One more step toward a warmer Arctic

Abstract

This study was motivated by a strong warming signal seen in mooring‐based and oceanographic survey data collected in 2004 in the Eurasian Basin of the Arctic Ocean. The source of this and earlier Arctic Ocean changes lies in interactions between polar and sub‐polar basins. Evidence suggests such changes are abrupt, or pulse‐like, taking the form of propagating anomalies that can be traced to higher‐latitudes. For example, an anomaly found in 2004 in the eastern Eurasian Basin took ∼1.5 years to propagate from the Norwegian Sea to the Fram Strait region, and additional ∼4.5–5 years to reach the Laptev Sea slope. While the causes of the observed changes will require further investigation, our conclusions are consistent with prevailing ideas suggesting the Arctic Ocean is in transition towards a new, warmer state.

Influence of the West Spitsbergen Current on the local climate

“…IOPAS investigations show that the main cause of the increase in northward volume and heat transport was the intensification of the northward currents. The results from the mooring array in Fram Strait confirm that such intensification took place in 2005(Schauer et al, 2008.…”

“…The IOPAS investigation shows that the intense activity of the western WSC branch, especially the great anticyclonic eddies carrying large heat anomalies, was very important as regards the increase in northward transport and raising the AW temperature in 2005(Walczowski and Piechura, 2007. The eddies were much larger than the frontal mesoscale features usually observed (Piechura and Walczowski, 1995).…”

“…The warm anomalies observed in the WSC core move with a mean speed of 3.6 cm/s (Polyakov et al 2005); the mean signal propagation velocity in the western branch is lower, approximately 1.9 cm/s (Walczowski and Piechura, 2007).…”

Relaxation of central Arctic Ocean hydrography to pre‐1990s climatology

“…Lags in water properties occur in part because, even if circulation remained constant, the transit times required to move a changed water property through the basin are measured in years [Polyakov et al, 2005]. For example, a 7-year lag between Atlantic water temperature rise in the Makarov Basin and that initially seen at the North Pole was found by Kikuchi et al [2005].…”

Simulated Response of the Arctic Freshwater Budget to Extreme NAO Wind Forcing

“…Atlantic Water (AW) entering the Arctic via the Barents shelf and West Spitzbergen Current (WSP) have warmed since the early 1990s, producing temperature anomalies in the Nansen Basin of roughly 118C in 2004 (Polyakov et al 2005). The increased penetration of AW caused the cold halocline (CHL) to retreat from the Amundsen Basin to the Makarov Basin in the mid-1990s (Steele and Boyd 1998), although measurements showed that it had returned to the Amundsen Basin in 2001 (Bjö rk et al 2002).…”