Earth Science
Content
4. Clouds actually generate heat, some of which is directed at the Earth. The Earth, like everything else, radiates infared energy (heat). Gas molecules in the air absorb some of this energy, and radiate energy of their own in all directions. Water molecules, like the vapor that makes up clouds, absorb more frequencies of infared energy than clear air does. They also have more matter than clear air. These two factors both contribute to clouds radiating more heat in all directions (including Earth) than clear air does, making the overall temperature on Earth warmer when there is cloud cover.
At night, that energy slowly fades away, but if there's clouds, it's like a blanket keeping it in, while it can disappear faster when there's no clouds (clear, starlit night). Think of it like a warm water bottle. it gives off more heat and cools down more quickly without the cover than with it - that's one of the reasons why you're advised to always put a cover around it. (Well, that and not getting burnt because too much heat is released at once.) You sometimes hear that "clouds act like a blanket" to keep temperatures from falling as low as they otherwise would if the sky were clear. It's true that the effect of clouds can be like a blanket. But they work in a much different way. A blanket keeps us warm by keeping the warm air our body creates from rising, which would allow cool air to reach our skin. The action of clouds is more complicated. Everything radiates infrared energy, or heat with the object's temperature determining how much energy and what kinds are radiated. The Earth is always radiating away infrared energy. Various molecules of gas in the air, especially water vapor and carbon dioxide, absorb some of this infrared energy. They, in turn, radiate energy away in all directions, including back to Earth. If the Earth had no atmosphere, its average temperature would be close to zero Fahrenheit instead of the 60 degrees it actually is. The tiny water droplets that make up clouds radiate even more heat than the gases in clear air. For one thing, the tiny droplets absorb some frequencies of infrared energy that the air's gases don't. As the energy is absorbed, it heats the droplets, which causes them to radiate energy. Then too, the cloud has more matter - the cloud droplets - to radiate heat in all directions, including back toward Earth, than clear air.
5 The temperature rises in the stratosphere because the ozone layer there absorbs the UV rays from the sun. With the rays absorbed, it causes the air particles to move faster, therefore, raising the temperature. The temperature can be as low as -100 degrees Fahrenheit at the tropopause on the equator, but then as you go towards the upper limit of the stratosphere, it rises to freezing. The Stratosphere extends from the tropopause up to 31 miles above the Earth's surface. This layer holds 19 percent of the atmosphere's gases and but very little water vapor. Temperature increases with height as radiation is increasingly absorbed by oxygen molecules which leads to the formation of Ozone. The temperature rises from an average -76°F (-60°C) at tropopause to a maximum of about 5°F (-15°C) at the stratopause due to this absorption of ultraviolet radiation. The increasing temperature also makes it a calm layer with movements of the gases slow.
The regions of the stratosphere and the mesosphere, along with the stratopause and mesopause, are called the middle atmosphere by scientists. The transition boundary which separates the stratosphere from the mesosphere is called the stratopause.
The stratosphere is layered in temperature because ozone (O3) here absorbs high energy UVB and UVC energy waves from the Sun and is broken down into monoatomic oxygen (O) and diatomic oxygen (O2). Monoatomic oxygen is found prevalent in the upper stratosphere due to the bombardment of UV light and the destruction of both ozone and diatomic oxygen.
6. A depletion of the ozone layer will increase the UV-radiation at ground level. Increasing doses of UV-B may cause skin cancer, eye cataracts, damage to the immune system in animals as well as human beings, and have an adverse impact on plant growth. The maps shows UV intensity at noon calculated from sun angle and satelitte measurements of the ozone layer. The model assumes clear sky conditions at sea level and average sun reflection. With increased altitude and reflection - for instance snow conditions in mountain areas - the UV dose can be considerably higher. The UV index used in the maps above has been developed by Environment Canada. It runs on a scale from 0 to 10, with 10 being a typical mid-summer, sunny day in the tropics. A relative scale ranging from low to extreme is also applied: In extreme conditions (UV Index higher than 9) light, sensitive and untanned skin may burn in less than 15 minutes. UV radiation will affect human health through for example sunburn, snow blindness, other eye damage, early ageing of the skin and rising rates of skin cancer. It may also cause suppression of the immune response system. It will likewise affect the productivity of aquatic and terrestrial eco-systems. Single-celled algae, chlorophyll and plant hormones are especially sensitive to UV radiation. As the ozone layer is reduced, the Earth's surface is exposed to more of the shorter UV wavelengths of the sun's radiation that damage living things. For each 10 percent depletion of the ozone layer, we can expect 20 percent more radiation in these damaging wavelengths.
