Regional Methane Emission Estimation Based on Observed Atmospheric Concentrations (2002-2012)

摘要: Methane (CH4) plays important roles in atmospheric chemistry and short-term forcing of climate. A clear understanding CH4’s budget emissions losses is required to aid sustainable management Earth’s future environment. We used an chemistry-transport model (JAMSTEC’s ACTM) for simulating CH4. global inverse modeling system has been developed estimating CH4 from 53 land regions 2002–2012 using measurements at 39 sites. An ensemble 7 inversions performed by varying a priori emissions. Global net varied between 505–509 524–545 Tg yr–1 during 2002–2006 2008–2012, respectively (ranges based on inversion cases), with step like increase 2007 agreement measurements. The did not account interannual variations OH radicals reacting the atmosphere. Our results suggest that recent update EDGAR inventory (version 4.2FT2010) overestimated total least 25 2010. emission since 2004 originated tropical southern hemisphere regions, coinciding non-dairy cattle stocks ~10 % 2002 (with 1056 million heads) 2012, leading enteric fermentation. All cases robustly estimated emissions, but poorly constrained seasonal cycle amplitude or phase consistently all due sparse observational network. Forward simulation both posteriori are compared independent aircraft validation. Based comparison, we reject upper limit (545 yr–1) as 14 too high which allows us further conclude over East Asia (mainly China) region was 7–8 2008–2012 periods, contrary 1–17