GOES-17 arrives at its GOES-West position of 137.2º W longitude

November 15th, 2018 |
Full Disk images of the 16 ABI bands from GOES-17 [click to play MP4 animation]

1500 UTC Full Disk images of the 16 ABI bands from GOES-17 [click to play MP4 animation]

* GOES-17 images posted here are preliminary and non-operational *

GOES-17 arrived at its GOES-West position of 137.2º W longitude on 13 November 2018, and began to transmit imagery via GOES Re-Broadcast (GRB) at 1500 UTC and the AWIPS Satellite Broadcast Network (SBN) at 1700 UTC on 15 November (NOAA/NESDIS article). A toggle between Full Disk images of the 16 ABI spectral bands from GOES-17 at 1500 UTC is shown above, with a 16-panel multi-band animation from 1515-2300 UTC shown below..

Full Disk images from the 16 ABI bands of GOES-17 [click to play MP4 animation]

Full Disk images from the 16 ABI bands of GOES-17 [click to play MP4 animation]

Full Disk GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images  are shown below.

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images [click to play animation | MP4]

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images [click to play animation | MP4]

The improved spatial resolution of GOES-17 (vs GOES-15) was very obvious at higher latitudes — a closer look at GOES-17 Water Vapor imagery (below) showed good detail associated with a gale-force occluded low in the Gulf of Alaska and a weaker low in the Bering Sea (surface analyses). Note that signatures of the higher terrain of mountain ranges across south-central and southeastern Alaska could be seen on the 7.3 µm and to a lesser extent the 6.9 µm images.

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images [click to play animation | MP4]

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images [click to play animation | MP4]

After sunrise, GOES-17 “Red” Visible (0.64 µm) images (below) provided a compelling view of the snow-covered Alaska Range (which includes Denali at 20,320 feet / 6,194 meters), the Wrangell Mountains (which includes Mt. Wrangell at 14,163 feet / 4,317 meters) and the Chugach Mountains (which includes Mount Marcus Baker, 13,176 feet / 4,016 meters). In particular, note the long shadows cast by Denali and the Alaska Range in the upper left portion of the images.

GOES-17

GOES-17 “Red” Visible (0.64 µm) images, with hourly plots of surface reports [click to play animation | MP4]

For a short time a GOES-17 Mesoscale Domain Sector was positioned over Hawai’i, providing images at 1-minute intervals (below).

GOES-17

GOES-17 “Red” Visible (0.64 µm) images, with hourly plots of surface observations [click to play animation | MP4]

Guam and the Northern Mariana Islands could be seen on the far western limb of Full Disk GOES-17 images (below). A few isolated tropical thunderstorms could be seen developing and collapsing in the vicinity of the islands.

GOES-17 "Red" Visible (0.64 µm) images, with hourly plots of surface observations [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm) images, with hourly plots of surface observations [click to play animation | MP4]

A portion of West Antarctica could be seen on the far southern limb of GOES-17 Full Disk images, along with a storm system in the South Pacific Ocean (below). Through gaps in the clouds, the northern edge of the Antarctic sea ice (source) was also evident in the Visible imagery.

GOES-17 "Red" Visible (0.64 µm) images [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images [click to play animation | MP4]

Over the Lower 48 states, AWIPS images of 1-minute GOES-17 “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) data (below) showed the smoke and thermal anomaly (darker red pixels near the center of the images) associated with the ongoing Camp Fire in northern California.

GOES-17

GOES-17 “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Farther to the south in central California, a comparison of 1-minute Shortwave Infrared images from GOES-16 (GOES-East) and GOES-17 revealed differences in the size and orientation of hot pixels of the Adler/Mountaineer/Moses Fires burning northeast of Porterville KPTV  in the foothills of the Sierra Nevada. These differences were due to the view angle from the 2 satellites — 62 degrees from GOES-16 over the Atlantic Ocean, vs. only 41 degrees from GOES-17 over the Pacific Ocean. There was a navigational jump with GOES-17 from 1831-1837 UTC, so those images were removed from the animation.