7. People do not fully understand how much energy is involved with even small weather fronts. The entire amount of energy to modify any weather front, by even a small amount is huge! The ability to accumulate and refocus this energy is not currently available and probably will not be in teh near future. As far back as the 1920s, the great Russian naturalist Aleksandr Chizhevskiy pointed out the interaction between solar activity and various natural processes on Earth, including the weather. He also drew attention to the role of ions in the atmosphere and their ability to absorb moisture. Today, ionisers that purify the air can be found in many homes. The prototype for these was the so-called "Chizhevskiy chandelier", designed back in the twenties. This "chandelier" bore an outward resemblance to the lighting chandeliers that were common in those days, but instead of producing light, it emitted a stream of electrons which combined with oxygen molecules to form negatively charged oxygen ions. Scientific developments at the end of the twentieth century also shed light on one of the mechanisms of the Sun s influence on the weather. The Russian scientists Pudovkin and Raspopov demonstrated the importance of the influence of galactic cosmic rays on the Earth s atmosphere and the role of solar activity in modulating the flow of rays reaching the atmosphere. At times of enhanced solar activity, the stronger solar wind and magnetic field in the Earth s magnetosphere have the effect of partially slowing and deflecting the flow of cosmic rays, while in years when the Sun is calm the flow of rays reaching the atmosphere is greater.
8. Every hailstone begins to form as an ice nucleus, a small cluster of supercooled water droplets or clumps of snow. This center is called a graupel, and it may continue to accumulate ice, melt in the thundercloud and turn to rain, or be smashed apart by other graupels. If a bug, piece of bark, seed, or stick gets blown up into the storm cloud, it creates another possible nucleus for a hailstone. If the thunderstorm is cold and windy enough, this graupel will accumulate layers of ice the way a dipped candle accumulates layers of wax, through a process called accretion. Opaque, whitish layers form when icy droplets trap air bubbles and stick to the graupel. Clear layers have accreted large drops of supercooled water that freeze when they encounter the hailstone. Of course, much larger hailstones can be made when two smaller ones freeze together.
Hail can accrete more layers when the hailstone blows up through layers of the thunderstorm. Even heavy hail will be kept aloft by strong enough updraughts. When the hail falls back through the storm due to gravity, it accretes even more layers, until it is so heavy it falls as precipitation. Hail forms in most tall, cumulonimbus storms that reach the colder upper atmosphere, but not all hail survives its trip once out of the thunderstorm.
9. precipitation in the form of ice pellets created by the freezingof rain as it falls ( distinguished from hail). glaze ( def. 17 ) .
Chiefly British . a mixture of rain and snow. ±verb (used without object) send down sleet. 5. to all as or like sleet. Origin: 1250 1300; (n.) ME slete; akin to LG slote, G Schlossen hail;(v.) ME sleten, deriv. of the n. Dictionary.com Unabridged Freezing rain is the name given to rain that falls when surface temperatures are below freezing. The raindrops become supercooled while passing through a sub-freezing layer of air, many hundred feet (or meters), just above the surface, and [1] then freeze upon impact with any object they encounter. The resulting ice, called glaze, can accumulate to a thickness of several centimetres. The METAR code for freezing rain is FZRA. A storm producing a significative thickness of freezing rain is often referred as an "ice storm". Freezing rain is notorious for causing travel problems on roadways, breaking tree limbs, and downing power lines. It is also known for being extremely dangerous to [2] aircraft since the ice can effectively 'remould' the shape of theairfoil.(See atmospheric icing.) Usually freezing rain is associated with the approach of a warm frontwhen cold air, at or below freezing temperature, is trapped in [3] the lower levels of the atmosphere as warmth streams in aloft. This happens, for instance, when a low pressure system moves from theMississippi River Valley toward the Appalachian Mountains and theSaint Lawrence River Valley of North America, in the cold season, and there is a strong high pressure system sitting further east. The warm air from the Gulf of Mexico is often the fuel for freezing precipitation. Freezing rain develops as falling snow encounters a layer of warm air usually around 800 mbar (800 hPa) level, then the snow completely melts and becomes rain. As the rain continues to fall, it passes through a thin layer of cold air just above the surface and cools to a temperature below freezing (0 °C (32 °F)). However, the drops themselves do not freeze, a phenomenon called supercooling (or forming "supercooled drops"). When the supercooled drops strike ground, power lines, tree branches, aircraft, or anything else below 0 °C (32 °F), they instantly freeze, forming a thin film of ice, hence freezing rain.
