{"id":27856,"date":"2018-04-23T23:59:03","date_gmt":"2018-04-23T23:59:03","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=27856"},"modified":"2018-04-25T21:09:22","modified_gmt":"2018-04-25T21:09:22","slug":"interesting-pattern-of-contrails-off-the-coast-of-southern-california","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/27856","title":{"rendered":"Contrails off the coast of Southern California"},"content":{"rendered":"<p><center><\/p>\n<blockquote class=\"twitter-tweet\" data-lang=\"en\">\n<p dir=\"ltr\" lang=\"en\">It looks like someone was having fun flying in circles. Check out the contrails southwest of San Diego captured by <a href=\"https:\/\/twitter.com\/hashtag\/GOES16?src=hash&amp;ref_src=twsrc%5Etfw\">#GOES16<\/a> yesterday afternoon. You can even see its shadow on the low clouds early in the animation. <a href=\"https:\/\/t.co\/PvUr2jNack\">pic.twitter.com\/PvUr2jNack<\/a><\/p>\n<p>\u2014 NWS San Diego (@NWSSanDiego) <a href=\"https:\/\/twitter.com\/NWSSanDiego\/status\/988719096845012992?ref_src=twsrc%5Etfw\">April 24, 2018<\/a><\/p><\/blockquote>\n<p><script async src=\"https:\/\/platform.twitter.com\/widgets.js\" charset=\"utf-8\"><\/script><\/center><\/p>\n<p>As pointed out by NWS San Diego, an interesting pattern of contrails formed off the coast late in the day on <a href=\"http:\/\/www.wpc.ncep.noaa.gov\/dailywxmap\/index_20180423.html\"><strong>23 April 2018<\/strong><\/a>. A comparison of GOES-16<em> (GOES-East)<\/em> &#8220;Red&#8221; Visible (<a href=\"http:\/\/cimss.ssec.wisc.edu\/goes\/OCLOFactSheetPDFs\/ABIQuickGuide_Band02.pdf\"><strong>0.64 \u00b5m<\/strong><\/a>), Near-Infrared &#8220;Cirrus&#8221; (<a href=\"http:\/\/cimss.ssec.wisc.edu\/goes\/OCLOFactSheetPDFs\/ABIQuickGuide_Band04.pdf\"><strong>1.37 \u00b5m<\/strong><\/a>) and &#8220;Clean&#8221; Infrared Window (<a href=\"http:\/\/cimss.ssec.wisc.edu\/goes\/OCLOFactSheetPDFs\/ABIQuickGuide_Band13.pdf\"><strong>10.3 \u00b5m<\/strong><\/a>) images<em><strong> (below)<\/strong><\/em> showed signatures during the daylight hours &#8212; Visible images revealed contrail shadows being cast upon the low-altitude cloud tops at <a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2018\/04\/G16_VIS_CIRRUS_CONTRAILS_SOCAL_23APR2018_958x638_B24_2018114_014225_0002PANELS_00003.GIF\"><strong>0142<\/strong><\/a> and <a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2018\/04\/G16_VIS_CIRRUS_CONTRAILS_SOCAL_23APR2018_958x638_B24_2018114_014725_0002PANELS_00004.GIF\"><strong>0147 UTC<\/strong><\/a> &#8212; with an Infrared signature persisting after sunset. These contrails were likely caused by military aircraft performing training exercises, since <a href=\"https:\/\/twitter.com\/NWSSanDiego\/status\/988552688148369408\"><strong>chaff was seen with radar<\/strong><\/a> in that same area on the previous day.<\/p>\n<p><div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a class=\"thumbnail\" href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2018\/04\/180423_goes16_visible_cirrus_infrared_SoCal_contrails_anim.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"thumbnail\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2018\/04\/G16_VIS_CIRRUS_IR_SOCAL_CONTRAILS_23APR2018_960x427_B2413_2018114_015225_0003PANELS_00005.GIF\" alt=\"GOES-16 \" width=\"640\" height=\"480\" \/><\/a><p class=\"wp-caption-text\">GOES-16 &#8220;Red&#8221; Visible<em> (0.64 \u00b5m, left),<\/em> Near-Infrared &#8220;Cirrus&#8221; <em>(1.37 \u00b5m, center)<\/em> and &#8220;Clean&#8221; Infrared Window <em>(10.3 \u00b5m, right)<\/em> images [click to play animation | <a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2018\/04\/180423_goes16_visible_cirrus_infrared_SoCal_contrails_anim.mp4\"><strong>MP4<\/strong><\/a>]<\/p><\/div>A better post-sunset signature was seen on a NOAA-15 Infrared Window (10.8 \u00b5m) image at 0212 UTC <em><strong>(below)<\/strong><\/em>. A comparison with the corresponding GOES-16 &#8220;Clean&#8221; Infrared Window (10.3 \u00b5m)\u00a0 image displayed a significant northwestward GOES-16 displacement due to<a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/217\"><strong> parallax<\/strong><\/a> &#8212; and the 1.1 km spatial resolution of AVHRR data resulted in a clearer contrail signature.