Human industry and transportation releases 3.3E+10L of water vapor through chemical reactions every year. As the released water vapor rises, it may contribute to the warming of earth’s atmosphere, because it has a uniquely high specific heat allowing it to carry significant energy. In this project, a scaled model of the atmosphere was built to test the effect of water vapor on temperature. A dry ice and acetone mixture was used as a refrigerant at the top of the model to simulate low temperatures at very high altitudes. Pressure variation was simulated by varying the volume of the model to correlate to the number of molecules in the atmosphere. To test the research question, controlled amounts of water vapor were injected into the model in 1 milliliter increments. The temperature of the zone, where the temperature was 0ºC, increased by 0.7ºC per milliliter of water added. The water vapor caused a lasting temperature effect at about 6500 m or 0.65 scale meters, because the water vapor releases its energy when it freezes. Water vapor only had a transient and minimal effect at the top and bottom of the laboratory model, because the total energy introduced was small compared to the column thermal mass. On a global scale, 1 milliliter of water in the model is equivalent to 1.46E+14 liters in earth’s atmosphere. At the current rate of hydrocarbon combustion the mid atmosphere temperature could rise about 0.7ºC every 12 years because of water vapor that is produced.
1Junior, Immaculate Heart High School, Oro Valley, Arizona. Poster Presentation SARSEF Grand Award: 1st Place, ISEF Finalist, UA Scholarship Awardee.