moves around the Sun with the earth. The day-night cycles creates a continuos expansion and contraction process. Additional heating of the atmosphere related with the solar activity could also force an expansion process in the atmosphere.
March 4, 2009jake (michigan)what is the purpose of the esrths atmosphere?Our planet's atmosphere is where the weather happens. It provides the oxygen needed for life, and keeps a more or less constant temperature on the planet. It also protects Earth and humanity from dangerous radiations from the Sun.
March 3, 2009laquinta (nc)what is the definition of a cirrus cloud?Cirrus clouds are the most common of the High Cloud (5000-13000m) group. They are composed entirely of ice and consist of long, thin, wispy streamers. They are commonly known as "mare's tails" because of their appearance. Cirrus clouds are usually white and predict fair weather.
March 2, 2009mark (bronx new york)what is the atmosphere?The atmosphere surrounds Earth and protects us by blocking out dangerous rays from the sun. The atmosphere is a mixture of gases that becomes thinner until it gradually reaches space. It is composed of Nitrogen (78%), Oxygen (21%), and other gases (1%).
February 20, 2009dylan (beton)what are the most important layers of the atmosphere?The atmosphere is divided into five layers depending on how temperature changes with height. It is thickest near the surface and thins out with height until it eventually merges with space. 1) The troposphere is the first layer above the surface and contains half of the Earth's atmosphere. Weather occurs in this layer. 2) Many jet aircrafts fly in the stratosphere because it is very stable. Also, the ozone layer absorbs harmful rays from the Sun. 3) Meteors or rock fragments burn up in the mesosphere. 4) The thermosphere is a layer with auroras. It is also where the space shuttle orbits. 5) The atmosphere merges into space in the extremely thin exosphere. This is the upper limit of our atmosphere.
February 20, 2009Courtney (N.C)How do winter storms form?Basically, winter storms form when an air mass of cold, dry, Canadian air moves south and interacts with a warm, moist air mass moving north from the Gulf of Mexico.
February 8, 2009Matthew (massachusetts/ usa)Who named the layers of the atmosphere?In 1902, Teisserenc de Bort named the two layers of the atmosphere known at that time, the "troposphere" and the "stratosphere". The same naming convention was used for higher layers discovered later.
January 30, 2009Emily (Ohio/United States)Is there a certain cloud that can bring a tornado?Cumulonimbus clouds belong to the Clouds with Vertical Growth group. They are generally known as thunderstorm clouds. A cumulonimbus cloud can grow up to 10km high. At this height, high winds will flatten the top of the cloud out into an anvil-like shape. Cumulonimbus clouds are associated with heavy rain, hail, lightning, and tornadoes.
January 22, 2009Emma (south caroilna conway 29526)What is the percent of strosphere ?
What are the temperatures that change and air pressure that change in each layer?
This figure shows the average temperature profile through the Earth's atmosphere. Temperatures in the thermosphere are very sensitive to solar activity and can vary from 500°C to 1500°C.
November 12, 2008Leydi (Miami, Fl)How earth rotation affects the movement of air, wind systems, types of fronts?The rotation of our planet indeed afect in a very complex manner the motion of the atmosphere. One of the most notorious effect related with the rotation of the planet is the Coriolis effect - an apparent deflection of air and water to the right in the NH and to the left in the SH.
November 4, 2008Catherine (Australia)With the greenhouse effect, I know that the IR is converted to the potential and kinetic energy of the GHG molecules but what, then, is the energy that is radiated back to the Earth? Do the molecules become saturated in the energy and ping off as a result?When sunlight warms the Earth’s surface, the heat is then radiated to the atmosphere. Some of this heat makes its way out of the Earth system, but along the way much of the heat is absorbed by greenhouse gases in the atmosphere. The infrared radiation strikes a molecule such as carbon dioxide and causes the bonds to bend and vibrate - this is called the absorption of IR energy. The molecule gains kinetic energy by this absorption of IR radiation. This extra kinetic energy may then be transmitted to other molecules such as oxygen and nitrogen and causes a general heating of the atmosphere.
October 31, 2008Tyrell (philadelphia,pa)without extra oxygen, man is restricted to what layer of the atmosphere?To the lower layer, the troposphere
September 30, 2008Nick (Florida)Does the weather move, or are we actually turning into the weather as the earth spins?Actually, it is a combination of both, known as differential rotation. Air moves due to the existence of temperature (or density) gradients, but at the same time the solid part is also moving with a slightly different speed that the atmosphere.
September 30, 2008lyndsey (Taiwan)What is a thunderhead?Thunderhead can refer to a cumulonimbus cloud seen during a thunderstorm.
September 24, 2008Madison (Iowa)What type of gas(s) are made up of in the Mesosphere?The mesosphere is composed of the same proportion of gases that the rest of the atmosphere, Nitrogen (78%), Oxygen (21%), and other gases (1%). This is the less known layer of the atmosphere. Visit our web page Mesosphere for more information.
September 24, 2008sharanya (karnataka,India)how are hailstones formed and what makes them fall?Hailstones begin to form as an ice nucleus that may continue to accumulate ice or can melt in the thundercloud and turn to rain. This nucleus could be formed from dirt, piece of bark, seed, etc. If the thunderstorm is cold enough, this nucleus will accumulate layers of ice through a process called accretion, until it is so heavy it falls as precipitation.
September 5, 2008(Oman)The influence of forests on atmospheric tempretureThey can influence the atmospheric temperature in several ways. For example, their darker color, when compared with cities and deserts, means that they absorb more solar energy, reflecting less back to the atmosphere. Fires on the forests not only heat the lower layers of the atmosphere, but also release tons of particulates and pollution. The forest also contributes to the atmosphere by taking CO2 and releasing oxygen (O2).
August 14, 2008sharanya (karnataka,India)how is atmosphere weighed?The weight of the Earth's atmosphere can be calculated as follows. Atmospheric pressure at sea level is on average 14.5 pounds per square inch = 10 tons/m2. This pressure is due to the weight of atmosphere above an area at sea level of one square meter. The radius of the Earth "r" is 5 925 km and so the surface area of the Earth (land and ocean) is 4 x pi x r2 = 4 x 3.142 x 59252 = 441 million kilometres2 = 441,000 billion meter2. Therefore the weight of the Earth's atmosphere is 441,000 billion x 10 = 4.41 million billion tons. Adapted from Accelerated Global Warming and Atmospheric CO2 Emissions.
June 30, 2008Haley (Tennessee)What is the atmosphere made up of?The atmosphere is a mixture of gases that becomes thinner until it gradually reaches space. It is composed of Nitrogen (78%), Oxygen (21%), and other gases (1%).