10 Actually because earth rotates, the winds don't blow in a straight line. If earth did not rotate they would go from north to south and south to north in a straight line. If the Earth's rotation slowed down gradually over millions of years, and this is the most likely scenario, it would be a very different story. If the Earth slowed down to one rotation every year, called synchronous rotation, every area on Earth would be in either sunlight or darkness for one year. This would be similar to what the Moon goes through where for two weeks the front side of the Moon is illuminated by the Sun followed by the front side being in darkness for two weeks. But what if the Earth stopped rotating completely? In that case, one half the Earth would be in daylight for half the year while the other side would be in darkness. The second half of the year it would be reversed. Temperature variations would be far more extreme then they are now. The temperature gradient would affect the wind circulation also. Air would move from the equator to the poles rather then in wind systems parallel to the equator as they are now. Even stranger would be the change in the Sun's position in the sky. In the above scenario, Sun would just have a seasonal motion up and down the sky towards the south due to the orbit of the Earth and its axial tilt. You would see the elevation of the Sun increase or decrease in the sky just as we now see the elevation of the Sun change from a single point on the Earth due to the Earth's daily rotation. 11. Thunder is the sound made by lightning. Depending on the nature of the lightning and distance of the listener, thunder can range from a sharp, loud crack to a long, low rumble (brontide). The sudden increase in pressure and temperature from lightning produces rapid expansion of the air surrounding and within a bolt of lightning. In turn, this expansion of air creates a sonic shock wave which produces the sound of thunder, often referred to as a clap, crack, or peal of thunder. The distance of the lightning can be calculated by the listener depending on when the sound is heard vs. the vision of the lightning strike.
Sound waves travel one kilometer in 2.9 seconds (or one mile in 4.6 seconds). Therefore the lightning was probably about 1.75 kilometers (1 mile) away. It you have a more accurate record of the delay between the lightning flash and the corresponding thunder clap, you may be able to calculate the distance with greater precision. Lightning is the visible part of an electrical discharge. Thunder is the resulting sound from the rapid expansion of the air after this electrical discharge. Thus, thunder results from lightning. So, if you see lightning there is always thunder (although you may be too far away to hear it, typically thunder isn't heard 15-20 miles from the lightning strike). When lightning strikes, light and sound both travel in all directions away from the point of the lightning strike. However, light travels much faster. In fact, it appears to travel instantaneously to humans. Sound travels much slower, at 344 meters/second (m/s) or two tenths of a mile/second (.2). So we see the lightning instantly, but we hear the thunder seconds later.
12. In science, it is known as the conservation of angular momentum. If you have something that is large and spinning slowly, you can make it spin faster making the object more compact. It like an ice skater as she starts her spin with her arms and one leg expanded outward. If she brings her arms and her leg in towards her body, she would spin a lot faster Tornadoes form under a certain set of weather conditions in which three very different types of air come together in a certain way. Near the ground lies a layer of warm and humid air, along with strong south winds. Colder air and strong west or southwest winds lie in the upper atmosphere. Temperature and moisture differences between the surface and the upper levels create what we callinstability. A necessary ingredient for tornado formation. The change in wind speed and direction with height is known as wind shear. This wind shear is linked to the eventual development of rotation from which a tornado may form. A third layer of hot dry air becomes established between the warm moist air at low levels and the cool dry air aloft. This hot layer acts as a cap and allows the warm air underneath to warm further...making the air even more unstable. Things start to happen when a storm system aloft moves east and begins to lift the various layers. Through this lifting process the cap is removed, thereby setting the stage for explosive thunderstorm development as strong updrafts develop. Complex interactions between the updraft and the surrounding winds may cause the updraft to begin rotating-and a tornado is born.
