Characteristics of near-inertial waves (NIWs) induced by the tropical storm Noul in South China Sea are analyzed based on situ observations, remote sensing, and analysis data. Remote sensing sea level anomaly data suggests that NIWs were influenced a southwestward moving anticyclonic eddy. The had comparable spectral density with internal tides, horizontal velocity 0.14–0.21 m/s. kinetic energy...

An idealized supercell simulation using the Regional Atmospheric Modeling System (RAMS) produced an elongated low-level mesocyclone that subsequently collapsed into a concentrated vortex. Though vorticity continually increased in the mesocyclone due to horizontal convergence, the collapse phase was additionally characterized by rapidly decreasing pressure, closed streamlines, and the creation o...

Laboratory observations and numerical experiments have shown that a variety of compound vortices can emerge in two-dimensional flow due to the instability of isolated circular vortices. The simple geometrical features of these compound vortices suggest that their description may take a simple form if an appropriately chosen set of functions is used. We employ a set which is complete on the infi...

1 Abstract The role of vorticity dynamics in vortex breakdown is examined in a theoretical and computational study. Under the assumptions of steady, incompressible, axisymmetric, invis-cid ow, a theory is developed concerning the interaction of vortex tilting and stretching in the breakdown process. This analytic theory is then connrmed using an unsteady, incompressible, axisymmetric viscous ow...

A study is made of some numerical calculations of two-dimensional and geostrophic turbulent flows. The primary result is that, under a broad range of circumstances, the flow structure has its vorticity concentrated in a small fraction of the spatial domain, and these concentrations typically have lifetimes long compared with the characteristic time for nonlinear interactions in turbulent flow (...

Nonlinear quasigeostrophic flows in two layers over a topographic slope are considered. Scaling the lower layer potential vorticity equation yields two parameters which indicate the degree of nonlinearity in the lower layer. The first, u' (the strength of the deep flow divided by the product of the effective bottom slope and the squared length scale), is related to the advection of relative vor...

We derive the dispersion relation for linearized small-amplitude gravity waves for various choices of non-constant vorticity. To the best of our knowledge, this relation is only known explicitly in the case of constant vorticity. We provide a wide range of examples including polynomial, exponential, trigonometric and hyperbolic vorticity functions.