Temporal Characteristics of CH4 Vertical Profiles Observed in the West Siberian Lowland Over Surgut From 1993 to 2015 and Novosibirsk From 1997 to 2015

摘要: We have carried out monthly flask sampling using aircraft, in the altitude range of 0-7 km, over boreal wetlands Surgut (61°N, 73°E; since 1993) and a pine forest near Novosibirsk (55°N, 83°E; 1997), both located West Siberian Lowland (WSL). The temporal variation methane (CH4) concentrations at all altitudes sites exhibited an increasing trend with stagnation during 2000-2006 as observed globally from ground-based networks. In addition to winter maximum seen other remote northern mid high latitudes, another seasonal was also summer, particularly lower WSL, which could be attributed emissions wetlands. Our measurements suggest that vertical gradient has been decreasing; mean CH4 difference between 5.5 km 1.0 changed 64±5 ppb 1995-1999 37±3 2009-2013 (mean ± standard error). No clear decline appeared Novosibirsk. Simulations atmospheric chemistry-transport model captured decrease when Europe decreased but increased regions south Siberia, e.g., East South Asia. At Novosibirsk, influence European relatively small. results regional around WSL did not change significantly period our observations.