Wave Groups Observed in Pancake Sea Ice

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Thomson, Jim, Gemmrich, Johannes, Rogers, W. Erick, Collins, Clarence O., Ardhuin, Fabrice
• 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 2019
• Subjects: [SDU]Sciences of the Universe [physics]; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Arctic; Pancake; Sea ice
• Online Access: https://insu.hal.science/insu-03683185; https://insu.hal.science/insu-03683185/document; https://insu.hal.science/insu-03683185/file/67763.pdf; https://doi.org/10.1029/2019JC015354

International audience Ocean surface waves propagating through sea ice are scattered and dissipated. The net attenuation occurs preferentially at the higher frequencies, and thus the spectral bandwidth of a given wave field is reduced, relative to open water. The reduction in bandwidth is associated with an increase in the groupiness of the wave field. Using Surface Wave Instrument Float with Tracking buoy data from the 2015 Arctic Sea State experiment, bandwidth is compared between pancake ice and open water conditions, and the linkage to group envelopes is explored. The enhancement of wave groups in ice is consistent with the simple linear mechanism of superposition of waves with narrowing spectral bandwidth. This is confirmed using synthetic data. Nonlinear mechanisms, which have been shown as significant in other ice types, are not found to be important in this data set.