Analysis of a Multi-Year Record of Ozonesondes over Summit Station, Greenland (2005-2016)

Questions remain about what controls both the seasonal cycle and the long-term trend of atmospheric ozone in the Arctic. Summit Station is situated in a unique location in the Arctic at 3200 meters above sea level at the highest point on the Greenland Ice Sheet. Here we analyze 550 ozonesonde profiles that were launched by the NOAA Earth System Research Laboratory from 2005 to 2016. The quality of ozonesonde profiles was assessed by identifying large gaps in the vertical profiles. In addition, climatological values of ozone were inserted above the maximum height of each profile to extend the measurements to 60 km. This reference profile was generated by scaling the subarctic winter standard atmosphere to the ozone values near the top of the profile. This allowed the calculation of total column ozone for each profile. The time-series of total column ozone, plus the variation of ozone in four atmospheric layers (troposphere, and low, middle, and upper stratosphere), are analyzed. The seasonal cycle of ozone at Summit is compared to other nearby Arctic stations and is shown to have slightly lower values, which is expected due to high elevation of Summit Station. To track the contribution of ozone transport from other latitudes during ozone events, back trajectories were calculated using NOAA’s HYSPLIT4 model.