June 27, 2008Damaris (Texas)What layer of the atmosphere contains the biosphere?The troposphere is the lowest layer of the Earth's atmosphere. It is considered part of the biosphere.
June 27, 2008Melanie (Fl)Which layer does moest weather conditons take place?Weather occurs in the Earth's troposphere.
May 13, 2008ziad (new york)Describe how the amount of air changes as you travel up through Earth's atmosphere.Most of the gases that form our atmosphere are (due to the gravitational atraction) concentrated close to the surface. At sea level, the number of atoms and molecules in a cubic centimeter of air is about 2x1019; however, the outermost atmosphere of our planet (above a few hundred kilometers) is a region of extremely low density, with about 2x107 particles per cubic centimeter of air near 600 km of altitude.
May 12, 2008Jovanni (Philippines)how does an eye of a cyclone or tornado was formed?There still an on-going debate about how the eye and eyewall are formed. Several scientists support the hypothesis that the existence of very strong winds cause air to be centrifuged out of the eye into the eyewall.
May 7, 2008Khaila (Louisiana)If there is no air in space what keeps the air inside the Earth?Explain why.Gravity is the force that keeps the atmosphere around our planet.
May 2, 2008Bryan (CA)"What is the region between the layers of the atmosphere called?"The region between layers is named with the same term as the lower of two layers, but adding "pause" at the end. For example, the transition boundary between the troposphere and the stratosphere is called the tropopause.
April 18, 2008Rica (Philippines)What are the gases found in/makes up the atmosphere?The atmosphere is a mixture of gases that becomes thinner until it gradually reaches space. It is composed of Nitrogen (78%), Oxygen (21%), and other gases (1%).
March 31, 2008kiran (new york)How does the compisition of gasas change as you travel up through the atmosphere?The atmosphere surrounds Earth and protects us by blocking out dangerous rays from the sun. The atmosphere is a mixture of gases that becomes thinner until it gradually reaches space. It is composed of Nitrogen (78%), Oxygen (21%), and other gases (1%). More information can be found in our web page The Earth's Atmosphere and the links therein.
March 19, 2008Brittany (Georgia)what is the ultimate cause of all weather?
and
what is the source of this ultimate cause of all weather?
There are several factors that interact in the troposphere to define weather. Heat energy and its dispersion, air pressure and movement, and the amount of moisture are the main players.
March 18, 2008Deseree (CA, USA)what are the various things you can find in each layer of the atmosphere? for example, what do you find in the biosphere?Our web page Layers of Earth's Atmosphere offers the information you are looking for and much more.
March 14, 2008tristuian (sc)why are the layers of the atmosphere so important?Atmospheric layers are different in composition, temperature, etc. Because we live in one of them, and the weather happens there (besides other human activities in other layers), it is important to know how they behave under different conditions.
February 15, 2008NADINE (PHILIPPINES)what causes storms?Storms are created when a center of low pressure develops, with a system of high pressure surrounding it. This combination can create winds and result in the formation of storm clouds.
February 15, 2008nadine (philippines)why are there different kinds of storms?Storms can be clasified in different ways. Most serious storms have heavy rains, winds, snow or hail. Some examples of severe weather are tornadoes, hurricanes and thunderstorms. All of these can cause massive damage where they occur.
February 12, 2008Katie (United states)In the troposphere, what does the air temperature do as the altitude increases?In the Earth troposphere the temperature generally decreases with increasing height.
February 5, 2008harris (FL America)the main idea of troposphereThe troposphere is the lowest layer of the Earth's atmosphere. The air is very well mixed and the temperature decreases with altitude. Air in the troposphere is heated from the ground up. The surface of the Earth absorbs energy and heats up faster than the air does. The heat is spread through the troposphere because the air is slightly unstable. Weather occurs in the Earth's troposphere.
January 30, 2008Debbie (usa)how does the amount of humidity in the air affect the amount of clouds in the sky?Clouds form when water accumulates around very small particles (aerosols). If there is no change in the amount of these particles, higher humidity would produce more water accumulation, which could result in an increase in the number of clouds.
January 15, 2008Jackie (Michigan)What type of weather/stuff happens in the mesosphere?In the Earth's mesosphere, the air is relatively mixed together and the temperature decreases with altitude. The atmosphere reaches its coldest temperature of around -90°C in the mesosphere. This is also the layer in which a lot of meteors burn up while entering the Earth's atmosphere. There are no important weather processes here.
January 12, 2008Laine (Louisiana/USA)Where do tornados form? on the ground or in the sky?Tornadoes form from severe thunderstorms. They have a very high energy density which means that they affect a small area but are very destructive to that area. They also don't last very long which makes it hard to learn about them. More information in our website Tornadoes.
January 8, 2008ashin (usa)What is the temperature in the Exosphere??????The exosphere is the outermost layer of the earth's atmosphere, starting at 500-1000 km above the surface and gradually thinning to the vacuum of space. At these altitudes the air is so tenuous that temperature has to be defined in terms of the energy of individual molecules: daytime energies reach well over a thousand degrees; at night the molecule radiates and its energy level falls to a few degrees of absolute zero.
January 3, 2008Andrew (South Carolina/United States)Explain how the air above the earth is warmed?There are different ways in which our atmosphere is warmed. The main ones are directly from the Sun rays, and because the radiation of heat from the surface of the Earth.
December 27, 2007Sarah (New York)What gases make up th Troposphere?The troposphere is primarily composed of nitrogen (78%) and oxygen (21%) with only small concentrations of other gases. Nearly all atmospheric water vapour is found in the troposphere.
December 27, 2007shelina (USA)explain why the total amount of nitrogen doesn't change?For a relatively short period of time, the amount of nitrogen on Earth's atmosphere remains approximately constant, moving around the different parts of the Nitrogen Cycle. But when long periods of time are considered, the amount of nitrogen does change. Please, visit our web page Earth's Primordial Atmosphere for further details.
December 17, 2007Emily (Louisiana)Why does weather only occur in the Tropospheric?It is true that most weather occurs in the troposhere, but there is still some weather related processes above the troposphere, but these layers are very stable and have much lower density.
