Surface drifters released in the central Red Sea during April 2010 detected a well‐defined anticyclonic eddy around 23°N. This eddy was ∼45–60 km in radius, with a swirl speed up to ∼0.5 m/s. The eddy feature was also evident in monthly averaged sea surface height fields and in current profiles measured on a cross‐isobath, shipboard CTD/ADCP survey around that region. The unstructured‐grid, Finite‐Volume Community Ocean Model (FVCOM) was configured for the Red Sea and process studies were conducted to establish the conditions necessary for the eddy to form and to establish its robustness. The model was capable of reproducing the observed anticyclonic eddy with the same location and size. Diagnosis of model results suggests that the eddy can be formed in a Red Sea that is subject to seasonally varying buoyancy forcing, with no wind, but that its location and structure are significantly altered by wind forcing, initial distribution of water stratification and southward coastal flow from the upstream area. Momentum analysis indicates that the flow field of the eddy was in geostrophic balance, with the baroclinic pressure gradient forcing about the same order of magnitude as the surface pressure gradient forcing.

The analytical model of Snyder and Kennedy [1983] for the whitecap coverage W and that of Srokosz [1985] for the probability of wave breaking B are developed into practically applicable forms by closely combining theoretical analysis and data fitting. The database consists of two parts: the data collected from published literature and those recently measured in the Bohai Bay. A time‐averaging technique is used to estimate the fourth spectral moment of the mean Joint North Sea Wave Project spectrum. The resulting expressions are simple, in which W and B depend only on the nondimensional fetch for a fetch‐limited sea.

Deoxygenation is a global problem in open oceans and coastal regions and has led to the expansion of oxygen minimum zones and coastal hypoxia. Here, using time series observations in the northern Yellow Sea, we illustrate the seasonality of deoxygenation and associated mechanisms in this semienclosed shelf ecosystem and explore the linkage of dissolved oxygen (DO) declines with seawater warming and anthropogenic eutrophication. Our results show that the DO concentration displayed a decreasing trend in winter, with rates of ~0.76 and ~0.78 μmol kg⁻¹ yr⁻¹ in the surface and bottom waters, respectively. The rapid decline in DO was also observed in the bottom water in summer, with a decreasing rate of ~1.43 μmol kg⁻¹ yr⁻¹. In winter, when the water column is vertically homogeneous, the near saturation of DO indicates that physical mixing overwhelmed biological activities, and the estimated results and a linear correlation between DO concentration and temperature suggest that ocean warming is the most plausible driver of deoxygenation in this region in winter. In the stratified water column during summer, increased nutrient availability at the surface and consequently enhanced productivity are responsible for the drawdown of DO in the bottom layer, and the stoichiometric pattern between DO and nitrate also suggests a cascading linkage between the exacerbation of eutrophic conditions and bottom deoxygenation. Our results provide strong evidence that a rapid, semienclosed shelf‐scale decline in DO is underway and highlight the necessity of nutrient reduction strategies in the future.