A post-processing tool for Aerosol Optical Properties calculations

Written by Gabriele Curci

Quick Links

• Download source code: Please ask by email
• User's Guide: FlexAOD page on the GEOS-Chem wiki
• Usage Policy: Same as GEOS-Chem User Community
  (i.e., please consider FlexAOD as a new development)

FlexAOD publications

• Jeong, J., Jo, D. S., Park, R. J., Lee, H.-M., Curci, G., Kim, S-W. (2020), Parametric analysis for global single scattering albedo calculations, Atmospheric Environment, https://doi.org/10.1016/j.atmosenv.2020.117616 [abstract (html)] [full-text (pdf, 4.2 Mb)]
• Tuccella, P., Curci, G., Pitari, G., Lee, S., Jo, D. S. (2020), Direct radiative effect of absorbing aerosols: sensitivity to mixing state, brown carbon and soil dust refractive index and shape, J. Geophys. Res., https://doi.org/10.1029/2019JD030967 [abstract (html)] [full-text (pdf, 2.5 Mb)]
• Curci, G., Alyuz, U., Barò, R., Bianconi, R., Bieser, J., Christensen, J. H., Colette, A., Farrow, A., Francis, X., Jiménez-Guerrero, P., Im, U., Liu, P., Manders, A., Palacios-Peña, L., Prank, M., Pozzoli, L., Sokhi, R., Solazzo, E., Tuccella, P., Unal, A., Vivanco, M. G., Hogrefe, C., and Galmarini, S. (2019), Modelling black carbon absorption of solar radiation: combining external and internal mixing assumptions, Atmos. Chem. Phys., 19, 181-204, https://doi.org/10.5194/acp-19-181-2019 [abstract (html)] [full-text (pdf, 4.1 Mb)]
• Jin, X., Fiore, A. M., Curci, G., Lyapustin, A., Civerolo, K., Ku, M., van Donkelaar, A., and Martin, R. V. (2019), Assessing uncertainties of a geophysical approach to estimate surface fine particulate matter distributions from satellite-observed aerosol optical depth, Atmos. Chem. Phys., 19, 295-313, https://doi.org/10.5194/acp-19-295-2019 [abstract (html)] [full-text (pdf, 4.0 Mb)]
• Souri, A. H., Choi, Y., Pan, S., Curci, G., Nowlan, C. R., Janz, S. J., Kowalewski, M. G., Liu, J., Herman, J. R., and Weinheimer, A. J. (2018), First Top-Down Estimates of Anthropogenic NOx Emissions Using High-Resolution Airborne Remote Sensing Observations, J. Geophys. Res., 7 march 2018, doi:10.1002/2017JD028009 [abstract (html)] [full-text (pdf, 5.2 Mb)]
• Lefevre, J., Menkes, C., Bani, P., Marchesiello, P., Curci, G., Grell, G. A., Frouin, R. (2015), Distribution of sulfur aerosol precursors in the SPCZ released by continuous volcanic degassing at Ambrym, Vanuatu, Journal of Volcanology and Geothermal Research, doi: 10.1016/j.jvolgeores.2015.07.018 [full-text (pdf, 3.0 Mb)]
• Curci, G., Hogrefe, C., Bianconi, R., Im, U., Balzarini, A., Baro, R., Brunner, D., Forkel, R., Giordano, L., Hirtl, M., Honzak, L., Jimenez-Guerrero, P., Knote, C., Langer, M., Makar, P.A., Pirovano, G., Perez, J.L., San Jose, R., Syrakov, D., Tuccella, P., Werhahn, J., Wolke, R., Zabkar, R., Zhang, J., Galmarini, S. (2015), Uncertainties of simulated aerosol optical properties induced by assumptions on aerosol physical and chemical properties: an AQMEII-2 perspective, Atmos. Environ., 115, 541-552, doi: 10.1016/j.atmosenv.2014.09.009 [Open Access full-text]
  
• Curci, G. (2013), Sensitivity tests with GEOS-Chem aerosol optical properties in comparison with satellite and sunphotometer, 6^th International GEOS-Chem Meeting, Harvard University, Cambridge, MA, USA, 6-9 May 2011. [Presentation (pdf, 4.2 Mb)]
• Curci, G., (2012), FlexAOD: A Chemistry-transport Model Post-processing Tool for A Flexible Calculation of Aerosol Optical Properties, Proceedings of the 9th International Symposium on Tropospheric Profiling, L'Aquila, Italy, September 2012, ISBN/EAN: 978-90-815839-4-7, [full-text (pdf, 370 kb)] [PowerPoint Presentation (pptx, 3.2 Mb)]
• Curci, G. (2011), A new GEOS-Chem post-processing tool for aerosol optical properties calculations, 5^th International GEOS-Chem Meeting, Harvard University, Cambridge, MA, USA, 2-5 May 2011. [Presentation (pdf, 1.9 Mb)]

Short description

Primary motivation for development of FlexAOD (Flexible Aerosol Optical Depth) is the increasing availability of ground-based (e.g. AERONET) and satellite-based (e.g. MISR and CALIPSO) measurements of atmospheric aerosol optical properties. In addition to Aerosol Optical Depth (AOD) at several wavelengths, also other properties such as the Single Scattering Albedo or the Size Distribution are becoming more common products.

The development of FlexAOD started as a post-processing tool for the GEOS-Chem chemistry-transport model. The standard on-line AOD diagnostic of GEOS-Chem chemistry-transport model (see GEOS-Chem wiki for details) may pose limits to full exploitation of the information content of aerosol observations in combination with model simulations. FlexAOD is aimed at filling this gap. The development of the code stems from the on-line AOD diagnostic of GEOS-Chem: aerosol optical properties are calculated for 6 «optical» aerosol species (inorganic ions (sulfate + nitrate + ammonium), organic carbon, blank carbon, sea salts, and soil dust) assumed as externally mixed. In its present version, FlexAOD allows the user to:

• calculate AOD at several wavelngths without repeating the chemistry-transport model simulation
• calculate additional aerosol optical properties (e.g. single scattering albedo, backscattering coefficient, asymmetry factor, etc.)
• extract aerosol concentrations and optical profiles at selected locations and times
• prepare aerosol input to Radiative Transfer Model (e.g. libRadtran)
• post-process the output of GEOS-Chem chemistry-transport models, while the interface with CHIMERE, CAMS, WRF/Chem is under development

The capabilities of FlexAOD will be gradually expanded. A few developments are on the pipeline (e.g. options for aerosol internal mixing assumptions, AERONET-like output variables, size-limited calculations (e.g. AOD due to particles less than 1 µm), more flexible treatment of aerosol species), and others might be coming out from the user community.

Please address any comment/suggestion to the author!

Acknowledgement

This activity is supported by the Italian Space Agency (ASI) in the frame of PRISMA.