The M-55 geophysica as a platform for the airborne polar experiment

The authors describe the Russian Stratospheric Aircraft M-55 Geophysica, an important new platform for earth observation, and describe some technical details of its inaugural mission. The M-55 has successfully conducted scien tific test flights in Pratica di Mare, Rome, in November 1996, and the firs t Airborne Polar Experiment (APE 1) from 19 December 1996 to 16 January 199 7 from Rovaniemi in northern Finland. Three test flights were carried out a t Pratica di Mare, and seven scientific mission flights during APE 1, when "quasi-Lagrangian" flight paths (flights in the wind direction, assuming th e stratosphere to be stationary over the flight period) and lee wave flight paths were employed. Combined sorties of the M-55 Geophysica and the DLR F alcon were performed, the latter acting as a pathfinder for the former, gui ding it to small regions of intense polar stratospheric cloud activity. The se small cloud patches are associated with intense atmospheric wave activit y over the Scandinavian mountains and other mountain ranges, and have been implicated in the observed depletion of stratospheric ozone. The Geophysica is well suited to probing atmospheric physics and chemistry in the harsh e nvironment of these clouds.