GOES-16 vs GOES-17 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

GOES-16 vs GOES-17 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

Woolsey Fire in southern California

November 9th, 2018 |

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) showed the thick smoke and hot thermal signature of the Woolsey Fire in southern California on 09 November 2018. On this day it exhibited extreme fire behavior, with the large thermal anomaly or fire “hot spot” (red enhancement) moving rapidly southwestward and reaching the coast (Wildfire Today). The fires were driven by hot, dry Santa Ana winds, which arrived at Camarillo KCMA around 19 UTC (11 AM local time) and reached the coast at Point Mugu Naval Air Station KNTD around 22 UTC (2 PM local time).

A longer animation of GOES-16 Shortwave Infrared imagery (below) begins at 2115 UTC (1:15 PM local time) on 08 November — when a Mesoscale Sector was first positioned over California — and ends 52.5 hours later at 0149 UTC on 11 November (5:49 PM local time on 10 November). The first Ventura County fire to show a pronounced thermal signature was the Hill Fire; the earliest appearance of Woolsey Fire pixels that were hot enough to be color-enhanced (yellow) was at 2254 UTC (30 minutes after the reported start time of 2224 UTC). The area of hottest (red) pixels then began to increase in coverage and spread toward the southwest after about 06 UTC on 09 November (10 PM local time on 08 November), when Santa Ana winds began to increase at higher elevations several miles inland. As was seen in the Visible / Shortwave Infrared animation above, the morning period from 15-19 UTC (7-11 AM local time) on 09 November was when the fire moved very quickly toward the California coast and the beaches of Malibu. After sunset on 09 November, the area and intensity of hot red/yellow pixels began to decrease, and after 10 UTC (2 AM local time) on 10 November only darker black fire pixels persisted. During the day on 10 November, color-enhanced hot fire pixels were again evident from 1726-2353 UTC (9:26 AM to 3:53 PM local time). Note that at 19 UTC the marine layer began to move inland, with the dewpoint jumping to 46ºF at KNTO and to 33ºF at KCMA an hour later — the fire responded to this influx of moist air by beginning to die down.

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

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

A nighttime comparison of Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images at 0923 UTC (1:23 AM local time) on 10 November (below) showed a marked reduction in coverage and intensity of hot pixels compared to 15 hours earlier.

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images at 0923 UTC [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images at 0923 UTC [click to enlarge]

The smoke was very dense as it moved out over the adjacent offshore waters of the Pacific Ocean on 09 November, as seen in a sequence of MODIS and VIIRS Visible images (below).

MODIS and VIIRS Visible images [click to enlarge]

MODIS and VIIRS Visible images [click to enlarge]

VIIRS True Color Red-Green-Blue (RGB) images from Suomi NPP at 2104 UTC and NOAA-20 at 2154 UTC on 09 November (below) also depicted the optically-thick nature of the smoke.

Suomi NPP VIIRS True Color image at 2104 UTC [click to enlarge]

Suomi NPP VIIRS True Color RGB image at 2104 UTC [click to enlarge]

NOAA-20 VIIRS True Color image at 2154 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2154 UTC [click to enlarge]

The smoke was so thick that Suomi NPP VIIRS Aerosol Optical Depth values exceeded 1.0 (below) —  this is likely due to the VIIRS Cloud Mask product (a component of the AOD algorithm)  falsely flagging the thick center portion of the smoke as “cloud”.

Suomi NPP VIIRS True Color RGB and Aerosol Optical Depth [click to enlarge]

Suomi NPP VIIRS True Color RGB and Aerosol Optical Depth [click to enlarge]

===== 11 November Update =====

GOES-16

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

Santa Ana winds began to increase again on 11 November — 1-minute GOES-16 Visible and Shortwave Infrared images (above) showed the development of new smoke plumes and hot thermal signatures around the periphery of the ongoing Woolsey Fire. As of 1812 UTC (10:12 AM local time), the fire had burned 83,275 acres and was listed as 10% contained.

