Publikationsdatum:
2016-06-02
Beschreibung:
Continuous measurements of atmospheric methane (CH 4 ) mole fractions measured by NOAA's Global Greenhouse Gas Reference Network in Barrow, AK (BRW), show strong enhancements above background values when winds come from the land sector from July through December from 1986-2014, indicating that emissions from arctic tundra continue through autumn and into early winter. Twenty-nine years of measurements show little change in seasonal mean land-sector CH 4 enhancements, despite an increase in annual mean temperatures of 1.2 ± 0.8 °C/decade (2σ). The record does reveal small increases in CH 4 enhancements in November and December after 2010 due to increased late-season emissions. The lack of significant long-term trends suggests more complex biogeochemical processes are counteracting the observed short-term (monthly) temperature sensitivity of 5.0 ± 3.6 ppb CH 4 /°C. Our results suggest that even the observed short-term temperature sensitivity from the Arctic will have little impact on the global atmospheric CH 4 budget in the long-term if future trajectories evolve with the same temperature sensitivity.
Print ISSN:
0094-8276
Digitale ISSN:
1944-8007
Thema:
Geologie und Paläontologie
,
Physik