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Photo by John Wagner
National Aeronautics and Space Administration scientist Jim Podolske pours liquid nitrogen into a laser absorption spectrometer used to measure carbon dioxide level in Earth’s atmosphere Monday, April 14, 2008. Liquid Nitrogen is added every twelve hours to chill the spectrometer’s laser to keep it properly operating at a specific wavelength. Scientists with NASA, the National Oceanic and Atmospheric Administration and the Department of Energy are in town to study pollution concentrations in Northern regions which are contributing to global climate change.