Smoke in the Gulf of Mexico

April 18th, 2019 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with surface fronts plotted in cyan [click to play animation | MP4]

GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed some clearing of the dense pall of smoke across the far western Gulf of Mexico in the wake of a cold front that was moving southward/southeastward off the Texas coast on 18 April 2019. The parallel wave clouds of an undular bore were also evident ahead of the cold front from 13-16 UTC — the bore was also causing horizontal convective roll perturbations in the smoke about 20-40 miles ahead of the wave clouds (1506 UTC image).

The hazy signature of smoke was better defined in GOES-16 True Color Red-Green-Blue (RGB) images from the AOS site (below). This smoke was the result of widespread annual Springtime agricultural burning across southern Mexico, Guatemala, Belize and Honduras. Toward the end of the day, additional small plumes of smoke and blowing dust could  be seen moving back across the Gulf of Mexico into the “cleaner” air behind the cold front.

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

Thermal anomalies or “hot spots” (yellow to red pixels) associated with the larger fires in Mexico, Guatemala, Belize and Honduras could be seen in GOES-16 Shortwave Infrared (3.9 µm) images (below).

GOES-16 Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

GOES-16 Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

A map of fires detected by Suomi NPP VIIRS on the previous day is shown below, as viewed using RealEarth.

Fires detected by Suomi NPP VIIRS on 17 April [click to enlarge]

Fires detected by Suomi NPP VIIRS on 17 April [click to enlarge]

Satellite signatures of the Notre Dame Cathedral fire in Paris, France

April 15th, 2019 |

EUMETSAT Meteosat-11 Shortwave Infrared (3.92 µm) images, with airport identifiers plotted in red [click to play animation | MP4]

EUMETSAT Meteosat-11 Shortwave Infrared (3.92 µm) images, with airport identifiers plotted in red [click to play animation | MP4]

The subtle thermal anomaly (or “hot spot”) from the Notre Dame Cathedral Fire was evident in 4.8-km resolution (at satellite nadir) EUMETSAT Meteosat-11 Shortwave Infrared (3.92 µm) imagery (above) as a cluster of brighter yellow pixels just north of Paris Orly International Airport (LFPO) near the center of the images on 15 April 2019.

The fire reportedly began around 1650 UTC; the maximum 3.92 µm brightness temperature sensed by Meteosat-11 was 284.5 K (11.35ºC) on the 1745 UTC image, not long after the fire had spread to the large spire of the cathedral (Meteosat-11 was actually scanning the Paris area at 1756 UTC, since the Meteosat Second Generation satellites scan each Full Disk from south to north). Clouds approaching from the west began to mask the fire signature at 1930 UTC.

Even though high clouds had begun to move overhead, a thermal signature (darker black pixel) could still be seen in 1-km resolution Metop-A and Metop-C Shortwave Infrared (3.75 µm) images at 2009 and 2048 UTC (below, courtesy of William Straka, CIMSS). The maximum 3.75 µm brightness temperature detected by Metop was 291.1 K (18.0ºC).

Metop-A and Metop-C Shortwave Infrared (3.74 µm) images at 2009 and 2048 UTC [click to enlarge]

Metop-A and Metop-C Shortwave Infrared (3.75 µm) images at 2009 and 2048 UTC [click to enlarge]

Fires in the Plains

April 8th, 2019 |

GOES-16 Shortwave Infrared (3.9 µm) and Fire Temperature product [click to play animation | MP4]

GOES-16 Shortwave Infrared (3.9 µm) and Fire Temperature product [click to play animation | MP4]

GOES-16 (GOES-East) Shortwave Infrared (3.9 µm) images and the corresponding GOES-16 Fire Temperature product (above) showed the thermal signatures of widespread fires across the Great Plains (primarily in the Flint Hills of Kansas and Oklahoma) on 08 April 2019. Although fairly small and often relatively brief, some of these fires become quite hot — exhibiting Fire Temperature values as high as 2762 K (or 4512ºF) southwest of Cottonwood, Kansas at 2011 UTC. These fires were typical Springtime prescribed burns and agricultural fields being cleared for planting.

One fire southwest of Salina, Kansas began to exhibit a prominent 3.9 µm thermal anomaly after 22 UTC, attaining a peak infrared brightness temperature of 95.6ºC (or 204ºF); a closer view of that fire is shown using GOES-16 Shortwave Infrared images along with Fire Temperature, Fire Area and Fire Power products (below). Note that during much of the time (for example, at 2221 UTC) there were no Fire Temperature, Fire Area or Fire Power values processed for the hottest 3.9 µm fire pixel — this is because the fire was producing a thick smoke plume, and the smoke-filled (on Visible imagery) hot pixel was flagged by the GOES Fire Detection and Characterization Algorithm (FDCA) Cloud Mask as a “cloudy pixel”. Beginning in May 2019, an updated algorithm will begin to produce the Fire Power parameter for all types of fire pixel (Processed fire, Saturated fire, Cloud-contaminated fire, and High/Medium/Low-probability fires), but the Fire Temperature and Fire Size parameters will only be available for the Processed fire category.