December 12, 2007michelle (illinois usa)why does most weather occur only in 1 layer of the atmosphereMost weather occurs in the troposhere. There is still some weather related processes above the troposphere, but these layers are very stable and have much lower density.
December 10, 2007marvin (western australia)which layer has jet streamsJet streams are found in the atmosphere at around 11 kilometers of altitude. The jet stream is mainly found in the tropopause, the transition region between the troposphere and the stratosphere.
December 10, 2007Jillian (PA/United States)How does the mesophere affect life on the Earth's surface?In the Earth's mesosphere, the air masses are relatively mixed together and the temperature decreases with altitude. Atmospheric temperatures reach the lowest average value of around -90°C in the mesosphere. This is also the layer in which a lot of meteors burn up while entering the Earth's atmosphere. Because the mesosphere lies between the maximum altitude for aircraft and the minimum altitude for orbital spacecraft, scientists can only study this region using sounding rockets.
October 18, 2007Dawson (FL)1. Need details of the EXOSPHERE
2. What is the Exosphere miles and/or kilometers?
3. What is the Exosphere Teperature (Celsius & Fahrenheit)?
4. What if anythin is located in the Exosphere? do you have pictures?
The exosphere starts at around 500 km of altitude, where the Earth's atmosphere becomes very thin and where atoms and molecules escape into space. The exosphere is on top of the thermosphere.
October 15, 2007ronel (Batangas Philippines)What objects can be seen in each layer of earth's atmosphere?Layers of the Earth's Atmosphere.
August 21, 2007Brittany (Western Australia)Why is the thermosphere hotter than the mesosphere?The temperature in the Thermosphere can reach 2000º C. It is so hot here because nitrogen and oxygen in the atmosphere absorb a good deal of radiation from space and convert it to heat.
August 21, 2007Nicolas (New Zealand)How does the activity of man affect the atmosphereThere are many ways in which humans affect the atmosphere, maybe he best known is the "greenhouse effect". The gases in the atmosphere that help retain heat are called greenhouse gases. These gases, primarily carbon dioxide (CO2), absorb heat instead of allowing it to escape into space. This "greenhouse effect" makes the planet a hospitable place. However, greenhouse gases can have negative effects, too. Human activity has increased the amount of CO2 in the atmosphere. Since the 1800s, industrialized societies have burned fossil fuels such as coal, oil, and natural gas; these processes all give off CO2. During the past 25 years, the amount of CO2 in the atmosphere has increased by about 8 percent. With more CO2 in the atmosphere, more heat is absorbed and retained, causing global temperatures to rise. Extracted from Weather: The Atmoshere.
July 27, 2007Amy (Australia, Qld)How thick are layers in the atmosphere?The troposphere goes to about 10km. The stratosphere from about 10 km to about 50km (40 km thick). From 50 km to about 85 km is the mesosphere (~35 km thick), and from about 85 km to about 500 km is the thermosphere (~400 km thick). This figure from our web site shows the different layers.
July 18, 2007GABY (CA)what are the 4 layers of the atmosphere?The atmosphere is divided into five layers. It is thickest near the surface and thins out with height until it eventually merges with space. 1) The troposphere is the first layer above the surface and contains half of the Earth's atmosphere. Weather occurs in this layer. 2) Many jet aircrafts fly in the stratosphere because it is very stable. Also, the ozone layer absorbs harmful rays from the Sun. 3) Meteors or rock fragments burn up in the mesosphere. 4) The thermosphere is a layer with auroras. It is also where the space shuttle orbits. 5) The atmosphere merges into space in the extremely thin exosphere. This is the upper limit of our atmosphere.
July 18, 2007windsor ()How did Earth get atmostphereScientists believe that Earth’s present atmosphere came from inside the planet. Volcanos might have spewed out water vapor, nitrogen compounds, carbon dioxide, ammonia, and methane. Interactions with radiation from the sun—and falling temperatures—caused large amounts of nitrogen to appear. Eventually, life came on the scene to add breathable oxygen and protective ozone, creating the air we breathe today. More information at this web page.
July 17, 2007Christopher (Australia)What is the composition of all the individual layers in the earths atmosphere?The atmosphere surrounds Earth and protects us by blocking out dangerous rays from the sun. The atmosphere is a mixture of gases that becomes thinner until it gradually reaches space. It is composed of Nitrogen (78%), Oxygen (21%), and other gases (1%). More information can be found in our web page The Earth's Atmosphere and the links therein.
July 11, 2007maggie (mi)what is thermospher temperature rangeThe thermosphere is the fourth layer of the Earth's atmosphere and is located above the mesosphere. The air is really thin in the thermosphere. A small change in energy can cause a large change in temperature. That's why the temperature is very sensitive to solar activity. When the sun is active, the thermosphere can heat up to 1,500°C or higher! More information in our webpage The Thermosphere.
July 11, 2007BOODHUN (MAURITIUS)Define a low pressure and high pressure area?A low pressure are has a lower atmospheric pressure that its sorroundings. The opposite is true for high pressure areas.
July 2, 2007jade (Hong Kong)Why is the thermosphere made of mostly hydrogen and helium?Because the extreme temperatures that can be reached at this height. The thermosphere is the fourth layer of the Earth's atmosphere and is located above the mesosphere. The air is really thin in the thermosphere. A small change in energy can cause a large change in temperature. That's why the temperature here is very sensitive to solar activity. When the sun is active, the thermosphere can heat up to 1,500°C or higher!
July 2, 2007Desmonnd (South africa)what are the first most charectoristics of the first layer of the atmosphereThe troposphere is the first layer above the surface and contains half of the Earth's atmosphere. Weather occurs in this layer.
May 21, 2007Mary (NY ,USA)why is the atmoshere divided into four layers?This image shows the changes in temperature with height. There you can see how the temperature profile has different characteristics for the different layers.
May 5, 2007jemel (massachusetts)how does the temperature change as you travel up through the atmosphereThere are different layers in the atmosphere where the temperature either increases or decreases with height!! For an image showing the temperature of the atmosphere throughout different layers, visite our web page.
May 5, 2007josue (Texas,U.S.A)WHAT IS THE FORCE THAT HELPS FORM THUNDER?Inside a thunderstorm, the + and - charges are separated into two sections. All of the + charges are at the top of the thunderstorm cloud. All of the - charges are at the bottom of the thunderstorm cloud. During a thunderstorm, the ground has a + charge. + and - charges are attracted to each other. The - charge at the bottom of the thunderstorm cloud wants to meet the + charge of the ground. The - charge of the cloud starts to rush toward the + charge at the ground. At the same time, the + charge rushes toward the - charge. It happens so fast that all we can see is a line of light. This is called lightning. More information in our web page Lightning and Thunder.
