POLSTAR in ’98 Airborne expedition to investigate the causes of
ozone loss in the region of the Polar Tropopause The measurement
campaign POLSTAR 98 took place in January – February 1998 in
Kiruna, northern Sweden, as part of the Ozone Research Programme
of the Federal Ministry for Education, Science, Research and
Technology (BMBF). The main aim of the “Polar Stratospheric
Aerosol Experiment” POLSTAR was to investigate the formation and
composition of the cirrus clouds that form in the region of the
upper troposphere and lower Stratosphere. It is suspected that
these ice clouds, or the chemical processes which occur on the
surface of the aerosol particles, play an important role in the
destruction of ozone. Two research aircraft based in Kiruna were
used for the measurement of particles and trace gases during the
experiment. A total of eight flights were made during the three
weeks of the experiment. Most of the flights involved both
aircraft flying in tight formation so as to allow simultaneous
measurements