{"id":2963,"date":"2009-07-13T23:59:36","date_gmt":"2009-07-13T23:59:36","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=2963"},"modified":"2016-11-16T23:40:35","modified_gmt":"2016-11-16T23:40:35","slug":"volcanic-plume-over-the-great-lakes-region","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/2963","title":{"rendered":"Volcanic plume over the Great Lakes region?"},"content":{"rendered":"
\"GOES-11<\/a>

GOES-11 and GOES-12 visible images<\/p><\/div>\n

A comparison of GOES-11 and GOES-12 visible channel images (above)<\/em><\/strong> revealed an aerosol plume aloft that was oriented northwest-to-southeast over the western Great Lakes region on 13 July 2009<\/a><\/strong>. This example shows the value of forward scattering to help in the identification these kinds of aerosol plumes — note how the plume is much brighter on the GOES-11 image than the GOES-12 image, due to the morning sun’s position in relation to GOES-11 (located at 135\u00ba West longitude)<\/em> versus GOES-12 (located at 75\u00ba West longitude)<\/em>. Also note how the hazy aerosol plume tended to “disappear” on both the GOES-11 and the GOES-12 visible images as the sun angle increased during the morning hours.<\/p>\n

Later in the day, this aerosol plume was easily seen on AWIPS images of the MODIS near-IR 1.3 \u00b5m “cirrus detection” channel (below)<\/em><\/strong>. The so-called “cirrus detection” channel helps to identify features that are effective scatters of light<\/em> — which includes cirrus ice crystals as well as airborne aerosols (such as dust, haze, volcanic ash, or volcanic sulfates).<\/p>\n

\"MODIS<\/a>

MODIS near-IR “cirrus detection” images<\/p><\/div>\n

This aerosol plume exhibited no obvious signal on any of the other conventional MODIS channels, such as the visible, IR window, and water vapor channels (below)<\/em><\/strong>. So was this aerosol feature due to smoke aloft from fires in Canada or Alaska, or was it a high-altitude volcanic sulfate plume (likely from the Sarychev Peak eruptions<\/a><\/strong> earlier in the Summer)?<\/p>\n

\"MODIS<\/a>

MODIS cirrus, visible, IR window, and water vapor channel images<\/p><\/div>\n

\"IASI<\/a>

IASI SO2 image (courtesy of Universit\u00c3\u00a9 Libre de Bruxelles)<\/p><\/div>\n

As it turns out, this plume was identified as an “SO2 alert” on the IASI SO2 product (above, courtesy of Universit\u00c3\u00a9 Libre de Bruxelles<\/a>)<\/em><\/strong>. This feature also exhibited SO2 concentrations of about 6-12 Dobson Units on the Aura OMI SO2 product (below, courtesy of NOAA\/NESDIS<\/a>)<\/em><\/strong>.<\/p>\n

\"OMI<\/a>

OMI SO2 image (courtesy of NOAA\/NESDIS)<\/p><\/div>\n

NOAA ARL HYSPLIT<\/a><\/strong> backward trajectories (below)<\/em><\/strong> suggest that the aerosol plume had spent some time over the Arctic region during the previous week or so, where we had seen similar evidence of high-altitude aerosol plumes on the GOES-11 visible images<\/a><\/strong> in early July.<\/p>\n

\"NOAA<\/a>

NOAA ARL backward trajectories<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"

A comparison of GOES-11 and GOES-12 visible channel images (above) revealed an aerosol plume aloft that was oriented northwest-to-southeast over the western Great Lakes region on 13 July 2009. This example shows the value of forward scattering to help in the identification these kinds of aerosol plumes — note how the plume is much brighter […]<\/p>\n","protected":false},"author":18,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[12,26,9],"tags":[],"class_list":["post-2963","post","type-post","status-publish","format-standard","hentry","category-modis","category-poes","category-volcanic-activity"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/2963","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=2963"}],"version-history":[{"count":21,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/2963\/revisions"}],"predecessor-version":[{"id":22635,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/2963\/revisions\/22635"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=2963"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=2963"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=2963"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}