Articles | Volume 18, issue 2
02 May 2022
Research article | 02 May 2022
Weakening and warming of the European Slope Current since the late 1990s attributed to basin-scale density changes
Matthew Clark et al.
No articles found.
Paul R. Halloran, Jennifer K. McWhorter, Beatriz Arellano Nava, Robert Marsh, and William Skirving
Geosci. Model Dev., 14, 6177–6195,Short summary
This paper describes the latest version of a simple model for simulating coastal oceanography in response to changes in weather and climate. The latest revision of this model makes scientific improvements but focuses on improvements that allow the model to be run simply at large scales and for long periods of time to explore the implications of (for example) future climate change along large areas of coastline.
Gandy Maria Rosales Quintana, Robert Marsh, and Luis Alfredo Icochea Salas
Ocean Sci., 17, 1385–1402,Short summary
The Equatorial Undercurrent (EUC) is a key influence on upwelling of nutrient-rich waters associated ecosystems off Peru. To quantify this influence, we backtrack upwelling waters in a computer model of ocean currents, annually, over 1989–2007. The EUC influence varies from year to year, dominating in warm El Niño years, when the EUC extends much closer to the Peruvian coast. In other years, more
localupwelling is associated with coastal winds, coincident with major key population shifts.
Emma L. Worthington, Ben I. Moat, David A. Smeed, Jennifer V. Mecking, Robert Marsh, and Gerard D. McCarthy
Ocean Sci., 17, 285–299,Short summary
The RAPID array has observed the Atlantic meridional overturning circulation (AMOC) since 2004, but the AMOC was directly calculated only five times from 1957–2004. Here we create a statistical regression model from RAPID data, relating AMOC changes to density changes within the different water masses at 26° N, and apply it to historical hydrographic data. The resulting 1981–2016 record shows that the AMOC from 2008–2012 was its weakest since the mid-1980s, but it shows no overall decline.
Robert Marsh, Ivan D. Haigh, Stuart A. Cunningham, Mark E. Inall, Marie Porter, and Ben I. Moat
Ocean Sci., 13, 315–335,Short summary
To the west of Britain and Ireland, a strong ocean current follows the steep slope that separates the deep Atlantic and the continental shelf. This “Slope Current” exerts an Atlantic influence on the North Sea and its ecosystems. Using a combination of computer modelling and archived data, we find that the Slope Current weakened over 1988–2007, reducing Atlantic influence on the North Sea, due to a combination of warming of the subpolar North Atlantic and weakening winds to the west of Scotland.
Jason Holt, Patrick Hyder, Mike Ashworth, James Harle, Helene T. Hewitt, Hedong Liu, Adrian L. New, Stephen Pickles, Andrew Porter, Ekaterina Popova, J. Icarus Allen, John Siddorn, and Richard Wood
Geosci. Model Dev., 10, 499–523,Short summary
Accurately representing coastal and shelf seas in global ocean models is one of the grand challenges of Earth system science. Here, we explore what the options are for improving this by exploring what the important physical processes are that need to be represented. We use a simple scale analysis to investigate how large the resulting models would need to be. We then compare this with how computer power is increasing to provide estimates of when this might be feasible in the future.
Heather Cannaby, Matthew D. Palmer, Tom Howard, Lucy Bricheno, Daley Calvert, Justin Krijnen, Richard Wood, Jonathan Tinker, Chris Bunney, James Harle, Andrew Saulter, Clare O'Neill, Clare Bellingham, and Jason Lowe
Ocean Sci., 12, 613–632,Short summary
The Singapore government commissioned a modelling study of regional projections of changes in (i) long-term mean sea level and (ii) the frequency of extreme storm surge and wave events. We find that changes to long-term mean sea level constitute the dominant signal of change to the projected inundation risk for Singapore during the 21st century, these being 0.52 m(0.74 m) under the RCP 4.5(8.5) scenario.
R. Marsh, V. O. Ivchenko, N. Skliris, S. Alderson, G. R. Bigg, G. Madec, A. T. Blaker, Y. Aksenov, B. Sinha, A. C. Coward, J. Le Sommer, N. Merino, and V. B. Zalesny
Geosci. Model Dev., 8, 1547–1562,Short summary
Calved icebergs account for around 50% of total freshwater input to the ocean from the Greenland and Antarctic ice sheets. As they melt, icebergs interact with the ocean. We have developed and tested interactive icebergs in a state-of-the-art global ocean model, showing how sea ice, temperatures, and currents are disturbed by iceberg melting. With this new model capability, we are better prepared to predict how future increases in iceberg numbers might influence the oceans and climate.
