MULTIDECADAL VARIABILITY IN HIGH-LATITUDE ICE
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Examination of records of fast-ice thickness and ice extent from four arctic marginal seas (Kara, Laptev, East Siberian, and Chukchi) indicates that long-term trends are small and generally statistically insignificant, while trends for shorter records are not indicative of the long-term tendencies due to strong low-frequency variability in these time series, which places a strong limitation on our ability to resolve long-term trends. Ice variability in the arctic marginal-ice zone is dominated by the MDV and, to a lesser degree, by decadal fluctuations. The MDV signal decays eastward, and is strongest in the Kara Sea, whereas in the Chukchi Sea, ice-extent and fast-ice variability is dominated by decadal fluctuations, and there is no evidence of the MDV. This is consistent with the correlation pattern of SAT station data and NAO (last figure in section "Arctic atmosphere"). Adapted from Polyakov et al. 2003b.
Our analysis of potential causes for the recent central Arctic Ocean salinification suggests that ice production and sustained draining of freshwater from the Arctic Ocean in response to winds are the key contributors. Further research is required to provide quantitative estimates of impacts freshwater export and ice production may have on high-latitude freshwater content changes. Adapted from Polyakov et al. 2007.