The studies on the absorption and fluorescence properties of the organic molecules included in surface microlayer (SML) and subsurface (SS) waters confirm that (i) the process of the structural changes in molecules of HMW to LMW, due to effects of photo- and biodegradation, occurs faster in the SML than in the SS; (ii) the organic molecules contained in the SML have a smaller molecular mass than in the SS. Hence, SML can specifically modify the physical processes associated with the sea surface.

This paper describes a near-surface ocean profiler (NSOP) that is deployed from a research vessel. The NSOP is used to sample the top 10 m of the ocean and pumps water back to the research ship for scientific analyses such as for trace gases. The precision in the depth of the seawater collection improves upon previous methods. The NSOP has been used to observe vertical gradients in the upper 5 m for temperature, carbon dioxide and dimethylsulfide.

Beach evolution analysis can be conducted using GIS methodologies, such as the well-known Digital Shoreline Analysis System (DSAS), in which error assessment based on shoreline positioning plays a significant role. In this study, a new approach is proposed to estimate the positioning errors due to tide and wave run-up influence.

The paper describes a numerical modelling methodology capable of reproducing the hydrodynamics, sediment transport, and morphological evolution of coastal zones under the combined action of waves and currents. The long-term beach response to different designs of coastal defence structures was assessed, as well as the formation of multiple sandbars on the beach slope. The methodology can be applied in engineering studies in order to evaluate the best solution to protect the coast against erosion.

The movable Dutch Maeslant surge barrier closes when the city of Rotterdam is threatened by floods due to a big storm on the North Sea. However, the barrier might get damaged and repair may be needed. The question is what is the probability that a second closure is necessary during the repair time? We solve the problem by using a huge dataset of weather situations that accumulates to more than 6000 years. It is found that two closures within a month occur on average once in every 150 years.

Waves measured at 12 m in the near-shore waters of the Gulf of Mannar for a 1-year period are used to examine the predominance of wind seas and swells through spectral characterization. The waves of the study region are under the control of sea breeze, with the maximum in the late evening and the minimum in the early morning. A total of 53 % of the surface height variance in the study area results from swells from the southeast and south; the remainder are wind seas from the east and southeast.

Sandy beaches are a common landscape feature of the Italian Adriatic coast. From an economic and touristic point of view, the unprotected beach of Senigallia is an important area, frequently monitored in the last decades. The annual evolution of the submerged bars can be related to the climate: waves from the NNE/ESE, characterized by larger/smaller steepness and relative height, induce seaward/shoreward bar migration and bar smoothing/steepening.

Recent Arctic studies suggest that sea-ice decline and permafrost thawing will affect the phytoplankton in the Arctic Ocean. However, in what way the plankton composition will change as the warming proceeds remains elusive. Here we show that the carbon composition of plankton might change as a function of the enhanced terrestrial organic carbon supply and progressive sea-ice thawing.

Studies of the propagation and evolution of the internal tide and development of non-linear internal waves as they cross the continental shelf are presented. Model simulations are based on wave theory, and the results are analyzed and compared with observations during the Coastal Mixing and Optics experiment. These waves are important: they transport momentum and energy, provide energy for vertical mixing, carry nutrients onto the continental shelf and resuspend and moving sediment.

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.

In the north-east Atlantic Ocean, the Bay of Biscay is an intersection between a coastal constrained dynamics (wide continental shelf and shelf break regions) and an eastern boundary circulation system. Based on a 10-year simulation using the coastal ocean model at high resolution (1 km), the interannual variability of small-scale dynamics has been described, implying a potential significant impact on vertical and horizontal mixing in this region.

Six surface drifters were tracked in the inner German Bight for between 9 and 54 days. Corresponding simulations were conducted based on currents from two hydrodynamic models. Effects of including either a direct wind drag or simulated Stokes drift were similar during most of the time. Results suggest that main sources of simulation errors were inaccurate Eulerian currents and lacking representation of sub-grid-scale processes. Substantial model errors often occurred under low wind conditions.

Simulations are used to examine the response of a shallow closed basin to a wind pulse. Features and differences of inertial oscillations and near-inertial internal waves are explored. The horizontal distribution of near-inertial energy is primarily controlled by the boundary effect on inertial oscillations, and the near-inertial internal wave makes a secondary effect. Near-inertial energy is reduced for cases with smaller water depths, due to energy transferred to seiches by barotropic waves.

Motivated by eddy-splitting near Dongsha island, the eddy's trajectory and the effect of topography on eddy evolution were explored using the MITgcm. Warm eddies propagate to the southwest while cold eddies propagate to the northwest in open oceans. The results of the model indicate that the eddy would split in a qualitative range, and the location of the eddy split-off is related to the island size. In addition, eddy-splitting is an important way to transform energy between different scales.