Building Bridges: An Example of Linking Global-Scale CO2 Fluxes to High-Resolution Urban CO2 Emissions

Abstract:

The past decade has seen an explosion in atmospheric carbon cycle research at increasingly disparate spatial scales. Global carbon flux inversion modeling based upon on satellite XCO2 data (e.g. GOSAT and OCO-2), such as the CMS-Flux system, have produced global time and space resolved CO2 fluxes but has often been limited to resolutions of 2.5 x 2 degrees or coarser. On the other hand, regional CO2 inversion modeling using in-situ and satellite data (OCO-2/OCO-3) has refined itself to ever higher spatial resolutions, now targeting cities and power plants at the scales of a few kilometers. While these two threads of research have been independently productive, little work has been done to bridge the gap in scales across the two areas. In this talk, we will discuss options for linking these two communities and data constraints through the Ocean Land Atmosphere Model (OLAM), a variable resolution general circulation model (GCM). We will discuss signal-to-noise considerations for detecting perturbations in urban fossil CO2, both with respect to time-space varying CO2 inflow from biology as well as uncertainty in fossil emission source and transport. We consider dozens of cities around the globe and on every continent. OLAM model simulations are evaluated, challenges discussed, and a roadmap forward to a next-generation multi-scale flux inversion system is proposed.