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What is meteorology? What is a meteorologist? What do meteorologists do? Where do meteorologists work? Would meteorology be a good career for me? Why does air pressure always decrease with increasing altitude? What can infrared satellite images tell us about clouds? Are the largest storms the most destructive ones? Why or why not? What is the role of the ionosphere? What is the difference between weather and climate? What information does a surface weather map provide about the weather? Explain how ozone might be thought to have both a beneficial and a detrimental role in the earth's atmosphere. Describe the various types of storms found in the earth's atmosphere. Can you find any correlation between storm size and storm duration? What instruments are used in meteorology? What role did the discovery of instruments play in the emergence of the science of meteorology? What causes air pressure? Is there air pressure on the moon? Describe some of the processes that release and remove carbon dioxide from the atmosphere. Is there any evidence that suggests that these processes are not in balance? There is currently concern that the amount of ozone in the stratosphere may be decreasing. Why would a decrease in ozone concentration be important? Draw a diagram showing how air temperature normally changes with height. Begin at the ground and end in the upper thermosphere. Be sure to label the four main layers. Give one important characteristic of each layer. Where on your diagram would the top of Mt. Everest, the ozone layer, and the ionosphere be found? What are the principal gaseous components of the earth's atmosphere? Where do scientists believe these gases came from? Explain why the invention of the telegraph should have resulted in more accurate weather predictions. What information might you find on a surface weather map that is not readily apparent on a satellite image? Under what circumstances might a person breathe stratospheric air? How often is it likely to happen in a typical student’s lifetime? Interpret basic weather information from surface weather maps Identify and label the major latitude belts of Earth Identify the tropopause and inversion layers on a graph of temperature vs. height What is the troposphere? |
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What is meteorology? Meteorology is the science of the atmosphere. It takes its name from the Greek word meteoron - something that happens high in the sky. The ancient Greeks observed clouds, winds, and rain and tried to understand how they are connected to one another. The weather was important in their relatively simple society because it affected the farmers who raised their food and their seamen who sailed the oceans. Today, our complex society and our environment are affected even more seriously by events and changes in the atmosphere. We must address many complicated issues and answer many difficult questions about the behavior of the atmosphere and its effects on the people of our planet. What is a meteorologist? The American Meteorological Society defines a meteorologist as a person with specialized education "who uses scientific principles to explain, understand, observe, or forecast the earth's atmospheric phenomena and/or how the atmosphere affects the earth and life on the planet." This education usually includes a bachelor's or higher degree from a college or university. Many meteorologists have degrees in physics, chemistry, mathematics, and other fields. The broader term "atmospheric science" often is used to describe the combination of meteorology and other branches of physical science that are involved in studying the atmosphere. What do meteorologists do? Basically, meteorologists study and predict the weather and climate and its relationship on other environmental processes and the impact on our lives and economy. Specifically meteorologists can have many different jobs including daily weather forecasting, atmospheric research, teaching, broadcasting and supporting clients through private sector meteorological companies. Weather Forecasting and Warnings Forecasting has always been at the heart of meteorology, and many young people have been drawn to the profession by the challenge of forecasting a natural event and seeing that forecast affect the lives of thousands of people. Weather forecasting involves many people in many countries because the systems that bring us our weather are hundreds of miles in extent and move across huge regions of the earth's surface as they grow and change. Several times each day, weather observers record atmospheric measurements at nearly 10,000 surface weather stations around the world and several thousand ships at sea. They release weather balloons at more than 500 stations to make upper-air measurements. Radar, aircraft and satellites also are used to collect data on what is happening in the atmosphere. This information is transmitted to world weather centers in the United States, the UK, Russia, and Australia, where computers produce analyses of global weather. National Weather Service (NWS) meteorologists in Washington, D.C., use these data as a starting point to produce guidance forecasts for the United States with sophisticated computer models. These guidance forecasts go to local offices where NWS meteorologists apply their skill and experience to fine-tune the predictions for their regions and specific towns and cities. The guidance forecasts are also used by private sector meteorologists who provide forecasting services for numerous clients. Broadcast meteorologists also review the guidance forecasts before preparing their own local and national forecasts on television and radio. An example of a private sector forecast service would be short-term, small-scale snow forecasts for city public works managers who need to know how many snowplows to put on the streets in various neighborhoods when a winter storm is on the way. Some private forecasters work for commodities traders who are concerned about the effects of