The HAUSGARTEN observatory consists of 21 stations at which, since 1999, abiotic and biotic processes in Fram Strait are being monitored. As the Transpolar Drift continuously transports sea ice from the central Arctic Ocean toward Fram Strait, some stations are covered seasonally or even year-round by closed ice pack. Previous studies have shown that when sea ice is present, it can exert direct or indirect effects on the underlying water column, extending all the way down to the seafloor. In this manuscript, we provide an overview and a more thorough assessment of the sea-ice conditions at the N3-5 and EGI-IV stations, focusing on both seasonal variability and long-term changes in satellite data. The western stations (EGI-IV) show significantly higher ice coverage, whereas the northeastern stations (N3-5) persistently exhibit lower ice concentrations. Somewhat unexpectedly, and in contrast to the rest of the Arctic, sea-ice concentration at these stations shows no significant trends-neither on an annual nor on a monthly timescale. Although no direct changes in ice coverage are apparent, noticeable changes in ice properties do occur. The age of the ice at both locations has declined sharply. Its origin has shifted northward, thereby reducing the proportion of ice formed in shallow-water regions and interrupting the transport of ice-rafted matter from the Siberian shelves towards Fram Strait.
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