Salt Lake Valley Light Rail (TRAX)-based

Measurements of Greenhouse Gases and Air Quality

PROJECT DESCRIPTION: This pilot project in collaboration with UTA TRAX demonstrates the feasibility of monitoring trace gas species and illustrates their temporal and spatial patterns within the Salt Lake Valley. Carbon dioxide (CO2), methane (CH4), and ozone (O3) were measured from a rail car on the TRAX red line for one month in the summer of 2014 (August 11th to September 12th). The maps below show the average concentrations of these gases over the month long project with both the height and the color of the bars representing the average concentration. The real-time displays are shown on Trax Real-Time Data Displays.
METHODOLOGY: Data were collected at 1 second (GPS location, CO2 and CH4) and 2 second (O3) intervals. The GPS data were then merged onto a 1000 point long transect along the Red Line. Then, for each time the train traversed the valley, we averaged all of the data at each transect point. For example, when the train pauses at a TRAX stop for 30 seconds, there will be 30 data points in one location, so we average these 30 data points into 1 value for that location. Finally, the data at each location along the transect is averaged over the whole month of the project, yielding the maps below.
DISCLAIMER: These data are preliminary and may be revised upon further analysis. They are being provided as a demonstration of the capabilities of this measurement platform, as an educational tool, and to engage the public.
PARTICIPANTS: Logan Mitchell, Erik Crossman, Ben Fasoli, Luke Leclair-Marzolf, John Lin, John Horel, Dave Bowling, Jim Ehleringer.
ACKNOWLEDGEMENTS: We gratefully thank UTA TRAX for allowing us to install our instruments on a rail car on the Red line which facilitated this project.
Questions or comments can be sent to Logan Mitchell and John Lin