Similarities in middle atmosphere structures

Similarities of middle atmosphere structures are analyzed on the basis of CRISTA 1 and SABER data which extend from the upper troposphere up into the lower thermosphere. An event of planetary wave breaking is identified that leads to the formation of a surf zone the middle mesosphere (70 km); its structures are seen in temperature, potential vorticity and trace gas mixing ratios. A second analysis compares the structures of the tropopause and the mesopause. A cold point mesopause and a dynamical (potential vorticity) mesopause are suggested similarly as they are used at the tropopause. A lapse rate mesopause, however, appears to be of little use. The dynamical mesopause appears to indicate a transport barrier similar as it is the case at the low altitudes. In summer a "split mesopause" is observed at middle to high latitudes. There is a zonal wind jet near to this apparent mesopause break which is similar to what can be observed at the tropopause.