As Greenland\u2019s ice retreats, it\u2019s fueling tiny ocean organisms. To test why, scientists turned to a computer model out of JPL and MIT that\u2019s been called a laboratory in itself.<\/p>\n
Runoff from Greenland\u2019s ice sheet is kicking nutrients up from the ocean depths and boosting phytoplankton growth, a new NASA-supported study<\/a> has found. Reporting in Nature Communications: Earth & Environment, the scientists used state-of-the art-computing to simulate marine life and physics colliding in one turbulent fjord. Oceanographers are keen to understand what drives the tiny plantlike organisms, which take up carbon dioxide and power the world\u2019s fisheries.<\/p>\n Greenland\u2019s mile-thick ice sheet is shedding some 293 billion tons<\/a> (266 billion metric tons) of ice per year. During peak summer melt, more than 300,000 gallons (1,200 cubic meters) of fresh water drain into the sea every second from beneath Jakobshavn Glacier<\/a>, also known as Sermeq Kujalleq,the most active glacier on the ice sheet. The waters meet and tumble hundreds of feet below the surface.<\/a><\/p>\n The meltwater plume is fresh and more buoyant than the surrounding saltwater. As it rises, scientists have hypothesized, it may be delivering nutrients like iron and nitrate \u2014 a key ingredient in fertilizer \u2014 to phytoplankton floating at the surface.<\/p>\n Researchers track these microscopic organisms because, though smaller by far than a pinhead, they\u2019re titans of the ocean food web. Inhabiting every ocean from the tropics to the polar regions, they nourish krill and other grazers that, in turn, support larger animals, including fish and whales.<\/p>\n Previous work using NASA satellite data found that the rate of phytoplankton growth in Arctic waters surged<\/a> 57% between 1998 and 2018 alone. An infusion of nitrate from the depths would be especially pivotal to Greenland\u2019s phytoplankton in summer, after most nutrients been consumed by prior spring blooms. But the hypothesis has been hard to test along the coast, where the remote terrain and icebergs as big as city blocks complicate long-term observations.<\/p>\n \u201cWe were faced with this classic problem of trying to understand a system that is so remote and buried beneath ice,\u201d said Dustin Carroll, an oceanographer at San Jos\u00e9 State University who is also affiliated with NASA\u2019s Jet Propulsion Laboratory in Southern California. \u201cWe needed a gem of a computer model to help.\u201d<\/p>\n To re-create what was happening in the waters around Greenland\u2019s most active glacier, the team harnessed a model of the ocean developed at JPL and the Massachusetts Institute of Technology in Cambridge. The model ingests nearly all available ocean measurements collected by sea- and satellite-based instruments over the past three decades. That amounts to billions of data points, from water temperature and salinity to pressure at the seafloor. The model is called Estimating the Circulation and Climate of the Ocean-Darwin<\/a> (ECCO-Darwin for short).<\/p>\n Simulating \u201cbiology, chemistry, and physics coming together\u201d in even one pocket along Greenland\u2019s 27,000 miles (43,000 kilometers) of coastline is a massive math problem, noted lead author Michael Wood, a computational oceanographer at San Jos\u00e9 State University. To break it down, he said the team built a \u201cmodel within a model within a model\u201d to zoom in on the details of the fjord at the foot of the glacier.<\/p>\n Using supercomputers at NASA\u2019s Ames Research Center in Silicon Valley, they calculated that deepwater nutrients buoyed upward by glacial runoff would be sufficient to boost summertime phytoplankton growth by 15 to 40% in the study area.<\/p>\n Could increased phytoplankton be a boon for Greenland\u2019s marine animals and fisheries? Carroll said that untangling impacts to the ecosystem will take time. Melt on the Greenland ice sheet is projected to accelerate in coming decades, affecting everything from sea level and land vegetation to the saltiness of coastal waters.<\/p>\n \u201cWe reconstructed what\u2019s happening in one key system, but there\u2019s more than 250 such glaciers around Greenland,\u201d Carroll said. He noted that the team plans to extend their simulations to the whole Greenland coast and beyond.<\/p>\n Some changes appear to be impacting the carbon cycle both positively and negatively: The team calculated how runoff from the glacier alters the temperature and chemistry of seawater in the fjord, making it less able to dissolve carbon dioxide. That loss is canceled out, however, by the bigger blooms of phytoplankton taking up more carbon dioxide from the air as they photosynthesize.<\/p>\n Wood added: \u201cWe didn\u2019t build these tools for one specific application. Our approach is applicable to any region, from the Texas Gulf to Alaska. Like a Swiss Army knife, we can apply it to lots of different scenarios.\u201d<\/p>\n Jane J. Lee \/ Andrew Wang Written by Sally Younger<\/p>\n 2025-101<\/p>\n","protected":false},"excerpt":{"rendered":"As Greenland\u2019s ice retreats, it\u2019s fueling tiny ocean organisms. To test why, scientists turned to a computer model…\n","protected":false},"author":2,"featured_media":64938,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[32],"tags":[47897,24382,7253,2300,14677,47895,23325,47898,9458,47896,79,47899],"class_list":{"0":"post-64937","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-aerosol","9":"tag-carbon-cycle","10":"tag-cloud","11":"tag-earth","12":"tag-earth-science","13":"tag-ice-glaciers","14":"tag-jet-propulsion-laboratory","15":"tag-ocean-ecosystem","16":"tag-oceans","17":"tag-pace-plankton","18":"tag-science","19":"tag-water-on-earth"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/64937","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=64937"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/64937\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/64938"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=64937"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=64937"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=64937"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
Jet Propulsion Laboratory, Pasadena, Calif.
626-379-6874 \/ 818-354-0307
jane.j.lee@jpl.nasa.gov<\/a> \/ andrew.wang@jpl.nasa.gov<\/a>\u00a0<\/p>\n