{"id":7648,"date":"2011-03-07T23:59:32","date_gmt":"2011-03-07T23:59:32","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=7648"},"modified":"2018-09-03T19:15:45","modified_gmt":"2018-09-03T19:15:45","slug":"contrails-over-eastern-north-dakota","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/7648","title":{"rendered":"Contrails over eastern North Dakota"},"content":{"rendered":"
\"POES<\/a>

POES AVHRR 10.8 \u00b5m “IR window” image<\/p><\/div>\n

A pair of interesting “Figure 8” aircraft condensation trails (or “contrails”) could be seen on a 1-km resolution POES AVHRR 10.8 \u00b5m “IR window” image over eastern North Dakota on 07 March 2011<\/a> (above)<\/em><\/strong>. The contrails appeared slightly colder (brighter white)<\/em> than the surrounding snow-covered ground surfaces. These contrail patterns were presumably made by military jets conducting training exercises from nearby Grand Forks Air Force Base<\/a><\/strong>.<\/p>\n

The contrail patterns were even more apparent on the corresponding POES AVHRR 3.7 \u00b5m “shortwave IR” image (below)<\/em><\/strong>. The contrail features appeared darker<\/strong> on the shortwave IR image due to reflection of solar radiation off the small supercooled water droplets that comprised the cloud features — and their shadows appeared as slightly cooler (brighter white)<\/em> signatures on the surface.<\/p>\n

\"POES<\/a>

POES AVHRR 3.7 \u00b5m “IR window” image<\/p><\/div>\n

On the 0.63 \u00b5m POES AVHRR visible image (below),<\/em><\/strong> the contrail shadows showed up very well as darker features against the bright snow-covered ground. Using an Interactive Image Fader Tool<\/a><\/strong>, the distance offset between the contrails themselves (darker features on the shortwave IR image)<\/em> and their shadows (darker features on the visible image)<\/em> was quite obvious — this distance offset was due to the fairly low sun angle at this time of the day over North Dakota in early March.<\/p>\n

\"POES<\/a>

POES AVHRR 0.63 \u00b5m visible image<\/p><\/div>\n

Tip of the hat to Gregg Gallina (NOAA\/NESDIS\/SAB<\/strong><\/a>) for bring this interesting feature to our attention!<\/p>\n","protected":false},"excerpt":{"rendered":"

A pair of interesting “Figure 8” aircraft condensation trails (or “contrails”) could be seen on a 1-km resolution POES AVHRR 10.8 \u00b5m “IR window” image over eastern North Dakota on 07 March 2011 (above). The contrails appeared slightly colder (brighter white) than the surrounding snow-covered ground surfaces. These contrail patterns were presumably made by military […]<\/p>\n","protected":false},"author":18,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[22,21,26],"tags":[],"class_list":["post-7648","post","type-post","status-publish","format-standard","hentry","category-avhrr","category-aviation","category-poes"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/7648","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/users\/18"}],"replies":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/comments?post=7648"}],"version-history":[{"count":15,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/7648\/revisions"}],"predecessor-version":[{"id":29681,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/7648\/revisions\/29681"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=7648"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=7648"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=7648"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}