13. Weather forecasting is the application of science and technology to predict the state of theatmosphere for a future time and a given location. Human beings have attempted to predict the weather informally for millennia, and formally since at least the nineteenth century. Weather forecasts are made by collecting quantitative data about the current state of the atmosphere and using scientific understanding of atmospheric processes to project how the atmosphere will evolve. Once an all-human endeavor based mainly upon changes in barometric pressure, current weather conditions, and sky condition, forecast models are now used to determine future conditions. Human input is still required to pick the best possible forecast model to base the forecast upon, which involves pattern recognition skills, teleconnections, knowledge of model performance, and knowledge of model biases. The chaotic nature of the atmosphere, the massive computational power required to solve the equations that describe the atmosphere, error involved in measuring the initial conditions, and an incomplete understanding of atmospheric processes mean that forecasts become less accurate as the difference in current time and the time for which the forecast is being made (the range of the forecast) increases. The use of ensembles and model consensus help narrow the error and pick the most likely outcome. There are a variety of end uses to weather forecasts. Weather warnings are important forecasts because they are used to protect life and property. Forecasts based on temperature and precipitation are important to agriculture, and therefore to traders within commodity markets. Temperature forecasts are used by utility companies to estimate demand over coming days. On an everyday basis, people use weather forecasts to determine what to wear on a given day. Since outdoor activities are severely curtailed by heavy rain, snow and the wind chill, forecasts can be used to plan activities around these events, and to plan ahead and survive them.
14Changing liquid at one temperature to vapor at the same temperature, requires that the "latent heat of vaporization" be supplied from somewhere. This energy comes from the surface that is doing the evaporating. Evaporation is a type of vaporization of a liquid, that occurs only on the surface of a liquid. The other type of vaporization is boiling, that instead occurs on the entire mass of the liquid. Evaporation is also part of the water cycle. Evaporation is a type of phase transition; it is the process by which molecules in a liquid state(e.g. water) spontaneously become gaseous (e.g. water vapor). Generally, evaporation can be seen by the gradual disappearance of a liquid from a substance [citation when exposed to a significant volume of gas. Vaporization and evaporation however, are not entirely the same processes.
needed]
On average, the molecules in a glass of water do not have enough heat energy to escape from the liquid. With sufficient heat, the liquid would turn into vapor quickly (see boiling point). When the molecules collide, they transfer energy to each other in varying degrees, based on how they collide. Sometimes the transfer is so one-sided for a molecule near the surface that it ends up with enough energy to escape.
Liquids that do not evaporate visibly at a given temperature in a given gas (e.g. cooking oil at room temperature) have molecules that do not tend to transfer energy to each other in a pattern sufficient to frequently give a molecule the heat energy necessary to turn into vapor. However, these liquids are evaporating. It is just that the process is much slower and thus significantly less visible. Evaporation is an essential part of the water cycle. Solar energy drives evaporation of water fromoceans, lakes, moisture in the soil, and other sources of water. In hydrology, evaporation and transpiration (which involves evaporation withinplant stomata) are collectively termed evapotranspiration. Evaporation is caused when water is exposed to air and the liquid molecules turn into water vapor which rises up and forms clouds. 15The Atacama Desert is a virtually rainless plateau in South America, covering a 600-mile (1,000 km) strip of land on the Pacific coast of South America, west of the Andes mountains. The Atacama desert is, according to NASA, National [1][2][3] Geographic and many other publications, the driest desert in the world, due to the rain shadow on the leeward side of [4] the Chilean Coast Range, as well as a coastal inversion layer created by the cold offshore Humboldt Current. The Atacama 2 [5] occupies 40,600 square miles (105,000 km ) in northern Chile, composed mostly ofsalt basins (salares), sand, and felsic lava flows towards the Andes.
16. Rising air cools at the regular rate because it is moving into lower air pressure aloft, and expanding. Expansion cools the air. Because the atmosphere cannot hold heat as it gets thinner with distance from the ground ... fewer molecules to vibrate ( which is what heat is at the molecular level ... vibrating molecules ). Plus, the ground retains heat and as air rises, it gets further and further from the ground. Read more: Why does air cool as it rises? | Answerbag http://www.answerbag.com/q_view/1037203#ixzz12IzkDJdw
17.
