Evidence of gravity waves off the spine of the Antarctic peninsula ? - one of the SH "hotspots" for these waves. Gravity waves(& their effects) are not well represented in models, and may represent a source of error in StratosphericPolarVortex forecasts - which in turn, for example, could be reflecting in surface sam forecasts. The large air parcel which breaks from the filament of pv, looks to me to possibly contain tropospheric air - the colour bar code at bottom of image places it near or below the pv threshold for the dynamic tropopause (1.5-2 pvu). The images are @ ~ 47hpa (600K isentropic surface).