References

ACP

Atmospheric Chemistry and Physics

ACP

Atmos. Chem. Phys.

1680-7324

Copernicus Publications

Göttingen, Germany

10.5194/acp-14-877-2014

A new method for evaluating the impact of vertical distribution on aerosol radiative forcing in general circulation models

Vuolo

M. R.

¹ ⁴ Schulz

https://orcid.org/0000-0003-4493-4158

¹ ² Balkanski

https://orcid.org/0000-0001-8241-2858

¹ Takemura

https://orcid.org/0000-0002-2859-6067

Laboratoire des Sciences du Climat et l'Environnement, UMR8212, CEA-CNRS-UVSQ, Gif-sur-Yvette, France

Norwegian Meteorological Institute, Oslo, Norway

Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan

now at: Institut National de la Recherche Agronomique, Thiverval-Grignon, France

24 01 2014

14 2 877 897

2014

This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/

This article is available from https://acp.copernicus.org/articles/14/877/2014/acp-14-877-2014.html

The full text article is available as a PDF file from https://acp.copernicus.org/articles/14/877/2014/acp-14-877-2014.pdf

The quantification and understanding of direct aerosol forcing is essential in the study of climate. One of the main issues that makes its quantification difficult is the lack of a complete understanding of the role of the vertical distribution of aerosols and clouds. This work aims at reducing the uncertainty of aerosol top-of-the-atmosphere (TOA) forcing due to the vertical superposition of several short-lived atmospheric components, in particular different aerosol species and clouds. We propose a method to quantify the contribution of different parts of the atmospheric column to the TOA forcing as well as to evaluate the contribution to model differences that is exclusively due to different spatial distributions of aerosols and clouds. We investigate the contribution of aerosol above, below and in clouds by using added diagnostics in the aerosol–climate model LMDz. We also compute the difference between the TOA forcing of the ensemble of the aerosols and the sum of the forcings from individual species in clear sky. This difference is found to be moderate for the global average (14%) but can reach high values regionally (up to 100%). Nonlinear effects are even more important when superposing aerosols and clouds. Four forcing computations are performed: one where the full aerosol 3-D distribution is used, and then three where aerosols are confined to regions above, inside and below clouds, respectively. We find that the TOA forcing of aerosols depends crucially on the presence of clouds and on their position relative to that of the aerosol, in particular for black carbon (BC). We observe a strong enhancement of the TOA forcing of BC above clouds, attenuation for BC below clouds, and a moderate enhancement when BC is found within clouds. BC above clouds accounts for only about 30% of the total BC optical depth but for 55% of the forcing, while forcing efficiency increases by a factor of 7.5 when passing from below to above clouds. <br><br> The different behaviour of forcing nonlinearities for these three components of the atmospheric column encouraged us to develop the method for application to inter-model variability studies by reading 3-D aerosol and cloud fields from different general circulation models (GCMs) into the same model. We apply the method to the comparison of forcing due to the aerosols and clouds distributions of the general circulation models LMDz and SPRINTARS. The different amount of BC above but also within clouds is revealed to play a major role on the differences of cloudy-sky forcings between the two models, which can exceed 100% regionally.

References 1

Albrecht, B. A.: Aerosols, cloud microphysics, and fractional cloudiness, Science, 245, 1227–1230, 1989.

Bellouin, N., Boucher, O., Haywood, J., and Reddy, M. S.: Global estimate of aerosol direct radiative forcing from satellite measurements, Nature, 438, 1138–1141, 2005.

Bellouin, N., Jones, A., Haywood, J., and Christopher, S. A.: Updated estimate of aerosol direct radiative forcing from satellite observations and comparison against the Hadley Centre climate model, J. Geophys. Res., 113, D10205, <a href="http://dx.doi.org/10.1029/2007JD009385">https://doi.org/10.1029/2007JD009385</a>, 2008.

Boucher, O. and Haywood, J.: On summing the components of radiative forcing of climate change, Clim. Dynam., 18, 297–302, 2001.

Boucher, O. and Pham, M.: History of sulfate aerosol radiative forcings, Geophys. Res. Lett., 29, 1308, <a href="http://dx.doi.org/10.1029/2001GL014048">https://doi.org/10.1029/2001GL014048</a>, 2002.

