“O-buoy 4” started measuring the concentrations of ozone, carbon dioxide and bromine monoxide in the air over the ice of the Arctic Ocean at latitude 88.15°N and longitude 157.49°W on September 5, 2011. The deployment of the instrumentation package took place during a survey mission of the Canadian Extended Continental Shelf Mapping Program conducted by the CCGS Louis S. St-Laurent icebreaker. The buoy is a component of join research project between six research groups in USA and Environment Canada. O-buoy 4 drifted with the ice by taking part into a wind driven ice circulation known as Transpolar Drift Stream, where ice moves from the Siberian coast of Russia across the Arctic and exits predominantly into the North Atlantic through the Fram Strait on the east coast of Greenland. It was successfully retrieved from the ice of the Fram Strait on August 25th, 2012. The recovery mission was organized by Dr. Edmond Hansen from the Norwegian Polar Institute. It was implemented with the help of the Norwegian Polar Institute and the crew of the Norwegian RV Lance. O-buoy 4 collected data on air composition, meteorological variables, the ice drift and the ice conditions through 355 days long journey across the High Arctic. Daily updated information was posted on open to the public web site: http://obuoy.datatransport.org/monitor through this measurement period. The instrumentation package gathered the longest O-buoy network based data set with all analytical sensors in proper operational mode. It recorded ozone and carbon dioxide concentrations over the ice of the Arctic Ocean throughout all four seasons providing details on their current, region specific and seasonal value and variability. It recorded carbon dioxide variations in the concentrations trough the ocean freezing and the ice melt periods. It was the first O-buoy that recorded data in the High Arctic as close to the North Pole as 89.515°N. O-buoy 4 captured the whole spring time ozone depletion season of 2012 around the North Pole after the French schooner TARA in 2007 with the first parallel measurements of bromine monoxide abundance and a complete suite of the surrounding environmental parameters. O-buoy 4 was the first O-buoy to start reporting data for the Marine Weather forecasting and to be used for wind direction and wind speed validation of the forecast models.