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Atmosphere - Structure and Composition. Atmospheric Composition. Variable Gases :. Water Vapor 0.1% to 5% (by volume) Carbon Dioxide 365 ppm Other "Greenhouse" gases. Water Vapor Pressure (mb) - January. Since the 1950s, the concentration of carbon dioxide
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Variable Gases: • Water Vapor 0.1% to 5% (by volume) • Carbon Dioxide 365 ppm • Other "Greenhouse" gases
Since the 1950s, the concentration of carbon dioxide has increased at a rate of about 1.8 ppm per year. The increase has occurred mainly because of anthropogenic combustion and deforestation of large tracts of woodland. Carbon dioxide increase since the 1950s
Experts Predict Polar Bear DeclineGlobal Warming Is Melting Their Ice Pack HabitatBy Blaine HardenWashington Post Staff WriterThursday, July 7, 2005
The photograph taken in 1928, above, shows how the Upsala Glacier, part of the South American Andes in Argentina, used to look. The ice on the Upsala Glacier today, shown in 2004 below, is retreating at least 180 ft. per year Time Magazine – March 26, 2006
Aerosols - particulates .....increasing? ….decreasng?
Atmospheric Aerosol Properties and Climate Impacts U.S. Climate Change Science Program Synthesis and Assessment Product 2.3 January 2009
Vertical Structure is Crucial • The world is a big place, but the atmosphere is very thin, and most of it is close to the ground • The atmosphere is most dense near the surface • At the top of Mount Denali (18,000 feet above sea level), the figure is 50% • Changes in atmospheric temperature and composition with height above the surface account for our weather and account for the “greenhouse effect”
18,000 feet --- 500 mb level Sea Level Pressure --- 1013 millibars
Atmospheric pressure is routinely plotted on maps by the use of lines called isobars. Each isobar connects points having equal air pressure with the pressure being expressed in units of millibars (mb) in the United States and kilopascals (kPa) in Canada. A surface weather map
Vertical Thermal Structure • Heated from below by latent and sensible heat fluxes • Heated in stratosphere by ozone absorption
July 19, 2010, 12:45 pm The Passing of a Climate Warrior Interview Q&A: Dr. Stephen Schneider, one of the world's leading climatologists, discusses the line between science and activism. The New Republic; Nov, 2009.