About Band 9

6.9 µm - "Mid-level Water Vapor" Band - 2 km resolution - Band 9 is the mid-level water vapor band. It is used for tracking middle-tropospheric winds, identifying jet streams, forecasting hurricane track and mid-latitude storm motion, monitoring severe weather potential, estimating mid-level moisture (for legacy vertical moisture profiles)and identifying regions where turbulence might exist. Surface features are usually not apparent in this band. Brightness Temperatures show cooling because of absorption of energy at 6.9 µm by water vapor.

The imager on GOES-16 features three mid-level water vapor bands instead of the single water vapor band on the GOES-13 Imager. The single water vapor band on GOES-13 contained a mixture of water vapor features over many levels of the troposphere, but GOES-16 enables us to focus on water vapor in the upper troposphere (band 8), the middle troposphere (band 9), or the lower troposphere (band 10). The GOES-13 Imager water vapor channel falls between ABI bands 8 and 9.

• For more details, see the Band 9 - ABI Quick Information Guide, (PDF, 550 KB)

*GOES-17 Infrared Image Quality

During post-launch testing of the GOES-17 ABI instrument, an issue with the instrument's cooling system was discovered. The loop heat pipe (LHP) subsystem, which transfers heat from the ABI electronics to the radiator, is not operating at its designed capacity. The consequence of this is that the ABI detectors cannot be maintained at their intended temperatures under certain orbital conditions. This is preventing adequate cooling for some of the infrared (IR) channels on the instrument during parts of the night, leading to partial loss of ABI imagery. Learn more.