We employ profiling floats with dissolved oxygen sensors to observe in situ temporal oxygen evolution below the mixed layer, allowing us to characterize net respiration of organic carbon in eight distinct regions over the globe. Export and export efficiency are generally high in locations with strong seasonal variability and low in locations of weak seasonality. Vertically integrated respiration is weakly, yet significantly, correlated with remote observations of chlorophyll, net primary production, and planktonic community size structure. These correlations suggest that regimes of high net primary production and large phytoplankton fuel elevated respiration at depth. Several regions of float‐based observations intersect with sites of other detailed observations (e.g., Hawaii and Sargasso Sea), which allows us to compare our results to independent studies. We find that there is good agreement among export production estimates at highly seasonal locations, and that float‐based observations may be biased low at weakly seasonal locations. We posit that the reason for the low‐latitude discrepancy is the relative steady state of oxygen concentration caused by weak seasonality and shallow wintertime mixed layer depths.

This study examines the global variability of the internal wave field near a depth of 1000 m using data from a set of 194 Argo floats equipped with Iridium communications, capable of measuring hourly temperature and pressure during the park phase of their 10-day cycles. These data have been used to estimate vertical isotherm displacements at hourly intervals, yielding a global measure of the heaving due to internal gravity waves. The displacement results have been employed to examine the global variability of these waves and how the displacement power spectrum compares to the canonical Garrett–Munk spectrum. Using the data, the authors find correlations between internal wave intensity and seafloor roughness, proximity to the seafloor, and the magnitude of the local barotropic velocity. The measurements also show large seamount-trapped waves at high latitudes and coastally trapped subinertial waves. These observations provide a rough global census of the nature of these waves that can ultimately be used in studies of ocean mixing.

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Data from coastal tide gauges, oceanographic moorings, and a numerical model show that Arctic storm surges force continental shelf waves (CSWs) that dynamically link the circumpolar Arctic continental shelf system. These trains of barotropic disturbances result from coastal convergences driven by cross-shelf Ekman transport. Observed propagation speeds of 600−3000 km day −1 , periods of 2−6 days, wavelengths of 2000−7000 km, and elevation maxima near the coast but velocity maxima near the upper slope are all consistent with theoretical CSW characteristics. Other, more isolated events are tied to local responses to propagating storm systems. Energy and phase propagation is from west to east: ocean elevation anomalies in the Laptev Sea follow Kara Sea anomalies by one day and precede Chukchi and Beaufort Sea anomalies by 4−6 days. Some leakage and dissipation occurs. About half of the eastward-propagating energy in the Kara Sea passes Severnaya Zemlya into the Laptev Sea. About half of the eastward-propagating energy from the East Siberian Sea passes southward through Bering Strait, while one quarter is dissipated locally in the Chukchi Sea and another quarter passes eastward into the Beaufort Sea. Likewise, CSW generation in the Bering Sea can trigger elevation and current speed anomalies downstream in the Northeast Chukchi Sea of 25 cm and 20 cm s −1 , respectively. Although each event is ephemeral, the large number of CSWs generated annually suggest that they represent a non-negligible source of time-averaged energy transport and bottom stress-induced dissipative mixing, particularly near the outer shelf and upper slope. Coastal water level and landfast ice breakout event forecasts should include CSW effects and associated lag times from distant upstream winds.

Despite sufficient wind forcing, internal waves in the South China Sea do not exhibit the strong near-inertial wave (NIW) peak that is typical in most of the world oceans. Using data from 10 contemporaneous moorings deployed in summer 2011, we show that strong isopycnal vertical tidal displacements transfer most of the near-inertial (NI) kinetic energy (KE) to frequencies higher than the inertial frequency in an Eulerian reference frame. Transforming to an isopycnal-following reference frame increases the KE at NI frequencies, suggesting the presence of NIWs. However, the projection onto a semi-Lagrangian coordinate system still underestimates the expected NI peak. To fully resolve NIWs requires the use of time-dependent vertical wavenumber–frequency spectra because the intrinsic frequency of the NIWs varies substantially, owing to Doppler shifting by lateral mesoscale flows. Here, we show NIW intrinsic frequency variations of ±0.2 cpd within few days, of similar magnitude as the observed variations of relative vorticity associated with the meandering Kuroshio.