Weather prediction starts with observations, techniques and equipment. Barometers are for making air pressure measurements and thermometers show temperature, usually on the Fahrenheit or Celsius scale. We use many types of hygrometers for determining humidity, as there are a lot of ways of stating and the airs moisture content. Winds are measured using an anemometer for speed and weather vanes or socks give the direction. Rain and snow gauges allow us to find out how much precipitation has fallen. See how to convert from one type to another. Our national governments and airport authorities use all of these devices on site to provide for safer aviation. http://www.stuffintheair.com/weatherequipment.html Take a picture of our planet and the current weather systems will be included. Sorting out technical issues like wavelength and resolution will help trained image interpreters draw useful information from the photographs. Things emit, absorb, transmit and reflect radiation and the people figure this all out, such as which ones are sources and which are obstacles. In fact they need the help of computers to do so. http://www.stuffintheair.com/image-satellite-weather.html Weather radar shows us current and recent weather in fine detail. Radar uses a fancy radio set that detects moving objects. Both digital and analog equipment is required to make picture creation possible. The use of wave physics is important here as well, as the subject can be quite technical. One machine quickly alternates between broadcasting and receiving signals, in the form of pulses, so passive targets can be detected. Technicians have to learn to deal with all types of problems and flaws naturally occurring in the system. Doppler radar adds another dimension of useful information to the picture. More details are available at http://www.stuffintheair.com/radar-real-time-weather.html What are weather balloons used for? To measure what is happening above. Atmospheric motions involve a great deal of wet and dry air undergoing elevation and pressure changes. It gets further complicated if heat or vapor flows in and out of an area, such as when the wind blows on or offshore, so a solid understanding of thermodynamics is required to comprehend it properly. Meteorologists use standard maps and graphs (with names like tephigram, skew-t or nomograms) to make the calculations. While involved in this serious analysis, an advanced concept called wet-bulb potential temperature can be a forecasters best friend. This specialized field of employment requires a four-year university degree plus extensive job-specific training. Links to pages explaining the more advanced concepts for those who need to know more have been placed near the end of the home page http://www.stuffintheair.com/ for quick reference. You will see pages about cloud generation processes, convection and lapse rates, thunderstorm creation, turbulence, stability, inversions, air quality and global warming. Overall, the most noticeable implement used in forecasting is the weather map. Meteorologists can see how winds will blow systems around (advection) and change their shape (deformation). If you were to visit the link below, you would learn that wind flows clockwise around a high pressure system (in the northern hemisphere) and why, as well as how atmospheric pressure relates to observable conditions (sunny, rainy etc.) And why. You have heard of the troposphere, stratosphere, mesosphere and thermosphere above us. They are all very different from each other, but consistent over the entire planet. Some maps show important large scale features such as air masses and jet streams. In order to be accurate, they have to incorporate influences such as the curvature and rotation of the earth. Again the presence or absence of moisture is crucial in all aspects of forecasting. For instance, we use that information for storm prediction and many more complicated things. That is because the latent heat stored in water vapor serves as a potent energy source to drive mechanical processes, which can then extract more heat from the vapor and so on. Another construct, vorticity, further enhances the twisting and lifting power of the atmosphere. The waves and streamlines on an assortment of weather maps carry special meanings for meteorologists as well. Again, an intuitive knowledge of physics greatly helps the forecaster understand, explain and prognosticate the situation. http://www.stuffintheair.com/ForecastMapWeather.html |
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