Fire detection « CIMSS Satellite Blog

Pyrocumulus clouds from Sunflower Fire in Arizona

May 15th, 2012

GOES-15 (left) and GOES-13 (right) 0.63 µm visible channel images (click image to play animation)

McIDAS images of GOES-15 (GOES-West) and GOES-13 (GOES-East) 0.63 µm visible channel data (above; click image to play animation) revealed the large smoke plume associated with the “Sunflower Fire” that was burning near Payson, Arizona on 15 May 2012. Note toward the end of the animation the appearance of pyrocumulous clouds with overshooting tops over the fire source region. Due to the different satellite viewing angles, the overshooting tops were brightly illuminated on the GOES-15 images, while casting a distinct shadow onto the top of the cloud/smoke plume on the GOES-13 images. Photos of the Sunflower fire from the ground can be seen on the Weather Underground site. Other fires were also burning at that time in Arizona, including the “Gladiator Fire“ located to the northwest of the Sunflower fire.

The GOES-13 satellite was placed into Rapid Scan Operations (RSO) mode later in the day, providing images as frequently as every 5-10 minutes (compared to the routine 15-minute image interval with GOES-15).

Posted in Fire detection, GOES-13, GOES-15 | No Comments »

“County Line Fire” in northern Florida

April 7th, 2012

GOES-13 0.63 µm visible channel images (click image to play animation)

McIDAS images of 1-km resolution GOES-13 0.63 µm visible channel data (above; click image to play animation) showed the large smoke plume emanating from the so-called “County Line Fire” that was burning in the Pinhook Swamp area (along the Baker and Columbia County line) of the Osceola National Forest in far northern Florida on 07 April 2012. Strong easterly winds early in the day promoted a long westward fetch of smoke transport toward the Florida Panhandle region, but a change in wind direction along with a reduction in wind speeds allowed the smoke to become more densely concentrated around the burn area later in the day. The smoke was reducing surface visibility and causing air quality problems (see the US Air Quality blog) at some locations across northern Florida.

A 250-meter resolution MODIS true-color Red/Green/Blue (RGB) image from the SSEC MODIS Today site (below; viewed using Google Earth) showed a closer view of the source region of the smoke plume.

MODIS true-color Red/Green/Blue (RGB) image (viewed using Google Earth)

Even though the smoke was quite thick over the fire source region, a comparison of AWIPS images of MODIS 0.65 µm visible channel and 3.7 µm shortwave IR channel data (below) showed how the fire “hot spot” (red to yellow to black color enhancement) could still easily be detected with the shortwave IR imagery.

MODIS 0.65 µm visible image + MODIS 3.7 µm shortwave IR image

A sequence of 1-km resolution MODIS and POES AVHRR 3.7 µm shortwave IR images (below) showed the diurnal change in size of the fire hot spot signature (red to yellow to black color enhancement).

MODIS and POES AVHRR 3.7 µm shortwave IR images

A comparison of 4-km resolution GOES-13 3.9 µm shortwave IR imagery with 1-km resolution MODIS 3.7 µm shortwave IR imagery in the early afternoon hours (below) demonstrated the advantage of higher spatial resolution for more accuately determining the exact location of the County Line fire in far northern Florida, as well as the ability to detect a few of the smaller fires that were burning at that time in other parts of Florida and southern Georgia.

MODIS 3.7 µm shortwave IR + GOES-13 3.9 µm shortwave IR images

Finally, a comparison of 375-meter resolution Suomi NPP VIIRS 3.74 µm shortwave IR and 11.450 µm longwave IR images (below) provided even greater detail about the location and size of the fire. Even though the core portion of the fire was hot enough to exhibit a “hot spot” on the longwave IR image, the superior high temperature sensitivity of the shortwave IR channel gave a much more accurate view of the full areal coverage of the most intense portion of the fire (red color enhancement) as well as the location of active fire lines (black enhacement) out ahead of the main fire hot spot.

Suomi NPP VIIRS 3.74 µm shortwave IR and 11.450 µm longwave IR images

Posted in Air quality, AVHRR, Fire detection, GOES-13, Google Earth, MODIS, POES, Red/Green/Blue (RGB) images, Suomi NPP, VIIRS | 1 Comment »

Lower North Fork Fire in Colorado

March 27th, 2012

GOES-15 + GOES-13 0.63 µm visible channel images

The “Lower North Fork Fire” near Aspen Park, Colorado began during the afternoon hours on 26 March 2012 and rapidly expanded to over 4100 acres in size. 2 fatalities resulted from this fire, with over 900 homes being evacuated and at least 27 homes damaged or destroyed. The combination of strong southwesterly winds (gusting in the 35-50 mph range) and very dry air (relative humidity values around 10%) created an environment that was favorable for rapid wildfire growth. A comparison of McIDAS images of GOES-15 (GOES-West) and GOES-13 (GOES-East) 0.63 µm visible channel data (above) showed the development of a large smoke plume with embedded pyrocumulus clouds.

The corresponding series of GOES-15 and GOES-13 3.9 µm shortwave IR images (below) revealed how quickly the fire “hot spot” (black to yellow to red color enhancement) grew in size.

GOES-15 + GOES-13 3.9 µm shortwave IR images

An AWIPS comparison of a 1-km resolution POES AVHRR 3.7 µm shortwave IR image with the corresponding 4-km resolution GOES-13 3.9 µm shortwave IR image just after 02 UTC or 8 pm local time (below) demonstrated the advantage of higher spatial resolution for more accurately identifying the location and areal coverage of the fire.

POES AVHRR 3.7 µm + GOES-13 3.9 µm shortwave IR images

A larger scale HD-format view of GOES-13 0.63 µm visible channel images (below; click image to play animation) revealed other interesting features across the region, such as (1) a large blowing dust plume oriented from southwest to northeast across Colorado, (2) a terrain-induced standing wave cloud over southwestern Colorado, (3) the development of a line of thunderstorms across eastern Wyoming, and (4) another smaller blowing dust plume across eastern Idaho. Animated GIF courtesy of Tim Schmit, NOAA/ASPB/CIMSS.