{"id":930211,"date":"2026-10-16T11:50:11","date_gmt":"2026-10-16T11:50:11","guid":{"rendered":"https:\/\/www.newsbeep.com\/au\/930211\/"},"modified":"2026-10-16T11:50:11","modified_gmt":"2026-10-16T11:50:11","slug":"rare-n2-dimer-could-let-scientists-answer-questions-about-global-nitrogen-cycle-research","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/au\/930211\/","title":{"rendered":"Rare N2 dimer could let scientists answer questions about global nitrogen cycle | Research"},"content":{"rendered":"

\"Algal<\/p>\n

A novel technique allowing measurement of biological loss of fixed nitrogen<\/a> using an unexplained anomaly in atmospheric dinitrogen\u2019s isotopic composition has been demonstrated by researchers. The work could help to answer fundamental questions about the global nitrogen cycle and potentially tackle issues such as groundwater remediation.<\/p>\n

Reactive nitrogen naturally enters the biosphere through nitrogen fixing bacteria or archaea, or occasionally through lightning. Humans add to this process using fertiliser, much of which leaches into watercourses and eventually into oceans. It is usually ultimately removed by anaerobic microbes that convert reactive nitrogen compounds back into either nitrogen gas or less benign species such as nitrous oxide. Quantifying biological dinitrogen production is therefore crucial to understanding Earth\u2019s ecology and human influence on it.<\/p>\n

Detecting biogenic nitrogen signals is exquisitely difficult, however, as Earth\u2019s atmosphere is 78% nitrogen. A common technique involves taking argon<\/a> as an inert reference standard for air and assuming that an increase in the ratio of nitrogen to argon reflects biogenic nitrogen production. However, argon is much more water soluble than nitrogen. \u2018Once you inject bubbles of air into water, it will elevate that ratio just like if you were producing biological N2,\u2019 explains geochemist Jiarui Liu<\/a> of the University of California, Santa Barbara.<\/p>\n

In 2017, researchers led by planetary scientist Edward Young<\/a> at the University of California, Los Angeles used a newly-developed mass spectrometer called Panorama to show that dimers of two rare nitrogen-15 atoms were approximately 2% more common than would be expected by chance in atmospheric dinitrogen.2 Though not fully understood, this is thought to arise from photochemical breaking and reforming of triple bonds in the very high atmosphere. In contrast, isotopic pairing in biogenic dinitrogen is stochastic. The relative abundance of molecules containing two nitrogen-15 atoms therefore provides a reliable isotopic signal of biologically produced dinitrogen.<\/p>\n

In the new work, Young and colleagues investigated this signal at various points on Earth. They were able to detect clear distinctions between the signatures in samples from two midwestern lakes \u2013 an urban one subject to nutrient pollution and a more pristine forested one \u2013 as well as a third, ice-covered one in Antarctica. They also detected the variation throughout the year in coastal basins of California, which are periodically refreshed with oxygen-rich water that suppresses water-column denitrification.<\/p>\n

Only a few laboratories in the world can presently analyse samples with sufficient detail to perform these experiments, and no gas-source mass spectrometer matches the resolution of Panorama. Nevertheless, the researchers believe the technique could potentially have wide ranging implications for questions about whether or not the global nitrogen cycle is in balance. \u2018Basically, the next step is to go out and sample more water to try to reduce the error bar on the loss,\u2019 says Liu. The work could also have more concrete applications, he believes, for more reliable monitoring of nitrate removal in groundwater used for drinking water.<\/p>\n

\u2018It\u2019s a very exciting advance,\u2019 says ecosystem ecologist Peter Groffman<\/a> at City University of New York. \u2018I\u2019ve been chasing around after N2 flux for a very long time and it\u2019s like the world\u2019s greatest contamination problem\u2026 It\u2019s a very clever and exciting advance that would allow us to measure denitrification to N2.\u2019 He wants to see whether it might be applicable to his own work on the even more challenging problem of measuring biogenic nitrogen fluxes in terrestrial environments, although he says \u2018I suspect that\u2019s going to be challenging.\u2019<\/p>\n","protected":false},"excerpt":{"rendered":"A novel technique allowing measurement of biological loss of fixed nitrogen using an unexplained anomaly in atmospheric dinitrogen\u2019s…\n","protected":false},"author":2,"featured_media":930212,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[64,63,128],"class_list":["post-930211","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-au","tag-australia","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/930211","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=930211"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/930211\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/930212"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=930211"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=930211"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=930211"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}