J. Holt, C. Schrum, H. Cannaby, U. Daewel, I. Allen, Y. Artioli, L. Bopp, M. Butenschon, B. A. Fach, J. Harle, D. Pushpadas, B. Salihoglu, and S. Wakelin
Revised manuscript not accepted
Beaugrand, G.: The North Sea regime shift: evidence, causes, mechanisms and consequences, Prog. Oceanogr., 60, 245–262, https://doi.org/10.1016/j.pocean.2004.02.018, 2004.
Behringer, D. and Xue, Y.: Evaluation of the global ocean data assimilation system at NCEP: The Pacific Ocean, Eighth Symposium on Integrated Observing and Assimilation Systems for Atmosphere, Oceans and Land Surface, 1–6, AMS 84th Annual Meeting, Washington State Convention and Trade Center, 11–15 January 2004, Seattle, Washington, 2004.
Berx, B., Hansen, B., Østerhus, S., Larsen, K. M., Sherwin, T., and Jochumsen, K.: Combining in situ measurements and altimetry to estimate volume, heat and salt transport variability through the Faroe–Shetland Channel, Ocean Sci., 9, 639–654, https://doi.org/10.5194/os-9-639-2013, 2013.
Blanke, B. and Raynaud, S.: Kinematics of the Pacific Equatorial Undercurrent: An Eulerian and Lagrangian approach from GCM results, J. Phys. Oceanogr., 27, 1038–1053, https://doi.org/10.1175/1520-0485(1997)027<1038:Kotpeu>2.0.Co;2, 1997.
Clark, M., Marsh, R., and Harle, J.: Code for “Weakening and warming of the European Slope Current since the late 1990s attributed to basin-scale density changes”, v2.0.0, Zenodo [code], https://doi.org/10.5281/zenodo.6415360, 2022.
Duchez, A., Frajka-Williams, E., Josey, S. A., Evans, D. G., Grist, J. P., Marsh, R., McCarthy, G. D., Sinha, B., Berry, D. I., and Hirschi, J. J.-M.: Drivers of exceptionally cold North Atlantic Ocean temperatures and their link to the 2015 European heat wave, Environ. Res. Lett., 11, 1–19, https://doi.org/10.1088/1748-9326/11/7/074004, 2016.
Garcia-Soto, C., Pingree, R. D., and Valdes, L.: Navidad development in the southern Bay of Biscay: Climate change and swoddy structure from remote sensing and in situ measurements, J. Geophys. Res.-Oceans, 107, 3118, https://doi.org/10.1029/2001jc001012, 2002.
Hátún, H., Payne, M. R., Beaugrand, G., Reid, P. C., Sando, A. B., Drange, H., Hansen, B., Jacobsen, J. A., and Bloch, D.: Large bio-geographical shifts in the north-eastern Atlantic Ocean: From the subpolar gyre, via plankton, to blue whiting and pilot whales, Prog. Oceanogr., 80, 149–162, https://doi.org/10.1016/j.pocean.2009.03.001, 2009.
Hátún, H., Larsen, K. M. H., Eliasen, S. K., and Mathis, M.: Major Nutrient Fronts in the Northeastern Atlantic: From the Subpolar Gyre to Adjacent Shelves, in: The Handbook of Environmental Chemistry, Springer Berlin Heidelberg, Berlin, Heidelberg, 1–45, https://doi.org/10.1007/698_2021_794 2021.
Holliday, N. P., Bersch, M., Berx, B., Chafik, L., Cunningham, S., Florindo-López, C., Hátún, H., Johns, W., Josey, S. A., Larsen, K. M. H., Mulet, S., Oltmanns, M., Reverdin, G., Rossby, T., Thierry, V., Valdimarsson, H., and Yashayaev, I.: Ocean circulation causes the largest freshening event for 120 years in eastern subpolar North Atlantic, Nature Commun., 11, 585, https://doi.org/10.1038/s41467-020-14474-y, 2020.
Holt, J., Wakelin, S., and Huthnance, J.: Down-welling circulation of the northwest European continental shelf: A driving mechanism for the continental shelf carbon pump, Geophys. Res. Lett., 36, L14602, https://doi.org/10.1029/2009GL038997, 2009.
Holt, J., Polton, J., Huthnance, J., Wakelin, S., O'Dea, E., Harle, J., Yool, A., Artioli, Y., Blackford, J., Siddorn, J., and Inall, M.: Climate-Driven Change in the North Atlantic and Arctic Oceans Can Greatly Reduce the Circulation of the North Sea, Geophys. Res. Lett., 45, 11827–11836, https://doi.org/10.1029/2018gl078878, 2018.
Huthnance, J. M., Holt, J. T., and Wakelin, S. L.: Deep ocean exchange with west-European shelf seas, Ocean Sci., 5, 621–634, https://doi.org/10.5194/os-5-621-2009, 2009.
