The first, long-term, in situ measurement of ozone depletion in the Antarctic ozone hole
We will present preliminary results from the first in situ ozone measurements during the formation of the Antarctica ozone hole. Three solid-state ozone photometers are being flown on long duration super pressure balloons as part of the international Concordiasi project. The super pressure balloons will follow an isopycnal trajectory and will provide a near-Lagrangian measurement platform in the polar vortex. The balloons will be launched from McMurdo Station, Antarctica, in early September and will maintain altitudes in the range of 16 – 20km. Ozone measurements will be taken at a cadence ranging from 15 minutes to 1 hour depending on the power availability and the rate of change of ozone. The ozone instrument and balloon platform is expected to have a 3 to 6 month lifetime and provide in situ measurements of both the formation and breakup of the Antarctic ozone hole. Barring technical mishaps, flights will continue until the balloons leave the Antarctic region during the collapse of the polar vortex. In addition to the ozone sensors, the balloons are carrying meteorological instruments and optical particle counters for the identification of polar stratospheric clouds. Launches of ozone sondes timed with overpasses of the long duration balloon from several participating Antarctic bases will provide verification and calibration of the long duration balloon borne instruments. A focus of the study will be the determination of ozone depletion rates, particularly in the presence of polar stratospheric clouds. This data set will be valuable for addressing some of the outstanding questions about stratospheric ozone depletion soon after polar sunrise and for constraining photochemical models that are used to predict the future state of stratospheric ozone.