Project Funding: 2012 - 2014

NRA: 2011 NASA: Carbon Monitoring System   

Funded by NASA

Abstract:
We propose to contribute to the NASA Carbon Monitoring System (CMS) with a fourdimensional variational (4D-var) inverse modeling capability for methane emissions in North America integrating satellite (GOSAT, TES), aircraft (CalNex, HIPPO, NOAA/CCGG), and surface-based (TCCON, NOAA/CCGG) observations. Our work will build on the existing CMS capability at JPL for carbon flux inversions using the adjoint of the global GEOS-Chem chemical transport model (CTM). Here we will apply the adjoint of the nested version of GEOS-Chem with 1/2o × 2/3o (~50 × 50 km2) horizontal resolution over North America and adjacent oceans. The nested model will enable fine-scale constraints on methane sources through the 4D-var inversion. We will focus on 2009 2011 when data from both GOSAT and TES are available together with aircraft campaign data over the US from CalNex (May July 2010) and HIPPO (June September 2011). Combined use of GOSAT and TES data will enable us to separate boundary layer and free tropospheric contributions to the methane column through the inversion. The satellite data will be ingested in the 4D-var inverse model while the suborbital data will be used for independent analysis of the optimized methane fluxes. We will conduct a targeted analysis of the CalNex period to constrain methane sources in California by applying both Lagrangian (STILT) and Eulerian (GEOS-Chem) inverse modeling approaches to the aircraft and satellite data, testing the effect of different meteorological data sets and of different a priori constraints. This analysis will provide a unique opportunity to assess inverse modeling uncertainties related to resolution, data type (satellite or aircraft), meteorological model, and inversion procedure. We will use results from our continental-scale inversion of methane fluxes to better understand and quantify the major sources contributing to methane emissions in North America, and to provide guidance to the US EPA for improving its national emission inventories. The inverse modeling capability for methane will be implemented into the existing CMS Flux Pilot Project at JPL for consistent inversion of CO2 and methane fluxes over North America using the same 4D-var system. This will provide a powerful facility to monitor the fluxes of the two most important anthropogenic greenhouse gases. Our work will be directly responsive to major climate policy initiatives in the US targeting methane emissions including the Global Climate Change and Clean Air Initiative of the US State Department and the Global Methane Initiative of the U.S. EPA. P.I. Daniel Jacob and CoI Steve Wofsy will join the CMS Science Team as part of this project.

Publications:

Barrera, Y. D., Nehrkorn, T., Hegarty, J., Sargent, M., Benmergui, J., Gottlieb, E., Wofsy, S. C., DeCola, P., Hutyra, L., Jones, T. 2019. Using Lidar Technology To Assess Urban Air Pollution and Improve Estimates of Greenhouse Gas Emissions in Boston. Environmental Science & Technology. 53(15), 8957-8966. DOI: 10.1021/acs.est.9b00650

Wecht, K. J., Jacob, D. J., Sulprizio, M. P., Santoni, G. W., Wofsy, S. C., Parker, R., Bosch, H., Worden, J. 2014. Spatially resolving methane emissions in California: constraints from the CalNex aircraft campaign and from present (GOSAT, TES) and future (TROPOMI, geostationary) satellite observations. Atmospheric Chemistry and Physics. 14(15), 8173-8184. DOI: 10.5194/acp-14-8173-2014

Wecht, K. J., Jacob, D. J., Frankenberg, C., Jiang, Z., Blake, D. R. 2014. Mapping of North American methane emissions with high spatial resolution by inversion of SCIAMACHY satellite data. Journal of Geophysical Research: Atmospheres. 119(12), 7741-7756. DOI: 10.1002/2014JD021551

More details may be found in the following project profile(s):

• North American Carbon Program (NACP) Project Profile
• NASA Carbon Monitoring System (CMS) Project Profile