Boucher, O., Schwartz, S., Ackerman, T., Anderson, T., Bergstrom, B., Bonnel, B., Chylek, P., Dahlback, A., Fouquart, Y., Fu, Q., Halthore, R., Haywood, J., Iversen, T., Kato, S., Kinne, S., Kirkevag, A., Knapp, K., Lacis, A., Laszlo, I., Mishchenko, M., Nemesure, S., Ramaswamy, V., Roberts, D., Russell, P., Schlesinger, M., Stephens, G., Wagener, R., Wang, M., Wong, J., and Yang, F.: Intercomparison of models representing direct shortwave radiative forcing by sulfate aerosols, J. Geophys. Res.-Atmos., 103, 16979–16998, 1998.

Chand, D., Anderson, T. L., Wood, R., Charlson, R. J., Hu, Y., Liu, Z., and Vaughan, M.: Quantifying above-cloud aerosol using spaceborne lidar for improved understanding of cloudy-sky direct climate forcing, J. Geophys. Res., 113, D13206, <a href="http://dx.doi.org/10.1029/2007JD009433">https://doi.org/10.1029/2007JD009433</a>, 2008.

Chand, D., Wood, R., Anderson, T. L., Satheesh S. K., and Charlson, R. J.: Satellite-derived direct radiative effect of aerosols dependent on cloud cover, Nat. Geosci., 2, 181–184, <a href="http://dx.doi.org/10.1038/NGEO437">https://doi.org/10.1038/NGEO437</a>, 2009.

Charlson, R. J., Schwartz, S. E., Hales, J. M., Cess, R. D., Coakley, J. A., Hansen, J. E., and Hofmann, D. J.: Climate forcing by anthropogenic aerosols, Science, 255, 423–430, 1992.

Chepfer, H., Bony, S., Winker, D., Chiriaco, M., Dufresne, J., and Sèze, G.: Use of CALIPSO lidar observations to evaluate the cloudiness simulated by a climate model, Geophys. Res. Lett., 35, L15804, <a href="http://dx.doi.org/10.1029/2008GL034207">https://doi.org/10.1029/2008GL034207</a>, 2008.

Chylek, P. and Wong, J. G. D.: Cloud radiative forcing ratio – An analytical model, Tellus A, 50, 259–264, 1998.

Conant, W. C., Seinfeld, J. H., Wang, J., Carmichael, G. R., Tang, Y., Uno, I., Flatau, P. J., Markowicz, K. M., and Quinn, P. K.: A model for the radiative forcing during ACE-Asia derived from CIRPAS Twin Otter and R/V Ronal H. Brown data and comparison with observations, J. Geophys. Res., 108, 8661, <a href="http://dx.doi.org/10.1029/2002JD003260">https://doi.org/10.1029/2002JD003260</a>, 2003.

Cooke, W. F. and Wilson, J. J. N.: A global black carbon aerosol model, J. Geophys. Res., 101, 19395–19409, 1996.

Corti, T. and Peter, T.: A simple model for cloud radiative forcing, Atmos. Chem. Phys., 9, 5751–5758, <a href="http://dx.doi.org/10.5194/acp-9-5751-2009">https://doi.org/10.5194/acp-9-5751-2009</a>, 2009.

Fouquart, Y. and Bonnel, B.: Computations of solar heating of the Earth s atmosphere: a new parameterization, Beitr. Phys. Atmos., 53, 35–62, 1980.

Gómez-Amo, J. L., di Sarra, A., Meloni, D., Cacciani, M., and Utrillas, M. P.: Sensitivity of shortwave radiative fluxes to the vertical distribution of aerosol single scattering albedo in the presence of a desert dust layer, Atmos. Environ., 44, 2787–2791, <a href="http://dx.doi.org/10.1016/j.atmosenv.2010.04.041">https://doi.org/10.1016/j.atmosenv.2010.04.041</a>, 2010.

Hansen, J., Sato, M., and Ruedy, R.: Radiative forcing and climate response, J. Geophys. Res., 102, 6831–6864, <a href="http://dx.doi.org/10.1029/96JD03436">https://doi.org/10.1029/96JD03436</a>, 1997.

Haywood, J. M. and Ramaswamy, V.: Global sensitivity studies of the direct radiative forcing due to anthropogenic sulfate and black carbon aerosols, J. Geophys. Res., 103, 6043–6058, 1998.

Haywood, J. M. and Shine, K. P.: Multi-spectral calculations of the direct radiative forcing of tropospheric sulphate and soot aerosols using a column model, Q. J. Roy. Meteor. Soc., 123, 1907–1930, 1997.

