This raster maps average atmospheric methane concentrations in 2016. The data used to create it is from the NASA Aqua satellite (specifically the AIRS instrument) that records monthly average atmospheric methane concentrations. AIRS collects methane data at different pressure levels. The raster depicts data at the 400 hPa level because that is where the instrument is most sensitive to methane concentration. The monthly data was consolidated using the NASA tool, Giovanni https://giovanni.gsfc.nasa.gov/giovanni/, to create a raster with annual average methane concentrations. Giovanni output two rasters: one for daytime averaged data and one for nighttime averaged data. ArcGIS was then used to combine the two rasters to create a single annual raster. A conversion factor of 1.0e+9 was multiplied to convert the final raster from mole fractions to parts per billion. The results are attached.
The Carnegie Endowment for International Peace would like to eventually incorporate a methane raster as a new layer in the Oil Climate Index (OCI) web tool http://oci.carnegieendowment.org/. Carnegie is currently updating the OCI, adding greenhouse gas comparisons of global gas fields and visualizing their methane emissions. Carnegie is planning to work with our OCI partners at Stanford to further analyze the methane concentration raster to separate out signal from noise and to identify potential methane concentration hot spots associated with oil and gas operations. This raster is useful when studying short term climate risks, especially when it comes to Arctic oil and gas resources.