Interannual and Decadal Variability of Sea Surface Temperature and Sea Ice Concentration in the Barents Sea

Abstract

Sea ice loss and accelerated warming in the Barents Sea have recently been one of the main concerns of climate research. In this study, we investigated the trends and possible relationships between sea surface temperature (SST), sea ice concentration (SIC), and local and large-scale atmospheric parameters over the last 39 years (1982 to 2020). We examined the interannual and long-term spatiotemporal variability of SST and SIC by performing an empirical orthogonal function (EOF) analysis. The SST warming rate from 1982 through 2020 was 0.35 ± 0.04 °C/decade and 0.40 ± 0.04 °C/decade in the ice-covered and ice-free regions, respectively. This climate warming had a significant impact on sea-ice conditions in the Barents Sea, such as a strong decline in the SIC (−6.52 ± 0.78%/decade) and a shortening of the sea-ice season by about −26.1 ± 7.5 days/decade, resulting in a 3.4-month longer summer ice-free period over the last 39 years. On the interannual and longer-term scales, the Barents Sea has shown strong coherent spatiotemporal variability in both SST and SIC. The temporal evolution of SST and SIC are strongly correlated, whereas the Atlantic Multidecadal Oscillation (AMO) influences the spatiotemporal variability of SST and SIC. The highest spatial variability (i.e., the center of action of the first EOF mode) of SST was observed over the region bounded by the northern and southern polar fronts, which are influenced by both warm Atlantic and cold Arctic waters. The largest SIC variability was found over the northeastern Barents Sea and over the Storbanken and Olga Basin. The second EOF mode revealed a dipole structure with out-of-phase variability between the ice-covered and ice-free regions for the SST and between the Svalbard and Novaya Zemlya regions for SIC. In order to investigate the processes that generate these patterns, a correlation analysis was applied to a set of oceanic (SST) and atmospheric parameters (air temperature, zonal, and meridional wind components) and climate indices. This analysis showed that SST and SIC are highly correlated with air temperature and meridional winds and with two climate indices (AMO and East Atlantic Pattern (EAP)) on an interannual time scale. The North Atlantic Oscillation (NAO) only correlated with the second EOF mode of SST on a decadal time scale.

Response of the copepod community to interannual differences in sea-ice cover and water masses in the northern Barents Sea

“…Since the cold climate period in the late 1970s, the Barents Sea has undergone a warming trend (Bagøien et al, 2020), marked by notable interannual and multidecadal variability, resulting in an overall sea surface temperature increase of about 1.5°C (Mohamed et al, 2022). In this perspective, the two investigated years were both relatively warm years, although on a generally slightly cooling trend since the record warm year 2016 (Bagøien et al, 2020).…”

An emerging pathway of Atlantic Water to the Barents Sea through the Svalbard Archipelago: drivers and variability

“…Over time, the AW presence in Storfjordrenna upstream of the study site has increased. Storfjordrenna is among the locations in the Barents Sea that have experienced the highest increase in sea surface temperature over the recent two decades (Barton et al, 2018;Bayoumy et al, 2022b). The climatological hydrographic maps and transects in Storfjordrenna (Section 3.1)…”

“…Storfjordrenna has had a positive sea surface temperature (SST) trend from 1982 to 2020 and the largest SST increase in the Barents Sea during the period from 1995 to 2007 (Bayoumy et al, 2022b), due to the increased inflow of AW following shallower isobaths than earlier. Following a year of record-low sea ice cover, the surface layers in Storfjorden and Storfjordrenna were replaced by warmer and more saline Arctic Water during summer 2016 (Vivier et al, 2023).…”

Western Barents Sea Circulation and Hydrography, past and present

“…This so-called "Atlantification" has led to increased production and northward expansion of boreal species (Ingvaldsen et al, 2021), and has been strongly correlated with the retreat of the sea ice edge ( Årthun et al, 2012). The sea ice area in the Barents Sea was reduced by 50% between 1998 and 2008, and the sea ice concentration over the ice-covered zone in the Barents Sea has decreased by almost 7% per decade from 1982 through 2020 ( Årthun et al, 2012;Mohamed et al, 2022). However, the position of the PF in the western Barents Sea appears to be unaffected by the sea ice edge and has remained relatively stable, despite an observed increase in the sea surface temperature gradient associated with the PF.…”