weather on crop production and prices. Others forecast the weather for athletic events such as professional football games and golf tournaments. Private forecasters also keep gas and electric companies informed about impending hot spells or cold waves that will put heavy demands on generating plants and transmission systems. Weather forecasting includes aviation meteorology. A number of larger airlines, both passenger and cargo haulers, have their own meteorology departments. However, many aviation forecasting services are provided by the NWS and commercial weather firms. Services provided range from terminal and en route forecasts to automated, computer-generated flight plans. An extension of forecasting is the provision of warnings for hazardous weather. These warnings inform the public, governments, and businesses of the dangers of approaching hurricanes, severe thunderstorms, flooding, and winter storms just to mention a few. Atmospheric Research Atmospheric research seeks to answer questions about our understanding of the atmosphere and how it works and impacts us. For example, atmospheric scientists are working to assess the threat of global warming by collecting and analyzing past and present data on worldwide temperature trends. Often research meteorologists work closely with scientists in basic physical disciplines such as chemistry, physics, and mathematics as well as with oceanographers, hydrologists, and researchers in other branches of environmental science. Mathematicians and computer scientists help meteorologists design computer models of atmospheric processes. Meteorologists and oceanographers work together to study many important ocean-atmosphere interactions. Research meteorologists work with biologists to try to understand how plants and animals interact with the atmosphere and with political scientists and economists to study the potential effects of global warming on our society. Meteorological Technology Development and Support Companies exist which design, manufacture, and market the instrumentation with which atmospheric measurements are made. The instrumentation can range from simple rain gauges and thermometers to computerized, self-contained, automated weather observing stations. At the far leading edge of instrumentation technology are those corporations that design and build weather satellites and Doppler radars. Hand-in-hand with the development of such technologically advanced equipment is, of course, the need for user requirement analyses and the genesis of sophisticated software. Information Services Many non-meteorological customers of weather information need tailored products and information to meet their needs. These customers include media outlets, weather-sensitive businesses, industrial complexes where weather can have an impact (refineries for example), transportation companies, ski resorts, etc. “Information services” include, among other things, acquiring raw meteorological data pertinent to individual customers, creating easily understood displays of critical weather information, and preparing forecast model output in formats which laymen can effectively utilize. They produce many of the colorful graphics that you see on television screens and newspaper pages Meteorologists in this area help planners and contractors locate and design airports, factories and many other kinds of construction projects. They provide climatological information for heating and air conditioning engineers. Forensic Services Whenever weather conditions have an impact on legal cases, forensic meteorologists are often called to reconstruct weather conditions which were occurring at the time of the event in question. The forensic meteorologist will retrieve and analyze archived weather record information (surface observations, radar, satellite, river information, etc.) and reconstruct the weather conditions for the location in question. Questions such as when did the highest hurricane winds at a particular building occur, was sun in the eyes of the driver or was it cloudy at the time of the accident, or was lightning present when the house caught fire are just a few examples of the types of questions forensic meteorologists answer for their clients. At times, forensic meteorologists are called to testify as expert witnesses in court cases that involve the weather. Broadcast Meteorology Media weathercasting for television, radio, and newspapers is perhaps the highest profile of all careers in meteorology. Broadcast meteorologists produce weather forecasts and related graphics for television. The broadcast meteorologist is responsible for gathering data, creating a forecast and then developing the graphical representation of their weather analysis for a television broadcast. A strong theoretical background in meteorology is a necessity, forecast experience is highly useful, and computer competence is helpful. Obviously, strong communication skills are essential, in terms of both oral and written communication. Broadcast meteorologists are often asked to act as environmental reporters, generating stories on a variety of earth topics. Other parts of the job may include forecast development for the Internet, radio stations, and newspapers. Broadcast meteorologists often represent a strong link to the community and are frequently called upon to bring weather into many local classrooms. Teaching Atmospheric science education at the college and university level has grown tremendously in recent years. In addition to classroom teaching, many university atmospheric scientists direct research that graduate students are performing to earn their degrees. Many institutions offer a major in meteorology or atmospheric science, while others provide atmospheric science courses to supplement related science and engineering fields or as part of a broader educational curriculum. Some colleges and universities offer courses in global change and earth systems science. In high schools and lower grades, atmospheric science usually is taught as part of other natural science courses. Training in