Greenhouse gases at local and regional scales: atmospheric observations and modeling the sources

To better understand dynamics of GHG sources and sinks and their links to climate change and anthropogenic factors, long-term continuous observations of atmospheric carbon dioxide (CO2) and methane (CH4) at local and regional scales are needed. During 2012, Earth Networks Inc. deployed more than 20 GHG-measuring cavity ring-down spectrometers (CRDS) at tall towers, as an initial part of a 50-site observing network installation. Data collected across the US reflects temporal and spatial variability of GHG emissions and dependence of atmospheric concentrations on local weather and larger scale transport patterns. In this study, trends in CO2 and CH4 observations during 2012, as well as anomalies and short duration changes are analyzed and compared with available gridded products. Coupled WRF-STILT system is used to provide the link between observed spatial and temporal patterns of atmospheric concentrations to surface fluxes and through inverse modeling to estimate GHG emissions over a domain divided into smaller regions. Dependence between spatial aggregation of emissions into regions and temporal resolution of the atmospheric concentrations from multiple sites, and the resulting uncertainties in emission estimates are analyzed in this study.