<\/p>\n<p><div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2018\/04\/180423_noaa15_goes16_infrared_SoCal_contrails_anim.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2018\/04\/180423_noaa15_goes16_infrared_SoCal_contrails_anim.gif\" alt=\"NOAA-15 AVHRR Infrared Window (10.8 \u00b5m) and GOES-16 ABI \" width=\"640\" height=\"480\" \/><\/a><p class=\"wp-caption-text\">NOAA-15 AVHRR Infrared Window <em>(10.8 \u00b5m)<\/em> and GOES-16 ABI &#8220;Clean&#8221; Infrared Window<em> (10.3 \u00b5m)<\/em> images [click to enlarge]<\/p><\/div>The pattern of contrails could also be followed after sunset using GOES-16 Low-level (<a href=\"http:\/\/cimss.ssec.wisc.edu\/goes\/OCLOFactSheetPDFs\/ABIQuickGuide_Band10.pdf\"><strong>7.3 \u00b5m<\/strong><\/a>), Mid-level (<a href=\"http:\/\/cimss.ssec.wisc.edu\/goes\/OCLOFactSheetPDFs\/ABIQuickGuide_Band09.pdf\"><strong>6.9 \u00b5m<\/strong><\/a>) and Upper-level (<a href=\"http:\/\/cimss.ssec.wisc.edu\/goes\/OCLOFactSheetPDFs\/ABIQuickGuide_Band08.pdf\"><strong>6.2 \u00b5m<\/strong><\/a>) imagery <em><strong>(below)<\/strong><\/em>.<\/p>\n<p><div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a class=\"thumbnail\" href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2018\/04\/180423_goes16_water_vapor_SoCal_contrails_anim.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"thumbnail\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2018\/04\/G16_WATER_VAPOR_SOCAL_CONTRAILS_23APR2018_960x427_B1098_2018114_024225_0003PANELS_00015.GIF\" alt=\"GOES-16 Low-level (7.3 \u00b5m, left), Mid-level (6.9 \u00b5m, center) and Upper-level (6.2 \u00b5m, right) Water Vapor images [click to play animation | MP4]\" width=\"640\" height=\"480\" \/><\/a><p class=\"wp-caption-text\">GOES-16 Low-level <em>(7.3 \u00b5m, left),<\/em> Mid-level <em>(6.9 \u00b5m, center)<\/em> and Upper-level<em> (6.2 \u00b5m, right)<\/em> Water Vapor images [click to play animation | <a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2018\/04\/180423_goes16_water_vapor_SoCal_contrails_anim.mp4\"><strong>MP4<\/strong><\/a>]<\/p><\/div>The GOES-16 Water Vapor <a href=\"http:\/\/cimss.ssec.wisc.edu\/goes\/wf\/\"><strong>weighting function<\/strong><\/a> plots<strong> (below)<\/strong> displayed a bi-modal distribution for all 3 spectral bands, with peaks near 300 hPa and 500 hPa. The absence of a distinct contrail signature on the 6.2 \u00b5m imagery suggests that these features were located closer to the 500 hPa pressure level.<\/p>\n<div style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2018\/04\/180424_00utc_knkx_wv_wf.jpeg\"><img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2018\/04\/180424_00utc_knkx_wv_wf.jpeg\" alt=\"GOES-16 Water Vapor weighting functions, calculated using rawinsonde data from San Diego CA [click to enlarge]\" width=\"640\" height=\"434\" \/><\/a><p class=\"wp-caption-text\">GOES-16 Water Vapor weighting functions, calculated using rawinsonde data from San Diego CA [click to enlarge]<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"<p>It looks like someone was having fun flying in circles. Check out the contrails southwest of San Diego captured by #GOES16 yesterday afternoon. You can even see its shadow on the low clouds early in the animation. pic.twitter.com\/PvUr2jNack \u2014 NWS San Diego (@NWSSanDiego) April 24, 2018 As pointed out by NWS San Diego, an interesting [&hellip;]<\/p>\n","protected":false},"author":18,"featured_media":27860,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[22,21,74,26],"tags":[],"class_list":["post-27856","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-avhrr","category-aviation","category-goes-16","category-poes"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/27856","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=27856"}],"version-history":[{"count":9,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/27856\/revisions"}],"predecessor-version":[{"id":27866,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/27856\/revisions\/27866"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/27860"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=27856"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=27856"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=27856"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}