Thermal signature of an Antares rocket launch

November 17th, 2018 |

GOES-16 Near-Infrared

GOES-16 Near-Infrared “Snow/Ice” (1.61 µm, left), Near-Infrared “Cloud Particle Size” (2.24 µm, center) and Shortwave Infrared (3.9 µm, right) images [click to play animation | MP4]

An Antares rocket was launched from the NASA Wallops Flight Facility on the Eastern Shore of Virginia (Space.com article) at 0901 UTC (4:01 AM local time) on 17 November 2018. At 0902 UTC a subtle thermal signature was seen just southeast of the launch site on GOES-16 (GOES-East) Near-Infrared “Snow/Ice” (1.61 µm). Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images (above). The thermal signature appeared at the center of each 0902 UTC image (where map outlines have been erased for clarity).

A corresponding thermal signature was also evident on 0902 UTC GOES-16 Low-level (7.3 µm). Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (below) — since the Water Vapor spectral bands are essentially Infrared bands, the signal was due to superheated air from the powerful First Stage rocket (which burned for 3.5 minutes after launch).

GOES-16 Low-level (7.3 µm, left). Mid-level (6.9 µm, center) and Upper-level (6.2 µm, right) Water Vapor images [click to play animation | MP4]

GOES-16 Low-level (7.3 µm, left), Mid-level (6.9 µm, center) and Upper-level (6.2 µm, right) Water Vapor images [click to play animation | MP4]

Taking a closer look with AWIPS, similar thermal signatures could be seen. Note that for the hottest pixel southeast of Wallops KWAL, the 3.9 µm Shortwave Infrared brightness temperature increased from 3.4ºC to 7.3ºC between 0857 and 0902 UTC — while the corresponding 10.3 µm “Clean” Infrared Window brightness temperature only increased from 3.7ºC to 4.0ºC.

GOES-16 Near-Infrared "Snow/Ice" (1.61 µm, left). Near-Infrared "Cloud Particle Size" (2.24 µm, center), Shortwave Infrared (3.9 µm, right) and "Clean" Infrared Window (10.3 µm) images [click to play animation | MP4]

GOES-16 Near-Infrared “Snow/Ice” (1.61 µm, top left),. Near-Infrared “Cloud Particle Size” (2.24 µm, top right), Shortwave Infrared (3.9 µm, bottom left) and “Clean” Infrared Window (10.3 µm, bottom right) images [click to play animation | MP4]

A 4-panel comparison of Near-Infrared and Water Vapor bands is shown below. The difference between spatial resolution is quite evident: 1 km at satellite sub-point for the 1.61 µm band vs 2 km for the Water Vapor (and all other Infrared) spectral bands.

GOES-16 Near-Infrared "Snow/Ice" (1.61 µm, top left). Low-level Water Vapor (7.3 µm, top right), Mid-level Water Vapor (6.9 µm, bottom left) and Upper-level Water Vapor (6.2 µm, bottom right) images [click to play animation | MP4]

GOES-16 Near-Infrared “Snow/Ice” (1.61 µm, top left), Low-level Water Vapor (7.3 µm, top right), Mid-level Water Vapor (6.9 µm, bottom left) and Upper-level Water Vapor (6.2 µm, bottom right) images [click to play animation | MP4]

A thermal signature was also apparent using the Split Water Vapor (6.2-7.3 µm) and Split Fire (2.24-1.61 µm) band differences.

Dry air within an Atlantic subtropical ridge

November 16th, 2018 |

GOES-16 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-16 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-16 (GOES-East) Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (above) showed a large region of very dry air within a subtropical ridge over the central North Atlantic Ocean on 16 November 2018. Infrared brightness temperatures were unusually warm (brighter yellow to red enhancement) on all 3 Water Vapor bands, especially along the western edge of the dry air.

A GOES-16 Upper-level Water Vapor image at 1700 UTC (below) showed a swath of NUCAPS sounding availability close to that time. The swath passed directly over the driest air within the subtropical ridge.

GOES-16 Upper-level (6.2 µm) Water Vapor image at 1700 UTC, with a swath of NUCAPS sounding availability [click to enlarge]

GOES-16 Upper-level Water Vapor image at 1700 UTC, with a swath of NUCAPS sounding availability [click to enlarge]

One of the green (high-quality) NUCAPS soundings within the arc of driest air (below) revealed a remarkably dry profile above the trade wind inversion — dewpoint values were -50ºC and colder within the 500-620 hPa layer, and dewpoint depressions were about 50ºC near the 550 hPa level.

NUCAPS sounding profile within the driest air [click to enlarge]

NUCAPS sounding profile within the driest air [click to enlarge]

Even though the middle to upper tropozphere was quite dry, note that the Total Precipitale Water (TPW) value calculated from the NUCAPS profile was 0.73 inch — there was still abundant tropical moisture within the marine boundary layer of the warm central Atlantic. The GOES-16 TPW product (below) showed minimum values of 0.6-0.8 inch in the region of driest air on the Water Vapor imagery (1800 UTC comparison). In contrast, TPW values over a large portion of the Lower 48 states were 0.6 inch or less, even in regions that appeared to be “moist” on the Water Vapor imagery.

GOES-16 Upper-level Water Vapor + Total Precipitable Water [click to play animation | MP4]

GOES-16 Upper-level Water Vapor + Total Precipitable Water [click to play animation | MP4]

Mesoscale Convective System in Argentina

November 13th, 2018 |

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with GLM Groups plotted in cyan/green [click to play MP4 animation]

In support of the RELAMPAGO-CACTI field experiment, GOES-16 (GOES-East) had a Mesoscale Domain Sector centered over northeastern Argentina on 13 November 2018 — and 1-minute “Clean” Infrared Window (10.3 µm) images with plots of GLM Groups (above) showed a large and long-lived Mesoscale Convective System moving eastward across far northeastern Argentina and expanding into southern Paraguay and southeastern Brazil. Note the large amount of lightning in the anvil region far southeast of the core of the convection.

The corresponding GOES-16 Infrared animation without lightning data is shown below. Minimum cloud-top infrared brightness temperatures often reached -90ºC and colder (yellow pixels embedded within darker violet regions).

GOES-16 "Clean" Infrared Window (10.3 µm) images [click to play MP4 animation]

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

A comparison of NOAA-20 VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images using RealEarth (below) provided a very detailed view of the MCS at 1703 UTC. On the Infrared image, storm-top signatures often associated with severe thunderstorms included a well-defined enhanced-V (with a pronounced cold/warm couplet) situated over the Paraguay/Argentina border, and a “warm trench” surrounding the cold overshooting top at the vertex of the enhanced-V over extreme southern Paraguay.

NOAA-20 VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images at 1703 UTC [click to enlarge]

NOAA-20 VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images at 1703 UTC [click to enlarge]

The warm trench signature was also evident on 2-km resolution GOES-16 Infrared imagery at that same time (below), just west of Posadas, Argentina SARP. However, the warm trench surrounding the small overshooting top was only apparent from 1700 to 1705 UTC — so it was remarkable timing to have an overpass of the NOAA-20 satellite capture the brief signature in greater detail (at 375-meter resolution). A similar short-lived small overshooting top was seen at the vertex of the enhanced-V signature for the 6-minute period centered at 1652 UTC.

GOES-16 "Clean" Infrared Window (10.3 µm) image at 1703 UTC, with and without GLM Groups plotted in cyan/green [click to enlarge]

GOES-16 “Clean” Infrared Window (10.3 µm) image at 1703 UTC, with and without GLM Groups plotted in cyan/green [click to enlarge]

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]