Aircraft dissipation trails over southern Wisconsin and northern Illinois

October 6th, 2019 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (above) revealed a series of aircraft “dissipation trails” drifting northeastward across southern Wisconsin and northern Illinois on 06 October 2019. These cloud features were caused by aircraft that were either ascending or descending through a layer of cloud composed of supercooled water droplets — cooling from wake turbulence (reference) and/or particles from jet engine exhaust acted as ice condensation nuclei to cause the small supercooled water droplets to turn into larger ice crystals (many of which then often fall from the cloud layer, creating “fall streak holes“).

A comparison of Suomi NPP VIIRS Visible (0.64 µm), Near-Infrared (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images (below) helped to confirm the presence of ice crystals within the aircraft dissipation trails: a darker appearance in the 1.61 µm image (since ice is a strong absorber of radiation at that wavelength), and a colder (brighter white) signature in the 3.74 µm image. In the enhancement applied to the 3.74 µm and 11.45 µm images, colors are applied to infrared brightness temperatures of -30ºC and colder — and the shades of yellow represent cloud-top brightness temperatures in the -30 to -39ºC range.

Suomi NPP VIIRS Visible (0.64 µm), Near-Infrared (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm), Near-Infrared (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Several of the “fall streak” clouds were seen in time-lapse videos of west- and east-facing AOSS rooftop cameras (below).

Time lapse of west-facing AOSS rooftop camera images [click to play YouTube video]

Time lapse of west-facing AOSS rooftop camera images (courtesy of Pete Pokrandt, AOSS) [click to play YouTube video]

Time lapse of east-facing AOSS rooftop camera images [click to play YouTube video]

Time lapse of east-facing AOSS rooftop camera images (courtesy of Pete Pokrandt, AOSS) [click to play YouTube video]

Severe turbulence southwest of Hawai’i

July 11th, 2019 |

GOES-17 Upper-level Water Vapor images, with pilot reports of turbulence [click to play animation | MP4]

GOES-17 Upper-level Water Vapor (6.2 µm) images, with pilot reports of turbulence [click to play animation | MP4]

An Air Canada flight encountered severe turbulence southwest of Hawai’i on 11 July 2019, which injured 37 passengers (media report 1 | media report 2 | pilot report text | pilot report location | flight path | flight data). GOES-17 (GOES-West)  Upper-level Water Vapor (6.2 µm) images (above) and Mid-level Water Vapor (6.9 µm) images (below) revealed subtle gravity waves propagating westward from clusters of thunderstorms located near 160º W longitude. In addition, a small and short-lived thunderstorm developed just north of the turbulence event, which also produced subtle gravity waves (those waves could have interfered with the other waves emanating from the larger storms to the east) — and an even smaller, shorter-lived convective cell developed very near to and right around the time of the 1411 UTC turbulence encounter.

Full-bit-depth images created using geo2grid are also available: 6.2 µm | 6.9 µm.

GOES-17 Mid-level Water Vapor (6.9 µm) images, with pilot reports of turbulence [click to play animation | MP4]

GOES-17 Mid-level Water Vapor (6.9 µm) images, with pilot reports of turbulence [click to play animation | MP4]

Eruption of the Raikoke volcano in the Kuril Islands

June 21st, 2019 |

Himawari-8 False Color RGB images [click to play animation | MP4]

Himawari-8 False Color RGB images [click to play animation | MP4]

For the first time since 1924, a major eruption of the Raikoke volcano occurred around 1800 UTC on 21 June 2019. Himawari-8 False Color Red-Green-Blue (RGB) images from the NOAA/CIMSS Volcanic Cloud Monitoring site (above) showed — via the brighter yellow areas — that a large portion of the volcanic plume was rich in both ash and sulfur dioxide (SO2). The Tokyo VAAC estimated the maximum ash height to be 43,000 feet (~13 km) above ground level — and CALIPSO CALIOP data indicated a maximum ash height around 12 km shortly after 02 UTC on 22 June (between 45-50º N latitude and 159-161º E longitude).

