{"id":4320,"date":"2022-10-11T09:00:53","date_gmt":"2022-10-11T07:00:53","guid":{"rendered":"https:\/\/nersc.no\/?p=4320"},"modified":"2023-11-22T09:28:53","modified_gmt":"2023-11-22T08:28:53","slug":"the-secrets-of-one-of-the-worlds-most-advanced-sea-ice-models","status":"publish","type":"post","link":"https:\/\/nersc.no\/en\/features\/the-secrets-of-one-of-the-worlds-most-advanced-sea-ice-models\/","title":{"rendered":"The secrets of one of the world\u2019s most advanced sea-ice models"},"content":{"rendered":"

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The secrets of one of the world\u2019s most advanced sea-ice models<\/h1><\/div>[vc_column_text]<\/p>\n

Researchers from the Nansen Center and colleagues in France, Germany, and Mali have improved how to simulate sea-ice movement in the Arctic. Their sea-ice model neXtSIM with a new and unique rheology is very good at producing accurate sea-ice forecasts and can possibly enhance climate predictions.\u00a0 <\/strong><\/h3>\n

Are you wondering now what \u201crheology\u201d means? Don\u2019t worry, we\u2019ll get to that. But first, let\u2019s start with sea-ice modelling and what it is good for. Researchers use computer models to investigate how sea ice in nature behaves, both in the past, the present, and the future. To do that, they use mathematical formulas to recreate processes as close to reality as feasible. This way they can for example\u00a0forecast sea-ice conditions such as thickness and extent for the upcoming days<\/strong>\u00a0(short time scales) or\u00a0predict how fast the ice will melt with a warming climate\u00a0<\/strong>(long time scales). Since the Arctic is warming much faster than the rest of the planet, scientists are extremely interested in what goes on there, both right now, and in the future.<\/p>\n

Sea-ice conditions are important for human activities in the Arctic, such as shipping, fishing, tourism, and research. The position of the sea-ice edge also has important implications for life in the ocean \u2013 along the ice edge, animals find a lot of food that is otherwise scarce. And more reliable climate predictions for the coming years are necessary to develop efforts for effectively adapting to climate change.\u00a0To be able to forecast how the sea ice will behave on short and longer timescales is therefore relevant on different levels.<\/strong><\/p>\n

The sea-ice model neXtSIM has been developed over the past years by researchers at NERSC in collaboration with researchers from France, to produce the best sea-ice forecasts and to improve climate predictions involving sea ice. It is functioning really well now, and its latest modifications are introduced in the recent article \u201cA new brittle rheology and numerical framework for large-scale sea-ice models\u201d. neXtSIM is already producing forecasts available to everyone with the new rheology 10 days ahead of time, benefitting people operating in the Arctic Ocean.\u00a0But how do researchers generally get a model to simulate the ice movement correctly?<\/strong><\/p>\n

In the Arctic winds and ocean currents act on sea ice, and the ice reacts to these forces. The study of how materials deform and move in response to a force is called rheology, the word originates from Greek and translates to \u201cstudy of flow\u201d.\u00a0In sea-ice models, the rheology is a description with mathematical formulas of how sea ice responds to winds and ocean currents.<\/strong><\/p>\n

Different sea-ice models use different formulas (rheologies) to define the sea-ice response to winds and ocean currents. Many simulate sea ice like something soft, but we know that it cracks in a brittle way when responding to force. All mathematical descriptions of sea-ice rheology have some kind of flaw, and the researchers at the Nansen Center and other institutions involved in developing the sea-ice model neXtSIM have been using the so-called Maxwell-Elasto-Brittle rheology in the past years. It performed well on short time scales, but they were not satisfied with its performance when predicting changes over multiple years.\u00a0So, they investigated how to modify this specific rheology to make neXtSIM produce even better short- and long-term forecasts.\u00a0\u00a0<\/strong><\/p>\n

Interestingly, rocks and sea ice break in a very similar way, and researchers in France developed a sea-ice rheology based on rock mechanics. The sea-ice modelling team at the Nansen Center implemented it in neXtSIM, and the team around Einar \u00d3lason recently further improved that rheology. Extensive testing has gone well: neXtSIM-produced sea-ice forecasts and actual satellite images of the Arctic show the same features. The model is now able to simulate nature as closely as currently possible.<\/strong><\/p>\n

\u00d3lason and his colleagues have recently published a paper on the new rheology, which they call the brittle Bingham-Maxwell rheology. This new rheology is the last step in the chain from rock mechanics models to a full-scale sea-ice model. It includes a way to include damage propagation: When a crack forms in sea ice, it freezes over and is pushed shut again, but this former line is more prone to breaking again, because the ice is weaker along it. Including formulas for this allows our researchers to\u00a0represent deformation happening to the Arctic sea ice on small and large scales,<\/strong>\u00a0from hundreds of kilometers down to kilometers, or even meters. This means that cracks in the sea ice can be simulated reliably, and the forecasts produced with neXtSIM are generally better than forecasts produced with other sea-ice models.\u00a0Better simulation of the cracks gives a better representation of atmosphere-ocean-ice interaction in the model, which will hopefully lead to more reliable climate predictions.<\/strong>[\/vc_column_text][vc_row_inner][vc_column_inner width=”2\/3″]

