During recent decades, historically unprecedented changes have been observed in the Arctic as climate warming has increased precipitation, river discharge, and glacial as well as sea-ice melting. Additionally, shifts in the Arctic’s atmospheric pressure field have altered surface winds, ocean circulation, and freshwater storage in the Beaufort Gyre. These processes have resulted in variable patterns of freshwater export from the Arctic Ocean, including the emergence of great salinity anomalies propagating throughout the North Atlantic. Here, we link these variable patterns of freshwater export from the Arctic Ocean to the regime shifts observed in Northwest Atlantic shelf ecosystems. Specifically, we hypothesize that the corresponding salinity anomalies, both negative and positive, alter the timing and extent of water-column stratification, thereby impacting the production and seasonal cycles of phytoplankton, zooplankton, and higher-trophic-level consumers. Should this hypothesis hold up to critical evaluation, it has the potential to fundamentally alter our current understanding of the processes forcing the dynamics of Northwest Atlantic shelf ecosystems.

MERCINA Working Group. 2012. Recent Arctic climate change and its remote forcing of Northwest Atlantic shelf ecosystems. Oceanography 25(3):208–213, https://doi.org/10.5670/oceanog.2012.64.

Technical Notes (316 MB pdf)

Belkin, I.M. 2004. Propagation of the “Great Salinity Anomaly” of the 1990s around the northern North Atlantic. Geophysical Research Letters 31, L08306, https://doi.org/10.1029/2003GL019334.

Belkin, I.M., S. Levitus, J. Antonov, and S.-A. Malmberg. 1998. “Great Salinity Anomalies” in the North Atlantic. Progress in Oceanography 41:1–68, https://doi.org/10.1016/S0079-6611(98)00015-9.

Bisagni, J.J., H.-S. Kim, and A. Chaudhuri. 2009. Interannual variability of the shelf-slope front position between 75° and 50°W. Journal of Marine Systems 78: 337–350, https://doi.org/10.1016/j.jmarsys.2008.11.020.

Dickson, R.R. 1999. All change in the Arctic. Nature 397:389–391, https://doi.org/10.1038/17018.

Dukhovskoy, D., M. Johnson, and A. Proshutinsky. 2006. Arctic decadal variability from an idealized atmosphere-ice-ocean model: Simulation of decadal oscillations. Journal of Geophysical Research 111, C06029, https://doi.org/10.1029/2004JC002820.

Frank, K.T., B. Petrie, J.S. Choi, and W.C. Leggett. 2005. Trophic cascades in a formerly cod-dominated ecosystem. Science 308:1,621–1,623, https://doi.org/10.1126/science.1113075.

Frank, K.T., B. Petrie, J.A.D. Fisher, and W.C. Leggett. 2011. Transient dynamics of an altered large marine ecosystem. Nature 477:86–89, https://doi.org/10.1038/nature10285.

Giles, K.A., S.W. Laxon, A.L. Ridout, D.J. Wingham, and S. Bacon. 2012. Western Arctic Ocean freshwater storage increased by wind-driven spin-up of the Beaufort Gyre. Nature Geoscience 5:194–197, https://doi.org/10.1038/ngeo1379.

Greene, C.H., B.C. Monger, and L.P. McGarry. 2009. Some like it cold. Science 324:733–734, https://doi.org/10.1126/science.1173951.

Greene, C.H., and A.J. Pershing. 2007. Climate drives sea change. Science 315:1,084–1,085, https://doi.org/10.1126/science.1136495.

Greene, C.H., A.J. Pershing, T.M. Cronin, and N. Cecci. 2008. Arctic climate change and its impacts on the ecology of the North Atlantic. Ecology 89:S24–S38, https://doi.org/10.1890/07-0550.1.

Hakkinen, S. 2002. Freshening of the Labrador Sea surface waters in the 1990’s: Another great salinity anomaly? Geophysical Research Letters 29(24):2,232, https://doi.org/10.1029/2002GL015243.

Koenigk, T., U. Mikolajewicz, H. Haak, and J. Jungclaus. 2007. Arctic freshwater export in the 20th and 21st centuries. Journal of Geophysical Research 112, G04S41, https://doi.org/10.1029/2006JG000274.

Loder, J.W., J.A. Shore, C.G. Hannah, and B.D. Petrie. 2001. Decadal-scale hydrographic and circulation variability in the Scotia-Maine region. Deep-Sea Research Part II 48:3–35, https://doi.org/10.1016/S0967-0645(00)00080-1.

McLaughlin, F., E. Carmack, A. Proshutinsky, R.A. Krishfield, C. Guay, M. Yamamoto-Kawai, J.M. Jackson, and B. Williams. 2011. The rapid response of the Canada Basin to climate forcing: From bellwether to alarm bells. Oceanography 24(3):146–159, https://doi.org/10.5670/oceanog.2011.66.

McPhee, M.G., A. Proshutinsky, J.H. Morison, M. Steele, and M.B. Alkire. 2009. Rapid change in freshwater content of the Arctic Ocean. Geophysical Research Letters 36, L10602, https://doi.org/10.1029/2009GL037525.

