Climatology and case studies of mesospheric gravity waves observed at polar latitudes.

摘要

Airglow is a faint light emission located at an altitude of 80--100 km in the upper mesosphere and lower thermosphere (MLT) region. Atmospheric gravity waves generated in the lower atmosphere are capable of propagating into the MLT region where they modulate the airglow emissions to form wave-like structures. Short-period gravity wave morphology and climatology have been measured at low-and mid-latitudes where they have been shown to transport large amounts of momentum into the upper atmosphere. However, only few case studies have been reported at high polar latitudes and to our knowledge no climatology has yet been established. This dissertation investigates the wave characteristics and propagation nature of short-period gravity waves observed over two Antarctic field stations (Halley at 76° S and Rothera at 68° S) during the 2000--2003 winter seasons, and thus represents the first climatology of short-period gravity waves at high latitudes.