Global simulation of tropospheric O3-NOx-hydrocarbon chemistry 1. Model formulation
نویسندگان
چکیده
We describe a global three-dimensional model for tropospheric O3-NOx-hydrocarbon chemistry with synoptic-scale resolution. A suite of 15 chemical tracers, including O3, NOx, PAN, HNO3, CO, H2O2, and various hydrocarbons, is simulated in the model. For computational expediency, chemical production and loss of tracers are parameterized as polynomial functions to fit the results of a detailed O3-NOx-hydrocarbon mechanism. The model includes state-of-the-art inventories of anthropogenic emissions and process-based formulations of natural emissions and deposition that are tied to the model meteorology. Improvements are made to existing schemes for computing biogenic emissions of isoprene and NO. Our best estimates of global emissions include among others 42 Tg N yr-1 for NOx (21 Tg N yr-1 from fossil fuel combustion, 12 Tg N yr-1 from biomass burning, 6 Tg N yr-1 from soils, and 3 Tg N yr-1 from lightning), and 37 Tg C yr-1 for acetone (1 Tg C yr-1 from industry, 9 Tg C yr-1 from biomass burning, 15 Tg C yr-1 from vegetation, and 12 Tg C yr-1 from oxidation of propane and higher alkanes).
منابع مشابه
Global simulation of tropospheric O3-NOx-hydrocarbon chemistry 2. Model evaluation and global ozone budget
Results from a global three-dimensional model for tropospheric O3-NOx-hydrocarbon chemistry are presented and evaluated with surface, ozonesonde, and aircraft measurements. Seasonal variations and regional distributions of ozone, NO, peroxyacetylnitrate (PAN), CO, ethane, acetone, and H2O2 are examined. The model reproduces observed NO and PAN concentrations to within a factor of 2 for a wide r...
متن کاملImpact of New Laboratory Studies of N2O5 Hydrolysis on Global Model Budgets of Tropospheric Nitrogen Oxides, Ozone, and OH
[1] We investigate the impact of new laboratory studies of N2O5 hydrolysis in aerosols on global model simulations of tropospheric chemistry. We use data from these new studies to parameterize the reaction probability (gN2O5) in the GEOS-CHEM global model as a function of local aerosol composition, temperature, and relative humidity. We find a much lower global mean gN2O5 (0.02) than commonly a...
متن کاملNet radiative forcing due to changes in regional emissions of tropospheric ozone precursors
[1] The global distribution of tropospheric ozone (O3) depends on the emission of precursors, chemistry, and transport. For small perturbations to emissions, the global radiative forcing resulting from changes in O3 can be expressed as a sum of forcings from emission changes in different regions. Tropospheric O3 is considered in present climate policies only through the inclusion of indirect ef...
متن کاملInfluence of convective transport on tropospheric ozone and its precursors in a chemistry-climate model
The impact of convection on tropospheric O3 and its precursors has been examined in a coupled chemistryclimate model. There are two ways that convection affects O3. First, convection affects O3 by vertical mixing of O3 itself. Convection lifts lower tropospheric air to regions where the O3 lifetime is longer, whilst mass-balance subsidence mixes O3-rich upper tropospheric (UT) air downwards to ...
متن کاملCharacterizing the tropospheric ozone response to methane emission controls and the benefits to climate and air quality
[1] Reducing methane (CH4) emissions is an attractive option for jointly addressing climate and ozone (O3) air quality goals. With multidecadal full-chemistry transient simulations in the MOZART-2 tropospheric chemistry model, we show that tropospheric O3 responds approximately linearly to changes in CH4 emissions over a range of anthropogenic emissions from 0–430 Tg CH4 a 1 (0.11–0.16 Tg tropo...
متن کامل