At night, that energy slowly fades away, but if there's clouds, it's like a blanket keeping it in, while it can disappear faster when there's no clouds (clear, starlit night). Think of it like a warm water bottle. it gives off more heat and cools down more quickly without the cover than with it - that's one of the reasons why you're advised to always put a cover around it. (Well, that and not getting burnt because too much heat is released at once.) You sometimes hear that "clouds act like a blanket" to keep temperatures from falling as low as they otherwise would if the sky were clear. It's true that the effect of clouds can be like a blanket. But they work in a much different way. A blanket keeps us warm by keeping the warm air our body creates from rising, which would allow cool air to reach our skin. The action of clouds is more complicated. Everything radiates infrared energy, or heat with the object's temperature determining how much energy and what kinds are radiated. The Earth is always radiating away infrared energy. Various molecules of gas in the air, especially water vapor and carbon dioxide, absorb some of this infrared energy. They, in turn, radiate energy away in all directions, including back to Earth. If the Earth had no atmosphere, its average temperature would be close to zero Fahrenheit instead of the 60 degrees it actually is. The tiny water droplets that make up clouds radiate even more heat than the gases in clear air. For one thing, the tiny droplets absorb some frequencies of infrared energy that the air's gases don't. As the energy is absorbed, it heats the droplets, which causes them to radiate energy. Then too, the cloud has more matter - the cloud droplets - to radiate heat in all directions, including back toward Earth, than clear air.
5 The temperature rises in the stratosphere because the ozone layer there absorbs the UV rays from the sun. With the rays absorbed, it causes the air particles to move faster, therefore, raising the temperature. The temperature can be as low as -100 degrees Fahrenheit at the tropopause on the equator, but then as you go towards the upper limit of the stratosphere, it rises to freezing. The Stratosphere extends from the tropopause up to 31 miles above the Earth's surface. This layer holds 19 percent of the atmosphere's gases and but very little water vapor. Temperature increases with height as radiation is increasingly absorbed by oxygen molecules which leads to the formation of Ozone. The temperature rises from an average -76°F (-60°C) at tropopause to a maximum of about 5°F (-15°C) at the stratopause due to this absorption of ultraviolet radiation. The increasing temperature also makes it a calm layer with movements of the gases slow.
The regions of the stratosphere and the mesosphere, along with the stratopause and mesopause, are called the middle atmosphere by scientists. The transition boundary which separates the stratosphere from the mesosphere is called the stratopause.
The stratosphere is layered in temperature because ozone (O3) here absorbs high energy UVB and UVC energy waves from the Sun and is broken down into monoatomic oxygen (O) and diatomic oxygen (O2). Monoatomic oxygen is found prevalent in the upper stratosphere due to the bombardment of UV light and the destruction of both ozone and diatomic oxygen.
6. A depletion of the ozone layer will increase the UV-radiation at ground level. Increasing doses of UV-B may cause skin cancer, eye cataracts, damage to the immune system in animals as well as human beings, and have an adverse impact on plant growth. The maps shows UV intensity at noon calculated from sun angle and satelitte measurements of the ozone layer. The model assumes clear sky conditions at sea level and average sun reflection. With increased altitude and reflection - for instance snow conditions in mountain areas - the UV dose can be considerably higher. The UV index used in the maps above has been developed by Environment Canada. It runs on a scale from 0 to 10, with 10 being a typical mid-summer, sunny day in the tropics. A relative scale ranging from low to extreme is also applied: In extreme conditions (UV Index higher than 9) light, sensitive and untanned skin may burn in less than 15 minutes. UV radiation will affect human health through for example sunburn, snow blindness, other eye damage, early ageing of the skin and rising rates of skin cancer. It may also cause suppression of the immune response system. It will likewise affect the productivity of aquatic and terrestrial eco-systems. Single-celled algae, chlorophyll and plant hormones are especially sensitive to UV radiation. As the ozone layer is reduced, the Earth's surface is exposed to more of the shorter UV wavelengths of the sun's radiation that damage living things. For each 10 percent depletion of the ozone layer, we can expect 20 percent more radiation in these damaging wavelengths.
