{"id":610,"date":"2008-02-19T23:59:39","date_gmt":"2008-02-19T23:59:39","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/610"},"modified":"2008-02-25T16:34:26","modified_gmt":"2008-02-25T16:34:26","slug":"using-modis-imagery-to-detect-stratusfog-over-snow-cover","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/610","title":{"rendered":"Using MODIS imagery to detect thin stratus\/fog over snow cover"},"content":{"rendered":"<p><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2008\/02\/080219_modis_anim.gif\" title=\"MODIS visible + snow\/ice + IR images (Animated GIF)\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2008\/02\/080219_modis_anim.gif\" title=\"MODIS visible + snow\/ice + IR images (Animated GIF)\" alt=\"MODIS visible + snow\/ice + IR images (Animated GIF)\" align=\"middle\" height=\"463\" width=\"480\" \/><\/a><\/p>\n<p>AWIPS images of the MODIS visible channel, the 1.6\u00c2\u00b5m near-IR &#8220;snow\/ice channel&#8221;, and the 11.0\u00c2\u00b5m &#8220;IR window&#8221; channel <em><strong>(above)<\/strong><\/em> revealed a large patch of supercooled water droplet stratus cloud (and\/or fog) over northeastern Utah on <a href=\"http:\/\/www.hpc.ncep.noaa.gov\/dailywxmap\/index_20080219.html\" title=\"19 February 2008 daily weather map\" target=\"_blank\"><strong>19 February 2008<\/strong><\/a>. This stratus\/fog cloud feature was confined to the lower elevations <strong>(<a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2008\/02\/METAR_Plot_20080219_1800.png\" title=\"AWIPS topography image\" target=\"_blank\">AWIPS topography image<\/a> | <a href=\"http:\/\/fermi.jhuapl.edu\/states\/maps1\/ut_c.gif\" title=\"Johns Hopkins topography image\" target=\"_blank\">Johns Hopkins topography image<\/a>)<\/strong> where several river valleys converge  just south of Vernal, Utah <em>(station identifier KVEL);<\/em> at the time of the images, the surface visibility at Vernal was restricted to 1 mile with fog. The areal extent of this cloud feature was difficult to judge using either the 1-km resolution MODIS visible image <em>(due to the bright white appearance of both the stratus\/fog and the surrounding non-cloudy snow cover)<\/em> or the 1-km resolution MODIS IR window image <em>(due to the light gray enhancement of both the cloud feature and the cold air that had collected within the remainder of the lower elevations)<\/em> &#8212; but on  the snow\/ice image, the contrast of the brighter gray-to-white enhancement of the supercooled water droplet stratus\/fog feature  really stood out against the dark appearance of the surrounding snow-covered terrain.<\/p>\n<p>The corresponding  250-meter resolution MODIS true color image from the <a href=\"http:\/\/www.ssec.wisc.edu\/modis-today\/index.php?satellite=a1&amp;product=true_color&amp;date=2008_02_19_050&amp;overlay_sector=false&amp;overlay_state=true&amp;overlay_coastline=true&amp;sector=USA2&amp;resolution=2000m\" title=\"SSEC MODIS Today site\" target=\"_blank\"><strong>SSEC MODIS Today<\/strong><\/a> site <em><strong>(below, viewed using Google Earth)<\/strong><\/em> showed the &#8220;translucent&#8221; nature of the patch of stratus\/fog &#8212; note that you can actually see the outlines of some of the converging rivers <em>(the Green River, White River, and Duchesne River)<\/em> through the optically-thin cloud feature.<\/p>\n<p><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2008\/02\/080219_modis_google.jpg\" title=\"MODIS true color image (Google Earth)\" target=\"_blank\"> <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2008\/02\/080219_modis_google.jpg\" title=\"MODIS true color image (Google Earth)\" alt=\"MODIS true color image (Google Earth)\" align=\"middle\" height=\"344\" width=\"480\" \/><br \/>\n<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>AWIPS images of the MODIS visible channel, the 1.6\u00c2\u00b5m near-IR &#8220;snow\/ice channel&#8221;, and the 11.0\u00c2\u00b5m &#8220;IR window&#8221; channel (above) revealed a large patch of supercooled water droplet stratus cloud (and\/or fog) over northeastern Utah on 19 February 2008. This stratus\/fog cloud feature was confined to the lower elevations (AWIPS topography image | Johns Hopkins topography [&hellip;]<\/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":[13,32,12,5],"tags":[],"class_list":["post-610","post","type-post","status-publish","format-standard","hentry","category-fog-detection","category-google-earth","category-modis","category-winter-weather"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/610","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=610"}],"version-history":[{"count":0,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/610\/revisions"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=610"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=610"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=610"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}