GOES-14 SRSO-R: Return flow of Gulf of Mexico moisture in eastern Texas; blowing dust and a wildfire in western Texas

February 1st, 2016

GOES-14 Visible (0.63 µm) images, with surface observations [click to play MP4 animation]

GOES-14 Visible (0.63 µm) images, with surface observations [click to play MP4 animation]

Day 1 of the 01-25 February 2016 test period of GOES-14 Super Rapid Scan Operations for GOES-R (SRSO-R) revealed some interesting features across the state of Texas. During the morning hours, the northward “return flow” of moisture from the Gulf of Mexico could be seen in the form of widespread fog and low stratus across the eastern part of the state on 1-minute interval GOES-14 Visible (0.63 µm) images (above; also available as a large 83 Mbyte animated GIF). Surface reports showed that dew point temperatures were as high as the 60s F along and just inland of the coast. GOES-13 derived products such as the MVFR Probability, LIFR Probability, and Low Cloud Thickness (FLS product training) showed the northward motion of the fog and low stratus during the preceding overnight hours.

During the afternoon hours, GOES-14 Visible (0.63 µm) images (below; also available as a large 91 Mbyte animated GIF) revealed the hazy signature of areas of blowing dust across southwest Texas, both ahead of and also in the wake of a cold frontal passage (surface analyses). Much of the blowing dust ahead of the cold front originated from dry lake beds in northern Mexico, which was then transported northeastward across Texas by strong southwesterly winds (an enhanced visible MP4 animation which shows the blowing dust better is available here). Blowing dust along and behind the cold front restricted the surface visibility to 1.0 miles at Big Spring (KBPG) and 2.5 miles at Midland (KMAF). Also note that early in the animation — beginning at 1800 UTC — there were small convective bands moving northeastward over the El Paso area, which produced light to moderate accumulating snow that reduced surface visibility to 1.0 miles at El Paso and Biggs Army Air Field (KBIF), and 2.0 miles at Ciudad Juarez, Mexico (MMCS).

GOES-14 Visible (0.63 µm) images, with surface reports [click to play MP4 animation]

GOES-14 Visible (0.63 µm) images, with surface reports [click to play MP4 animation]

GOES-14 Shortwave Infrared (3.9 µm) images (below; also available as a large 52 Mbyte animated GIF) showed the “hot spot” signature (darker black to red pixels) associated with a large grass fire which developed in the Big Bend National Park area, beginning around 2300 UTC. The hot spot was seen to diminish not long after the arrival of cooler air (lighter shades of gray) behind the cold front. Surface air temperatures were quite warm in Texas ahead of the cold front, with daytime highs of 91º F at Del Rio (KDRT)  and 95º F — the highest temperature recorded for the day in the lower 48 states — farther to the southeast at Cotulla.

GOES-14 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

GOES-14 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

GOES-14 Water Vapor (6.5 µm) images (below; also available as a large 57 Mbyte animated GIF) showed a broad ascending belt of moisture curving cyclonically over central and eastern Colorado, where moderate snow and significant accumulations were occurring at a number of locations.

GOES-14 Water Vapor (6.5 µm) images, with surface weather symbols [click to play MP4 animation]

GOES-14 Water Vapor (6.5 µm) images, with surface weather symbols [click to play MP4 animation]

A blog post discussing this ascending belt of moisture in more detail can be found here; a YouTube animation of GOES-14 Infrared Window (10.7 µm) images is available here.

===== 02 February Update =====

GOES-14 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

GOES-14 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

During the subsequent overnight  hours, an undular bore developed along and just ahead of the advancing cold front, as seen in GOES-14 Shortwave Infrared (3.9 µm) images (below; also available as a large 107 Mbyte animated GIF). A detailed view of the undular bore was also captured at 0859 UTC (3:59 AM local time) on Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images (below).