7. People do not fully understand how much energy is involved with even small weather fronts. The entire amount of energy to modify any weather front, by even a small amount is huge! The ability to accumulate and refocus this energy is not currently available and probably will not be in teh near future. As far back as the 1920s, the great Russian naturalist Aleksandr Chizhevskiy pointed out the interaction between solar activity and various natural processes on Earth, including the weather. He also drew attention to the role of ions in the atmosphere and their ability to absorb moisture. Today, ionisers that purify the air can be found in many homes. The prototype for these was the so-called "Chizhevskiy chandelier", designed back in the twenties. This "chandelier" bore an outward resemblance to the lighting chandeliers that were common in those days, but instead of producing light, it emitted a stream of electrons which combined with oxygen molecules to form negatively charged oxygen ions. Scientific developments at the end of the twentieth century also shed light on one of the mechanisms of the Sun s influence on the weather. The Russian scientists Pudovkin and Raspopov demonstrated the importance of the influence of galactic cosmic rays on the Earth s atmosphere and the role of solar activity in modulating the flow of rays reaching the atmosphere. At times of enhanced solar activity, the stronger solar wind and magnetic field in the Earth s magnetosphere have the effect of partially slowing and deflecting the flow of cosmic rays, while in years when the Sun is calm the flow of rays reaching the atmosphere is greater.
8. Every hailstone begins to form as an ice nucleus, a small cluster of supercooled water droplets or clumps of snow. This center is called a graupel, and it may continue to accumulate ice, melt in the thundercloud and turn to rain, or be smashed apart by other graupels. If a bug, piece of bark, seed, or stick gets blown up into the storm cloud, it creates another possible nucleus for a hailstone. If the thunderstorm is cold and windy enough, this graupel will accumulate layers of ice the way a dipped candle accumulates layers of wax, through a process called accretion. Opaque, whitish layers form when icy droplets trap air bubbles and stick to the graupel. Clear layers have accreted large drops of supercooled water that freeze when they encounter the hailstone. Of course, much larger hailstones can be made when two smaller ones freeze together.
Hail can accrete more layers when the hailstone blows up through layers of the thunderstorm. Even heavy hail will be kept aloft by strong enough updraughts. When the hail falls back through the storm due to gravity, it accretes even more layers, until it is so heavy it falls as precipitation. Hail forms in most tall, cumulonimbus storms that reach the colder upper atmosphere, but not all hail survives its trip once out of the thunderstorm.
9. precipitation in the form of ice pellets created by the freezingof rain as it falls ( distinguished from hail). glaze ( def. 17 ) .
Chiefly British . a mixture of rain and snow. ±verb (used without object) send down sleet. 5. to all as or like sleet. Origin: 1250 1300; (n.) ME slete; akin to LG slote, G Schlossen hail;(v.) ME sleten, deriv. of the n. Dictionary.com Unabridged Freezing rain is the name given to rain that falls when surface temperatures are below freezing. The raindrops become supercooled while passing through a sub-freezing layer of air, many hundred feet (or meters), just above the surface, and [1] then freeze upon impact with any object they encounter. The resulting ice, called glaze, can accumulate to a thickness of several centimetres. The METAR code for freezing rain is FZRA. A storm producing a significative thickness of freezing rain is often referred as an "ice storm". Freezing rain is notorious for causing travel problems on roadways, breaking tree limbs, and downing power lines. It is also known for being extremely dangerous to [2] aircraft since the ice can effectively 'remould' the shape of theairfoil.(See atmospheric icing.) Usually freezing rain is associated with the approach of a warm frontwhen cold air, at or below freezing temperature, is trapped in [3] the lower levels of the atmosphere as warmth streams in aloft. This happens, for instance, when a low pressure system moves from theMississippi River Valley toward the Appalachian Mountains and theSaint Lawrence River Valley of North America, in the cold season, and there is a strong high pressure system sitting further east. The warm air from the Gulf of Mexico is often the fuel for freezing precipitation. Freezing rain develops as falling snow encounters a layer of warm air usually around 800 mbar (800 hPa) level, then the snow completely melts and becomes rain. As the rain continues to fall, it passes through a thin layer of cold air just above the surface and cools to a temperature below freezing (0 °C (32 °F)). However, the drops themselves do not freeze, a phenomenon called supercooling (or forming "supercooled drops"). When the supercooled drops strike ground, power lines, tree branches, aircraft, or anything else below 0 °C (32 °F), they instantly freeze, forming a thin film of ice, hence freezing rain.
