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. Hide

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. Hide

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. Hide

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. Hide

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. Hide

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. Hide

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. Hide

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. Hide

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. Hide

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. Hide

We developed a new method for the determination of dissolved nitric oxide (NO) in discrete seawater samples based on the combination of a purge-and-trap setup and a fluorometric detection of NO. With this method we have a reliable and comparably easy to use method to measure oceanic NO surface concentrations, which can be used to decipher both its temporal and spatial distributions as well as its biogeochemical pathways in the oceans. Hide

Climate models are the best tool available to estimate the ocean’s response to climate change, notably sea level rise. To trust the models, we need to compare them to the real ocean in key areas. Here we do so in the North Atlantic, where deep waters form, and show that inaccurate location, extent and frequency of the formation impact the representation of the global ocean circulation and how much heat enters the Arctic. We also study the causes of the errors in order to improve future models. Hide