GOES-15 began planned supplemental operations on Aug 4 to provide additional Eastern Pacific tropical cyclone support due to the operational impacts from the GOES-17 ABI Loop Heat Pipe anomaly (details here) This support is planned to continue through Sep 3. Given the coverage over the western US, the GOES-15 Imager also captured the intense wildfire activity, which allowed for comparisons with the newer GOES-17 ABI. Example comparisons between the two Imagers remind us of some of the improvements we have in wildfire monitoring with the GOES-R era satellites.
Starting with the 3.9 um SWIR imagery, abundant wildfire hot spots are diagnosed from both satellites across northern California on 08 Aug 2021 (Fig 1). However, the smaller/cooler fires that appear as faint hot spots in the ABI imagery, are very difficult to impossible to discern in the GOES-15 Imagery due to the poorer spatial resolution. The difference in temporal cadences is obvious, with the routine 5-minute imagery of the ABI allowing for smoother animations, for the ability to detect fires earlier, and for easier tracking of fire evolution with time. The image navigation from ABI is significantly better than that of GOES-15 at this point, with no noticeable movement from image to image. Finally, the saturation temperature in the ABI SWIR channel is much higher than previously.
A similar comparison is made between the VIS channels in order to observe the smoke plumes (Fig 2). In addition to those points referenced previously, the higher spatial resolution in the VIS makes clearer the areas of smoke including their source points, smoke edges, and development of pyrocu.
The 5-min ABI imagery shown above is from the routinely available CONUS sector. Of course, forecasters can request 1-min mesoscale imagery whenever desired, allowing for wildfire hot spots and smoke plumes to be detected even earlier, and tracked in more detail (Fig 3).
Bill Line, NESDIS and CIRA