10 Actually because earth rotates, the winds don't blow in a straight line. If earth did not rotate they would go from north to south and south to north in a straight line. If the Earth's rotation slowed down gradually over millions of years, and this is the most likely scenario, it would be a very different story. If the Earth slowed down to one rotation every year, called synchronous rotation, every area on Earth would be in either sunlight or darkness for one year. This would be similar to what the Moon goes through where for two weeks the front side of the Moon is illuminated by the Sun followed by the front side being in darkness for two weeks. But what if the Earth stopped rotating completely? In that case, one half the Earth would be in daylight for half the year while the other side would be in darkness. The second half of the year it would be reversed. Temperature variations would be far more extreme then they are now. The temperature gradient would affect the wind circulation also. Air would move from the equator to the poles rather then in wind systems parallel to the equator as they are now. Even stranger would be the change in the Sun's position in the sky. In the above scenario, Sun would just have a seasonal motion up and down the sky towards the south due to the orbit of the Earth and its axial tilt. You would see the elevation of the Sun increase or decrease in the sky just as we now see the elevation of the Sun change from a single point on the Earth due to the Earth's daily rotation. 11. Thunder is the sound made by lightning. Depending on the nature of the lightning and distance of the listener, thunder can range from a sharp, loud crack to a long, low rumble (brontide). The sudden increase in pressure and temperature from lightning produces rapid expansion of the air surrounding and within a bolt of lightning. In turn, this expansion of air creates a sonic shock wave which produces the sound of thunder, often referred to as a clap, crack, or peal of thunder. The distance of the lightning can be calculated by the listener depending on when the sound is heard vs. the vision of the lightning strike.
Sound waves travel one kilometer in 2.9 seconds (or one mile in 4.6 seconds). Therefore the lightning was probably about 1.75 kilometers (1 mile) away. It you have a more accurate record of the delay between the lightning flash and the corresponding thunder clap, you may be able to calculate the distance with greater precision. Lightning is the visible part of an electrical discharge. Thunder is the resulting sound from the rapid expansion of the air after this electrical discharge. Thus, thunder results from lightning. So, if you see lightning there is always thunder (although you may be too far away to hear it, typically thunder isn't heard 15-20 miles from the lightning strike). When lightning strikes, light and sound both travel in all directions away from the point of the lightning strike. However, light travels much faster. In fact, it appears to travel instantaneously to humans. Sound travels much slower, at 344 meters/second (m/s) or two tenths of a mile/second (.2). So we see the lightning instantly, but we hear the thunder seconds later.
12. In science, it is known as the conservation of angular momentum. If you have something that is large and spinning slowly, you can make it spin faster making the object more compact. It like an ice skater as she starts her spin with her arms and one leg expanded outward. If she brings her arms and her leg in towards her body, she would spin a lot faster Tornadoes form under a certain set of weather conditions in which three very different types of air come together in a certain way. Near the ground lies a layer of warm and humid air, along with strong south winds. Colder air and strong west or southwest winds lie in the upper atmosphere. Temperature and moisture differences between the surface and the upper levels create what we callinstability. A necessary ingredient for tornado formation. The change in wind speed and direction with height is known as wind shear. This wind shear is linked to the eventual development of rotation from which a tornado may form. A third layer of hot dry air becomes established between the warm moist air at low levels and the cool dry air aloft. This hot layer acts as a cap and allows the warm air underneath to warm further...making the air even more unstable. Things start to happen when a storm system aloft moves east and begins to lift the various layers. Through this lifting process the cap is removed, thereby setting the stage for explosive thunderstorm development as strong updrafts develop. Complex interactions between the updraft and the surrounding winds may cause the updraft to begin rotating-and a tornado is born.
