{"id":17729,"date":"2020-04-30T19:21:10","date_gmt":"2020-04-30T11:21:10","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/icesat-2-laser-scanning-satellite-tracks-how-billions-of-tons-of-polar-ice-are-lost\/"},"modified":"2020-04-30T19:21:10","modified_gmt":"2020-04-30T11:21:10","slug":"icesat-2-laser-scanning-satellite-tracks-how-billions-of-tons-of-polar-ice-are-lost","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/icesat-2-laser-scanning-satellite-tracks-how-billions-of-tons-of-polar-ice-are-lost\/","title":{"rendered":"ICESat-2 laser-scanning satellite tracks how billions of tons of polar ice are lost"},"content":{"rendered":"<figure id=\"attachment_561364\" aria-describedby=\"caption-attachment-561364\" style=\"width: 630px\" class=\"wp-caption aligncenter\"><img fetchpriority=\"high\" decoding=\"async\" class=\"size-full-width wp-image-561364\" src=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2020\/04\/200430-antarctic-630x471.jpg\" alt=\"\" width=\"630\" height=\"471\" srcset=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2020\/04\/200430-antarctic-630x471.jpg 630w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2020\/04\/200430-antarctic-1260x942.jpg 1260w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2020\/04\/200430-antarctic-768x574.jpg 768w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2020\/04\/200430-antarctic-1536x1149.jpg 1536w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2020\/04\/200430-antarctic.jpg 1658w\" sizes=\"(max-width: 630px) 100vw, 630px\"><figcaption data-nosnippet=\"\" id=\"caption-attachment-561364\" class=\"wp-caption-text\">This color-coded map shows the amount of ice gained or lost by Antarctica between 2003 and 2019. Dark reds and purples show large average rates of ice loss near the Antarctic coast, while blues show smaller rates of ice gain in the interior. (Smith et al. \/ Science \/ AAAS via UW)<\/figcaption><\/figure>\n<p>A satellite mission that bounces laser light off the ice sheets of Antarctica and Greenland has found that hundreds of billions of tons\u2019 worth of ice are being lost every year due to Earth\u2019s changing climate.<\/p>\n<p>Scientists involved in NASA\u2019s ICESat-2 project report in the journal Science that the net loss of ice from those regions has been responsible for 0.55 inches of sea level rise since 2003. That\u2019s slightly less than a third of the total amount of sea level rise observed in the world\u2019s oceans over that time.<\/p>\n<p>To track how the ice sheets are changing, the ICESat-2 team compared the satellite\u2019s laser scans with similar measurements that were taken by the original ICESat spacecraft from 2003 to 2009. (ICESat stands for \u201cIce, Cloud and Elevation Satellite.\u201d)<\/p>\n<p>\u201cIf you watch a glacier or ice sheet for a month, or a year, you\u2019re not going to learn much about what the climate is doing to it,\u201d Ben Smith, a glaciologist at the University of Washington and lead author of the Science paper, said in a NASA news release. \u201cWe now have a 16-year span between ICESat and ICESat-2 and can be much more confident that the changes we\u2019re seeing in the ice have to do with the long-term changes in the climate.\u201d<\/p>\n<p><iframe title=\"NASA Mission Maps 16 Years of Ice Loss\" src=\"https:\/\/www.youtube.com\/embed\/lP_SCsMsxZI?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen=\"\" data-ratio=\"0.5625\" data-width=\"800\" data-height=\"450\" style=\"display: block; margin: 0px; width: 800px; height: 450px;\"><\/iframe><\/p>\n<p>ICESat-2 was launched in 2018 to begin what\u2019s expected to be a three-year science mission. The satellite\u2019s laser altimeter sends 10,000 pulses of light down to Earth\u2019s surface every second, and times how long it takes for the reflected pulses to come back. The pulse rate, measured with an accuracy that\u2019s within a billionth of a second, is interpreted to produce high-precision measurements of an ice sheet\u2019s elevation.<\/p>\n<p>Scientists can track how those measurements change over the course of a year to within an inch. For the Science study, they fed the readings from ICESat and ICESat-2 into a computer model that converted changes in volume into changes in mass.<\/p>\n<p>Smith and his colleagues found that the ice sheets are getting thicker in the interior of Antarctica and Greenland, probably due to increased snowfall. But in both cases, the rising ice in the interior is far outweighed by ice loss around the edges.