{"id":51983,"date":"2023-04-27T20:30:22","date_gmt":"2023-04-27T20:30:22","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=51983"},"modified":"2023-05-19T20:09:31","modified_gmt":"2023-05-19T20:09:31","slug":"comparing-three-different-rgbs-after-an-eruption","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/51983","title":{"rendered":"Comparing three different RGBs after the eruption of Shiveluch"},"content":{"rendered":"\n<figure class=\"wp-block-video\"><video height=\"1088\" style=\"aspect-ratio: 990 \/ 1088;\" width=\"990\" controls loop src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2023\/04\/HIMAWARI-9_AHI_dust_ash_so2_20230410_2300_to_20230415_0000_3Tileanim.mp4\"><\/video><figcaption class=\"wp-element-caption\">Himawari-9 Dust RGB (Top), Ash RGB (middle) and SO2 RGB (bottom), 2300 UTC 10 April 2023 &#8211; 0000 UTC 15 April 2023<\/figcaption><\/figure>\n\n\n\n<p>There are different RGBs available to monitor volcanic signatures within a cloud, and three common ones are shown above.  The <a href=\"https:\/\/rammb.cira.colostate.edu\/training\/visit\/quick_guides\/Dust_RGB_Quick_Guide.pdf\">Dust RGB<\/a> and the <a href=\"https:\/\/rammb.cira.colostate.edu\/training\/visit\/quick_guides\/GOES_Ash_RGB.pdf\">Ash RGB<\/a> use identical channels\/channel differences that are scaled differently.  All three RGBs (here is the The <a href=\"https:\/\/rammb.cira.colostate.edu\/training\/visit\/quick_guides\/Quick_Guide_SO2_RGB.pdf\">SO<sub>2<\/sub> RGB<\/a> Quick Guide) include Band 11 information;  Band 11 detects radiation in the part of the electromagnetic spectrum that is sensitive to absorption by SO<sub>2<\/sub>.  For the Sheviluch eruption (described in blog posts <a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/51654\">here<\/a> and <a href=\"https:\/\/satelliteliaisonblog.com\/2023\/04\/12\/april-10-volcanic-eruption-in-russia\/\">here<\/a>)  that occurred just at the beginning of this animation above, the SO<sub>2<\/sub> signal &#8212; bright yellow in the SO<sub>2<\/sub> RGB &#8212; persists the longest.  That, of course, will not be the case with every eruption;  that&#8217;s why one must use more than one product to monitor an eruption.<\/p>\n\n\n\n<p>Note that &#8220;Keep Out Zones&#8221; are apparent in the imagery above as regions of no data around 1440 UTC, when the Himawari-9 imager is turned off when it is pointing a little too closely towards the Sun.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p><a href=\"https:\/\/www.data.jma.go.jp\/mscweb\/data\/himawari\/\">Himawari-9 imagery in this blog post are courtesy of JMA<\/a>.  The Full-Disk HSD data were processed into RGB images using <a href=\"https:\/\/www.ssec.wisc.edu\/software\/geo2grid\/introduction.html\">geo2grid<\/a>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>By 14 April, much of the signal has shifted eastward out of Himawari-9&#8217;s field of view.  The animation below, from GOES-18, shows the three RGBs from 0000 UTC on 14 April through 0000 UTC on 20 April.  The signal of enhanced SO2 in particular has remarkable staying power.<\/p>\n\n\n\n<figure class=\"wp-block-video\"><video height=\"1088\" style=\"aspect-ratio: 990 \/ 1088;\" width=\"990\" controls loop muted src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2023\/05\/GOES-18_ABI_RadF_dust_ash_so2_20230414_0000_to_20230420_0000anim.mp4\"><\/video><figcaption class=\"wp-element-caption\">GOES-18 Dust RGB (Top), Ash RGB (middle) and SO2 RGB (bottom), 0000 UTC 14 April 2023 &#8211; 0000 UTC 20 April 2023<\/figcaption><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>There are different RGBs available to monitor volcanic signatures within a cloud, and three common ones are shown above. The Dust RGB and the Ash RGB use identical channels\/channel differences that are scaled differently. All three RGBs (here is the The SO2 RGB Quick Guide) include Band 11 information; Band 11 detects radiation in the [&hellip;]<\/p>\n","protected":false},"author":19,"featured_media":51985,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[132,73,9],"tags":[],"class_list":["post-51983","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-geo2grid","category-himawari-9","category-volcanic-activity"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/51983","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\/19"}],"replies":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/comments?post=51983"}],"version-history":[{"count":7,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/51983\/revisions"}],"predecessor-version":[{"id":52415,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/51983\/revisions\/52415"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/51985"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=51983"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=51983"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=51983"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}