Ocean processes occur on a huge range of spatial scales, from the global circulation many megameters in size, to the scales of millimeters to centimeters where molecular diffusion and viscosity act. Actual mixing of water masses occurs only on the smallest scales. Oceanic circulation models, such as those used to predict future climate change, do not resolve scales larger than 10 km and often are much coarser. Even localized models used to study coastal ecosystem dynamics rarely can resolve scales smaller than a few hundred meters. A wide range of physical processes can occur in the unresolved scales, as sketched in the cartoon below.

As ocean circulation models have become more developed and observations of the ocean have become more detailed, it is becoming clear that these models require detailed descriptions of these small scale processes in order to make accurate predictions. However, they do not and probably cannot simulate these scales directly. This is even more true in the coastal and estuarine environment. The challenge to small scale oceanography is to develop parameterizations of small scale ocean processes which are based on a solid physical understanding, yet are simple enough to be used in larger scale models.

Oceanographers studying small-scale processes use a variety of tools ranging from specialized "microstructure" instruments designed to measure the smallest scales of oceanic variability, to numerical models of ocean mixed layers or internal waves, to analytical theories of these processes. However, the focus is mostly on the design, execution and analysis of measurement programs aimed at understanding specific scientific problems. This field work can occur anywhere in the world in environments that range from the tropics to Puget Sound to the Arctic and estuaries to hurricanes. Studies are becoming increasingly more interdisciplinary with ample opportunities to integrate aspects of biological oceanography, sediment transport and meteorology into this work.

The School of Oceanography has long been a leader in the study and teaching of small-scale oceanography, particularly through cooperative work with the Applied Physics Laboratory. Students have the opportunity to work with a team of engineers and technicians to design and conduct measurement programs using advanced instrumentation.