A comparison of an Aqua MODIS False Color RGB image with the corresponding Ash Height, Ash Loading and Ash Effective Radius retrieved products at 0310 UTC on 22 June (below) indicated maximum ash height values of 18-20 km (black pixels) immediately downwind of the eruption site. Maximum Himawari-8 Ash Height values were in the 16-18 km range.

Aqua MODIS False Color RGB, Ash Height, Ash Loading and Ash Effective Radius at 0310 UTC on 22 June [click to enlarge]

Aqua MODIS False Color RGB image with Ash Height, Ash Loading and Ash Effective Radius retrieved products [click to enlarge]

In a comparison of Himawari-8 Upper-level (6.2 µm), Mid-level (6.9 µm) and Low-level (7.3 µm) Water Vapor images (below), since the 7.3 µm spectral band is also sensitive to SO2 absorption, those images showed a good signature of the leading filament of volcanic SO2 as it was transported east-southeastward over the North Pacific Ocean.

Water Vapor images from Himawari-8: Upper-level (6.2 µm, top), Mid-level (6.9 µm, middle) and Low-level (7.3 µm, bottom) [click to play animation | MP4]

Water Vapor images from Himawari-8: Upper-level (6.2 µm, top), Mid-level (6.9 µm, middle) and Low-level (7.3 µm, bottom) [click to play animation | MP4]

Similarly, the GOES–17 (GOES-West) Low-level Water Vapor (7.3 µm) images also showed the filament of volcanic SO2 that was being drawn into the circulation of a Gale Force Low south of the Aleutian Islands. As a result, the Anchorage VAAC issued aviation Volcanic Ash Advisories that covered large areas of the North Pacific Ocean and southern Bering Sea; they continued to estimate the maximum ash height to be 43,000 feet. Around 16 UTC on 22 June, CALPSO CALIOP data sampled a small portion of the ash at an altitude near 17 km (between 45-50º N latitude, 155-157º W longitude).

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

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

VIIRS True Color RGB and Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP as viewed using RealEarth are shown below at approximately 01 UTC, 02 UTC and 03 UTC on 22 June. The combination of True Color and Infrared imagery indicated that volcanic ash was present a multiple altitudes.

VIIRS True Color RGB and Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP [click to enlarge]

VIIRS True Color RGB and Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP at 01, 02 and 03 UTC on 22 June [click to enlarge]

Due to the highly-oblique satellite viewing angle of GOES-17, multiple Raikoke eruption pulses of significant vertical extent were clearly evident in GOES-17 “Red” Visible (0.64 µm) images (below).

GOES-17

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

A somewhat less oblique view from the west was provided by the NSMC FY-2G satellite (below).

NSMC FY-2G Visible (0.73 µm) images [click to play animation | MP4]

NSMC FY-2G Visible (0.73 µm) images [click to play animation | MP4]

Himawari-8 “Red” Visible (0.64 µm) images (below) provided another interesting view of the multiple eruption pulses — and since the eruption began around 5 AM local time, long early morning shadows were cast by the initial bursts of tall volcanic clouds. A faster animation revealed shock waves propagating radially outward from the eruption site.

Himawari-8

Himawari-8 “Red” Visible (0.64 µm) images [click to play animation | MP4]




Incidentally, an astronaut aboard the International Space Station took a photo of the volcanic cloud at 2246 UTC on 21 June — and the two Visible images that bracket that time (2240 and 2250 UTC) from GOES-17 and Himawari-8 are shown below.

Photo taken by an astronaut on the International Space Station [click to enlarge]

Photo taken by an astronaut on the International Space Station at 2246 UTC [click to enlarge]

GOES-17 Visible (0.64 µm) images at 2240 and 2250 UTC {click to enlarge]

GOES-17 Visible (0.64 µm) images at 2240 and 2250 UTC {click to enlarge]

Himawari-8 Visible (0.64 µm) images at 2240 and 2250 UTC {click to enlarge]

Himawari-8 Visible (0.64 µm) images at 2240 and 2250 UTC {click to enlarge]

===== 23 June Update =====

Himawari-8 False Color RGB images [click to play MP4 animation]

Himawari-8 False Color RGB images [click to play MP4 animation]

A 2-day animation of 10-minute Himawari-8 False Color images (above) showed the ash- and SO2-rich volcanic plume (brighter shades of yellow) eventually being transported northeastward across the western Aleutian Islands and circulating cyclonically over the Bering Sea. Similarly, this volcanic cloud transport was also seen in the corresponding GOES-17 False Color imagery.