The new smoke plumes (as well as residual smoke from previous days of burning) could be seen on VIIRS True Color RGB imagery from Suomi NPP at 2029 UTC and NOAA-20 at 2114 UTC (below). The entire image swaths as captured and processed by the Direct Broadcast ground station at CIMSS/SSEC can be seen here and here.

Suomi NPP VIIRS True Color RGB image at 2029 UTC [click to enlarge]

Suomi NPP VIIRS True Color RGB image at 2029 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2114 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2114 UTC [click to enlarge]

Camp Fire in northern California

November 8th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, top left), Shortwave Infrared (3.9 µm, top right), “Clean” Infrared Window (10.3 µm, bottom left) and Fire Temperature (bottom right) [click to play animation | MP4]

The Camp Fire started at 1433 UTC or 6:33 AM local time on 08 November 2018 in Northern California; the rapid spread of the fire prompted evacuations and forced road closures. GOES-16 (GOES-East) GOES-16 “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm), “Clean” Infrared Window (10.3 µm) and Fire Temperature (above) showed the evolution of the fire at 5-minute intervals — especially noteworthy were the rapid vertical jump of the smoke column seen at 1547 UTC (which cast a long shadow), and Fire Temperature values that exceeded 2000 K (bright red pixels) at numerous times with a maximum value just over 2300 K.

A GOES-16 Mesoscale Domain Sector was positioned over California beginning at 2115 UTC, providing imagery at 1-minute intervals — a comparison of Visible and Shortwave Infrared images (below) showed how quickly the hot thermal signature of the fire (yellow to red enhancement) advanced southwestward during the remaining 3 hours of daylight. Just northwest of the fire, Chico (station identifier KCIC) reported very low relative humidity values (6% at 21 UTC), as seen by the large spread between temperature and dewpoint late in the day.

GOES-16

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

1-km resolution NOAA-18 AVHRR Visible (0.64 µm), Near-Infrared “Vegetation” (0.86 µm), Shortwave Infrared (3.7 µm) and Infrared Window (10.8 µm) images (below) showed the bifurcation of the smoke plume as well as the large, very hot thermal signature of the fire at 1712 UTC or 9:12 AM local time.

NOAA-18 AVHRR Visible (0.64 µm), Near-Infrared "Vegetation" (0.86 µm), Shortwave Infrared (3.7 µm) and Infrared Window (10.8 µµ) images [click to enlarge]

NOAA-18 AVHRR Visible (0.64 µm), Near-Infrared “Vegetation” (0.86 µm), Shortwave Infrared (3.7 µm) and Infrared Window (10.8 µm) images [click to enlarge]

NOAA-20 Visible (0.64 µm), Near-Infrared

NOAA-20 VIIRS Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Higher spatial resolution views were provided by NOAA-20 VIIRS Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.45 µm) images (above) and by Aqua MODIS Visible (0.65 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.0 µm) images (below). [Note: the NOAA-20 VIIRS images are incorrectly labeled as Suomi NPP]

Aqua MODIS Visible (0.65 µm), Near-Infrared

Aqua MODIS Visible (0.65 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Alternative views of the NOAA-20 VIIRS and Aqua MODIS images are shown below (using legacy AWIPS-1).They include Shortwave Infrared images from the 2 satellites, which reveal the very large (approximately 10 miles in length) thermal anomaly or fire “hot spot”. Due to the very dry atmosphere over the region (MODIS 6.7 µm Water Vapor image), the smoke could be clearly seen on the MODIS 1.37 µm Cirrus image (since there was very little attenuation of upwelling 1.37 µm radiation by middle/upper-tropospheric water vapor).