May 5, 2007shane (n.c , usa)what layer of the amosphere does planes fly in?Most of the flying occurs in the troposphere. For an image showing what man-made and natural phenomena occur in each layer of the atmosphere, visit here.
April 4, 2007Taylor (Arizona)What height is the tropopause,the stratopause, and the mesopause?The tropopause, at about 10 km of altitud,. is the limit between the troposphere and the stratosphere. Between the stratosphere and the mesosphere is the stratopause (at about 50 km), and the uper part of the mesosphere is the mesopause (about 85 km).
March 30, 2007liz (california, usa)would there be wind without the sun? why or why not?The main cause for winds is the existence of horizontal differences in air pressure (air flows form areas of higher pressure to areas of lower pressure). Differences in air pressure are caused by uneven heating of the Earth's surface. Therefore, the sun (solar energy) is the ultimate cause of wind. For more information, visit the web page Wind, Global Wind Systems and the Coriolis Effect.
March 28, 2007AlexDo you know what the ozone layer is?The ozone layer is the part of the atmosphere with relatively high concentrations of ozone (O3). This layer is mainly located in the lower part of the stratosphere (15 to 35 km above Earth's surface) although the thickness varies seasonally and geographically.
March 5, 2007Amber (Georgia)Why is there 7 layers in the atmosphere?The atmosphere is a mixture of gases that becomes thinner until it gradually reaches space. It is composed of Nitrogen (78%), Oxygen (21%), and other gases (1%). The atmosphere is divided into five layers depending on how temperature changes with height. Our web page Layers of the Earth Atmosphere describes the different layers.
March 5, 2007stacey (malaysia)What will happen if acid rain is not overcome?Acid rain can have harmful impacts on the ecosystems in the environment. It acidifies the soil and water where it falls, damaging or even killing plants and animals. Surface water acidification can lead to a decline in, and loss of, fish populations and other aquatic species including frogs, snails and crayfish. Acid rain affects trees, usually by weakening them through damage to their leaves. Certain types of building stone, such as limestone and marble, can be gradually dissolved in acid rain. The long-term effects of acid rain could be devastating.
March 1, 2007Sharon (GA)What objects lie in the Stratosphere? (example: stars, rockets, meteroids, etc.)Many jet aircrafts fly in the stratosphere because it is very stable. It also contains the ozone layer, which absorbs harmful rays from the Sun.
February 22, 2007Judy (wa)What is the Width of each layer in Earth 's atmosphere ? Answer please it's due on 2/14/07Troposphere: From surface to about 10 km. Stratosphere: From 20 to about 50 km. Mesosphere: From about 50 to about 85 km. Thermosphere: Over 90 km. More detailed information at our web page Temperature of the Atmosphere.
February 22, 2007Judy (wa)What is the Width of each layer in Earth 's atmosphere ? Answer please it's due on 2/14/07Troposphere: From surface to about 10 km. Stratosphere: From 20 to about 50 km. Mesosphere: From about 50 to about 85 km. Thermosphere: Over 90 km. More detailed information at our web page .
February 22, 2007Judy (wa)What is the range temperture of the mesosphere ?The mesosphere covers from about 50 km to the range of 80 km to 85 km, and its temperature decreases with height from about -10 to about -70 degree C.
February 22, 2007claus (BC, Canada)I would like to know the formulae for calculating the volume of the earht's atmosphere ... say to the 99% of mass which I believe is within 31Kilometers from earth
Should I just assume the volume of the larger sphere and deduct the smaller... but the earth is not round. Can you send me to a link?
Thanks
Claus
The mesosphere covers from about 50 km to the range of 80 km to 85 km, and its temperature decreases with height from about -10 to about -70 degree C.
February 22, 2007Faith (Tennessee)What kind of cloud brings sleet and freezing rain?Cummulonimbus clouds are storm clouds associated precipitation like rain, sleet, hail, etc.
February 22, 2007lindsey (nj)how do different air pressures in two air masses cause dramatic changes in weather patternsMost weather occurs along the periphery of air masses at boundaries called fronts. For example, in winter an arctic air mass (very cold and dry air) can move over the ocean, picking up some warmth and moisture from the warmer ocean and becoming a maritime polar air mass - one that is still fairly cold but contains moisture. If that same polar air mass moves south from Canada into the southern U.S. it will pick up some of the warmth of the ground, but due to lack of moisture it remains very dry. This is called a continental polar air mass. Pressure is related with the air masses through the fact that cold, dry air is more dense than warm, moist air. If hot air masses are the same height, the cold air will have higher pressure at the earth's surface.
January 25, 2007Brittany (Arizona)What is the average temperature of the whole Troposphere?The troposphere starts at the Earth's surface and extends 8 to 1.5 kilometers high. The temperature drops with height from about 17 to -52 degrees Celsius.
January 25, 2007Crystal (Texas)What are the 5 layers of the atmosphere calledThe Earth's atmosphere is divided vertically into four layers based on temperature: the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
January 23, 2007debra (CANADA)What is the temperature of the stratosphereThe stratosphere starts just above the troposphere and extends up to 50 kilometers high. The temperature in this region increases gradually to -3 degrees Celsius, due to the absorbtion of ultraviolet radiation.
January 17, 2007zachary (canada)how does the greenhouse effect effect our planet?The presence in the atmosphere of gases like carbon dioxide, nitrous oxide, and methane, causes the trapping of the Sun energy. In other words, without greenhouse gases, the heat would leave our planet and Earth would be considerably cooler.
January 14, 2007skilar (united states ohio)what are some facks about the TroposphereThe troposphere is where all weather takes place. It is the lowest layer of the Earth's atmosphere. The air is very well mixed and the temperature decreases with altitude. Air in the troposphere is heated from the ground up. The surface of the Earth absorbs energy and heats up faster than the air does. The heat is spread through the troposphere because the air is slightly unstable. For more information, please visit our web page The Troposphere.
January 5, 2007Chavon (Ohio)what is another name for very low clouds?Low clouds (clouds with bases are around 6,500 feet or 2,000 meters), are usually of the nimbostratus, stratocumulus, stratus, cumulus and cumulonimbus type.
January 5, 2007divya (India)what is cyclones? Please explainThe definition of cyclone is: an area of low pressure around which winds blow counterclockwise in the Northern Hemisphere. Also the term used for a hurricane in the Indian Ocean and in the Western Pacific Ocean.

