Geostrophic Turbulence

Abstract

In this chapter, we will discuss aspects of turbulent flows on spatial scales around and larger than the (first baroclinic) Rossby radius, which are ubiquitous and important for many aspects of the large-scale ocean circulation and often are referred to as mesoscale ocean eddies. As discussed in Section 5.1, motions on these scales are strongly constrained by rotation and stratification and have a very small aspect ratio and hence are nearly two-dimensional. Turbulent motions in two dimensions differ in important aspects from the three-dimensional motions considered in Chapter 11. Therefore, this chapter could also be called two-dimensional turbulence. Idealized two-dimensional turbulence will be discussed in the following section, while Section 12.2 is devoted to the more realistic inhomogeneous situation of the real ocean. In Section 12.3 we discuss alternative averaging frameworks to differentiate between advective and diffusive effects of turbulent mixing.