The temporal changes of the oceans eddy variability and the underlying dynamical causes are investigated. The study is based on a 18.5 year long time series of satellite altimetry sea surface height (SSH) anomalies (TOPEX/Poseidon, Jason-1 and Jason-2), from which statistics for the eddy kinetic energy field (EKE) are computed. In this study it is demonstrated that the most energetic regions coincide with major current systems, meandering jets and frontal areas. These are the domains where SSH non-gaussianity is acquainted most likely due to inhomogeneities in the ocean. It is also shown that the distribution of SSH skewness and kurtosis can be used to assess the seasonal variations of meandering jets and ocean surface circulation processes. The extent to which the eddy field is reacting to changes in the wind forcing is addressed. EKE fields, computed from an eddy-resolving global circulation model STORM driven both by NCEP forcing and by climatology, are used complementary to the altimetry. The results suggest that changes of EKE depict a complex pattern and are far from uniform. A comparison of the time series of wind stress and EKE suggests that changing winds cause a response in eddy activity. In several parts of the ocean there is no direct relation between the wind forcing and the increase in EKE, pointing to non-local forcing effects of eddy variability. On basin average, changes in EKE appear to be correlated with climate modes. Ocean variability contains all temporal and spatial scales. The investigation of temporal changes in EKE and its causes was extended through spectral analysis, which is appropriate for estimating the impact of different scales on the overall energy distribution. The global frequency spectra for altimetry is aliased by tidal residuals. In the Atlantic through a joint data-model analysis it is evident that as the resolution increases the model’s spectra gets closer to the altimetry. Regionally, the shape of the frequency spectra of SSH has steeper slopes at higher frequencies and flatter slopes at lower frequencies. The slopes of wavenumber spectra in high energy regions, dominated by non-linearity, follow roughly k−4 or k−3 at the mesoscale. Thus, surface quasi-geostrophy turbulence theory appears more appropriate to provide a dynamical explanation of these spectral slopes. The low energy regions have flatter slopes ranging from −3 to −2. Further research is needed in order to clarify the causes of EKE on a global scale.