Fig. 4: Evaluation of Suomi-NPP Cross-track Infrared Sounder (CrIS) ethane retrievals against ground-based observations from the Network for the Detection of Atmospheric Composition Change (NDACC).
From: Space-based observations of tropospheric ethane map emissions from fossil fuel extraction
NDACC observations are averaged over ±2 h of the local satellite overpass time. CrIS observations reflect a 3 × 3 pixel mean (0.5° × 0.625° resolution) centered on the NDACC site. The black line shows a standard major axis fit, with parameters given inset (intercept units: 1016 molecules cm−2). Vertical scaling corrections (Methods) have been applied to the CrIS columns for the six high-altitude sites (Altzomoni, Maido, Mauna Loa, Izaña, Rikubetsu, and Zugspitze). The 1:1 line is also shown (dashed gray line).
