Gravity waves observed by lidar at the center and edge of the Southern polar vortex

Abstract

Our Rayleigh lidar systems provide temperature profiles up to 100 km altitude at both a site at southern hemisphere mid-latitudes and at South Pole. Very strong orographic gravity waves dominate in the lee of the Southern Andes in winter, a region proximate to the polar vortex edge where strong winds prevail. In contrast, despite being situated within the stable polar vortex core, continuous but weaker gravity waves are observed above Amundsen-Scott station at South Pole. Potential sources for these waves include catabatic winds flowing across the Transantarctic Mountains – which also give rise to polar stratospheric clouds-, polar vortex dynamics, or lateral progagation from mid-latitudes. We present examples of gravity wave measurements and statistical analyses derived from our multi-year, ongoing datasets.