NOAA-20 Visible (0.64 µm), Day/Night Band (0.7 µm), Near-Infrared "Snow/Ice" (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 Visible (0.64 µm), Day/Night Band (0.7 µm), Near-Infrared “Snow/Ice” (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Aqua MODIS Visible (0.65 µm), Near-Infrared "Cirrus" (1.37 µm), Near-Infrared "Snow/Ice" (1.61 µm), Shortwave Infrared (3.7 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Aqua MODIS Visible (0.65 µm), Near-Infrared “Cirrus” (1.37 µm), Near-Infrared “Snow/Ice” (1.61 µm), Shortwave Infrared (3.7 µm) and Infrared Window (11.0 µm) images [click to enlarge]

As a result of the unusual dryness air mass across the region, the 00 UTC Oakland sounding set a record low Total Precipitable Water value for the date (3 mm or 0.12 inch):

 

The Aqua MODIS Total Precipitable Water product at 2123 UTC (below) showed widespread values in the 3-5 mm range (darker shades of brown) over much or northern California. 12 hours later, the TPW value from the 12 UTC Oakland sounding was slightly lower (2.9 mm or 0.11 inch) — and the MODIS TPW product at 0921 UTC continued to show widespread dry air over California.

Aqua MODIS Total Precipitable Water product and Visible (0.65 µm) image at 2123 UTC [click to enlarge]

Aqua MODIS Total Precipitable Water product and Visible (0.65 µm) image at 2123 UTC [click to enlarge]

True Color Red-Green-Blue (RGB) imagery from NOAA-20 VIIRS (below) provided a good view of the smoke.

NOAA-20 VIIRS True Color RGB image [click to enlarge]

NOAA-20 VIIRS True Color RGB image [click to enlarge]

A NOAA-15 AVHRR Shortwave Infrared image at 0225 UTC or 6:25 PM local time (below) depicted the very large thermal anomaly of the fire.

NOAA-15 AVHRR Shortwave Infrared (3.7 µm) image; major highways are plotted in cyan, with Interstate highways plotted in red [click to enlarge]

NOAA-15 AVHRR Shortwave Infrared (3.7 µm) image; major highways are plotted in cyan, with Interstate highways plotted in red [click to enlarge]

The smoke had an adverse  impact on air quality over 100 miles from the fire source: the surface visibility dropped to 1 mile at Santa Rosa KSTS and 2 miles at San Francisco International Airport KSFO (below).

Time series of surface observations for Santa Rosa [click to enlarge]

Time series of surface observations from Santa Rosa [click to enlarge]

Time series of surface observations from San Francisco International Airport [click to enlarge]

Time series of surface observations from San Francisco International Airport [click to enlarge]

===== 09 November 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]

Nighttime VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images from NOAA-20 at 0849 UTC (above) and Suomi NPP at 0942 UTC (below) revealed the bright glow and the large, hot thermal anomaly of the Camp Fire.

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

VIIRS True Color RGB images from Suomi NPP at 2104 UTC and NOAA-20 at 2154 UTC (below) showed the broad extent of the smoke from the Camp Fire in northern California as well as the Woolsey Fire in southern California. These images were captured and processed by the CIMSS/SSEC Direct Broadcast ground station.

Suomi NPP VIIRS True Color RGB image at 2104 UTC [click to enlarge]

Suomi NPP VIIRS True Color RGB image at 2104 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2154 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2154 UTC [click to enlarge]

An animation of 1-minute GOES-16 Visible and Shortwave Infrared images (below) revealed several plume jumps over the fire source from 15-19 UTC — and toward the end of the day, a decrease in the areal coverage and intensity of hot pixels indicated that extreme fire conditions were easing and containment efforts were slowing the spread of the fire.

GOES-16 "Red" Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

Abnormally dry to extreme drought conditions across California were a contributing factor to this and other wildfires across the state.

US Drought Monitor conditions as of 06 November [click to enlarge]

US Drought Monitor conditions as of 06 November [click to enlarge]

====== 11 November Update =====

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images [click to play animation]

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images [click to play animation]

A sequence of Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images centered at Paradise, California viewed using RealEarth (above) showed the spread of the Camp Fire thermal anomaly (dark black pixels) during the period 1943 UTC on 08 November to 1046 UTC on 11 November.