For more information about this topic, please visit our web page Hurricanes.
December 6, 2006brittany (alaska)what is the layers of the earths atmosphere?The atmosphere is divided into five layers. It is thickest near the surface and thins out with height until it eventually merges with space. 1) The troposphere is the first layer above the surface and contains half of the Earth's atmosphere. Weather occurs in this layer. 2) Many jet aircrafts fly in the stratosphere because it is very stable. 3) Meteors or rock fragments burn up in the mesosphere. 4) The thermosphere is a layer with auroras. 5) The atmosphere merges into space in the extremely thin exosphere. This is the upper limit of our atmosphere. For more information visit our page a href="/earth/Atmosphere/layers.html">Layers of the Earth's Atmosphere
November 30, 2006Kelli (SouthCarolina/unitedstates)The troposphere contains about 75%f what in the atmosphere?The Troposphere is the lowest layer of the atmosphere and contains about 95 % of the mass of air in the Earth's atmosphere.
November 20, 2006katelynd (new zealand)what are the differences between climate and weather?Weather is the mix of events that happen each day in our atmosphere including temperature, rainfall and humidity. Weather is not the same everywhere. Perhaps it is hot, dry and sunny today where you live, but in other parts of the world it is cloudy, raining or even snowing. Everyday, weather events are recorded and predicted by meteorologists worldwide. Climate in your place on the globe controls the weather where you live. Climate is the average weather pattern in a place over many years. So, the climate of Antarctica is quite different than the climate of a tropical island. Hot summer days are quite typical of climates in many regions of the world, even without the affects of global warming. Information adapted from: http://eo.ucar.edu/basics/index.html
June 15, 2001Ghada (11, Saudi Arabia)What does climate mean?The earth's climate is generally defined as the average weather over a long period of time. A place or region's climate is determined by both natural and anthropogenic (human-made) factors.
May 9, 2001(14, New York, USA)Where can I find information about the mesosphere and exosphere?The mesophere and exosphere are layers of the Earth's atmosphere.
March 27, 2001Allison (11, Mississippi, USA)About how many layers are in the atmosphere?There are 5 layers in the Earth's atmosphere.
February 5, 2001Melissa (South Carolina, USA)Does our wind come from solar wind?Though the solar wind does drive some processes that affect life on Earth, it is not responsible for the wind. Most simply, winds on Earth are due to differences in pressure within the atmosphere.
November 20, 2000Krystle (USA)How is lightning formed? And how do the storms form? What causes them to happen when they happen?This page should help you out!
October 30, 2000Tom (Bethesda)What is the stratosphere?The stratosphere is the second layer of the Earth's atmosphere (going from the ground up). The famous ozone layer is in the stratosphere.
October 12, 2000Casey (Missouri, USA)Why do rainbows occur?Here's a page on why rainbows occur!
September 29, 2000Kenny (Colorado, USA)How far is the atmosphere from Earth?Well, the atmosphere actually starts right at the solid surface of the Earth. So if you go out in the backyard and lie down on the grass...the atmosphere is right there even just an inch above the grass. The first layer of the atmosphere starts right where we live. That layer of the atmosphere is called the troposphere. But the atmosphere does extend out really far...to about 250 miles or 400 kilometers above the Earth's surface. That last layer of the Earth's atmosphere is called the exosphere.
August 16, 2000Andy (New Zealand)When the temperature drops to 0 centigrade at ground level is there a warm layer of air above it and if so what height dose the warm level start and finish?

