The Arctic tropopause fold

Analyses of research-aircraft observations, satellite total-columnar-ozone retrievals, and synoptic upper-air soundings are used to describe the structure of Arctic jetstreams and their associated frontal zones and tropopause folds. These analyses document the presence of major tropopause folding events within the Arctic that occur at the flanks of large-scale (about 2000 km) polar vortices. One example shows a solar vortex and its associated tropopause fold and Arctic front that migrated from the high Canadian Arctic southward into midlatitudes over central North America. Total columnar ozone measurements from the Total Ozone Mapping Spectrometer are shown to identify the location of polar vortices and the mesoscale (about 200 km) ozone gradients at the flanks of these vortices, which coincide with regions of Arctic tropopause folding and associated stratospheric-tropospheric exchange processes.