1-minute GOES-16 Visible and Shortwave Infrared images (below) showed the development of new smoke plume and hot thermal signatures around the periphery of the ongoing Camp Fire during the day on 11 November. As of 1849 UTC (10:49 AM local time), the fire had burned 109,000 acres and was listed as 25% contained.

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

The new smoke plume — as well as residual smoke from previous days of burning — could be seen on VIIRS True Color RGB imagery from Suomi NPP at 2029 UTC and NOAA-20 at 2114 UTC (below). The entire image swaths as captured and processed by the Direct Broadcast ground station at CIMSS/SSEC can be seen here and here.

Suomi NPP VIIRS True Color RGB image at 2029 UTC [click to enlarge]

Suomi NPP VIIRS True Color RGB image at 2029 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2114 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2114 UTC [click to enlarge]

The Camp Fire has claimed 42 lives and destroyed 6,522 homes and 260 businesses, making it both the deadliest and the most destructive wildfire on record for the state of California.

Fog/stratus dissipation in southern Louisiana

October 30th, 2018 |

GOES-16

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

The topic of a conversation on Twitter, GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) revealed curious circular areas of fog/stratus dissipation across southern Louisiana on the morning of 30 October 2018. — making it a natural candidate for the “What the heck is this?” blog category.

GOES-16 GEOCAT Low IFR Probability and Fog/Low Stratus Depth products (below) indicated that this fog and low stratus had been increasing in coverage and spreading northward across Louisiana during the preceding nighttime hours (VIIRS fog/stratus Brightness Temperature Difference images) — and the fog/stratus was relatively shallow, only having a depth of about 300 feet or less. In fact, if you look closely at the Visible animation above, a few small spots of slightly brighter cloud can be seen in the vicinity of Baton Rouge KBTR which are tall objects (such as refinery stacks, and even the State Capitol building) protruding above the fog/stratus and acting as an obstacle to their flow.

GOES-16 Low Instrument Flight Rules (IFR) Probability [click to play animation | MP4]

GOES-16 Low Instrument Flight Rules (IFR) Probability [click to play animation | MP4]

GOES-16 Fog/Low Stratus Depth product [click to play animation | MP4]

GOES-16 Fog/Low Stratus Depth product [click to play animation | MP4]

A sequence of 4-panel comparisons of GOES-16 “Blue” Visible (0.47 µm), “Red” Visible (0.64 µm) and Near-Infrared “Vegetation” (0.86 µm) images with Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images (below) showed no indication of any substantial differences between the cloud material within the circular features and the adjacent fog/stratus. The largest “outer rings” of the dissipating fog/stratus areas had a small amount of vertical extent, which cast a shadow that was best seen in the Near-Infrared 0.86 µm and 1.61 µm images.

4-panel comparisons of GOES-16

Sequence of 4-panel comparisons of GOES-16 “Blue” Visible (0.47 µm), “Red” Visible (0.64 µm), Near-Infrared “Vegetation” (0.86 µm), “Snow/Ice” (1.61 µm), and “Cloud Particle Size” (2.24 µm), and Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

The most plausible explanation for the circular dissipation features turned out to be fires that were set in sugar cane fields following harvest — particulates in the smoke could have “seeded” the fog/stratus cloud layer, either changing the particle size distribution or making the cloud more susceptible to faster dissipation after sunrise due to solar heating of black carbon nuclei within the cloud droplets.  An Aqua MODIS Shortwave Infrared (3.7 µm) image from the previous afternoon (below) did reveal a number of small thermal anomalies or fire “hot spots” (yellow to red pixels) across the region at 1909 UTC (2:09 PM local time).

Aqua MODIS Shortwave Infrared (3.7 µm) image [click to enlarge]

Aqua MODIS Shortwave Infrared (3.7 µm) image [click to enlarge]

Similarly, GOES-16 Shortwave Infrared images on 29 October (below) also showed signatures of widespread small and generally short-lived fires (darker black pixels) across southern Louisiana. Surface winds were very light across that area (KARA | KPTN | KNBG | KMSY | KNEW), minimizing smoke dispersion from any fires.

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]