Constraining Carbon Emission Estimates from the Los Angeles Megacity through use of Remote-sensing Techniques and a Time-reversed Lagrangian Particle Dispersion Model

Friday, 19 December 2014
Lacey Holland1, John C Lin1, Debra Wunch2, Paul O Wennberg2 and Coleen Marie Roehl2, (1)University of Utah, Salt Lake City, UT, United States, (2)California Institute of Technology, Pasadena, CA, United States
Much of the global increase in carbon dioxide (CO2) is related to urban activity. Accurate greenhouse gas (GHG) inventories in urban environments are important to inform responsible policy decisions toward GHG reduction, such as California Assembly Bill #32, and more recently, the Obama Administration proposed rule changes to reduce GHG emissions from power plants.

As a megacity (metropolitan area with a population >10 million people), the Los Angeles metropolitan area has been the locus of a number of studies seeking to constrain CO2 emissions. In this work, we adopt an approach toward the atmospheric transport modeling of urban emissions that examines co-emitted pollutants (CO, CO2, CH4) in the LA megacity environment. This approach leverages observations from the ground-based Total Carbon Column Observing Network (TCCON) and space-borne GHG observations through use of the Stochastic Time-Inverted Lagrangian Transport (STILT) model to produce an atmospheric inversion of GHGs in the LA megacity environment. This work seeks to develop accurate GHG emission estimates within a framework that leverages TCCON, along with high-resolution satellite observations (<3 km2 footprint) from the recently launched OCO-2 satellite mission to resolve spatial variability on scales that presently challenge Eulerian models.