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\n\t\t\t\t\"\"\n\t\t\t\t\n\t\t\t<\/figure>[\/vc_column_inner][vc_column_inner width=”1\/3″][vc_column_text]Sea ice breaks in distinctive patterns that span the entire Arctic \u2013 known as Linear Kinematic Features (LKFs). This image shows the shear (difference in motion on either side of a crack) as observed by satellite (left), simulated by the new rheology (centre), and simulated by a more traditional rheology (right). Image from \u201cA new brittle rheology and numerical framework for large-scale sea-ice models\u201d, CC BY-NC-ND 4.0.[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_column_text]The authors Einar \u00d3lason, Guillaume Boutin, Anton Korosov, Pierre Rampal, and Timothy Williams from the Nansen Center have been part of the Nansen Legacy project<\/a>. This paper constitutes one of their most important contributions to the project. Einar \u00d3lason on the recent article, Nansen Legacy, and neXtSIM: \u201cWe went into the Nansen Legacy project wanting to demonstrate how the rheology we were using in neXtSIM would give us insights into atmosphere-ocean-ice interactions \u2013 only to find out that the rheology itself wasn\u2019t good enough. With this latest work, we\u2019ve addressed that problem and we now understand the processes better and we have a powerful new tool at our disposal to address the questions we originally posed. This is emblematic of cutting-edge research, where you think you understand what is going on, only to be proven wrong by your next result. It\u2019s this constant discovery that makes the work so fascinating!\u201d\u00a0<\/em>[\/vc_column_text][vc_row_inner][vc_column_inner width=”2\/3″]
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\n\t\t\t\t\"\"\n\t\t\t\t\n\t\t\t<\/figure>[\/vc_column_inner][vc_column_inner width=”1\/3″][vc_column_text]Researchers in the Nansen Legacy project work both on the ice in the Arctic and in offices across the country. They all have the same goal: to find out as much as possible about the changing Arctic. Credit: Nansen Legacy\/Andreas Wolden[\/vc_column_text][\/vc_column_inner][\/vc_row_inner]\n \n
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Om Nansen Legacy – Arven etter Nansen<\/h1>\n

Arven etter Nansen er et unikt og holistisk forskningsprosjekt som vil levere integrert vitenskapelig kunnskap om et marint klima og \u00f8kosystem i rask endring. En ny kunnskapsbase er n\u00f8dvendig for \u00e5 legge til rette for en b\u00e6rekraftig forvaltning av det nordlige Barentshavet og det tilgrensende Polhavet gjennom det 21. \u00e5rhundret.<\/p>\n

Mer informasjon om prosjektet finner du her<\/a>.<\/p><\/div>

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Publikasjon<\/h1>\n

Journal of Advances in Modeling Earth Systems:<\/strong>
\n“A new brittle rheology and numerical framework for large-scale sea-ice models”<\/p>

Les artikkelen\"Pil<\/a><\/p><\/div>[\/vc_column][\/vc_row][vc_row][vc_column][\/vc_column][\/vc_row]<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

[vc_row][vc_column width=”2\/3″ css=”.vc_custom_1693479579188{background-color: #ffffff !important;}”][vc_column_text] Researchers from the Nansen Center and colleagues in France, Germany, and Mali have improved how to simulate sea-ice movement in the Arctic. Their sea-ice model neXtSIM with a new and unique rheology is very good at producing accurate sea-ice forecasts and can possibly enhance climate predictions.\u00a0 Are you wondering now […]<\/p>\n","protected":false},"author":4,"featured_media":2913,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_relevanssi_hide_post":"","_relevanssi_hide_content":"","_relevanssi_pin_for_all":"","_relevanssi_pin_keywords":"","_relevanssi_unpin_keywords":"","_relevanssi_related_keywords":"","_relevanssi_related_include_ids":"","_relevanssi_related_exclude_ids":"","_relevanssi_related_no_append":"","_relevanssi_related_not_related":"","_relevanssi_related_posts":"","_relevanssi_noindex_reason":"","footnotes":""},"categories":[80],"tags":[],"class_list":["post-4320","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-features"],"acf":[],"publishpress_future_action":{"enabled":false,"date":"2026-04-26 15:49:01","action":"change-status","newStatus":"draft","terms":[],"taxonomy":"category","extraData":[]},"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/posts\/4320","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/comments?post=4320"}],"version-history":[{"count":2,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/posts\/4320\/revisions"}],"predecessor-version":[{"id":5979,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/posts\/4320\/revisions\/5979"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/media\/2913"}],"wp:attachment":[{"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/media?parent=4320"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/categories?post=4320"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nersc.no\/en\/wp-json\/wp\/v2\/tags?post=4320"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}