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Smoke over Indonesia and the western tropical Pacific Ocean

October 26th, 2015
H8_RGB_08-26October2015_0200_anim

RGB Composites from Himawari-8 (0.47 µm, 0.51 µm and 0.64 µm used for blue, green and red, respectively) 0200 UTC from 08-26 October 2015. (Click to animate)

Many of the islands in Indonesia have been shrouded in smoke for much of October. RGB composites from Himawari-8, above, for 0200 UTC on each day from 08-26 October 2015 testify to the dense smoke, especially over the island of Borneo. News reports suggest the haze will persist through the end of the year. This is in part due to the strong El Nino event ongoing; El Nino events typically suppress rainfall over the western tropical Pacific basin.

Smoke detection using visible channels, such as those combined in the true color imagery above, is straightforward. At night, however, visible imagery is not available. The animation below shows the difficulty in detecting smoke using infrared imagery. Although parts of the smoke plume show up, the widespread pall of smoke is not captured. Hot spots can be detected using the 3.9 µm (and 2.3 µm) bands on Himawari-8, but viewing the transport of the resultant smoke is a challenge. Except for the VIIRS Day/Night Band imagery from Suomi NPP, then, nighttime smoke detection relies on model output (Source).

H8_RGB_08-26October2015_0200_anim

16-panel Himawari-8 multispectral animation, hourly from 0000 UTC/20 October to 0100/21 October. Top row: 0.47µm, 0.51µm, 0.64µm, 0.86µm ; Second Row: 1.6µm, 2.3µm, 3.9µm, 6.2µm; Third Row: 6.9µm, 7.3 µm, 8.6 µm, 9.6 µm; Bottom Row: 10.4µm, 11.2 µm, 12.4µm, 13.3µm (Click to animate)

The SSEC RealEarth web map server can be used to take a closer look at the islands of Borneo and Sumatra from 20-26 October. Daily comparisons of Suomi NPP VIIRS fire detections and true-color RGB images shown below revealed that although there was a gradual decreasing trend in the number and areal coverage of fires by 26 October, a great deal of smoke still remained over much of the region.

Daily comparisons of Suomi NPP VIIRS fire detections and true-color RGB images, from 20-26 October [click to animate]

Daily comparisons of Suomi NPP VIIRS fire detections and true-color RGB images, from 20-26 October [click to animate]

A daily time series plot of weather conditions at the major airport of Kuala Lumpur, below, showed that the surface visibility was often restricted to less than 1 mile during the 20-26 October period.

Daily time series of surface reports from Kuala Lumpur [click to animate]

Daily time series of surface reports from Kuala Lumpur [click to animate]

Suomi NPP VIIRS Day/Night Band Visible Imagery (0.70 µm) 1837 UTC on 26 October 2015 [click to enlarge]

Suomi NPP VIIRS Day/Night Band Visible Imagery (0.70 µm) 1837 UTC on 26 October 2015 [click to enlarge]

The Suomi NPP VIIRS instrument contains a day-night sensor that produces useful visible imagery when illuminated by the Moon (and a full Moon occurred on 27 October 2015). The image above from 1837 UTC on 26 October (Courtesy William Straka, SSEC) shows a pall of smoke from Borneo to Sumatra. Thunderstorms are also present over the South China Sea and Borneo. An toggle of the Day Night Band, the 3.9 µm infrared and the 1.6 µm infrared imagery shows that hot spots associated with fires can be detected (enhanced as orange in the 3.9 µm and white in the 1.6 µm), but the associated smoke is mostly undetected in the infrared.

Two sites, one NASA and one NOAA, can give additional information about the smoke. The toggle below, taken from imagery at the NASA site, shows MODIS True-Color imagery, Aeorosol Optical Depth (AOD) (in NASA Worldview, with units) (in cloud-free regions) and retrieved Carbon Monoxide concentrations (in NASA Worldview, with units). AODs are very large, and CO concentrations are off the scale.