meteorology is good preparation for a career as a science teacher at any level. Where do meteorologists work? http://www.qureshiuniversity.com/aviation-meteorology.html Aviation meteorology Agricultural meteorology Hydrometeorology Nuclear meteorology Maritime meteorology U.S. Government Traditionally, the largest employer of meteorologists in this country has been the United States Government. Many work for the National Oceanic and Atmospheric Administration (NOAA), which includes the National Weather Service. Some are on active duty with the military services, primarily the Air Force and the Navy, while others are civilian employees of the Department of Defense. Other federal agencies such as the National Aeronautics and Space Administration (NASA), the Department of Energy, and the Department of Agriculture also employ meteorologists. Federal government agencies conduct atmospheric research. The National Oceanic and Atmospheric Administration (NOAA) operates a dozen environmental research laboratories. The more well-known labs include the Atlantic Oceanographic and Meteorological Laboratory, which houses the Hurricane Research Division (Miami, Florida); the Climate Diagnostics Center (Boulder, Colorado); and the National Severe Storms Laboratory (Norman, Oklahoma). The National Aeronautics and Space Administration (NASA) is also involved in a variety of basic research programs at its research facilities: the Goddard Space Flight Center (GSFC) in Greenbelt, Maryland; the Langley Research Center in Hampton, Virginia; and the Marshall Space Flight Center in Huntsville, Alabama. The Goddard Institute for Space Studies (GISS) in New York City falls under GSFC and, in cooperation with Columbia University, has been a leader in global change studies. The National Center for Atmospheric Research (NCAR) in Boulder, Colorado, also is heavily involved in global change studies, but as one would infer from its title, its research covers a myriad of atmospheric science disciplines. NCAR is sponsored by the National Science Foundation and managed by the University Corporation for Atmospheric Research (UCAR). UCAR is an international community of scientists, engineers, and technicians dedicated to enhancing understanding of the atmosphere. Among other things, UCAR recruits visiting scientists for various government and military research efforts. It also manages the NOAA Postdoctoral Program in Climate and Global Change. This program pairs recently graduated postdoctorates with host scientists at U.S. institutions. The objective of the program is to help create the next generation of researchers needed for global climate studies. Private Companies One of the fastest growing areas for meteorologists is the private sector. There are increasing employment opportunities for meteorologists in industry, private consulting firms, and research organizations. Many television stations employ professional meteorologists to present weather information to their viewers. Private sector meteorologists provide a variety of services to industries and other organizations. Some are consulting meteorologists with their own companies and others worked for corporations. In recent years, a rapidly growing specialty in meteorology has been in the area of information services. Private companies have developed computerized information systems to provide specialized weather data and displays. Private sector meteorologists also provide local weather forecasts to many radio and television stations that do not employ their own meteorologists. Weather forecasting and observing at a few air force bases also is carried out by commercial companies on a contract basis. Complementing government research work, a number of private organizations, many of them small businesses, perform research. Most of the larger corporations doing research centered around the atmospheric sciences advertise their capabilities in the Bulletin of the American Meteorological Society professional directory. Universities University meteorologists teach and work in atmospheric research programs. In addition to holding a faculty or teaching position, university and college professors often perform research, typically supported by government or foundation grants. Over 100 universities and colleges in the United States and Canada employ atmospheric scientists. Opportunities span North America from the University of Alaska, Fairbanks to the University of Miami in Florida. There are even non-continental places in the country for employment such as the University of Hawaii in Honolulu and the University of Puerto Rico in Mayaguez. Continental U.S. institutions of higher learning with programs in the atmospheric sciences range from large state universities to small colleges to specialized institutions. Would meteorology be a good career for me? Here are some questions you may want to ask yourself if you are considering a career in meteorology: * Am I curious about the world around me and why it is the way it is? * Would I like to work in a field of science that has many important applications in human affairs such as warning others of hazardous weather or investigating the atmospheric forces that shape our weather and climate? * Am I challenged by the idea of applying basic scientific principles to understand the behavior of the atmosphere? * Am I intrigued by the concept of using mathematics as a language to describe things that happen in the world around me? * Do I enjoy science and math courses? * Would I like to work with supercomputers, satellites and other sophisticated research tools? * Am I open to change? There are no right or wrong answers, but all of these questions are closely related to the nature of modern meteorology and the challenges of our changing atmosphere. http://www.ametsoc.org/careercenter/careers.html http://csep10.phys.utk.edu/astr161/lect/earth/atmosphere.html |
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Layers of the Atmosphere The atmosphere of the Earth may be divided into several distinct layers, as the following figure indicates.  
