Atmospheric sulfur cycle simulated in the global model GOCART: Model description and global properties

Abstract

Abstract. The Georgia Tech/Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model is used to simulate the atmospheric sulfur cycle. The model uses the assimilated meteorological data from the Goddard Earth Observing System Data Assimilation System (GEOS DAS). Global sulfur budgets from a 6-year simulation for SOe, sulfate, dimethylsulfide (DMS), and methanesulfonic acid (MSA) are presented in this paper. In a normal year without major volcanic perturbations, about 20% of the sulfate precursor emission is from natural sources (biogenic and volcanic), and 80% is anthropogenic; the same sources contribute 33% and 67%, respectively, to the total sulfate burden. A sulfate production efficiency of 0.41-0.42 is estimated in the model, an efficiency which is defined as a ratio of the amount of sulfate produced to the total amount of SOe emitted and produced in the atmosphere. This value indicates that less than half of the SOe entering the atmosphere contributes to the sulfate production, the rest being removed by dry and wet depositions. In a simulation for 1990 we estimate a total sulfate production of 39 Tg S yr -•, with 36% and 64% from in-air and in-cloud oxidation, respectively, of SOe. We also demonstrate that major volcanic eruptions, such as the Mount Pinatubo eruption in 1991, can significantly change the sulfate formation pathways, distributions, abundance, and lifetime. Comparison with other models shows that the parameterizations for wet removal or wet production of sulfate are the most critical factors in determining the burdens of SO2 and sulfate. Therefore a priority for future research should be to reduce the large uncertainties associated with the wet physical and chemical processes.

Air quality modelling in the summer over the eastern Mediterranean using WRF-Chem: chemistry and aerosol mechanism intercomparison

“…The differences between the two simulations using the MOSAIC aerosol mechanism may be attributed to the chemical processes that act as sources/sinks of SO 2 . The inclusion of the heterogeneous SO 2 cloud oxidation in the RMS mechanism results in higher sulfate aerosol concentrations (NMB = 38 %), as described in de Brugh et al (2011) and Balzarini et al (2015). Elemental carbon is underestimated by all three mechanisms indicating lack of emission sources.…”

“…Guenther et al (2012). We use the Air Force Weather Agency (AFWA) dust scheme that was developed based on the Marticorena and Bergametti (1995) dust emission scheme in the Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model (Chin et al, 2000). The EDGAR-HTAP (Emission Database for Global Atmos.…”

“…Since this simulation uses the same aerosol mechanism with the MM simulation, and therefore the same heterogeneous nucleation rates from sulfuric acid (H 2 SO 4 ) to sulfate aerosols, the differences between the CM and MM simulations are attributed to the chemical processes that act as sources/sinks of H 2 SO 4 . The RMS mechanism includes the heterogeneous SO 2 cloud oxidation (de Brugh et al, 2011;Balzarini et al, 2015), which results in higher sulfate aerosol concentrations compared to CM and MM.…”

Evaluation of GOME satellite measurements of tropospheric NO2 and HCHO using regional data from aircraft campaigns in the southeastern United States

“…Photolysis frequencies are computed using the Fast-J radiative transfer algorithm [Wild et al, 2000] which includes Rayleigh scattering as well as Mie scattering by clouds and aerosols. Aerosol fields affecting radiation and heterogeneous chemistry are 3-D monthly means from a 1996-1997 simulation with the GOCART model [Chin et al, 2000;Ginoux et al, 2001;Chin et al, 2002] which uses the same GEOS meteorological fields and transport algorithms as GEOS-CHEM.…”

An Unreported Asian Dust (Kosa) Event in Hokkaido, Japan: A Case Study of 7 March 2016

“…Recently, the next version of re-analysis data, called MERRA-2, was released (Bosilovich et al 2015), in which aerosol components were produced using the GOCART module (e.g., Chin et al 2000Chin et al , 2002Ginoux et al 2001;Colarco et al 2010) in the Goddard Earth Observing System, version 5 (GEOS-5) (Rienecker et al 2008). The aerosol data assimilation method uses MODIS, and other stellated-derived and ground-based Aerosol Optical Depth (AOD) data (e.g., Buchard et al 2016b;Randles et al 2016Randles et al , 2017.…”