MODIS True Color Imagery, Aerosol Optical Depth and CO Concentrations on 26 October 2015 [click to enlarge]

MODIS True Color Imagery, Aerosol Optical Depth and CO Concentrations on 26 October 2015 [click to enlarge]

Grass fire in Colorado

September 19th, 2015

GOES-15 (left panels) and GOES-13 (right panels) Visible (0.63 µm) and Shortwave infrared (3.9 µm) images [click to play animation]

GOES-15 (left panels) and GOES-13 (right panels) Visible (0.63 µm) and Shortwave infrared (3.9 µm) images [click to play animation]

GOES-15 (GOES-West) and GOES-13 (GOES-East) Visible (0.63 µm) and Shortwave infrared (3.9 µm) images (above; click to play animation; also available as an MP4 movie file) showed the smoke plume and “hot spot” (dark black to red pixels) associated with a large and fast-burning grass fire in north-central Colorado on the afternoon of 18 September 2015. The smoke plume was more apparent in the GOES-13 visible images, due a more favorable “forward scattering” sun-satellite geometry. The fire burned an estimated 12,669 acres, and dense smoke forced the closure of Interstate 76 for about an hour in the afternoon.

On the following day, the fire burn scar could be seen in a comparison of Suomi NPP VIIRS  true-color and false-color images from the SSEC RealEarth site (below).

Suomi NPP VIIRS true-color and false-color images [click to enlarge]

Suomi NPP VIIRS true-color and false-color images [click to enlarge]

Due to the darker color and the lack of vegetation, the grass fire burn scar also exhibited a much warmer signature on the Terra MODIS Land Surface Temperature (LST) product (below) — LST values were as high as 112º F (darker orange color enhancement) within the burn scar, compared to LST values in the 80s and 90s F in surounding areas.

Terra MODIS Land Surface Temperature product [click to enlarge]

Terra MODIS Land Surface Temperature product [click to enlarge]

GOES-14 SRSO-R: central Montana wildfire

August 15th, 2015

GOES-15 (left), GOES-14 (center), and GOES-13 (right) 3.9 µm shortwave IR images [click to play MP4 animation]

GOES-15 (left), GOES-14 (center), and GOES-13 (right) 3.9 µm shortwave IR images [click to play MP4 animation]

A comparison of 4-km resolution GOES-15 (GOES-West), GOES-14, and GOES-13 (GOES-East) 3.9 µm shortwave infrared images (above; click to play MP4 animation; also available as a 9.4 Mbyte animated GIF) showed the development and evolution of the “hot spot” (dark black to yellow to red color enhancement) associated with a small wildfire that formed near the border of Fergus and Petroleum counties in central Montana during the afternoon hours on 15 August 2015. With GOES-15 Routine Scan mode “SUB-CONUS” sectors, images were available up to 6 times per hour (at :00, :11, :15, :30, :41, and :45); with GOES-13 in Rapid Scan Operations (RSO) mode, images were available up to 8 times per hour (at :00, :07, :15, :25, :30, :37, :45, and :55). The GOES-14 satellite had been placed into Super Rapid Scan Operations for GOES-R (SRSO-R) mode, providing images at 1-minute intervals to emulate what will be available with mesoscale sectors from the ABI instrument on GOES-R.

For the central Montana wildfire, the first unambiguous signature of a darker black wildfire hot spot began to appear on each satellite after about 1945 UTC, with the first color-enhanced pixels (signifying a shortwave IR brightness temperature of 331.9 K) showing up on the 2026 UTC GOES-14 image. The hottest fire pixel  on the GOES-15 images was 336.5 K at 2130 UTC, while the hottest fire pixel on GOES-13 images was 329.8 K at 2125 UTC. From 2120 to 2130 UTC, the hottest GOES-14 fire pixels were 341.2 K (the saturation temperature of the 3.9 µm detectors on that satellite).

With the finer spatial resolution of the shortwave IR detectors on the polar-orbiting MODIS (1-km) and VIIRS (375-meter) instruments, a fire hot spot was first detected on the 1857 UTC VIIRS image (below).

Terra/Aqua MODIS and Suomi NPP VIIRS 3.7 µm shortwave IR images [click to enlarge]

Terra/Aqua MODIS and Suomi NPP VIIRS 3.7 µm shortwave IR images [click to enlarge]