Shipborne eddy covariance observations of methane fluxes constrain Arctic sea emissions

• We demonstrate direct eddy covariance (EC) observations of methane (CH4) fluxes between the sea and atmosphere from an icebreaker in the eastern Arctic Ocean. EC-derived CH4 emissions averaged 4.58, 1.74, and 0.14 mg m(-2) day(-1) in the Laptev, East Siberian, and Chukchi seas, respectively, corresponding to annual sea-wide fluxes of 0.83, 0.62, and 0.03 Tg year(-1) . These EC results answer concerns that previous diffusive emission estimates, which excluded bubbling, may underestimate total emissions. We assert that bubbling dominates sea-air CH4 fluxes in only small constrained areas: A similar to 100-m(2) area of the East Siberian Sea showed sea-air CH4 fluxes exceeding 600 mg m(-2) day(-1); in a similarly sized area of the Laptev Sea, peak CH4 fluxes were similar to 170 mg m(-2) day(-1). Calculating additional emissions below the noise level of our EC system suggests total ESAS CH4 emissions of 3.02 Tg year(-1) closely matching an earlier diffusive emission estimate of 2.9 Tg year(-1).

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences (hsv//eng)

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)