<\/p>\n<figure id=\"attachment_561373\" aria-describedby=\"caption-attachment-561373\" style=\"width: 300px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-561373\" src=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2020\/04\/200430-greenland-239x300.jpg\" alt=\"\" width=\"300\" height=\"376\" srcset=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2020\/04\/200430-greenland-239x300.jpg 239w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2020\/04\/200430-greenland-1226x1536.jpg 1226w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2020\/04\/200430-greenland-1634x2048.jpg 1634w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2020\/04\/200430-greenland-630x790.jpg 630w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2020\/04\/200430-greenland.jpg 1805w\" sizes=\"(max-width: 300px) 100vw, 300px\"><figcaption data-nosnippet=\"\" id=\"caption-attachment-561373\" class=\"wp-caption-text\">This color-coded map shows the amount of ice gained or lost by Greenland between 2003 and 2019. Dark reds and purples show large rates of ice loss near the coasts. Blues show smaller rates of ice gain in the interior of the ice sheet. (Smith et al. \/ Science \/ AAAS via UW)<\/figcaption><\/figure>\n<p>Greenland\u2019s ice sheet lost an average of 200 billion tons of ice per year, while Antarctica\u2019s ice sheet had an annual loss of 118 billion tons of ice, the research team reported. One billion tons of ice represents enough water to fill 400,000 Olympic-sized swimming pools.<\/p>\n<p>\u201cThese first results looking at land ice confirm the consensus from other research groups, but they also let us look at the details of change in individual glaciers and ice shelves at the same time,\u201d said Tom Neumann, ICESat-2 project scientist at NASA\u2019s Goddard Space Flight Center.<\/p>\n<p>In Antarctica, the prime areas for ice loss are West Antarctica and the Antarctic Peninsula, where warmer seas are melting the ice. In Greenland, the Kangerlussuaq and Jakobshavn glaciers have lost 14 to 20 feet of elevation per year due to warmer summer temperatures.<\/p>\n<p>The researchers also studied the floating ice shelves around Antarctica, which are harder to track because they rise and fall with the tides. Close analysis of the ICESat-2 data found that West Antarctica\u2019s Thwaites and Crosson ice shelves have thinned the most, losing an average of 16 feet and 10 feet per year, respectively.<\/p>\n<p>\u201cWhat we expect by the end of the century is on the order of 2, 3, maybe 4 feet of sea level rise,\u201d Alex Gardner, a glaciologist at NASA\u2019s Jet Propulsion Laboratory, said in a video about the study. \u201cBecause we have all of our infrastructure that is built around the coasts, we have a lot of vulnerability to a meter change in sea level rise.\u201d<\/p>\n<p><em>The study in Science, \u201cPervasive Ice Sheet Mass Loss Reflects Competing Ocean and Atmosphere Processes,\u201d was funded by NASA. In addition to Smith and Neumann, co-authors include are Helen Fricker, Alex Gardner, Brooke Medley, Johan Nilsson, Fernando Paolo, Nicholas Holschuh, Susheel Adusumilli, Kelly Brunt, Bea Csatho, Kaitlin Harbeck, Thorsten Markus, Matthew Siegfried and H. Jay Zwally.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>This color-coded map shows the amount of ice gained or lost by Antarctica between 2003 and 2019. Dark reds and purples show large average rates of ice loss near the Antarctic coast, while blues show smaller rates of ice gain in the interior. (Smith et al. \/ Science \/ AAAS via UW) A satellite mission [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[4834,1123,651,4835,2872,190,21,4368],"class_list":["post-17729","post","type-post","status-publish","format-standard","hentry","category-news","tag-antarctica","tag-climate-change","tag-environment","tag-greenland","tag-icesat-2","tag-nasa","tag-space","tag-university-of-washington"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/17729"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=17729"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/17729\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=17729"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=17729"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=17729"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}