Diatoms are the primary source of nutrition and energy for the Southern Ocean ecosystem. Microalgae, including diatoms, synthesise biological macromolecules such as lipids, proteins and carbohydrates for growth, reproduction and acclimation to prevailing environmental conditions. Here we show that three key species of Southern Ocean diatom (Fragilariopsis cylindrus, Chaetoceros simplex and Pseu...

■ Abstract The coexistence in the deep ocean of a finite, stable stratification, a strong meridional overturning circulation, and mesoscale eddies raises complex questions concerning the circulation energetics. In particular, small-scale mixing processes are necessary to resupply the potential energy removed in the interior by the overturning and eddy-generating process. A number of lines of ev...

Multiple equilibria in a coupled ocean–atmosphere–sea ice general circulation model (GCM) of an aquaplanet with many degrees of freedom are studied. Three different stable states are found for exactly the same set of parameters and external forcings: a cold state in which a polar sea ice cap extends into the midlatitudes; a warm state, which is ice free; and a completely sea ice–covered ‘‘snowb...

This paper summarizes the ocean surface net energy flux simulated by fifteen atmospheric general circulation models constrained by realistically-varying sea surface temperatures and sea ice as part of the Atmospheric Model Intercomparison Project. In general, the simulated energy fluxes are within the very large observational uncertainties. However, the annual mean oceanic meridional heat trans...

Recently, various forms of ocean energy such as wave, tidal, marine current, and ocean thermal energy conversion are considered as source of alternative clean energy because of the increased oil price, international political issues, and global warming issues, etc. For this reason, underwater robot is believed to play a key role in both development and protection of the ocean. Until now, underw...

A two-dimensional numerical model with a space grid of about 14 km is applied to calculate diurnal tidal constituents K1 and O1 in the Arctic Ocean. Calculated corange and cotidal charts show that along the continental slope, local regions of increased sea level amplitude, highly variable phase and enhanced currents occur. It is shown that in these local regions, shelf waves (topographic waves)...

Waves are familiar to us all--such as ocean waves, sound waves, light waves, and waves in a string. Waves may appear to be traveling or appear to be standing still. There are those being transported by a medium as for the ocean or in a guitar string and those that travel best through empty space such as the electromagnetic spectrum including visible light. Waves are a common means by which ener...

But over the past 150 years, the noise levels in our oceans have increased significantly. This is due to human activity. The propeller noise from shipping has raised the baseline for low-frequency ambient ocean sound worldwide. There is noise produced by undersea construction, such as pile-driving (e.g., hammering posts into the seafloor, such as for docks or drilling platforms). Sonar is used ...