Thawing tundra soils and newly rotting sea ice bubbles are rich in carbon monoxide (5--100 ppm) for a few weeks in May--June. Recent air samples in the vicinity of Barrow, Alaska, showed dramatic increase near the coast and overland. Several hundred kilometers out over winter sea ice the atmosphere concentration of CO was 0.02--0.06 ppm. Near the coast over rotting sea ice the concentration was 0.09 ppm. Inland, atmospheric carbon monoxide rose to a 0.2 ppm. Short term enrichments of carbon monoxide at the tundra and sea ice surfaces have been observed in the past.