First of all, regardless of the surface temperature, it is possible for air above the surface to be warmer. Typically, the temperateure decreases as we go up for the 10-20 km.

However, at some height the air may actually get warmer for just a little while. This is called an inversion. Inversion can occur at almost any altitude. Clouds usually form near an inversion.

July 13, 2000Christin (California, USA )What is thought to be the likely origin of the modern Earth's atmoshere?

Scientists believe our atmosphere was formed when gases seeped out of the Earth. There were large amounts of water vapor that became lakes. Nitrogen and carbon dioxide also leaked out of the Earth. These gases were unable to escape the Earth's gravitational pull. Eventually, there was enough gas to create an atmosphere.

June 26, 2000Angelina (Canada )What surveillance methods exist to track or predict tornadoes?Read tornado forecasting to find out!
June 13, 2000Elly (Virginia, USA )How does a helium balloon work?

This is a simple question of density. Helium is less dense than the air around it. And we all know that less dense air rises! You can do the simple experiment with water and cooking oil. Put them in a glass, and the oil will always float above the water because it is less dense.

May 12, 2000Tammy (26, Ohio, USA)When is a tornado more likely to form day or night or when have most formed?Tornadoes can form at any time, day or night. The important thing is to have the right conditions. A tornado can't just form out of thin air!

First of all, tornadoes can only form from one type of cloud. Only the most advanced and largest clouds can make tornadoes. Plus, there must be a high level of instability in the atmosphere, and a high dew point.

May 12, 2000Patrick (Illinois, USA)Why is there a difference of heights of the tropopause level at two different locations?

The height of the tropopause depends on a number of factors, including the surface temperature.

The temperature of the tropopause does not change much, but the surface temperature changes greatly around the globe. In the Arctic regions, the surface temperature is obviously lower than the tropics. It takes a lot longer for the temperature to drop in the tropics, so naturally the tropopause has to be higher.