===== 24 June Update =====

GOES-17 SO2 RGB images [click to play animation | MP4]

GOES-17 SO2 RGB images [click to play animation | MP4]

GOES-17 SO2 RGB imagery (above) continued to show a signature of the volcanic cloud (brighter shades of yellow) from the Raikoke eruption over a large portion of the Bering Sea on 24 June. Volcanic ash advisories were issued for flight altitudes as high as 40,000 feet — and a pilot report of SO2 over the Bering Sea at 47,000 feet was received at 1822 UTC (below).

GOES-17 SO2 RGB, Split Clout Top Phase (11.2-8.4 µm) and Dust RGB images, with a pilot report of SO2 [click to enlarge]

GOES-17 SO2 RGB, Split Clout Top Phase (11.2-8.4 µm) and Dust RGB images, with a pilot report of SO2 [click to enlarge]

===== 25 June Update =====

GOES-17 SO2 RGB images [click to play animation | MP4]

GOES-17 SO2 RGB images [click to play animation | MP4]

GOES-17 SO2 RGB images (above) showed the persistent signature of the SO2-rich volcanic cloud as much of it remained within the circulation of a quasi-stationary low pressure system in the Bering Sea.

An interesting Pilot Report north of the Aleutians at 36,000 feet (below) noted thin grey-colored layers below the altitude of the aircraft. GOES-17 Air Mass RGB images showed a subtle brown/tan plume — could this have been a thin filament of ash from the Raikoke eruption that was drawn into the circulation of the Bering Sea low?

GOES-17 SO2 RGB, Air Mass RGB, Dust RGB and Split Cloud Top Phase (11.2-8.4 µm) images, with a 2008 UTC Pilot Report [click to enlarge]

GOES-17 SO2 RGB, Air Mass RGB, Dust RGB and Split Cloud Top Phase (11.2-8.4 µm) images, with a 2008 UTC Pilot Report [click to enlarge]

Another Pilot Report farther to the west at 2119 UTC (below) was close to the southern edge of the GOES-17 SO2 signatures, but no sulphur odor was reported; however, they did note the presence of an apparent ash layer south of Shemya in the western Aleutian Islands.

GOES-17 SO2 RGB and Split Cloud Top Phase (11.2-8.4 µm) images, with a 2119 UTC Pilot Report [click to enlarge]

GOES-17 SO2 RGB and Split Cloud Top Phase (11.2-8.4 µm) images, with a 2119 UTC Pilot Report [click to enlarge]

Large-scale blowing dust event

April 10th, 2019 |

GOES-16 Split Window (10.3-12.3 µm) images [click to play animation | MP4]

GOES-16 Split Window (10.3-12.3 µm) images [click to play animation | MP4]

Strong winds — gusting as high as 77 mph in New Mexico and 88 mph in Texas — associated with a rapidly-intensifying midlatitude cyclone generated large plumes of blowing dust (originating from southeastern Arizona,southern New Mexico, northern Mexico and western Texas) on 10 April 2019. GOES-16 (GOES-East) Split Window (10.3-12.3 µm) images (above) helped to highlight the areas of blowing dust, which initially developed along and behind a cold front after 15 UTC.

GOES-16 Split Window (10.3-12.3 µm) images, with hourly plots of surface winds and gusts [click to play animation | MP4]

GOES-16 Split Window (10.3-12.3 µm) images, with hourly plots of surface wind barbs and gusts [click to play animation | MP4]

GOES-16 Split Window images with hourly plots of surface wind barbs and gusts (above) showed the distribution of strong winds across the region, while plots of the surface visibility (below) showed decreases to 1/4 mile at Deming, New Mexico, 1/2 mile at Lubbock, Texas and 4 miles at Altus, Oklahoma.

