Online simulations of global aerosol distributions in the NASA GEOS‐4 model and comparisons to satellite and ground‐based aerosol optical depth

Abstract

[1] We have implemented a module for tropospheric aerosols (GOCART) online in the NASA Goddard Earth Observing System version 4 model and simulated global aerosol distributions for the period 2000-2006. The new online system offers several advantages over the previous offline version, providing a platform for aerosol data assimilation, aerosol-chemistry-climate interaction studies, and short-range chemical weather forecasting and climate prediction. We introduce as well a methodology for sampling model output consistently with satellite aerosol optical thickness (AOT) retrievals to facilitate model-satellite comparison. Our results are similar to the offline GOCART model and to the models participating in the AeroCom intercomparison. The simulated AOT has similar seasonal and regional variability and magnitude to Aerosol Robotic Network (AERONET), Moderate Resolution Imaging Spectroradiometer, and Multiangle Imaging Spectroradiometer observations. The model AOT and Angstrom parameter are consistently low relative to AERONET in biomass-burning-dominated regions, where emissions appear to be underestimated, consistent with the results of the offline GOCART model. In contrast, the model AOT is biased high in sulfate-dominated regions of North America and Europe. Our model-satellite comparison methodology shows that diurnal variability in aerosol loading is unimportant compared to sampling the model where the satellite has cloud-free observations, particularly in sulfate-dominated regions. Simulated sea salt burden and optical thickness are high by a factor of 2-3 relative to other models, and agreement between model and satellite over-ocean AOT is improved by reducing the model sea salt burden by a factor of 2. The best agreement in both AOT magnitude and variability occurs immediately downwind of the Saharan dust plume.Citation: Colarco, P., A. da Silva, M. Chin, and T. Diehl (2010), Online simulations of global aerosol distributions in the NASA GEOS-4 model and comparisons to satellite and ground-based aerosol optical depth,

Development towards a global operational aerosol consensus: basic climatological characteristics of the International Cooperative for Aerosol Prediction Multi-Model Ensemble (ICAP-MME)

“…DMS emissions (converted to SO 2 and then to sulfate) are based on Kettle et al (1999). Dust and sea salt emissions are as in Colarco et al (2010). Total mass of sulfate and hydrophobic and hydrophilic modes of carbonaceous aerosols are tracked, while for dust and sea salt the particle size distribution is explicitly resolved across five non-interacting size bins for each.…”

“…In addition to traditional meteorological parameters (winds, temperatures, etc. ; Rienecker et al, 2008), GEOS-5 includes modules to represent aerosols (Colarco et al, 2010) and tropospheric-stratospheric chemical constituents (Pawson et al, 2008), and their respective radiative feedback. Aerosols are handled through a version of the GO-CART (Chin et al, 2002) run online and radiatively coupled in GEOS-5.…”

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.…”

The GOddard SnoW Impurity Module (GOSWIM) for the NASA GEOS-5 Earth System Model: Preliminary Comparisons with Observations in Sapporo, Japan

“…Currently the mass concentration scheme is separately calculated outside of the snowpack model (currently 3 snow layers) (Lynch-Stieglitz 1994;Stieglitz et al 2001) in the Catchment LSM Koster et al 2000). The GOSWIM calculates the mass concentrations of the LAA depositions directly, using outputs from Goddard Chemistry Aerosol Radiation and Transport (GOCART) module (Chin et al 2000(Chin et al , 2002Ginoux et al 2001;Colarco et al 2010), coupled into NASA GEOS-5 (e.g., Rienecker et al 2008;Nowottnick et al 2011).…”