![\"Multi-panel](\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2020\/01\/200129_goes16_16bands_SD_contrail_anim.gif\")
<\/a>Multi-panel images of all 16 ABI spectral bands from GOES-16 [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>Multi-panel images of all 16 ABI<\/strong><\/a> spectral bands from GOES-16 (GOES-East) (above)<\/strong><\/em> revealed an interesting circular contrail over northeastern South Dakota on 29 January 2020<\/strong><\/a>. A signature of this contrail was evident in all 16 bands — visible, near-infrared and infrared. This feature was likely formed by a military aircraft performing training exercises over the area.<\/p>\n A sequence of GOES-16 ABI spectral band images covering that same 1751-2001 UTC time period (below)<\/strong> <\/em>provided a larger view of the circular contrail — whose diameter was about 10-12 miles — along with a linear contrail located about 30 miles to the southwest.<\/p>\n Sequence of GOES-16 ABI spectral band images [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>A toggle between GOES-16 “Red” Visible (0.64 \u00b5m<\/strong><\/a>) and Near-Infrared “Cirrus” (1.37 \u00b5m)<\/strong><\/a> images at 1911 UTC (below)<\/strong><\/em> showed that the darker<\/em> signature seen in the Visible imagery was a shadow cast by the higher-altitude contrail onto the top of the low-altitude stratus clouds. A similar northwestward shadow offset (of about 5 miles) was apparent with the linear contrail feature.<\/p>\n GOES-16 “Red” Visible (0.64 \u00b5m)<\/em> and Near-Infrared “Cirrus” (1.37 \u00b5m)<\/em> images at 1911 UTC [click to enlarge]<\/p><\/div>The southwestward shift of the higher-altitude contrail (with respect to the surface shadow) was not<\/strong> due to parallax — this webapp<\/strong><\/a> shows that the direction of parallax shift over that region would be northwestward<\/em> for cloud features at altitudes of 15,000 feet and 30,000 feet (below)<\/strong><\/em>.<\/p>\n Parallax correct vectors (green arrows)<\/em> and magnitudes (red. in km)<\/em> for cloud features at 15,000 feet and 30,000 feet over the CONUS domain [click to enlarge]<\/p><\/div>Plots of rawinsonde data<\/strong><\/a> from Aberdeen, South Dakota (below)<\/strong> <\/em>showed an increase in moisture during the day within the 500-300 hPa layer — due to its relatively slow southeastward propagation, the circular contrail likely existed within the lower portion of that layer (where wind speeds were less).<\/p>\n Plots of rawinsonde data from Aberdeen, South Dakota [click to enlarge]<\/p><\/div>A signature of the circular contrail was seen in all 3 of the GOES-16 Water Vapor spectral bands — weighting functions<\/strong><\/a> derived using rawinsonde data from Aberdeen, South Dakota (below)<\/strong><\/em> showed either primary or secondary peaks within the 500-300 hPa layer.<\/p>\n<\/a><\/a><\/a><\/a>