Preparation for tethered Ozone Sounding Ozone Sounding Tethered Balloon Flight Electric winch with 1000 m tether Atmospheric Chemistry and on-site core analysis Continuous melter field system Field Continuous Melter System Melting and analyzing 3 m of firn Melter Head and firn core Unannounced Inspection of Melter Melter Head T control and debubbler View of the Ellsworth Mountains. Science with a view Inside the Atmo-Shelter ... Flagged trail out to shelter Low visibility and drifting snow Stormy conditions Extracting the firn core Drilling a 2" core A 2" firn core Transferring the 2" core Shallow Core Drilling Getting the core out ... Shallow Core Drilling Mark Wumkes, Chief Driller in command