5 Multiscale analysis is used to derive two sets of coupled models, each based on the same distinguished limit, to represent the interaction of the midlatitude oceanic synoptic scale — where coherent features such as jets and rings form — and the mesoscale, defined by the internal deformation scale. The synoptic scale and mesoscale overlap at low and mid latitudes, and are hence synonymous in m...

Surface quasigeostrophic turbulence (Held et al. 1995) is not an exotic geophysical effect, but rather a generic description of quasigeostrophic turbulence at vertical surfaces of sharp change in the mean environment (vertical boundaries are an extreme example). Tulloch and Smith (2006, 2008) argued that surface quasigeostrophic (SQG) effects are consistent with many perplexing features of the ...

Recent observational analysis reveals the central role of three multi-cloud types, congestus, stratiform, and deep convective cumulus clouds, in the dynamics of large scale convectively coupled Kelvin waves, westward propagating two-day waves, and the Madden–Julian oscillation. The authors have recently developed a systematic model convective parametrization highlighting the dynamic role of the...

The evolution of a counter-rotating vortex pair in a stably stratified fluid is investigated using direct numerical simulations. The study focuses on the short-wavelength elliptic instability occurring in this flow and the subsequent decay of the vortices. Depending on the level of stratification, as characterized by the Froude number which indicates the time scale of buoyancy to that of the in...

The local budget of eddy kinetic energy (EKE) for both high-frequency (HF, 2–6 days) and intermediatefrequency (IF, 7–29 days) eddies are evaluated for Northern Hemisphere boreal winter using the 31-year (1979/ 80–2010/11) NCEP-DOE reanalysis. A new form of EKE equation is used to isolate the kinetic energy generation/ destruction due to interactions among eddies of different timescales. The ma...

In this work the eddy resolving data sets of salinity, temperature, and oxygen content aquired in the framework of the German-Russian project MESODYN (MESOscale DYNamics) in the Arkona Basin, the Bornholm Basin, the Stolpe Furrow, and the Eastern Gotland Basin during summer and winter stratification situations are utilized to examine to which extent the observations at the central monitoring st...