As the launch date for GOES-R nears, the need to fully understand the nuances of the individual bands on the Advanced Baseline Imager becomes increasingly important. Unlike the current GOES imagers, the ABI will have two bands in the traditional infrared window portion of the spectrum: one centered at 10.35 µm and another centered at 11.2 µm. In much of the GOES-R Risk Reduction and Algorithm Working Group activities up to this point, researchers have simply assumed that the 11.2 µm band would be the "default" window band because it is most similar to the predecessor instruments (both GOES and the Meteosat SEVIRI's 10.8 µm band). The channel having the most similar characteristics as the ABI's 10.35 band was the MODIS Airborne Simulator's (MAS) band 44; it was centered at 10.55 µm and was not chosen as one of the MODIS bands. We propose that the 10.35 µm band is a more appropriate window band for surface viewing applications primarily because there is less water vapor absorption compared to 11.2 µm.

For some applications, such as identifying cold thunderstorm tops, the differences between the 10.35 and 11.2 µm brightness temperatures are negligible. However, differences can be more significant in clear sky conditions in the warm season, and especially when the window band is used as part of a band difference product. For example, a common split window difference (~10-12 µm) is sometimes used to infer low level water vapor amounts, so choosing the cleanest possible window to include in the difference is critical. In this presentation, we will make the case for the ABI 10.35 µm band by showing radiative transfer model simulation results, simulated satellite imagery, and simulated band difference imagery.

Disclaimer: The views, opinions, and findings contained in this article are those of the authors and should not be construed as an official National Oceanic and Atmospheric Administration (NOAA) or U.S. Government position, policy, or decision.