{"id":268,"date":"2006-11-27T20:56:09","date_gmt":"2006-11-27T20:56:09","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/2006\/11\/27\/cold-air-in-the-yukon-territory\/"},"modified":"2007-06-02T04:52:52","modified_gmt":"2007-06-02T04:52:52","slug":"cold-air-in-the-yukon-territory","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/268","title":{"rendered":"Cold air in northwestern Canada"},"content":{"rendered":"

\"NOAA-15<\/a>
\nA very cold arctic air mass had been building over central Alaska and northwestern Canada during the latter half of November 2006 (surface air temperatures colder than -40 F\/-40 C have been reported daily over that region since 21 November). A NOAA-15 AVHRR 10.8\u00c2\u00b5m “IR window channel” image centered over the southern Yukon Territory (above)<\/strong><\/em> on 27 November (surface analysis<\/strong>)<\/a> revealed that the coldest air (-40 to -50 C, darker blue enhancement) was settling into the lower elevations of the river valleys. Narrow lakes along and south of the Yukon Territory \/ British Columbia border exhibited significantly warmer IR brightness temperatures (-10 to -20 C, orange to yellow enhancement), due to heat radiating upward through the snow and ice covered lake surfaces.<\/p>\n

A similar IR image centered a bit farther east over the Northwest Territories (below)<\/strong><\/em> showed warmer brightness temperatures over the higher terrain of the Mackenzie and Selwyn Mountains (-20 to -30 C, yellow to cyan enhancement) — those higher terrain features rose above the level of the strong temperature inversion<\/a><\/strong> which was trapping the coldest air near the surface at lower elevations. This IR image also revealed a comparatively warm signature (0 to -20 C, red to yellow enhancement) from the snow and ice covered surface of Great Bear Lake in the northern portion of the image. The 1-km resolution of the NOAA-15 AVHRR instrument showed the small-scale structure of these temperature features much better than the “4-km” resolution of GOES-11 (which had degraded to an effective resolution of about 12 km, due to the ~65 degree satellite viewing angle) — this is quite apparent looking at a NOAA-15 \/ GOES-11 IR image fader<\/a><\/strong> (Java applet).
\n\"NOAA-15<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

A very cold arctic air mass had been building over central Alaska and northwestern Canada during the latter half of November 2006 (surface air temperatures colder than -40 F\/-40 C have been reported daily over that region since 21 November). A NOAA-15 AVHRR 10.8\u00c2\u00b5m “IR window channel” image centered over the southern Yukon Territory (above) […]<\/p>\n","protected":false},"author":18,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[22,18,26,5],"tags":[],"class_list":["post-268","post","type-post","status-publish","format-standard","hentry","category-avhrr","category-goes-11","category-poes","category-winter-weather"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/268","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=268"}],"version-history":[{"count":0,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/268\/revisions"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=268"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=268"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=268"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}