Influence of Atmospheric Transport on Estimates of Variability in the Global Methane Burden

Autor: Sudhanshu Pandey, Sander Houweling, Maarten Krol, Ilse Aben, Narcisa Nechita‐Banda, Kirk Thoning, Thomas Röckmann, Yi Yin, Arjo Segers, Edward J. Dlugokencky
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Geophysical Research Letters, Vol 46, Iss 4, Pp 2302-2311 (2019)
Druh dokumentu: article
ISSN: 1944-8007
0094-8276
DOI: 10.1029/2018GL081092
Popis: Abstract We quantify the impact of atmospheric transport and limited marine boundary layer sampling on changes in global and regional methane burdens estimate using tracer transport model simulations with annually repeating methane emissions and sinks but varying atmospheric transport patterns. We find the 1σ error due to this transport and sampling effect on annual global methane increases to be 1.11 ppb/year and on zonal growth rates to be 3.8 ppb/year, indicating that it becomes more critical at smaller spatiotemporal scales. We also find that the trends in inter‐hemispheric and inter‐polar difference of methane are significantly influenced by the effect. Contrary to a negligible trend in the inter‐hemispheric difference of measurements, we find, after adjusting for the transport and sampling, a trend of 0.37 ± 0.06 ppb/year. This is consistent with the emission trend from a 3‐D inversion of the measurements, suggesting a faster increase in emissions in the Northern Hemisphere than in the Southern Hemisphere.
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