Dynamics regulating major trends in Barents Sea temperatures and subsequent effect on remotely sensed particulate inorganic carbon

Abstract

A more comprehensive understanding of how ocean temperatures influence coc colithophorid production of particulate inorganic carbon (PIC) will make it easier to constrain the effect of ocean acidification in the future. We studied the effect of temperature on Emiliania huxleyi PIC production in the Barents Sea using ocean colour remote sensing data. Gross annual PIC production was calculated for 1998−2011 from SeaWiFS and MODIS data and coupled with results from previous studies to create a time-series from 1979−2011. Using that data, we investigated (1) correlations between various climate indices, models and temperature recordings of the Kola transect, and (2) the dynamics of temperature and PIC production. A strong inverse correlation (r 2 = 0.88) was found between the strength of the North Atlantic subpolar gyre (SPG) with a 3 yr lead and major trends in temperatures from the Kola transect. The effect of ocean temperature on PIC production was complex but generally positive, explaining roughly 50% of the annual variability and indicating that rising temperatures in the North Atlantic may favour coccolithophorid PIC production in the Barents Sea. Positive phases of the Atlantic multidecadal oscillation tended to precede PIC blooms by 1 yr.

Increased intrusion of warming Atlantic water leads to rapid expansion of temperate phytoplankton in the Arctic

“…NAC, Norwegian Atlantic Current; WSC, West Spitzbergen Current; NCC, North Cape Current; NZC, Novaya Zemlya Current; PC, Persey Current; ESC, East Spitzbergen Current (after [Harris, Plueddemann, & Gawarkiewicz, 1998]) good proxy for E. huxleyi calcite concentration in the Barents Sea because the coccolithophore population there is of low diversity and overwhelmingly dominated by E. huxleyi (Giraudeau et al, 2016). Furthermore, satellite PIC products have been successfully validated during E. huxleyi blooms in the Barents Sea (Burenkov, Kopelevich, Rat'kova, & Sheberstov, 2011;Giraudeau et al, 2016;Hovland, Dierssen, Ferreira, & Johnsen, 2013) and in other bloom areas (Balch et al, 2005;Holligan et al, 1993). The exclusion of PIC data in shallow coastal waters with bottom depth below 100 m helped minimize spurious high PIC concentrations caused by strong light backscattering from resuspended particles (Broerse et al, 2003) and excluded coastal fjords in which the coccolithophore population is more diverse than in offshore waters (Volent et al, 2011).…”

Multidecadal increase in North Atlantic coccolithophores and the potential role of rising CO 2

“…It has been hypothesized that an "ocean dynamical thermostat" (14) response of the EEP to solar and volcanic forcing induced a cool, La Niñalike mean state during the MCA and a warmer, El Niño-like state during the LIA (6). This hypothesis has found some support in central Pacific corals (15), North American tree rings documenting medieval megadroughts (16), and multiproxy climate field reconstructions (6). In each of these cases, however, direct confirmation from the EEP has been lacking.…”

“…Instead, the Atlantic Multidecadal Oscillation (AMO) becomes the top predictor in this model, and other climate modes [Arctic Oscillation (AO) and Multivariate ENSO Index (MEI)] rise in their ranking relative to RF_LOCAL and RF_GLOBAL, reflecting the importance of interannual variability. Recent studies have linked the AMO with phytoplankton (20) and coccolithophore variability (15). The AMO index tracks temperature anomalies in the North Atlantic, and its positive trend in recent decades could mask global warming or enhance CO 2 effects (Fig.…”

On the Recent Ambiguity of the North Atlantic Subpolar Gyre Index

“…The general aim of EOF analysis is to efficiently extract the most dominant modes of variability from large data sets by decomposing the associated space-time field into spatial patterns and time indices, or principal components (Wilks, 2006). This analysis has been demonstrated to be skillful in capturing the essential dynamics of the subpolar gyre (SPG), which is now recognized to have significant implications for a wide range of climatic (Lohmann et al, 2009a), and ecological (Hátún, Payne, Beaugrand, et al, 2009;Hátún, Payne, & Jacobsen, 2009;Hátún et al, 2016;Hátún, Azetsu-Scott, et al, 2017;Hátún, Olsen, et al, 2017;Hovland et al, 2013;Solmundsson et al, 2010) aspects of the North Atlantic Ocean.…”