Morison, J., R. Kwok, C. Peralta-Ferriz, M. Alkire, I. Rigor, R. Andersen, and M. Steele. 2012. Changing Arctic Ocean freshwater pathways. Nature 481:66–69, https://doi.org/10.1038/nature10705.

Mountain, D.G. 2003. Variability in the properties of Shelf Water in the Middle Atlantic Bight, 1977–1999. Journal of Geophysical Research 108(C1), 3014, https://doi.org/10.1029/2001JC001044.

Overland, J.E. 2011. Potential Arctic change through climate amplification processes. Oceanography 24(3):176–185, https://doi.org/10.5670/oceanog.2011.70.

Overland, J.E., and M. Wang. 2010. Large-scale atmospheric changes are associated with the recent loss of Arctic sea ice. Tellus 62A:1–9, https://doi.org/10.1111/j.1600-0870.2009.00421.x.

Pershing, A.J., C.H. Greene, J.W. Jossi, L. O’Brien, J.K.T. Brodziak, and B.A. Bailey. 2005. Interdecadal variability in the Gulf of Maine zooplankton community with potential impacts on fish recruitment. ICES Journal of Marine Science 62:1,511–1,523, https://doi.org/10.1016/j.icesjms.2005.04.025.

Proshutinsky, A.Y., and M.A. Johnson. 1997. Two circulation regimes of the wind-driven Arctic Ocean. Journal of Geophysical Research 102:12,493–12,514, https://doi.org/10.1029/97JC00738.

Proshutinsky, A., R. Krishfield, M.-L. Timmermans, J. Toole, E. Carmack, F. McLaughlin, W.J. Williams, S. Zimmermann, M. Itoh, and K. Shimada. 2009. Beaufort Gyre freshwater reservoir: State and variability from observations. Journal of Geophysical Research 114, C00A10, https://doi.org/10.1029/2008JC005104.

Proshutinsky A., M.-L. Timmermans, I. Ashik, A. Beszczynska-Moeller, E. Carmack, I. Frolov, R. Krishfield, F. McLaughlin, J. Morison, I. Polyakov, and others. 2011. The Arctic: Ocean. Pp. S145–S148 in State of the Climate in 2010. J. Blunden, D.S. Arndt, and M.O. Baringer, eds, Bulletin of the American Meteorological Society 92(6).

Rabe, B., M. Karcher, U. Schauer, J. Toole, R. Krishfield, S. Pisarev, F. Kauker, R. Gerdes, and T. Kikuchi. 2011. An assessment of Arctic Ocean freshwater content changes from the 1990s to the 2006–2008 period. Deep-Sea Research Part I 58:173–185, https://doi.org/10.1016/j.dsr.2010.12.002.

Rodionov, S.N. 2004. A sequential algorithm for testing climate regime shifts. Geophysical Research Letters 31, L09204, https://doi.org/10.1029/2004GL019448.

Shindell, D. 2003. Whither Arctic climate? Science 299:215–216, https://doi.org/10.1126/science.1080855.

Smith, P.C., R.W. Houghton, R.G. Fairbanks, and D.G. Mountain. 2001. Interannual variability of boundary fluxes and water mass properties in the Gulf of Maine and on Georges Bank: 1993–1997. Deep-Sea Research Part II 48:37–70, https://doi.org/10.1016/S0967-0645(00)00081-3.

Steele, M., J. Morison, W. Ermold, I. Rigor, M. Ortmeyer, and K. Shimada. 2004. Circulation of summer Pacific halocline water in the Arctic Ocean. Journal of Geophysical Research 109, C02027, https://doi.org/10.1029/2003JC002009.

Sundby, S., and K. Drinkwater. 2007. On the mechanisms behind salinity anomaly signals of the northern North Atlantic. Progress in Oceanography 73:190–202, https://doi.org/10.1016/j.pocean.2007.02.002.

Thompson, D.J.W., and J.M. Wallace. 1998. The Arctic Oscillation signature in the wintertime geopotential height and temperature fields. Geophysical Research Letters 25:1,297–1,300, https://doi.org/10.1029/98GL00950.

Timmermans, M.-L., A. Proshutinsky, R.A. Krishfield, D.K. Perovich, J.A. Richter-Menge, T.P. Stanton, and J.M. Toole. 2011. Surface freshening in the Arctic Ocean’s Eurasian Basin: An apparent consequence of recent change in the wind-driven circulation. Journal of Geophysical Research 116, C00D03, https://doi.org/10.1029/2011JC006975.

Wang, J., J. Zhang, E. Watanabe, K. Mizobata, M. Ikeda, J.E. Walsh, X. Bai, and B. Wu. 2009. Is the Dipole Anomaly a major driver to record lows in the Arctic sea ice extent? Geophysical Research Letters 36, L05706, https://doi.org/10.1029/2008GL036706.

Wu, B., J. Wang, and J.E. Walsh. 2006. Dipole Anomaly in the winter Arctic atmosphere and its association with sea ice motion. Journal of Climate 19:210–225, https://doi.org/10.1175/JCLI3619.1.

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