The Troposphere The troposphere is where all weather takes place; it is the region of rising and falling packets of air. The air pressure at the top of the troposphere is only 10% of that at sea level (0.1 atmospheres). There is a thin buffer zone between the troposphere and the next layer called the tropopause. The Stratosphere and Ozone Layer Above the troposphere is the stratosphere, where air flow is mostly horizontal. The thin ozone layer in the upper stratosphere has a high concentration of ozone, a particularly reactive form of oxygen. This layer is primarily responsible for absorbing the ultraviolet radiation from the Sun. The formation of this layer is a delicate matter, since only when oxygen is produced in the atmosphere can an ozone layer form and prevent an intense flux of ultraviolet radiation from reaching the surface, where it is quite hazardous to the evolution of life. There is considerable recent concern that manmade flourocarbon compounds may be depleting the ozone layer, with dire future consequences for life on the Earth. The Mesosphere and Ionosphere Above the stratosphere is the mesosphere and above that is the ionosphere (or thermosphere), where many atoms are ionized (have gained or lost electrons so they have a net electrical charge). The ionosphere is very thin, but it is where aurora take place, and is also responsible for absorbing the most energetic photons from the Sun, and for reflecting radio waves, thereby making long-distance radio communication possible. The structure of the ionosphere is strongly influenced by the charged particle wind from the Sun (solar wind), which is in turn governed by the level of Solar activity. One measure of the structure of the ionosphere is the free electron density, which is an indicator of the degree of ionization. Here are electron density contour maps of the ionosphere for months in 1957 to the present. Compare these simulations of the variation by month of the ionosphere for the year 1990 (a period of high solar activity with many sunspots) and 1996 (a period of low solar activity with few sunspots): http://csep10.phys.utk.edu/astr161/lect/earth/atmosphere.html |
 Without our atmosphere, there would be no life on earth. Two gases make up the bulk of the earth's atmosphere: nitrogen (78%), and oxygen (21%). Argon, carbon dioxide and various trace gases make up the remainder. Scientists divided the atmosphere into four layers according to temperature: , stratosphere, mesosphere, and thermosphere. The temperature drops as we go up through the troposphere, but it rises as we move through the next layer, the stratosphere. The farther away from earth, the thinner the atmosphere gets. 1. TROPOSPHERE  This is the layer of the atmosphere closest to the Earth's surface, extending up to about 10-15 km above the Earth's surface. It contains 75% of the atmosphere's mass. The troposphere is wider at the equator than at the poles. Temperature and pressure drops as you go higher up the troposphere. The Tropopause: At the very top of the troposphere is the tropopause where the temperature reaches a (stable) minimum. Some scientists call the tropopause a "cold trap" because this is a point where rising water vapour cannot go higher because it changes into ice and is trapped. If there is no cold trap, Earth would loose all its water! The uneven heating of the regions of the troposphere by the Sun causes convection currents and winds. Warm air from Earth's surface rises and cold air above it rushes in to replace it. When warm air reaches the tropopause, it cannot go higher as the air above it (in the stratosphere) is warmer and lighter ... preventing much air convection beyond the tropopause. The tropopause acts like an invisible barrier and is the reason why most clouds form and weather phenomena occur within the troposphere. greenhouse effect The Greenhouse Effect: Heat from the Sun warms the Earth's surface but most of it is radiated and sent back into space. Water vapour and carbon dioxide in the troposphere trap some of this heat, preventing it from escaping thus keep the Earth warm. This trapping of heat is called the "greenhouse effect". However, if there is too much carbon dioxide in the troposphere then it will trap too much heat. Scientists are afraid that the increasing amounts of carbon dioxide would raise the Earth's surface temperature, bringing significant changes to worldwide weather patterns ... shifting in climatic zones and the melting of the polar ice caps, which could raise the level of the world's oceans. Do you know why the amount of carbon dioxide is increasing? 