Atmospheric Forcing on the Barents Sea Winter Ice Extent

Abstract

The atmospheric forcing on the Barents Sea ice extent during winter [December–February (DJF)] has been investigated for the period 1967–2002. The time series for the sea ice extent is updated and includes the winter of 2005, which marks a new record low in the wintertime Barents Sea ice extent, and a linear trend of −3.5% decade−1 in the ice extent was found. Covariability between the Barents Sea ice extent and the atmospheric mean seasonal flow and the synoptic cyclones has been discussed separately. For the mean flow, linear correlations and regression analysis reveal that anomalous northerly (southerly) winds prevail in the Nordic Seas during winters with extensive (sparse) Barents Sea ice extent. Some of the variability in the mean flow is captured by the North Atlantic Oscillation (NAO); however, the wintertime link between the Barents Sea ice extent and the NAO is moderate. By studying the cyclone activity in the high-latitude Northern Hemisphere using a dataset of individual cyclones, two regions that influence the wintertime Barents Sea ice extent were identified. The variability in the northward-moving cyclones traveling into the Arctic over East Siberia was found to covary strongly with the Barents Sea ice extent. The main mechanism is believed to be the change in the Arctic winds and in ice advection connected to the cyclones. In addition, cyclone activity of northward-moving cyclones over the western Nordic Seas was identified to strongly influence the Barents Sea ice extent. This relationship was particularly strong on decadal time scales and when the ice extent lagged the cyclone variability by 1–2 yr. The lag indicates that the mechanism is related to the cyclones’ ability to modulate the inflow of Atlantic water into the Nordic Seas and the transport time of oceanic heat anomalies from the Nordic Seas into the Barents Sea. Multiple regression indicates that the two mechanisms may explain (or at least covary with) 46% of the wintertime Barents Sea variance over the 1967–2002 period and that 79% of the decadal part of the ice variability may be predicted 2 yr ahead using information about the decadal cyclone variability in the Nordic Seas.

The Arctic Winter Sea Ice Quadrupole Revisited

“…This lends support to the idea that it is the gradient at the interface of the Siberian high that is key in determining the sea ice evolution (discussed further below) and that this regional variability is not necessarily well represented by large-scale metrics such as the Arctic Oscillation. This result is consistent with previous studies that have suggested that local SLP gradients control interannual Barents Sea ice variability (Sorteberg and Kvingedal 2006;Schlichtholz and Houssais 2011;Inoue et al 2012;Herbaut et al 2015) and with studies that have suggested a combined role of both the Aleutian low and Siberian high in driving ice-ocean conditions in the Sea of Okhotsk (e.g., Parkinson 1990;Tachibana et al 1996;Nakanowatari et al 2015, among others).…”

An analytical model for wind-driven Arctic summer sea ice drift

“…Many previous observational analyses provided only statistical connections between the southerly winds and sea ice cover. For example, the strength of southwesterlies over the Barents Sea is well correlated with sea ice cover in winter (Sorteberg and Kvingedal, 2006;Liptak and Strong, 2014), and the development of anomalous southerlies over the Pacific sector of the Arctic is often followed by a reduction of sea ice cover in the spring and summer (Wu et al, 2006;Serreze et al, 2003). We demonstrate that the southerly wind-induced sea ice advection, accelerated by wind-induced surface Ekman flow, can substantially decrease SIC over a timescale of 1 week.…”

Indicator-Based Assessment of Marine Biological Diversity–Lessons from 10 Case Studies across the European Seas

“…Though a progressive northward recovery of kelp forests extent is observed, its recovery status is still partial in northern Norway (Sivertsen, 2006;Rinde et al, 2014). (2) In northernmost part of the Barents sea, sea-ice extent is undergoing a particularly dramatic decrease (Parkinson et al, 1999) with a significant decrease rate of −3.5% per decade of winter ice extent (Sorteberg and Kvingedal, 2006) as a response to climate warming (Boitsov et al, 2014). This dramatic loss of habitat has consequences on the associated communities (Kovacs et al, 2011) as well as in the functioning of the Barents sea ecosystem as a whole (Wassmann et al, 2006).…”