March 20, 2000Holly (Canada)Does rain fall in droplets because the water molecules are attracted to each other by electrostatic forces, or is this just another theory?During a storm, water molecules in clouds begin to form around dust particles. These molecules are mixed up inside the clouds and combine to form tiny droplets. At some point the droplets get too big for the cloud to hold, and they begin to fall out. As they fall, they collect more molecules and eventually form rain droplets. During stronger storms, the winds can keep the droplets inside the clouds for longer periods of time, so we get larger droplets. However, rain droplets can only get so large before they are broken up during their fall through the sky.
March 1, 2000Vivek (India)How can I understand the mechanism of the monsoons ?This page, from USA Today, has a good diagram to check out.
February 9, 2000Eledy (Pennsylvania, USA)Can you tell the weather from clouds? If so how?You can't really tell the weather from clouds, but they will give you an idea of what the weather will be like in the near future. If you look outside and there are only scattered, thin clouds, then you don't have to worry about any rain or snow for a while.

But if there are many grey, tall clouds, you better get inside because a storm is probably on its way! Also, the amount of cloud cover will affect the temperature at night. If the sky is clear, then the heat from the Earth can escape into space. But when it's cloudy, the clouds absorb some of the heat, keeping it a little warmer at night.

January 25, 2000Angie (Florida, USA)What is the atmospheric pressure on Mars compared to Earth?The average pressure on the surface of Mars is only 7 millibars which is less than 1% of Earth's.
January 25, 2000Beth (Ohio, USA)i am studying global warming and the green house effect in my 9th grade science class. i was wondering what is the difference between the two and what would happen if we were to expierence either one?The difference is, one causes the other. The greenhouse effect is the main cause of global warming. Basically, the greenhouse effect describes the process of heat being trapped in our atmosphere.

Certain gases in our atmosphere, like water vapor and carbon dioxide, absorb the radiation given off by our Earth. Normally, this radiation would escape into space, but these gases absorb it, and then release radiation that travels back to Earth.

When this radiation reaches Earth, we experience global warming.

January 10, 2000Richard (Missouri, USA)I picture the jetstreams as flowing like water. I believe that the winds react the same way as water flowing down a stream. When someone throws a object into the flow it creates little swirles that moves along the way of the flow until thet staightenout.This is what I think happens when the shuttle creates when passing through. Can this happen?That's actually an excellent way to look at it. Both air and water are fluids, so they have very similar properties as far as their motion is concerned.
December 24, 1999Jasmin(Alabama, USA)how does pollution effect the atmostspere?Pollution causes all kinds of problems! Some kinds make acid rain that kills our plants and fish. Others cause breathing problems, like smog.

Even more cause a decrease in ozone, which protects us from harmful ultraviolet light from the Sun. So as you can see, it's very important to limit pollution!

December 3, 1999Dan (Michigan, USA)What causes the jet stream and why does it exist?The jet streams (there is more than one) are caused by temperature differences in the atmosphere.

The most famous jet stream is the Polar Jet Stream. It forms where the cold, polar air meets the warm air from the tropics. The large temperature difference between these two causes a large pressure difference as well.

Air from high pressure flows in the direction of low pressure. Since the pressure changes so quickly, the air flows between pressures very fast. The strong winds are formed, which are called jet streams.

December 3, 1999Jack (Massachusetts, USA)What is meant by supersaturation as it applies to cloud formation?Supersaturation refers to the amount of water present in the cloud. A cloud can only hold a certain amount of water. That amount depends on the pressure, volume and temperature of the cloud and water. This amount is usually called humidity.

Humidity is measured in percent, and so the hypothetically, a cloud can only reach 100% humidity. However, sometimes the percentage goes slightly higher, which means there is actually some liquid water in the cloud. In this case, the cloud is said to be supersaturated.

