{"id":7706,"date":"2011-03-17T21:08:28","date_gmt":"2011-03-17T21:08:28","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=7706"},"modified":"2011-03-18T16:38:26","modified_gmt":"2011-03-18T16:38:26","slug":"plume-of-unknown-etiology-moving-over-alaska","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/7706","title":{"rendered":"“Plume of unknown etiology” moving over Alaska"},"content":{"rendered":"
\"GOES-11<\/a>

GOES-11 0.65 \u00c2\u00b5m visible channel images (click image to play animation)<\/p><\/div>\n

McIDAS images of GOES-11 0.65 \u00c2\u00b5m visible channel data (above; click image to play animation)<\/strong><\/em> showed an interesting “dark plume” feature that was moving in an arc from far northeastern Russia, across the East Siberian Sea and Chukchi Sea, and finally over far northwestern Alaska on 16 March – 17 March 2011<\/strong>.<\/p>\n

When viewed from a more western angle using MTSAT-2 0.73 \u00c2\u00b5m visible channel images (below; click image to play animation),<\/strong><\/em> the plume feature (which can be seen moving over far northwestern Alaska in the upper right portion of the images)<\/em> also exhibited a darker appearance, similar to that seen on the GOES-11 visible imagery. This darker appearance was due to backward scattering of light from the particles within the plume.<\/p>\n

 <\/p>\n

\"MTSAT-2<\/a>

MTSAT-2 0.73 \u00c2\u00b5m visible channel images (click image to play animation)<\/p><\/div>\n

AWIPS images of POES AVHRR 0.86 \u00c2\u00b5m visible channel data (below)<\/strong><\/em> provided more of a “direct view from above”,\u00c2\u00a0 and revealed that the main body of the plume was basically transparent (allowing details of the sea ice to be seen through the plume)<\/em>.\u00c2\u00a0 However, the plume edges<\/em> appeared to have some vertical structure, being thick enough to cast shadows onto the sea ice below.<\/p>\n

\"POES<\/a>

POES AVHRR 0.86 \u00c2\u00b5m visible channel images<\/p><\/div>\n

It is interesting to note that this plume feature did not exhibit any notable signature on POES AVHRR 12.0 \u00c2\u00b5m IR images (below)<\/strong><\/em>.<\/p>\n

\"POES<\/a>

POES AVHRR 12.0 \u00c2\u00b5m IR images<\/p><\/div>\n

A series of MODIS true color Red\/Green\/Blue (RGB) images (below; courtesy of the GINA, University of Alaska<\/a><\/strong>) again showed the transparent nature of the main body of the plume feature, except for the thicker edges which\u00c2\u00a0 were casting shadows.<\/p>\n

\"MODIS<\/a>

MODIS true color Red\/Green\/Blue (RGB) images (courtesy of University of Alaska, GINA)<\/p><\/div>\n

Could this feature have been an aged volcanic plume that was being transported aloft over the Arctic? AWIPS images of the MODIS Volcanic Ash Mass Loading product (below)<\/strong><\/em> did display a few isolated very small patches exhibiting 1-10 tons per square kilometer of loading at 04:44 UTC on 17 March, but there was no temporal continuity when examining the Ash Mass Loading product before or after this particular time.<\/p>\n

\"MODIS<\/a>

MODIS Volcanic Ash Mass Loading product<\/p><\/div>\n

\"Volcanic<\/a>

Volcanic Ash Height product<\/p><\/div>\n

The corresponding MODIS Volcanic Ash Height product (above)<\/strong><\/em> indicated that these features were located at an altitude of 3-4 km, while the MODIS Ash Mass Effective Particle Radius product (below)<\/strong><\/em> showed values in the 3-5 \u00c2\u00b5m range.<\/p>\n

\"Volcanic<\/a>

Volcanic Ash Particle Effective Radius product<\/p><\/div>\n

However, rather than an aged volcanic ash plume, a more plausible explanation of the feature seen on satellite imagery is the long-range transport of smoke and pollution from industrial sources in northeastern China. A calculation of 96-hour backward trajectories using the NOAA ARL HYSPLIT<\/a><\/strong> model (below)<\/em><\/strong> indicated that air parcels arriving at 3 points along the plume at an altitude of 6-km had originated within the boundary layer over northeastern China on 13 March. MODIS images showing the thick haze over that region can be found on the US Air Quality “Smog Blog”<\/a><\/strong>.<\/p>\n

\"NOAA<\/a>

NOAA ARL HYSPLIT back trajectories arriving at the 4km, 6km, and 8km altitudes<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"

McIDAS images of GOES-11 0.65 \u00c2\u00b5m visible channel data (above; click image to play animation) showed an interesting “dark plume” feature that was moving in an arc from far northeastern Russia, across the East Siberian Sea and Chukchi Sea, and finally over far northwestern Alaska on 16 March – 17 March 2011. When viewed from […]<\/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":[37,22,18,12,20,26,45,38],"tags":[],"class_list":["post-7706","post","type-post","status-publish","format-standard","hentry","category-arctic","category-avhrr","category-goes-11","category-modis","category-mtsat","category-poes","category-redgreenblue-rgb-images","category-what-the-heck-is-this"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/7706","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=7706"}],"version-history":[{"count":17,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/7706\/revisions"}],"predecessor-version":[{"id":7723,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/7706\/revisions\/7723"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=7706"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=7706"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=7706"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}