{"id":4302,"date":"2010-01-03T23:59:11","date_gmt":"2010-01-03T23:59:11","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=4302"},"modified":"2010-01-05T16:27:48","modified_gmt":"2010-01-05T16:27:48","slug":"galeras-volcano-erupts-in-colombia","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/4302","title":{"rendered":"Galeras volcano erupts in Colombia"},"content":{"rendered":"
\"GOES-11,<\/a>

GOES-11, GOES-14, and GOES-12 10.7 \u00c2\u00b5m IR and 6.7\/6.5 \u00c2\u00b5m water vapor images<\/p><\/div>\n

The Galeras volcano<\/a><\/strong> in Colombia (located in the Andes Mountains near Colombia’s border with Ecuador) experienced an explosive eruption around 00:43 UTC on 03 January 2010<\/strong> (Washington VAAC advisory messages<\/a><\/strong>). McIDAS images of the GOES-11, GOES-14, and GOES-12 10.7 \u00c2\u00b5m IR (top 3 panels)<\/em><\/strong> and 6.7\/6.5 \u00c2\u00b5m water vapor channel data (bottom 3 panels)<\/em><\/strong> showed the volcanic cloud as it spread outward and drifted to the west for several hours following the eruption.<\/p>\n

GOES-11 (GOES-West, positioned at 135\u00c2\u00ba West longitude)<\/em> only imaged the region once every 3 hours during a full disk scan (in this example, at 00:00, 03:00, and 06:00 UTC). GOES-14 (positioned at 105\u00c2\u00ba West longitude)<\/em> was emulating GOES-West operations during the final days of its NOAA Science Test<\/a><\/strong>, and except for the 3-hourly full disk scans, its imaging area was terminated just to the east of the volcano. GOES-12 (GOES-East, positioned at 75\u00c2\u00ba West longitude)<\/em> had the best, most consistent view of the South American region.<\/p>\n

Note how the signature of the volcanic cloud becomes more difficult to follow on the IR imagery, but is still faintly recognizable for an additional 1-2 hours on the water vapor imagery. The different appearance of the GOES-11 water vapor imagery is due to the fact that the 6.7 \u00c2\u00b5m water vapor channel on GOES-11 is a much “narrower” channel (spectrally) compared to the 6.5 \u00c2\u00b5m water vapor channel on GOES-12 and GOES-14; in addition, the large viewing angle from GOES-11 has shifted the water vapor weighting function<\/a><\/strong> to higher (colder) altitudes, making the features appear darker blue to white with this particular water vapor color enhancement.<\/p>\n

\"GOES-11<\/a>

GOES-11 IR difference product (10.7 \u00c2\u00b5m - 12.0 \u00c2\u00b5m)<\/p><\/div>\n

A simple method for identifying and tracking volcanic ash clouds is the use of a “reverse absorption” or “split window” IR difference product, subtracting the brightness temperature values of the 12.0 \u00c2\u00b5m IR channel from the 10.7 \u00c2\u00b5m IR channel. The GOES-11 IR difference product at 03:00 and 06:00 UTC (above)<\/em><\/strong> showed that the volcanic ash cloud had drifted westward over Ipiales (station identifier SKIP)<\/em> and Pasto (station identifier SKPS)<\/em> in Colombia, and was moving just to the north of Quito, Ecuador (station identifier SEQU)<\/em>. Note that on the more recent GOES satellites — GOES-12 and beyond — the 12.0 \u00c2\u00b5m IR channel on the Imager instrument<\/a><\/strong> has been replaced with a 13.3 \u00c2\u00b5m IR channel, preventing the application of this type of IR difference volcanic ash identification on the more recently-launched GOES satellites.<\/p>\n

A corresponding IR difference product using the MODIS 11.0 \u00c2\u00b5m and 12.0 \u00c2\u00b5m channels at 03:25 and 06:25 UTC is shown below. With finer spatial resolution than GOES (1 km, vs 4 km),<\/em> the edges of the ash cloud feature appear with greater clarity on the MODIS images.<\/p>\n

\"MODIS<\/a>

MODIS IR difference product (11.0 \u00c2\u00b5m - 12.0 \u00c2\u00b5m)<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"

The Galeras volcano in Colombia (located in the Andes Mountains near Colombia’s border with Ecuador) experienced an explosive eruption around 00:43 UTC on 03 January 2010 (Washington VAAC advisory messages). McIDAS images of the GOES-11, GOES-14, and GOES-12 10.7 \u00c2\u00b5m IR (top 3 panels) and 6.7\/6.5 \u00c2\u00b5m water vapor channel data (bottom 3 panels) showed […]<\/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":[18,19,40,12,9],"tags":[],"class_list":["post-4302","post","type-post","status-publish","format-standard","hentry","category-goes-11","category-goes-12","category-goes-14","category-modis","category-volcanic-activity"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/4302","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=4302"}],"version-history":[{"count":24,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/4302\/revisions"}],"predecessor-version":[{"id":4305,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/4302\/revisions\/4305"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=4302"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=4302"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=4302"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}