IOC, SCOR, and IAPSO (Intergovernmental Oceanographic Commission; Scientific Committee on Oceanic Research; International Association for the Physical Sciences of the Oceans): The International thermodynamic equation of seawater – 2010: calculation and use of thermodynamic properties [includes corrections up to 31st October 2015], Paris, France, UNESCO, 196 pp., Intergovernmental Oceanographic Commission Manuals and Guides, 56, https://doi.org/10.25607/OBP-1338, 2015.
Jacobsen, S., Gaard, E., Hátún, H., Steingrund, P., Larsen, K. M. H., Reinert, J., Ólafsdóttir, S. R., Poulsen, M., and Vang, H. B. M.: Environmentally Driven Ecological Fluctuations on the Faroe Shelf Revealed by Fish Juvenile Surveys, Frontiers in Marine Science, 6, 559, https://doi.org/10.3389/fmars.2019.00559, 2019.
Josey, S. A., Hirschi, J. J. M., Sinha, B., Duchez, A., Grist, J. P., and Marsh, R.: The Recent Atlantic Cold Anomaly: Causes, Consequences, and Related Phenomena, Annu. Rev. Mar. Sci., 10, 475–501, https://doi.org/10.1146/annurev-marine-121916-063102, 2018.
Kalnay, E., Kanamitsu, M., Kistler, R., Collins, W., Deaven, D., Gandin, L., Iredell, M., Saha, S., White, G., Woollen, J., Zhu, Y., Chelliah, M., Ebisuzaki, W., Higgins, W., Janowiak, J., Mo, K. C., Ropelewski, C., Wang, J., Leetmaa, A., Reynolds, R., Jenne, R., and Joseph, D.: The NCEP/NCAR 40-Year Reanalysis Project, B. Am. Meteorol. Soc., 77, 437–472, https://doi.org/10.1175/1520-0477(1996)077<0437:Tnyrp>2.0.Co;2, 1996.
Marsh, R., Josey, S. A., de Cuevas, B. A., Redbourn, L. J., and Quartly, G. D.: Mechanisms for recent warming of the North Atlantic: Insights gained with an eddy-permitting model, J. Geophys. Res.-Oceans, 113, C04031, https://doi.org/10.1029/2007JC004096, 2008.
Marsh, R., Haigh, I. D., Cunningham, S. A., Inall, M. E., Porter, M., and Moat, B. I.: Large-scale forcing of the European Slope Current and associated inflows to the North Sea, Ocean Sci., 13, 315–335, https://doi.org/10.5194/os-13-315-2017, 2017.
McQuatters-Gollop, A., Raitsos, D. E., Edwards, M., Pradhan, Y., Mee, L. D., Lavender, S. J., and Attrill, M. J.: A long-term chlorophyll dataset reveals regime shift in North Sea phytoplankton biomass unconnected to nutrient levels, Limnol. Oceanogr., 52, 635–648, https://doi.org/10.4319/lo.2007.52.2.0635, 2007.
Mooney, C.: Why some scientists are worried about a surprisingly cold `blob' in the North Atlantic Ocean, Washington Post, https://www.washingtonpost.com/news/energy-environment/wp/2015/09/24/why-some-scientists-are-worried-about-a-cold-blob-in-the-north-atlantic-ocean/, (last access: 1 March 2022), 2015.
Nishida, T., Kitakado, T., Matsuura, H., and Wang, S.-P.: Validation of the Global Ocean Data Assimilation System (GODAS) data in the NOAA National Centre for Environmental System (NCEP) by theory, comparative studies, applications and sea truth, IOTC 9th WPB meeting, Victoria, Seychelles, IOTC-2011-WPTT13-INF05, 1–18, 2011.
NOAA, E.S.R.L.: NCEP Global Ocean Data Assimilation System (GODAS) at NOAA ESRL/PSD, https://www.esrl.noaa.gov/psd/data/gridded/data.godas.html, last access: January 2019.
Pingree, R.: Ocean structure and climate (Eastern North Atlantic): in situ measurement and remote sensing (altimeter), J. Mar. Biol. Assoc. UK, 82, 681–707, https://doi.org/10.1017/S0025315402006082, 2002.
Porter, M., Inall, M. E., Hopkins, J., Palmer, M. R., Dale, A. C., Aleynik, D., Barth, J. A., Mahaffey, C., and Smeed, D. A.: Glider observations of enhanced deep water upwelling at a shelf break canyon: A mechanism for cross-slope carbon and nutrient exchange, J. Geophys. Res.-Oceans, 121, 7575–7588, https://doi.org/10.1002/2016JC012087, 2016.
The European Slope Current (SC) is a northward-flowing current running parallel to the UK coastline. It is forced by changes in the density gradient of the wider North Atlantic Ocean. As the North Atlantic has warmed since the late 1990s, these gradients have changed strength and moved, reducing the volume and speed of water feeding into the SC. The SC flows into the North Sea, where changes in the species distribution of some plankton and fish have been seen due to the warming inputs.
The European Slope Current (SC) is a northward-flowing current running parallel to the UK...