GOES-16 Split Window (10.3-12.3 µm) images, with hourly plots of surface visibility [click to play animation | MP4]

GOES-16 Split Window (10.3-12.3 µm) images, with hourly plots of surface visibility [click to play animation | MP4]

GOES-16 True Color Red-Green-Blue (RGB) images (below; courtesy of Rick Kohrs, SSEC) depicted the blowing dust as shades of tan to light brown. Willcox Playa was the source of the dust plume coming from southeastern Arizona. Note that the dust plume emanating from White Sands, New Mexico was lighter in appearance compared to the other tan/brown-colored areas of blowing dust — this is due to the white gypsum sand that comprises the surface of White Sands National Monument.

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

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

250-meter resolution MODIS True Color RGB images from the MODIS Today site (below) provided a more detailed view of the plume streaming northeastward from its White Sands source. On the later Aqua image, dense tan-colored areas of blowing dust had developed below the thin higher-altitude veil of brighter gypsum aerosols that had earlier been lofted from White Sands.

MODIS True Color RGB images from Terra and Aqua [click to enlarge]

MODIS True Color RGB images from Terra and Aqua [click to enlarge]

A NOAA-20 True Color RGB image viewed using RealEarth is shown below. 19 UTC surface observations at 3 sites near White Sands included Las Cruces KLRU (visibility 3 miles, wind gusting to 46 knots), Alamogordo KALM (visibility 3 miles, wind gusting to 43 knots) and Ruidoso KSRR (visibility 5 miles, wind gusting to 55 knots). The strong winds and dense areas of blowing dust reducing surface visibility not only impacted ground transportation but also posed a hazard to aviation.

NOAA-20 True Color RGB image at 1928 UTC [click to enlarge]

NOAA-20 True Color RGB image at 1928 UTC [click to enlarge]

===== 11 April Update =====

In a larger-scale view of GOES-16 Split Window images (below), the yellow dust signature could be followed during the subsequent overnight hours and into the following day on 11 April, as the aerosols were being transported northeastward across the Upper Midwest. There were widespread reports and photos of dust residue on vehicles and tan/brown-colored snow in parts of Nebraska, Iowa, Minnesota and Wisconsin.

GOES-16 Split Window (10.3-12.3 µm) images [click to play animation | MP4]

GOES-16 Split Window (10.3-12.3 µm) images [click to play animation | MP4]

IDEA forward trajectories (below) — initialized from a cluster of elevated Aura OMI Aerosol Index points over Mexico, New Mexico and Texas — passed directly over areas of model-derived precipitation across the Upper Midwest, providing further support of precipitation scavenging of dust aerosols. Interestingly, a similar event of long range dust transport occurred on 10-11 April 2008.

IDEA forward trajectories initialized from a cluster of elevated Aqua MODIS Aerosol Optical Depth points over NM/TX [click to play animation]

IDEA forward trajectories initialized from a cluster of elevated Aqua MODIS Aerosol Optical Depth points over NM/TX [click to play animation]

HYSPLIT model 24-hour forward trajectories initialized at 3 locations — El Paso, Lubbock and Amarillo in Texas — showed a few of the likely dust transport pathways toward the Upper Midwest at 3 different levels (below).

HYSPLIT model forward trajectories initialized at El Paso, Lubbock and Amarillo, Texas [click to enlarge]

HYSPLIT model 24-hour forward trajectories initialized at El Paso, Lubbock and Amarillo, Texas [click to enlarge]

GOES-16 True Color RGB images from the AOS site (below) showed that some clouds across the Upper Midwest exhibited a subtle light brown hue at times.

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

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

===== 12 April Update =====

GOES-16 Split Window (10.3-12.3 µm) images [click to play animation | MP4]

GOES-16 Split Window (10.3-12.3 µm) images [click to play animation | MP4]

GOES-16 Split Window (10.3-12.3 µm) images (above) showed that the yellow signature of dust aerosols aloft had wrapped all the way around the southern and eastern sectors of the occluded low on 12 April.

Ground-based lidar at the University of Wisconsin – Madison confirmed the presence of elevated levels of aerosol loading between the surface and 6 km.

Lidar aerosol class [click to enlarge]

Lidar aerosol class [click to enlarge]