This paper makes use of historic tide gauge measurements at Port Louis in the Falkland Islands made by James Clark Ross in 1842 to see whether there have been long-term changes in the ocean tide at that location. The conclusion is that there is no evidence for any significant change, which contrasts with tide gauge findings from other parts of the world over similar timescales.

In the northwestern Barents Sea, we study the Barents Sea Polar Front formed by Atlantic Water meeting Polar Water. Analyses of ship and glider data from October 2020 to February 2021 show a density front with warm, salty water intruding under cold, fresh water. Short-term variability is linked to tidal currents and mesoscale eddies, influencing front position, density slopes and water mass transformation. Despite seasonal changes in the upper layers, the front remains stable below 100 m depth.

A long-term mooring array in the Fram Strait allows for an evaluation of decadal trends in temperature in this major oceanic gateway into the Arctic. Since the 1980s, the deep waters of the Greenland Sea and the Eurasian Basin of the Arctic have warmed rapidly at a rate of 0.11°C and 0.05°C per decade, respectively, at a depth of 2500 m. We show that the temperatures of the two basins converged around 2017 and that the deep waters of the Greenland Sea are now a heat source for the Arctic Ocean.

In this study, we explored how water accumulates in a coastal estuary, a key factor affecting the estuary's environmental health and ecosystem. We revealed significant bottom accumulations influenced by plume fronts and velocity convergence, with notable seasonal variability. By analyzing trajectories, we identified subregions with distinct accumulation patterns and examined their interconnections, highlighting the substantial impact of tides and river discharge on these dynamics.

A unique dataset of glider observations reveals tidal beams south of New Caledonia – an internal-tide-generation hot spot in the southwestern tropical Pacific. Observations are in good agreement with numerical modeling output, highlighting the glider's capability to infer internal tides while assessing the model's realism of internal-tide dynamics. Discrepancies are in large part linked to eddy–internal-tide interactions. A methodology is proposed to deduce the internal-tide surface signature.

In applications related to search and rescue or pollution mitigation, gaining insights into turbulent processes at a fine scale on the ocean surface is crucial. This research suggests combining numerical model outputs with Lagrangian drifter measurements to enhance the reconstruction of surface current velocity fields. The findings demonstrate a notable enhancement (approximately 50 %) in the model's ability to replicate the movement of passive tracers in the Dover Strait.

Atlantic water (AW) is a key driver of change in the Barents Sea. We studied an emerging pathway through the Svalbard Archipelago that allows AW to enter the Barents Sea. We found that the Atlantic sector near the study site has warmed over the past 2 decades; that Atlantic-origin waters intermittently enter the Barents Sea through the aforementioned pathway; and that heat transport is driven by tides, wind events, and variations in the upstream current system.

Ocean dynamics result from the interplay of internal processes and external inputs, primarily from the atmosphere. It is crucial to discern between these factors to gauge the ocean's intrinsic predictability and to be able to attribute a signal under study to either external factors or internal variability. Employing a simple analysis, we successfully characterized this variability in the Mediterranean Sea and compared it with the oceanic response induced by atmospheric conditions.

In summer, deep, cold waters rise to the surface along and off the Vietnamese coast. This upwelling of water lifts nutrients, inducing biological activity that is important for fishery resources. Strong tides occur on the shelf off the Mekong Delta. By increasing the mixing of ocean waters and modifying currents, they are a major factor in the development of upwelling on the shelf, accounting for ~75 % of its average summer intensity.

Sea surface temperature (SST) is an essential variable to understanding the Earth's climate system, and its accurate monitoring from space is essential. Since satellite measurements are hindered by cloudy/rainy conditions, data gaps are present even in merged multi-sensor products. Since optimal interpolation techniques tend to smooth out small-scale features, we developed a deep learning model to enhance the effective resolution of gap-free SST images over the Mediterranean Sea to address this.

Tides in the Mediterranean Sea are typically of low amplitude, but twin experiments with and without tides demonstrate that tides affect the circulation directly at scales away from those of the tides. Analysis of the energy changes due to tides shows that they enhance existing oscillations, and internal tides interact with other internal waves. Tides also increase the mixed layer depth and enhance deep water formation in key regions. Internal tides are widespread in the Mediterranean Sea.

We evaluate the eastern equatorial Atlantic's (EEA's) seasonal cycle and interannual variability in the Ocean Model Intercomparison Project Phases 1 and 2 (OMIP1 and OMIP2) for 1985–2004. While both simulate EEA patterns, biases like a diffusive thermocline and insufficient cooling exist during the development of the Atlantic cold tongue. OMIP1 exhibits 51% (33%) larger interannual sea surface temperature (sea surface height) variability than OMIP2, attributed to differences in wind forcing.