An evaluation of TRACE-P emission inventories from China using a regional model and chemical measurements

Abstract

We evaluate the TRACE-P emission inventories for gaseous and particulate pollutants from East Asia using chemical measurements made at a rural site in China during the China-MAP Field Intensive in conjunction with a coupled regional climate/chemical transport modeling system. Time-dependent, three-dimensional fields for trace gas and particulate matter concentrations over East Asia are simulated by an updated version of the Regional Acid Deposition Model (RADM) driven by the TRACE-P emission inventories along with meteorology fields calculated by the NCAR Regional Climate Model (RegCM) for the month of November 1999. Model-calculated SO₂ is in good agreement with measurements, while CO and particulate carbon (PC) are significantly smaller, and particulate sulfate (SO₄²⁻ ) is somewhat smaller. Our calculations suggest that increases in the TRACE-P emission inventory of CO by ∼50% and PC by 60–90% would bring the model-calculated CO, PC, and particulate sulfate concentration into agreement with the China-MAP observations. If these increases were spread uniformly throughout China and the year, it would require that there be additional emissions in China of CO and PC of 60 Tg yr⁻¹ and 2.5–4 Tg yr⁻¹, respectively. Further analysis of high resolution gas species measurements suggests that the missing CO emissions are likely to be associated with SO₂ emissions from coal burning. This in turn suggests that coal-burning facilities in China are operating at significantly lower efficiencies than currently assumed.