We quantified the impacts of variations in meteorological parameters and emissions on decadal, interannual, and seasonal variations of atmospheric black carbon (BC) in the Tibetan Plateau for 1980-2010 using a global 3-dimensional chemical transport model driven by the Modern Era Retrospective-analysis for Research and Applications (MERRA) meteorological fields. From 1980 to 2010, simulated surface BC concentrations and all-sky direct radiative forcing at the top of the atmosphere due to atmospheric BC increased by 0.15 mu g m(-3) (63%) and by 0.23 W m(-2) (62%), respectively, averaged over the Tibetan Plateau (75-105 degrees E, 25-40 degrees N). Simulated annual mean surface BC concentrations were in the range of 0.24-0.40 mu g m(-3) averaged over the plateau for 1980-2010, with the decadal trends of 0.13 mu g m(-3) per decade in the 1980s and 0.08 in the 2000s. The interannual variations were -5.4% to 7.0% for deviation from the mean, 0.0062 mu g m(-3) for mean absolute deviation, and 2.5% for absolute percent departure from the mean. Model sensitivity simulations indicated that the decadal trends of surface BC concentrations were mainly driven by changes in emissions, while the interannual variations were dependent on variations of both meteorological parameters and emissions. Meteorological parameters played a crucial role in driving the interannual variations of BC especially in the monsoon season.

We quantified the impacts of variations in meteorological parameters and emissions on decadal trends and interannual variations of black carbon (BC) in China for 1980-2010 using a global chemical transport model (GEOS-Chem) driven by the Modern Era Retrospective-analysis for Research and Applications meteorological fields. Model results reasonably captured the decadal and interannual variations of observed BC in China. From 1980 to 2010, simulated surface concentrations and tropospheric column burdens of BC increased by 0.21 mu gm(-3) (29%) and by 0.29mgm(-2) (37%), respectively, averaged over China; the corresponding all-sky direct radiative forcing at the top of the atmosphere increased by 0.35Wm(-2) (51%). Considering variations in both meteorological parameters and emissions for 1980-2010, simulated annual mean surface concentrations (column burdens) of BC were in the range of 0.7-1.0 mu gm(-3) (0.8-1.1mgm(-2)) averaged over China. The associated decadal trends were 0.31 mu gm(-3)decade(-1) (0.29mgm(-2)decade(-1)) in the 1980s, -0.20 (-0.10) in the 1990s, and 0.16 (0.21) in the 2000s. The interannual variations were -20% to 15% (-20% to 11%) for deviation from the mean, 0.068 mu gm(-3) (0.069mgm(-2)) for mean absolute deviation, and 7.7% (7.1%) for absolute percent departure from the mean. Model sensitivity simulations indicated that the decadal trends of surface concentrations and column burdens of BC were mainly driven by changes in emissions, while the interannual variations were dependent on variations of both meteorological parameters and emissions.