November 15, 1999Rob (Pennsylvania, USA)I am concerned about the greenhouse effect and its role in our future. How does it affect our environment? How does it effect our lives? What will happen if nothing is done about it? What solutions have been proposed to reduce or eliminate this problem? Where can I learn more about this?This page, from the Environmental Defense Fund, would be a good place to start your research: lots of links, and things you can do to help out.
October 6, 1999Richard (Iowa, USA)What effect does the space shuttle have on the jet streams when it goes into and return from outer space?I don't think this topic has been studied, but in theory the shuttle shouldn't change the jet streams at all.
Jet streams are long, thin lines of strong winds. The winds reach speeds higher than 200 miles per hour! This makes the jet streams very d ifficult to change.
If the shuttle travels through a stream, it will most likely feel effects similar to an airplane. But the jet stream will just keep on going!
July 26, 1999Colleen (California)Does lightning strike ships at sea?Yes, lightning strikes do occur at sea. In fact, a boat is just about the worst place to be during a thunderstorm because it is the highest point around (unless of course there's a taller ship nearby).
June 8, 1999Igor (England)Why do the hurricanes have anti cyclonic patterns in the northern hemisphere?Hurricanes show this pattern in the northern hemisphere because the Coriolis effect causes winds to begin to flow in a north-easterly direction. When low pressure begins to form north of the equator, winds flow inward trying to fill in the low and are deflected to the right causing a counter-clockwise rotation to form. The opposite rotation will occur southern hemisphere.
May 10, 1999Hannah (Minnesota,USA)why is weather so unpredictable? Why does weather change so much?Weather is so unpredictable because there are many things that can change it! For example, if there is a nice warm day in Minnesota and cold air from Canada comes down and mixes, a lot of things can happen. The temperature will decrease, the humidity may change, a storm may form, etc. Scientists are now able to use the newest technology to predict what will probably happen in each situation, but they can't always be sure! As our technology becomes more adva nced are predictions will get more exact!
May 3, 1999Jim (Nebraska, USA)What causes the Jet Stream(s)?The two jet streams are caused by the temperature gradient in the Earth's atmosphere. The Earth's air is generally cooler at poles and warmer at the equator. This temperature difference causes dramatic differences in pressure, which in turn causes intense winds.
February 4, 1999Bri Why do clouds float? Why don't they just fall to Earth? Everything clouds are made of falls to Earth. Why not clouds?Clouds are made of very tiny particles of water and ice. They form when water vapor condenses on dust particles in the atmosphere. These cloud droplets are so small that gravity can't pull them down. The droplets can combine together to form rain drops. The rain drops are what fall to the ground; they are so big that gravity can pull them down.
November 23, 1998Andrea (Florida, USA)There is a concern by scientists that there is not enough ozone in the ozone layer of the atmosphere. Local radio stations say that there is too much ozone when the pollution level is high. Is there 'good' ozone and 'bad' ozone? Please explain.The difference here is in where the ozone is located, not what it's made of. The reason that ozone is good for you in the stratosphere and not good on the surface of the earth is a matter of what it does. The ozone layer protects the earth by reflec ting harmful radiation back into space. However, the chemicals in ozone, for example in the form of acid rain, can be very destructive to the environment and man-made objects.
August 27, 1998Akshar (Kansas, USA)How long is the average lifespan of a cloud?Clouds can last anywhere from a few minutes to days. The lifespan of a cloud depends upon its type. Cumulonimus clouds can last for a few minutes, or, in the case of huge storms, twelve hours or more. Small cumulus clouds last around 10 to 15 minut es.
June 17, 1998Emily (Florida, USA)How far do we travel from the ground until we get to space?There is not an exact starting place for where the Earth's atmosphere ends and space begins. The Earth's atmosphere just gets less and less as you travel higher and higher. Most scientists (if hard-press ed) would say that the atmosphere ends around 100 kilometers above the Earth, but even at that height, part of the Earth's atmosphere is there (mostly hydrogen).
May 29, 1998Elliot (Texas, USA)Why doesn't it rain sometimes during a tornado?Actually, it never rains during a tornado. Tornadoes form in an updraft where air is going up into the storm. The air that's going up also pushes the raindrops up so they can't fall to the ground. But, it can rain near a tornado. Sometimes people will look at a tornado through the rain; they call this a rain-wrapped tornado.
May 29, 1998Sathasivan (Japan) If I imagine that the Earth spinning as a ball rotating in a bucket of water, there should be a boundry layer, turbulent region, etc. Where are those in the atmosphere around the globe? Or is it wrong to think in that line.No, you're right; that is the correct way to think of the atmosphere. Friction with the surface of the Earth creates what is known as the Planetary Boundry Layer. It is hard to model the PBL mathematically because it is very complex. The layer usually extends from the surface to about 1 kilometer, although this can vary from 30 meters to 3 kilometers depending on the stability of the atmosphere. As a reference, the lowest 1 km contains about 10% of the mass of the atmosphere.
May 22, 1998Leigh (Illinois, USA) What is the temperature range that snow will fall?You'd be surprised at the temperature range when it can snow. It never gets too cold to snow. As the temperature drops, the snowflakes just become smaller. It will even snow when the temperature is above freezing! This usually happens when the above freezing air is only close the the ground and there's colder air above it. The air also has to be dry near the ground. This is because the snowflakes will begin to melt slightly as they fall through the warmer air but the melted water will evaporate quickly into the dry air. This evaporation will cool the air around the snowflake and prevent it from melting completely.
May 22, 1998Sara (Portugal) How did the oxygen first get into the Earth's atmosphere?As the story goes, about 2.7 billion years ago, a type of cyanobacteria appeared on the scene (the evolutionary scene, that is!). Its name? Stromatolites. This cyanobacteria had the ability to photosynthesize. Oxygen is a by-product of photosynthe sis. As these stromatolites continued to photosynthesize, oxygen continued to accumulate in the atmosphere. We call our atmosphere the 'modern atmosphere' because it does have oxygen in it.
May 5, 1998Sonnyboy (South Carolina, U.S.A.) Does lightning come out of the sky or from the ground?Lightning actually goes from the cloud to the ground and from the ground to the cloud. The electrical spark goes back and forth many times very rapidly, which we see as a single bolt of lightning.
January 14, 1998Matt (Indiana, USA)What are the gases in the Earth's atmosphere other than argon, carbon dioxide, nitrogen, oxygen?The Earth's atmosphere is primarily composed of nitrogen (78%) and oxygen (21%). The remaining 1% is made of carbon dioxide, water vapor, argon, and trace gases. The trace gases include neon, helium, krypton, and xenon. These are only present in mi nute amounts.
January 14, 1998Neil (California, USA)What is the average depth of the Earth's atmosphere?The Earth's atmosphere extends thousands of kilometers into space. However, past about 550 kilometers, the air is extremely thin. In fact, about 99% of the total mass of the atmosphere is below the altitude of 32 kilometers.

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