Sea water thermodynamics is arguably one of the most central and fundamental areas concerning oceanography: how should we measure/interpret something as basic as temperature, salinity, heat and/or energy of sea water? The review is a tour de force by one of the leading experts of the subject area, summarising the development of sea water thermodynamics to date (spanning the author's career), highlights important subtleties that oceanographers should know, and provides interesting outlooks for further directions for investigation. Make no mistake, the review is by no means an easy or a short read, and the material will require time and effort to digest properly. This is likely one of those journeys where there simply is no shortcut, but this is an excellent guide to help those willing to undertake that journey.

Warm-core eddies detached from the Loop Current play a crucial role in transporting substantial heat from the Caribbean to the Gulf of Mexico. Using satellite altimetric observations, the drivers of the detachment and separation of Loop Current eddies were revealed. A notably elongated Loop Current and the intensified presence of cyclonic eddies west of the Florida Shelf are key factors in the process of eddy detachment. Conversely, for the separation of these eddies, it is crucial that intensified cyclonic eddies occur on both sides of the Loop Current. The co-occurrence of eastern and western cyclonic eddies in the Loop Current bottleneck zone leads to the formation of a large cyclonic structure. The latter seems to prevent newly formed Loop Current eddies from reattaching and can limit the growth of the Loop Current during several months. These findings underscore the crucial role of cyclonic eddies in regulating the detachment and separation of Loop Current eddies.

The Caribbean Through-Flow is an important conduit between the North Atlantic Subtropical Gyre and the upper branch of the Atlantic Meridional Overturning circulation. Gradone et al. used observations collected during a series of consecutive 90-days glider transects during summer 2024. Their results show a significant decline in the magnitude of the zonal transport (by about 50%) which is attributed to a shift in dynamics from geostrophic balance to increased mesoscale activity. They provide an important insight into how ocean gliders in combination with other data streams help to further understand mesoscale circulation and quantify the contributions of eddies to transport in this understudied region of the Caribbean.

This is an interesting study using a large rotating tank in the laboratory to simulate the flow through the Strait of Gibraltar. Laboratory experiments in geophysical fluid dynamics are increasingly rare, yet are highly visual and stimulating. The results are of high impact for understanding the processes such as tides determining the exchange between the Mediterranean and the Atlantic.

The sea surface microlayer (SML) is the thin layer on top of the ocean that is in direct contact with the atmosphere which is crucial for air–sea interactions. A novel paper shows data profiles close to the water surface in a mesocosm experiment. Using microsensor profiles at high vertical resolution, it shows dissolved oxygen and temperature gradients from the air, through the sea surface microlayer and into the water below. Phytoplankton bloom dynamics and surfactant concentrations influence the oxygen concentration and the diffusive layer depth but not temperature gradients. This has implications for air-sea exchanges across the sea surface microlayer.