Wave climate analysis in the ice-free waters of Kara Sea

Abstract

Sea surface waves in the Kara Sea can vigorously generate and grow owing to the increasing ice cover reduction in recent years. This study aims to quantitatively determine the wave climate in the ice-free waters of Kara Sea based on the ECMWF ERA-Interim dataset. Wave parameters, such as the mean and extreme significant wave heights (SWH), periods (MWP), and their trends, roses and co-occurrences are adequately investigated. The optimal years from 2005 to 2018 are chosen when the summer ice-free extent continuously maintains at the maximum. Results reveal that the SWH and MWP are slightly higher in September than in August. The largest waves predominantly occur in the zone of 77∘N-79∘N and 67∘E-80∘E. The temporal linear trends of SWH and MWP are estimated but not statistically significant in most zones. The mean SWH and MWP remain stable with small fluctuations, while the extreme ones show a noticeable interannual variation. In addition, roses of SWH and MWP indicate that in the northern zone directions from SSW to NNW are predominant, while in the southern zone ones from NW to NE are prevalent. Moreover, the co-occurrences of simultaneous SWH and MWP are put forward. The SWH of 0.5–2.5 m with MWP of 4–7 s largely occur in the northern zone, while the SWH of 0.5–2 m with MWP of 3–6 s mainly appear in the southern zone.