Aircraft hole punch and distrail cloud features over southern Lake Michigan

December 20th, 2017 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, top) and Near-Infrared “Snow/Ice” (1.61 µm. bottom) images, with surface station identifiers plotted in yellow [click to play MP4 animation]

GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (above) revealed a number of aircraft “hole punch clouds” and cloud dissipation or “distrail” features drifting eastward across southern Lake Michigan and adjacent states on 20 December 2017. 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 the jet engine exhaust acting as ice condensation nuclei 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“). The darker gray appearance of the hole punch clouds on 1.61 µm images confirms that the features were composed of ice crystals (since ice is a strong absorber of radiation at that wavelength).

A good example of a hole punch cloud adjacent to a longer distrail feature was seen over far southeastern Minnesota and the Minnesota/Wisconsin border, using 250-meter resolution Aqua MODIS true-color and false-color Red-Green-Blue (RGB) images from the MODIS Today site (below). Glaciated (ice crystal) cloud features appeared as darker shades of cyan in the false-color image.

Aqua MODIS true-color and false-color RGB images [click to enlarge]

Aqua MODIS true-color and false-color RGB images [click to enlarge]

A very detailed view of a hole punch cloud over Lake Michigan was provided by 30-meter resolution Landsat-8 false-color imagery at 1635 UTC, viewed using RealEarth (below).

Landsat-8 false-color RGB image [click to enlarge]

Landsat-8 false-color RGB image [click to enlarge]

===== 21 December Update =====

Another example of numerous aircraft hole punch and distrail cloud features was seen on Terra MODIS true-color and false-color RGB images on 21 December. over northern Illinois and northern Indiana (below).

Terra MODIS true-color and false-color images [click to enlarge]

Terra MODIS true-color and false-color RGB images [click to enlarge]

Aircraft distrails and contrails

December 30th, 2013 |
Suomi NPP VIIRS 0.64 µm visible channel and false-color RGB images

Suomi NPP VIIRS 0.64 µm visible channel and false-color RGB images

Two signatures of aircraft traffic sometimes seen in satellite imagery are (1) dissipation trails, or “distrails”, and (2) condensation trails, or “contrails”. On 30 December 2013, examples of both were seen over Virginia and West Virgina. Multiple layers of clouds existed over the region as a cold frontal boundary was moving eastward; ahead of the cold front patchy areas of low-level supercooled water droplet clouds were drifting northeastward across North Carolina and Virginia, and examples of aircraft distrails could be seen in a comparison of Suomi NPP VIIRS 0.64 µm visible channel and false-color Red/Green/Blue (RGB) images at 17:29 UTC (above). When aircraft penetrated the supercooled water droplet cloud deck, particles in their exhaust acted as ice condensation nuclei which then created narrow lines of glaciated (ice) clouds in their wake. One particularly vivid example of a distrail was oriented from southwest to northeast over central Virginia. Ice clouds appeared as varying shades of red in the RGB image, in contrast to supercooled water droplet clouds which showed up as brighter white features.

Farther to the west, a wide band of higher-altitude ice clouds existed as part of an elongated warm conveyor belt that was approaching the East Coast of the US. A comparison of Suomi NPP VIIRS 3.74 µm shortwave IR channel and 11.45 µm IR channel images at 17:29 UTC (below) revealed the presence of widespread contrails over much of West Virginia into western Virginia. The contrails were nearly as cold as the underlying high-altitude cirrus clouds on the 11.45 µm IR image, making their identification more difficult — however, the contrails were quite evident on the shortwave IR image, since their smaller particles were very efficient reflectors of solar radiation (making them exhibit a warmer, darker gray signature).

Suomi NPP VIIRS 3.74 µm shortwave IR and 11.45 µm IR channel images

Suomi NPP VIIRS 3.74 µm shortwave IR and 11.45 µm IR channel images

Other examples of aircraft distrails can be found in previous blog posts.

Valley fog in Kentucky, and aircraft “distrails” in South Carolina

December 5th, 2012 |
GOES-13 0.63 µm visible channel images (click image to play animation)

GOES-13 0.63 µm visible channel images (click image to play animation)

Two features of interest appeared on McIDAS images of GOES-13 0.63 µm visible channel data (above; click image to play animation) on the morning of 05 December 2012: (1) fingers of valley fog across much of Kentucky, which dissipated as daytime heating and boundary layer mixing increased, and (2) a pair of aircraft dissipation trails (or “distrails”) that first appeared north of Sumter (KSSC) and drifted east-northeastward between Florence (KFLO) and Darlington (KUDG). It is likely that these distrails (highlighted with yellow ‘>’ symbols) formed as aircraft heading to or from Columbia, South Carolina (KCAE) passed through the supercooled water droplet cloud layer, causing glaciation and subsequent fallout of the ice crystals to create the elongated clearing lines.

Hole punch clouds and aircraft distrails over Georgia and South Carolina

February 17th, 2012 |
GOES-13 0.63 µm visible channel images

GOES-13 0.63 µm visible channel images

McIDAS images of 1-km resolution GOES-13 0.63 µm visible channel data (above) showed that there were a number of “hole punch clouds” and long “aircraft dissipation trails” (or “distrails”) drifting east-northeastward over eastern Georgia and the northern half of South Carolina on 17 February 2012. These features occur when aircraft ascend or descend through a cloud layer composed of supercooled water droplets — particles from the jet engine exhaust act as ice nuclei that initiate glaciation. The resulting relatively large ice crystals then begin to fall out of the supercooled water droplet cloud layer, causing the hole punch or aircraft dissipation trail to appear.

A closer view using a 250-meter resolution Terra MODIS true-color Red/Green/Blue (RGB) image from the SSEC MODIS Today site (below; viewed using Google Earth) shows more structural details of some of the hole punch and distrail features at 15:47 UTC (10:47 am local time). The aircraft likely penetrated the supercooled water droplet cloud over Georgia, after which the hole punch and distrail signatures grew as the cloud drifted east-northeastwrad over South Carolina.

MODIS true color Red/Green/Blue (RGB) image (viewed using Google Earth)

MODIS true color Red/Green/Blue (RGB) image (viewed using Google Earth)

A comparison of 250-meter resolution Terra MODIS true-color and false-color Red/Green/Blue (RGB) images (below) helps to verify that the hole punch and distrail features were indeed composed of ice crystals (which appear as cyan on the false-color image, in contrast to the brighter white supercooled water droplet cloud features).

MODIS true-color and false-color Red/Green/Blue (RGB) images

MODIS true-color and false-color Red/Green/Blue (RGB) images