reprocessed and analysed laser-based readings gathered in 30 years of research flights<\/a> over the Arctic ice.<\/p>\nThe survey flights, which cover a total distance of roughly 76,000 kilometres, show for the first time that the frequency of Arctic pressure ridges north of Greenland and in Fram Strait is decreasing by 12.2% and their height by 5% per decade.<\/p>\n
Data from the Lincoln Sea, an area where particularly old ice is known to accumulate, paints a similar picture. Here, the frequency is declining by 14.9% and the height by 10.4% per decade.<\/p>\n
\u201cUntil now, it\u2019s remained unclear how pressure ridges were changing,\u201d explained Dr Thomas Krumpen, a sea-ice expert at the AWI and the study\u2019s main author.<\/p>\n
\u201cMore and more of the Arctic consists of ice that melts in the summer and is no more than a year old. This young, thin ice can more readily be deformed and more rapidly forms new pressure ridges.\u201d<\/p>\n
He continued: \u201cThe fact that pressure ridges are nonetheless in decline is due to the dramatic melting of older floes.<\/p>\n
\u201cThe loss of this multiyear ice is so severe that we\u2019re observing an overall decline in pressure-ridge frequency, even though the thin young ice is easier to deform.\u201d<\/p>\n
How the changes affect the overall Arctic ecosystem<\/h3>\n To draw conclusions regarding Arctic-wide changes, the researchers combined all observational data to develop a metric. Then, with the aid of satellite data, they applied it to the Arctic as a whole.<\/p>\n
However, to estimate the direct effects of the observed changes on the Arctic ecosystem, models need to be developed to reflect both physical and biological processes in sea ice of various ages.<\/p>\n
Although we know that pressure ridges are home to a range of organisms, we still lack a deeper understanding of the role of pressure-ridge age.<\/p>\n
Yet this aspect is especially important, as the percentage of ridges that don\u2019t survive their first summer is on the rise.<\/p>\n
AWI sea-ice physicist Dr Luisa von Albedyll, who contributed to the study, said: \u201cActually, the ice should drift more slowly when the sails shrink since there\u2019s less area for the transfer of momentum.<\/p>\n
\u201cThis indicates that other changes are producing just the opposite effect. Stronger ocean currents or a smoother ice underside due to more intensive melting could be contributing factors.<\/p>\n
She concluded: \u201cTo answer these open questions and gain a better grasp of the complex interrelationships, we have made the entire dataset available in a public archive, ensuring that other researchers can use it and integrate it into their studies.\u201d<\/p>\n
Future areas for research<\/h3>\n An expedition with the research vessel Polarstern is planned for next summer, focusing on investigating the biological and biogeochemical differences between floes and Arctic pressure ridges of different ages and provenances.<\/p>\n
At the same time, there will be extensive aerial survey flights with the research aircraft.<\/p>\n
According to Krumpen, the combination of observations will provide better insights into the complex interactions between the sea ice, climate and ecosystem.<\/p>\n","protected":false},"excerpt":{"rendered":"
Across the Arctic, multiyear ice is increasingly melting, dramatically reducing the frequency and size of Arctic pressure ridges.<\/p>\n","protected":false},"author":22,"featured_media":54296,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[24433],"tags":[689,24549],"acf":[],"yoast_head":"\n
Detailed aerial data marks decrease in Arctic pressure ridges<\/title>\n \n \n \n \n \n \n \n \n \n \n \n \n\t \n\t \n\t \n \n \n \n \n \n\t \n\t \n\t \n