13. Weather forecasting is the application of science and technology to predict the state of theatmosphere for a future time and a given location. Human beings have attempted to predict the weather informally for millennia, and formally since at least the nineteenth century. Weather forecasts are made by collecting quantitative data about the current state of the atmosphere and using scientific understanding of atmospheric processes to project how the atmosphere will evolve. Once an all-human endeavor based mainly upon changes in barometric pressure, current weather conditions, and sky condition, forecast models are now used to determine future conditions. Human input is still required to pick the best possible forecast model to base the forecast upon, which involves pattern recognition skills, teleconnections, knowledge of model performance, and knowledge of model biases. The chaotic nature of the atmosphere, the massive computational power required to solve the equations that describe the atmosphere, error involved in measuring the initial conditions, and an incomplete understanding of atmospheric processes mean that forecasts become less accurate as the difference in current time and the time for which the forecast is being made (the range of the forecast) increases. The use of ensembles and model consensus help narrow the error and pick the most likely outcome. There are a variety of end uses to weather forecasts. Weather warnings are important forecasts because they are used to protect life and property. Forecasts based on temperature and precipitation are important to agriculture, and therefore to traders within commodity markets. Temperature forecasts are used by utility companies to estimate demand over coming days. On an everyday basis, people use weather forecasts to determine what to wear on a given day. Since outdoor activities are severely curtailed by heavy rain, snow and the wind chill, forecasts can be used to plan activities around these events, and to plan ahead and survive them.
14Changing liquid at one temperature to vapor at the same temperature, requires that the "latent heat of vaporization" be supplied from somewhere. This energy comes from the surface that is doing the evaporating. Evaporation is a type of vaporization of a liquid, that occurs only on the surface of a liquid. The other type of vaporization is boiling, that instead occurs on the entire mass of the liquid. Evaporation is also part of the water cycle. Evaporation is a type of phase transition; it is the process by which molecules in a liquid state(e.g. water) spontaneously become gaseous (e.g. water vapor). Generally, evaporation can be seen by the gradual disappearance of a liquid from a substance [citation when exposed to a significant volume of gas. Vaporization and evaporation however, are not entirely the same processes.
needed]
On average, the molecules in a glass of water do not have enough heat energy to escape from the liquid. With sufficient heat, the liquid would turn into vapor quickly (see boiling point). When the molecules collide, they transfer energy to each other in varying degrees, based on how they collide. Sometimes the transfer is so one-sided for a molecule near the surface that it ends up with enough energy to escape.
Liquids that do not evaporate visibly at a given temperature in a given gas (e.g. cooking oil at room temperature) have molecules that do not tend to transfer energy to each other in a pattern sufficient to frequently give a molecule the heat energy necessary to turn into vapor. However, these liquids are evaporating. It is just that the process is much slower and thus significantly less visible. Evaporation is an essential part of the water cycle. Solar energy drives evaporation of water fromoceans, lakes, moisture in the soil, and other sources of water. In hydrology, evaporation and transpiration (which involves evaporation withinplant stomata) are collectively termed evapotranspiration. Evaporation is caused when water is exposed to air and the liquid molecules turn into water vapor which rises up and forms clouds. 15The Atacama Desert is a virtually rainless plateau in South America, covering a 600-mile (1,000 km) strip of land on the Pacific coast of South America, west of the Andes mountains. The Atacama desert is, according to NASA, National [1][2][3] Geographic and many other publications, the driest desert in the world, due to the rain shadow on the leeward side of [4] the Chilean Coast Range, as well as a coastal inversion layer created by the cold offshore Humboldt Current. The Atacama 2 [5] occupies 40,600 square miles (105,000 km ) in northern Chile, composed mostly ofsalt basins (salares), sand, and felsic lava flows towards the Andes.
16. Rising air cools at the regular rate because it is moving into lower air pressure aloft, and expanding. Expansion cools the air. Because the atmosphere cannot hold heat as it gets thinner with distance from the ground ... fewer molecules to vibrate ( which is what heat is at the molecular level ... vibrating molecules ). Plus, the ground retains heat and as air rises, it gets further and further from the ground. Read more: Why does air cool as it rises? | Answerbag http://www.answerbag.com/q_view/1037203#ixzz12IzkDJdw
17.
