APE-GAIA Airborne Polar Experiment Geophysica Aircraft in Antarctica

Abstract

In the frame of the “Airborne Polar Experiment” (APE) a Russian military plane M55 has been converted in a high flying research platform for investigations of the polar lower stratosphere and upper troposphere. With the first campaign, carried out in the Arctic during the winter 1996–97, the M55-Geophysica aircraft was shown to be a reliable and powerful tool, to access geographical and altitude ranges, which can be only partially covered by other platforms. A new mission of the M55 has been recently conducted over the Antarctic Peninsula, aiming at studying the chemical processes responsible for stratospheric ozone losses by means of a remote sensing payload. The APE-GAIA campaign (Geophysica Aircraft In Antarctica) took place from the airport of Ushuaia (Argentina) from 15 September to 15 October 1999. The geographical location of the operative base (Ushuaia, 55°S is the southernmost airfield suitable for the M55) permitted to reach the borders of the polar vortex and to fly along its edge; the selected period was the most suitable for the study of ozone depletion and recovery chemistry. The scientific payload was basically composed by remote-sensing instrumentation (middle and far-infrared FT spectrometers, UV-Visible spectrometer, lidars). In-situ analysis of O3, H2O and other trace gases contributed to better constrain the remote observations. First priority issues of the 6 flights of the mission have been the latitude and altitude dependence of ozone loss cycles during the depletion phase and the mixing mechanisms between the polar vortex and the mid and low latitude air masses.