Minutes of the May 19, 2008 Meeting
Smoky Mountain AMS Chapter
Around 12 people first met for dinner at "Calhoun’s on the River" in Knoxville. Afterwards, around 20 people met for the meeting on the University of Tennessee Ag campus to hear our speaker: Robert N. Compton of the Department of Physics and Chemistry at the University of Tennessee. Dr. Compton's talk was entitled "The Changing Earth’s Atmosphere" and the following was a synopsis:
"The atmosphere surrounding the Earth has always been in a state of change. Presently, the air that we breathe is 78% nitrogen, 21% oxygen, 0.93% argon and 0.0383% carbon dioxide plus a number of other trace gases along with the changing water vapor. The concentration of carbon dioxide is ~ 383 parts per million by volume. Of great concern is the well documented fact that the concentration of CO2 has been rising and, aside from seasonal variations, this increase is well correlated with the introduction of man made sources of CO2 (burning of coal, combustion, etc.). The temperature of the Earth is established by a delicate balance between heat from the Earth’s crust (radioactivity), radiation from the Sun and re-radiation from the Earth’s surface to the surrounding Universe. Clouds and aerosols also play a major role in the radiation balance. Carbon dioxide and other infrared absorbing gases in the atmosphere trap some of the heat being re-radiated out into space. The analogy to a Greenhouse has given the name Greenhouse Gases to these trace gases. There is gathering data to suggest that the Earth is warming on average and this Global Warming has been attributed in part to the increase in Greenhouse Gases. The ever-present water vapor in the atmosphere is the largest contributor to the Green House gases. The Earth acts much like the human body in which a “fever” of a few degrees can be a life threatening situation. Phase changes (e.g., ice to water) can take place within small temperature changes. Many fear that the Earth may experience a “heat stroke” due to Global Warming. This talk will attempt to discuss some of the science in the debate over Global Warming. In so doing, we will also take note of the changing pH of the oceans which some attribute to the increase of carbon dioxide in the atmosphere.
A large part of the discussion on atmospheric composition and radiative energy balance (i.e., Earth’s temperature) will be based upon measurements by the Compton group, particularly Dr. Stuart Hager, Ms. Maria Olivaris and Dr. Jeff Steill, at the University of Tennessee. We have been carrying out infrared absorption spectroscopy measurements using the Sun as the IR light source. Tracking the IR absorption as the Sun rises over the Smoky Mountains and sets over the Bull Run and Kingston Steam Plants."
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