2. STRATOSPHERE ozone layer This layer lies directly above the troposphere and is about 35 km deep. It extends from about 15 to 50 km above the Earth's surface. The lower portion of the stratosphere has a nearly constant temperature with height but in the upper portion the temperature increases with altitude because of absorption of sunlight by ozone. This temperature increase with altitude is the opposite of the situation in the troposphere. The Ozone Layer: The stratosphere contains a thin layer of ozone which absorbs most of the harmful ultraviolet radiation from the Sun. The ozone layer is being depleted, and is getting thinner over Europe, Asia, North American and Antarctica --- "holes" are appearing in the ozone layer. Do you know why there are "ozone holes"? 3. MESOSPHERE Directly above the stratosphere, extending from 50 to 80 km above the Earth's surface, the mesosphere is a cold layer where the temperature generally decreases with increasing altitude. Here in the mesosphere, the atmosphere is very rarefied nevertheless thick enough to slow down meteors hurtling into the atmosphere, where they burn up, leaving fiery trails in the night sky. 4. THERMOSPHERE The thermosphere extends from 80 km above the Earth's surface to outer space. The temperature is hot and may be as high as thousands of degrees as the few molecules that are present in the thermosphere receive extraordinary large amounts of energy from the Sun. However, the thermosphere would actually feel very cold to us because of the probability that these few molecules will hit our skin and transfer enough energy to cause appreciable heat is extremely low. http://www.vtaide.com/png/atmosphere.htm | |||||||||||||||||||||
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What is atmospheric thermodynamics? What are the various related to atmospheric thermodynamics? What is lapse rate? What is potential temperature? What is atmospheric stability and the various methods that define atmospheric stability? What is boundary layer development? What are the effects of meteorology on plume dispersion? What is wind velocity? What is wind rose diagram and what are the uses of it? Determination of mixing height. QUESTIONS 1. What term is used by meteorologists to describe the temperature change in the atmosphere that occurs with increasing height? 2. What is the lapse rate that is the dividing line between stable and unstable atmospheric conditions? 3. What type plume from an elevated source produces highest ground level concentration of pollutant? 4. What type graphical display is used to estimate the stability of the atmosphere? 5. Describe the inversion condition and how it may effect air pollution from a tall stack. 6. What are the three general methods that can be used to maximize the dilution capacity of the atmosphere? 7. What are the three most important meteorological variables to be measured for air pollution work? 8. What are the various layers of the atmosphere? 9. What is humidity? Give the relationship between specific volume and density. 10. Give the perfect gas equation. 11. State the two laws of thermodynamics. 12. Define specific heats at constant volume and at constant pressure. 13. State Carnot's law. 14. What are the changes called that occur at constant pressure, temperature, volume and entropy? 15. State adiabatic law. 16. State hydrostatic equation. 17. What is lapse rate? 18. What is potential temperature and where it is useful? 19. Define atmospheric stability and specify one way of determining it. 20. List out the various methods for determining atmospheric stability. 21. What is the difference between P-G method and P-G / NWS method? 22. State the relationship between wind speed ratio and atmospheric stability. 23. State the concept of boundary layer development. 24. What are the various effects of meteorology on plume dispersion? 25. State an equation to show the relationship between wind speed and height in the surface boundary layer. 26. What is the purpose of beaufort scale? 27. What is wind rose diagram and what is the use of it? 28. What is mixing height? 29. What are the various steps involved in finding maximum mixed height? | |||||||||||||||||||||
