Thin ice and storms: Sea ice deformation from buoy arrays deployed during N-ICE2015

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Itkin, Polona, Spreen, Gunnar, Cheng, Bin, Doble, Martin, Girard-Ardhuin, Fanny, Haapala, Jari, Hughes, Nick, Kaleschke, Lars, Nicolaus, Marcel, Wilkinson, Jeremy
• Other Authors: Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: sea ice; Arctic; [SDU]Sciences of the Universe [physics]; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Svalbard; Arctic Basin; Sea ice
• Online Access: https://insu.hal.science/insu-03682746; https://insu.hal.science/insu-03682746/document; https://insu.hal.science/insu-03682746/file/JGR%20Oceans%20-%202017%20-%20Itkin%20-%20Thin%20ice%20and%20storms%20Sea%20ice%20deformation%20from%20buoy%20arrays%20deployed%20during%20N%25u2010ICE2015.pdf; https://doi.org/10.1002/2016JC012403

International audience Arctic sea ice has displayed significant thinning as well as an increase in drift speed in recent years. Taken together this suggests an associated rise in sea ice deformation rate. A winter and spring expedition to the sea ice covered region north of Svalbard-the Norwegian young sea ICE2015 expedition (N-ICE2015)—gave an opportunity to deploy extensive buoy arrays and to monitor the deformation of the first-year and second-year ice now common in the majority of the Arctic Basin. During the 5 month long expedition, the ice cover underwent several strong deformation events, including a powerful storm in early February that damaged the ice cover irreversibly. The values of total deformation measured during N-ICE2015 exceed previously measured values in the Arctic Basin at similar scales: At 100 km scale, N-ICE2015 values averaged above 0.1 d -1 , compared to rates of 0.08 d -1 or less for previous buoy arrays. The exponent of the power law between the deformation length scale and total deformation developed over the season from 0.37 to 0.54 with an abrupt increase immediately after the early February storm, indicating a weakened ice cover with more free drift of the sea ice floes. Our results point to a general increase in deformation associated with the younger and thinner Arctic sea ice and to a potentially destructive role of winter storms.