Decorrelation scales for Arctic Ocean hydrography – Part I: Amerasian Basin Ocean Science DOI 10.5194/os-14-161-2018 2 March 2018 We estimated spatial and temporal decorrelation scales of temperature and salinity in the Amerasian Basin in the Arctic Ocean. The estimated scales can be applied to representation error assessment in the ocean data assimilation system for the Arctic Ocean. Read more
Response to Filchner–Ronne Ice Shelf cavity warming in a coupled ocean–ice sheet model – Part 1: The ocean perspective Ocean Science DOI 10.5194/os-13-765-2017 21 September 2017 A coupled model has been developed to study the interaction between the ocean and the Antarctic ice sheet. Simulations for present-day climate yield realistic ice-shelf melt rates and a grounding line position close to the observed state. In a warm-water-inflow scenario, the model suggests a substantial thinning of the ice shelf and a local retreat of the grounding line. The coupled model yields a stronger increase in ice-shelf basal melt rates than a fixed-geometry control experiment. Read more
The double high tide at Port Ellen: Doodson’s criterion revisited Ocean Science DOI 10.5194/os-13-599-2017 20 July 2017 Some places experience double high tides, where the tide starts to ebb for a short while, only to briefly flood again before finally receding. The result is a very long high tide with weak currents, and is important for navigational purposes. The existing theory for when and where double high tides occur does not always capture them, and it can only be applied to double highs occurring on a twice-daily tide. Here, the criterion has been generalized to capture all double high or low tides. Read more
Characteristics and causes of Deep Western Boundary Current transport variability at 34.5∘ S during 2009–2014 Ocean Science DOI 10.5194/os-13-175-2017 2 March 2017 This study investigates the variability of the Deep Western Boundary Current at 34.5° S. This current carries a large part of the cold deep limb of the Meridional Overturning Circulation, which is a crucial part of the ocean system and has impacts on global weather patterns. Study of this current in the South Atlantic has been limited in the past, and this new study provides insights into the strength and variability of the current as well as the causes for the observed changes. Read more
Observed and simulated full-depth ocean heat-content changes for 1970–2005 Ocean Science DOI 10.5194/os-12-925-2016 26 July 2016 A new method of observing ocean heat content throughout the entire ocean depth is provided. The new method is compared with simulated ocean heat content changes from climate models. The comparisons are carried out in various depth layers of the ocean waters. It is found that there is excellent agreement between the models and the observations. Furthermore, we propose that changes to ocean heat content be used as a fundamental metric to evaluate climate models. Read more
Mapping turbulent diffusivity associated with oceanic internal lee waves offshore Costa Rica Ocean Science DOI 10.5194/os-12-601-2016 26 April 2016 Lee waves play a significant role in ocean mixing but are difficult to study with traditional casts, moorings, and tows due to their stationary nature and limited spatial extent. We develop a new method to estimate turbulent diffusivity from seismic data and find elevated levels of turbulence associated with lee waves in the mid-water and around the seafloor that are 5 times greater than surrounding waters and 50 times greater than open-ocean diffusivities. Read more
Changes in extreme regional sea surface height due to an abrupt weakening of the Atlantic meridional overturning circulation Ocean Science DOI 10.5194/os-10-881-2014 7 November 2014 As an extreme scenario of dynamical sea level changes, regional sea surface height (SSH) changes that occur in the North Atlantic due to an abrupt weakening of the Atlantic meridional overturning circulation (AMOC) are simulated. Two versions of the same ocean-only model are used to study the effect of ocean model resolution on these SSH changes. Read more
Weighing the ocean with bottom-pressure sensors: robustness of the ocean mass annual cycle estimate Ocean Science DOI 10.5194/os-10-701-2014 11 August 2014 We use ocean bottom-pressure measurements from 17 tropical sites to determine the annual cycle of ocean mass. We show that such a calculation is robust, and use three methods to estimate errors in the mass determination. Read more
Impact of a 30% reduction in Atlantic meridional overturning during 2009–2010 Ocean Science DOI 10.5194/os-10-683-2014 6 August 2014 The Atlantic meridional overturning circulation comprises warm upper waters flowing northward, becoming colder and denser until they form deep water in the Labrador and Nordic Seas that then returns southward through the North and South Atlantic. We have been monitoring the circulation at 25° N since 2004 and report on the results here. Read more
Sources of 21st century regional sea-level rise along the coast of northwest Europe Ocean Science DOI 10.5194/os-10-473-2014 19 June 2014 There are various contributions to sea level rise, including effects in the solid earth, gravity field, changes in ocean mass due to ice loss from ice sheets and glaciers, thermal expansion, alterations in ocean circulation driven by climate change and changing freshwater fluxes, and the intensity of storm surges. Focusing on the coastline of northwest Europe, we consider these processes and their relative impact on 21st century regional mean sea levels and the 50-year return flood height. Read more
