Archive for October, 2006

Fatal fire in California

Thursday, October 26th, 2006

GOES-11 3.9µm IR animation
The large (40,000 acre or 63 square mile)  “Esperanza wildfire” started during the early morning hours on 26 October 2006 in a portion of the San Bernardino National Forest near Banning, California (west of Palm Springs); this fire quickly burned out of control, and was responsible for the deaths of 5 firefighters. Santa Ana winds across the region were creating favorable conditions for rapid fire growth (the dew point at nearby Palm Springs dropped from 55˚F at 19 UTC on 25 October to -1˚F at 07 UTC on 26 October). GOES-11 3.9µm IR imagery (QuickTime animation, above) showed very hot brightness temperatures (yellow to red enhancement) in the vicinity of this large fire — hot fire pixels were first evident at 08:15 UTC (01:15 AM local time), and image pixel values reached the saturation temperature of the GOES-11 3.9µm detectors (337.2˚K / 64˚C / 147˚F) as early as 12:45 UTC (5:45 AM local time). The Wildfire ABBA product (GOES-11 | GOES-12) also indicated saturated fire pixels (yellow) in that area (20:45 UTC WF_ABBA image).

GOES-11 visible channel imagery (QuickTime animation, below) showed a very large smoke plume from this fire, which was dispersed in different directions due to directional wind shear between the surface and the 500 hPa level (~18,000 feet in altitude). MODIS imagery of the fire from 26 October is posted on the UMBC Air Quality Smog Blog, while the IDEA Aerosol Optical Depth product from the following day shows continued smoke transport out across the adjacent Pacific Ocean.
GOES-11 visible image animation

Power plant plumes

Thursday, October 19th, 2006

AWIPS MODIS fog/stratus product
The AWIPS image of MODIS 11.0µm-3.7µm “fog/stratus product” (above) reveals several long plumes embedded within the extensive stratus cloud deck (yellow to red enhancement) that covered much of northern and central Minnesota during the pre-dawn hours on 19 October. These plumes likely originated at large coal-fired power plants (or paper mills?) located across that region — emissions from these industrial sources may have acted as cloud condensation nuclei, causing a higher concentration of smaller supercooled cloud droplets downwind of the plants.

The MODIS Cloud Phase product (below, lower left panel) showed that this stratus deck was primarily a water-phase cloud (blue enhancement); MODIS 11.0µm IR window channel brightness temperatures were generally around -14 C across that region, indicating that the stratus cloud was composed of supercooled water droplets. Note that these power plant plumes were not evident on the 4 km resolution GOES fog/stratus product (below, upper right panel). The GOES sounder Cloud Top Height values were around 11-12 kft over the area.
AWIPS MODIS + GOES comparison