GOES-16 Shortwave Infrared (3.9 µm, upper left), Fire Temperature (upper right), Fire Area (lower left) and Fire Power (lower right) [click to play animation | MP4]

GOES-16 Shortwave Infrared (3.9 µm, upper left), Fire Temperature (upper right), Fire Area (lower left) and Fire Power (lower right) [click to play animation | MP4]

A sequence of MODIS and VIIRS Shortwave Infrared (3.7 µm) images from the Aqua, Suomi NPP and NOAA-20 satellites (below) showed a more detailed view of the fire thermal signatures (black to yellow to red enhancement) during the 1.5 hours between 1822 and 2001 UTC.

Sequence of MODIS and VIIRS Shortwave Infrared (3.7 µm) images from 1822-2001 UTC [click to enlarge]

Sequence of MODIS and VIIRS Shortwave Infrared (3.7 µm) images from 1822-2001 UTC [click to enlarge]

Most of the small fires did not produce particularly large smoke plumes, but the density of the fires led to a rather large pall of smoke over the region as seen in GOES-16 “Red” Visible (0.64 µm) images (below). Note the smoke plume emanating from the fire southwest of Salina, Kansas (as previously discussed). Most of the smoke was dispersed above the boundary layer — but the surface visibility was reduced by smoke at sites such as Coffeyville, Chanute and Eureka in southeastern Kansas and Bartlesville in northeastern Oklahoma.

GOES-16 "Red" Visible (0.64 µm) images [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) images [click to play animation | MP4]

===== 09 April Update ====

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

As some of the larger fires in southern Kansas continued burning into the night, their thermal signature could be seen in NOAA-20 VIIRS Shortwave Infrared (3.74 µm) image (darker gray to black pixels), along with their bright glow in the corresponding VIIRS Day/Night Band (0.7 µm) image at 0818 UTC or 3:18 am CDT (above). Note: the NOAA-20 images are incorrectly labeled as Suomi NPP.

Wildfires on the Korean Peninsula

April 4th, 2019 |

JMA Himawari-8 Shortwave Infrared (3.9 µm) images, with plots of surface reports (metric units) [click to play animation | MP4]

JMA Himawari-8 Shortwave Infrared (3.9 µm) images, with hourly plots of surface reports in metric units [click to play animation | MP4]

2.5-minute rapid scan JMA Himawari-8 Shortwave Infrared (3.9 µm) images (above) showed numerous thermal anomaly (or “hot spot”, darker red to black pixels) signatures of wildfires across southeastern North Korea and northeastern South Korea on 04 April 2019 (media story). The fires were fanned by strong west-southwest winds in the wake of a cold frontal passage associated with an anomalously-deep midlatitude cyclone moving across far northeastern China (surface analyses); winds gusted to 53 knots at Yangyang International Airport (station identifier RKNY) to the south of Sokcho at 09 UTC (below). Standing wave clouds — forming in response to the strong westerly winds — were seen downwind of the mountainous terrain of the eastern Korean Peninsula from 1030-1930 UTC.

Time series of surface weather data at Yangyang, South Korea [click to enlarge]

Time series of surface weather data at Yangyang, South Korea [click to enlarge]

Comparisons of VIIRS Day/Night Band (0.7 µm), Near-infrared (1.61 µm and 2.25 µm), Shortwave Infrared (3.75 µm and 4.05 µm) and Infrared Window (11.45 µm) images from NOAA-20 at 1649 UTC and Suomi NPP at 1739 UTC are shown below (courtesy of William Straka, CIMSS). A subtle thermal signature of the largest fires — located between Gangneug and Donghae, and also near Sokcho — was even apparent as darker pixels on the Infrared Window (I-Band 5, 11.45 µm) images. On the Day/Night Band images, note the striking lack of city lights in the southeastern portion of North Korea in these nighttime scenes.

NOAA-20 VIIRS Day/Night Band (0.7 µm), Near-infrared (1.61 µm and 2.24 µm), Shortwave Infrared (3.75 µm and 4.05 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm), Near-infrared (1.61 µm and 2.25 µm), Shortwave Infrared (3.75 µm and 4.05 µm) and Infrared Window (11.45 µm) images at 1649 UTC [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm), Near-infrared (1.61 µm and 2.24 µm), Shortwave Infrared (3.75 µm and 4.05 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm), Near-infrared (1.61 µm and 2.25 µm), Shortwave Infrared (3.75 µm and 4.05 µm) and Infrared Window (11.45 µm) images at 1739 UTC [click to enlarge]

Thermal signatures of the fires were also captured by KMA COMS-1 Shortwave Infrared (3.9 µm) imagery (below), but not as well as with Himawari-8 given the inferior spatial resolution (4 km, vs 2 km for Himawari-8) and image frequency (15 minutes, vs 2.5 minutes with the Himawari-8 Japan Sector).

KMA COMS-1 Shortwave Infrared (3.9 µm) images, with hourly plots of surface reports in metric units [click to play animation | MP4]

KMA COMS-1 Shortwave Infrared (3.9 µm) images, with hourly plots of surface reports in metric units [click to play animation | MP4]