{"id":47866,"date":"2022-09-11T09:31:00","date_gmt":"2022-09-11T09:31:00","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=47866"},"modified":"2022-09-13T15:51:57","modified_gmt":"2022-09-13T15:51:57","slug":"5-1-micrometers-and-iasi","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/47866","title":{"rendered":"5.1 micrometers and IASI"},"content":{"rendered":"\n

A previous post<\/a> discussed the 5.1 micrometer channel that might be part of the imager (GXI) to fly on GeoXO, the next-generation satellite (beyond GOES-R) to be launched in the 2030s. That previous post, however, used Cross-track Infrared Sounder (CrIS<\/a>) data, and CrIS observes close to, but not at, 5.1 micrometers. However, the Infrared Atmospheric Sounding Interferometer (IASI<\/a>) that is part of the payload on Metop-B and Metop-C (it was on Metop-A as well!) does take observations at 5.1 micrometers. The animation shows a Metop-A IASI observations at 5.1, 6.19, 6.9 and 7.3 micrometers (or wavenumbers 1950, 1615, 1438 and 1369) from a granule over Europe. Of note is apparent moisture aloft — shown as cooler brightness temperatures especially at 6.9 micrometers — that has no apparent signal at 5.1 micrometers because of less sensitivity to mid-tropospheric water vapor at the shorter wavelength. Indeed, 5.1 micrometer brightness temperatures are much warmer than the other channels.<\/p>\n\n\n\n

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Metop-A observations at 5.1, 6.19, 6.9 and 7.3 micrometers, 1140 UTC on 15 January 2007. (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n

A greyscaled image of 5.1 micrometers, below, shows how the boundary layer influences the signal in clear air.<\/p>\n\n\n\n

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5.1 micrometer image from IASI data (click to enlarge)<\/figcaption><\/figure>\n\n\n\n
\n\n\n\n

What did geostationary imagery look like on this day? Meteosat-8 imagery at 6.19 and 7.3 micrometers is shown below.<\/p>\n\n\n\n

\"\"<\/a>
Meteosat-8 Bands 5 and 6 (6.2 and 7.3 micrometers) at 1930 UTC on 15 January 2007 (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n

How dry was this airmass over the Mediterranean? Soundings from 0000 and 1200 UTC on 15 January 2007 (link<\/a>, from the Wyoming Sounding site<\/a>) show total precipitable water values between 10 and 14 mm.<\/p>\n\n\n\n

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The addition of the 5.1 micrometer channel is designed to aid in convective forecasting: gradients in water vapor very low in the atmosphere should be apparent.<\/p>\n","protected":false},"excerpt":{"rendered":"

A previous post discussed the 5.1 micrometer channel that might be part of the imager (GXI) to fly on GeoXO, the next-generation satellite (beyond GOES-R) to be launched in the 2030s. That previous post, however, used Cross-track Infrared Sounder (CrIS) data, and CrIS observes close to, but not at, 5.1 micrometers. However, the Infrared Atmospheric […]<\/p>\n","protected":false},"author":19,"featured_media":47875,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[124,58],"tags":[],"class_list":["post-47866","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-geoxo","category-metop"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/47866","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\/19"}],"replies":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/comments?post=47866"}],"version-history":[{"count":9,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/47866\/revisions"}],"predecessor-version":[{"id":47893,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/47866\/revisions\/47893"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/47875"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=47866"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=47866"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=47866"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}