The first two images below show northern Florida as viewed by NOAA-12 as it passed over at 7:29 PM EDT on Monday, June 22, 1998. The images cover the same area, from the Florida/Georgia border on the top to just south of Cape Canaveral in the southeast corner. On the color image the St. Johns River is seen as a dark somewhat sinuous feature running north/south in northeastern Florida. Just to the west of the river is a parallel band of thunderstorms, the high storm clouds cast shadows toward the east from the low sun in the west.
The color image on the left is a composite of 3 channels of the AVHRR imager on the satellite. Channel 1 is in the visible range and is colored red, channel 2 is in the near infrared and is colored green, channel 4 is in the far infrared is and colored blue after being reversed. The peak reflectance from vegetation falls in channel 2, so the green color does represent vegetation mostly. Channel 4 shows the thermal emission, warmer areas emit more, but this channel has been reversed to make clouds bright instead of dark.
The fires are marked by a series of smoke plumes blowing toward the west between the St. Johns River and Cape Canaveral. The plumes appear yellow in this color combination. Another area of smoke is visible near the northwest corner of the color image.
The image on the left is from AVHRR channel 3 which cuts through the smoke and shows the fires themselves as bright areas. The deep black areas are clouds which are colder and darker than the warm earth below. Note the channel 3 image shows smaller fires than the color composite smoke plume image.
The image below is was obtained in the early morning of Tuesday. It is from channel 3, the AVHRR channel that shows fires well. The fires appear fewer and somewhat less intense. This commonly occurs at night when the cooler temperatures and higher humidity make the fires less strong.
