Assessment of Ground-based Atmospheric Observations for Tracking Changes in Greenhouse Gas Emissions from Urban Areas

Author: Thomas Nehrkorn, and K. McKain
Date: 
December 8, 2011
Type: 
Poster presentation
Venue: 
AGU Fall Meeting 2011
Citation: 

K. McKain, S.C. Wofsy, Thomas Nehrkorn, Janusz Eluszkiewicz (2011) Assessment of Ground-based Atmospheric Observations for Tracking Changes in Greenhouse Gas Emissions from Urban Areas. AGU Fall Meeting 2011.

The fairness and effectiveness of agreements to limit greenhouse gas emissions depends on our ability to verify reported changes in emissions using direct atmospheric observations. The goal of this work was to test whether ground-based measurements of greenhouse gases from urban regions can be used to quantify changes in emissions. We performed an atmospheric inversion for Salt Lake City, Utah using an existing dataset of CO2 measurements, prior estimates of emissions, and a high-resolution Lagrangian atmospheric transport model. By comparing simulated and observed CO2 for Salt Lake City, we were able to constrain emissions to within 15%. Substantial improvements in our ability to estimate emissions using urban surface observations are not expected because of limitations imposed by the character of the data, namely the dominance of the stochastic component of the signal and the inverse relationship between the daily cycle of emissions and CO2 concentration enhancements. Based on these results, we believe ground- and space-based measurements of column enhancements in the urban dome offer a superior route for verification purposes.