Air Quality Science
Twenty years of hourly carbon dioxide concentration measurements have been obtained at the University of Utah. The data clearly show a long steady rise in CO2 concentrations tracking the atmosphere as a whole. This is the signature driving global warming. But there are also more local signatures. In winter, concentrations in the Salt Lake valley spike as pollution is trapped by the “inversion”. More often, pollution drops on the weekends, and also there are once daily variations due to the rush hour.
Using a mathematical technique called a Fourier Transform, a small discovery was made that the daily variations are not just once per day, but twice per day, three times per day, and so on, each subsequent cycle having a slightly smaller amplitude. In mathematics and physics, this sequence is known as a harmonic series; harmonic because the sequence also lies at the core of creation of the musical scale and the manufacture of tone by common musical instruments. In fact, based on the information of frequency and amplitude in the daily signatures, it was possible to superimpose all these cycles, increase the frequency from once per day to an audible musical note at higher frequency, and notice that the manufactured “tone” sounds very much like an oboe. This is interesting, because although the oboe is very difficult to play, a double reed forcing a conical bore is one of the first instruments created by humans. To think that we as residents of Salt Lake in all our complexity behave similarly to such a simple musical device is fascinating.
– Tim Garrett
The variation of carbon dioxide (CO2) and temperature over the past 800,000 years, as derived from Antarctic ice cores. The in-situ measurements of CO2 in Salt Lake City, the dataset underlying the musical piece, are shown for the past two decades in gray. In addition, the observed CO2 from Mauna Loa, Hawaii are shown to indicate the global scale buildup of CO2 from human activities around the world. (courtesy of Logan Mitchell)
Musical Composition Data
The data that underly this musical composition derive from continuous measurements of carbon dioxide (CO2), the main long-lived gas that warms the Earth’s surface and the main culprit underlying climate change. These observations of CO2 levels in the ambient atmosphere are carried out on the University of Utah campus, originally in the Department of Biology and then moving to the Utah Atmospheric Trace gas & Air Quality (U-ATAQ) lab in the Department of Atmospheric Sciences. This dataset represents one of the longest-running urban observations around the world, tracking the increase of CO2 from emissions and human activities in Salt Lake City, superimposed upon the global scale buildup from human society (see Figure left).
– John Lin
For more information on these data and the associated scientific and policy applications, see the following:
CO2 AND CARBON EMISSIONS FROM CITIES: LINKAGES TO AIR QUALITY, SOCIOECONOMIC ACTIVITY, AND STAKEHOLDERS IN THE SALT LAKE CITY URBAN AREA
Lin, J.C., et al., CO2 and carbon emissions from cities: linkages to air quality, socioeconomic activity and stakeholders in the Salt Lake City urban area, Bulletin of the American Meteorological Society.
