Heat in the Barents Sea: transport, storage, and surface fluxes

Abstract

A column model is set up for the Barents Sea to explore sensitivity of surface fluxes and heat storage from varying ocean heat transport. Mean monthly ocean transport and atmospheric forcing are synthesised and force the simulations. Results show that by using updated ocean transports of heat and freshwater the vertical mean hydrographic seasonal cycle can be reproduced fairly well.Our results indicate that the ∼70 TW of heat transported to the Barents Sea by ocean currents is lost in the southern Barents Sea as latent, sensible, and long wave radiation, each contributing 23-39 TW to the total heat loss. Solar radiation adds 26 TW in the south, as there is no significant ice production.The northern Barents Sea receives little ocean heat transport. This leads to a mixed layer at the freezing point during winter and significant ice production. There is little net surface heat loss annually in the north. The balance is achieved by a heat loss through long wave radiation all year, removing most of the summer solar heating.During the last decade the Barents Sea has experienced an atmospheric warming and an increased ocean heat transport. The Barents Sea responds to such large changes by adjusting temperature and heat loss. Decreasing the ocean heat transport below 50 TW starts a transition towards Arctic conditions. The heat loss in the Barents Sea depend on the effective area for cooling, and an increased heat transport leads to a spreading of warm water further north.

Dense water formation and circulation in the Barents Sea

“…Based on measurements from 1997-2007 the mean AW inflow is 2.0 Sv, with a maximum of 2.8 Sv in January and an April minimum of 1.1 Sv (Smedsrud et al, 2010). Higher inflow during winter is related to stronger winds due to passing atmospheric lows (Ingvaldsen et al, 2002).…”

“…Warm periods are characterized by higher salinities Levitus et al, 2009), lower ice cover (Vinje, 2009) and higher overall heat loss of the AW throughflow (Smedsrud et al, 2010;Årthun and Schrum, 2010), which all favor CDW formation by general cooling of AW. CDW non-banks is strongly linked to the heat loss in the region of the main AW throughflow (Fig.…”

“…The eastern Barents Sea seems to be a key area with correlation coefficients of 0.6-0.8 and a 15 times increase of CDW transport (from 0.04 to 0.6 Sv) over the region. This area corresponds to the extent of the winter mean 0 • C surface isotherm, indicative of the position of the Polar Front and size of cooling area (Smedsrud et al, 2010). Changes in cooling area are associated with changes in ocean heat transport (Smedsrud et al, 2010), driving large interannual heat loss variability west of Novaya Zemlya (Årthun and Schrum, 2010).…”

Advection in polar and sub-polar environments: Impacts on high latitude marine ecosystems

“…3) include a net inflow into the Barents Sea of $2 Sv (Skagseth et al, 2008;Smedsrud et al, 2010). These waters flow through the Barents Sea, losing heat during transit, and eventually enter the Arctic Basin via the St. Anna Trough (Smedsrud et al, 2010) (Fig. 3).…”

“…These waters originate in the North Atlantic, where winter mixing and convection brings them to the surface. Because they are also warm (Smedsrud et al, 2010), the southern Barents Sea remains ice-free, even in winter, facilitating a long growing season (Hodal and Kristiansen, 2008;Arrigo and Van Dijken, 2011). As a result, the Barents Sea is one of the most productive regions of the Arctic Ocean, both in total primary production and per unit of surface area (Wassmann et al, 2006;Arrigo and Van Dijken, 2011).…”