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What is a Tornado? The phenomenon of tornadoes is so well known that just about everyone has at least heard of them. A monstrous, black funnel descends from the sky winding its way over the ground, utterly indifferent to every living thing in its path. In fact, a tornado is defined as a violently rotating column of air extending from a thunderstorm to the ground. With most violent tornadoes capable of tremendous destruction and wind speeds of 250 mph or more, they are truly nature's most violent wind. The path of destruction from a tornado can be in excess of one mile wide and 50 miles long. There have been tornadoes with wind speeds up to 300 miles per hour!! Fortunately, speeds this high are very rare, occurring in only 2% of tornadoes. A similar phenomenon to tornadoes is a funnel cloud, which is simply a tornado that does not touch down. When a tornado happens over water, the tremendous power of the upward draft through the center of the cyclone causes a sucking action (like a vaccuum), which draws water up inside creating a water spout. These can travel over water onto dry land, turning into a tornado. Why Do They Happen? The simplest explanation for what causes tornadoes is the rapid convection of air. A good analogy to explain how convection works would be water in a pot on the stove; the water at the bottom heats first since it's closer to the heat source, causing the water molecules in the hotter area of the pan near the bottom to accelerate. Then they bombard the other, cooler water molecules and set them in motion upward through the water column. This causes the differing water temperatures in the pot to circulate around inside (without ever having to stir it with a spoon!). The same conditions happen in the air in the lower and upper atmosphere. When very warm, humid air that is close to the ground continues to heat up from the heat rising off the ground it rises upward rapidly towards superheated, dry air that is forcing that air down towards the ground. Think of the warm, humid air layer above the ground as starting to "boil" and push its way upward. When it rapidly breaks through the mid-to-upper layer of stable, dry air into the cooler, moist air of the upper atmosphere, those rapidly moving air molecules pick up speed, forcing the air currents to flow downward rapidly. This reaction happens very quickly and gains momentum as the wind shear increases. Typically, the rotating column of air begins parallel to the horizon, but then swings down and touches the ground. This is when it becomes painfully visible to all because the dirt, dust and debris the twister is picking up, colors the column black. It's kind of hard to imagine that something so small and invisible to the human eye - air molecules - could move with such tremendous energy and cause such a gigantic wind phenomenon. Where Do they Occur? The incidence of tornadoes is very well documented in the U.S. and in Canada. The frequent incidence of very large, dangerous tornadoes in the U.S. in the Great Plains area between the Rocky Mountains and Appalachians has earned it the nickname, "tornado alley". They happen here most frequently because of the favorable conditions. They need lots and lots of warm, humid air. This usually comes in from the Gulf of Mexico. And the rotating thunderstorms, called supercells, that spawn the biggest tornadoes need low-level winds that shift direction and grow stronger just above the ground. The higher and drier elevations of the Rockies allow a hot, dry layer of air to blow over the region from the southwest. Above 10,000 feet, cooler air races east over the region. These wind flows stack up over the center of the nation, creating low and mid level wind shear, which spawns the violent twisters. During a Tornado Signs of an Approaching Storm Some tornadoes strike rapidly, without time for a tornado warning, and sometimes without a thunderstorm in the vicinity. When you are watching for rapidly emerging tornadoes, it is important to know that you cannot depend on seeing a funnel: clouds or rain may block your view. The following weather signs may mean that a tornado is approaching: * A dark or green-colored sky. * A large, dark, low-lying cloud. * Large hail. * A loud roar that sounds like a freight train. How do we categorize these different storms? Tornado Ratings
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