Hourdin, F., Musat, I., Bony, S., Braconnot, P., Codron, F., Dufresne, J.-L., Fairhead, L., Filiberti, M.-A., Friedlingstein, P., Grandpeix, J.-Y., Krinner, G., Levan, P., Li, Z.-X., and Lott, F.: The LMDZ4 general circulation model: climate performance and sensitivity to parametrized physics with emphasis on tropical convection, Clim. Dynam., 27, 787–813, 2006.

IPCC, Climate Change 2007: The Physical Science Basis, Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K. B., Tignor, M., and Miller, H. L., Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2007.

Koffi, B., Schulz, M., Breon, F.-M., Griesfeller, J., Winker, D., Balkanski, Y., Bauer, S., Berntsen, T., Chin, M., Collins, W. D., Dentener, F., Diehl, T., Easter, R., Ghan, S., Ginoux, P., Gong, S., Horowitz, L. W., Iversen, T., Kirkevag, A., Koch, D., Krol, M., Myhre, G., Stier, P., and Takemura, T.: Application of the CALIOP layer product to evaluate the vertical distribution of aerosols estimated by global models: AeroCom phase I results, J. Geophys. Res., 117, D10201, <a href="http://dx.doi.org/10.1029/2011JD016858">https://doi.org/10.1029/2011JD016858</a>, 2012.

Li, J., Hu, Y., Huang, J., Stamnes, K., Yi, Y., and Stamnes, S.: A new method for retrieval of the extinction coefficient of water clouds by using the tail of the CALIOP signal, Atmos. Chem. Phys., 11, 2903–2916, <a href="http://dx.doi.org/10.5194/acp-11-2903-2011">https://doi.org/10.5194/acp-11-2903-2011</a>, 2011.

Liao, H. and Seinfeld, J. H.: Radiative forcing by mineral dust aerosols: Sensitivity to key variables, J. Geophys. Res., 103, 31637–31645, 1998.

Liu, Q. and Weng, F.: Advanced Doubling–Adding Method for Radiative Transfer in Planetary Atmospheres, J. Atmos. Sci., 63, 3459–3465, 2006.

Meloni, D., Sarra, A. D., Iotio, T. D., and Fiocco, G.: Influence of the vertical profile of Saharan dust on the visible direct radiative forcing, J. Quant. Spectrosc. Ra., 93, 497–413, 2005.

Morcrette, J. J. and Fouquart, Y.: The overlapping of cloud layers in shortwave radiation parameterizations, J. Atmos. Sci., 43, 321–328, 1986.

Myhre, G., Samset, B. H., Schulz, M., Balkanski, Y., Bauer, S., Berntsen, T. K., Bian, H., Bellouin, N., Chin, M., Diehl, T., Easter, R. C., Feichter, J., Ghan, S. J., Hauglustaine, D., Iversen, T., Kinne, S., Kirkevåg, A., Lamarque, J.-F., Lin, G., Liu, X., Lund, M. T., Luo, G., Ma, X., van Noije, T., Penner, J. E., Rasch, P. J., Ruiz, A., Seland, Ø., Skeie, R. B., Stier, P., Takemura, T., Tsigaridis, K., Wang, P., Wang, Z., Xu, L., Yu, H., Yu, F., Yoon, J.-H., Zhang, K., Zhang, H., and Zhou, C.: Radiative forcing of the direct aerosol effect from AeroCom Phase II simulations, Atmos. Chem. Phys., 13, 1853–1877, <a href="http://dx.doi.org/10.5194/acp-13-1853-2013">https://doi.org/10.5194/acp-13-1853-2013</a>, 2013.

Peters, K., Quaas, J., and Bellouin, N.: Effects of absorbing aerosols in cloudy skies: a satellite study over the Atlantic Ocean, Atmos. Chem. Phys., 11, 1393–1404, <a href="http://dx.doi.org/10.5194/acp-11-1393-2011">https://doi.org/10.5194/acp-11-1393-2011</a>, 2011.

Podgorny, I. A. and Ramanathan, V.: A modeling study of the direct effect of aerosols over the tropical Indian Ocean, J. Geophys. Res., 106, 24097–24105, 2001.

Quaas, J., Boucher, O., and Breon, F. M.: Aerosol indirect effects in POLDER satellite data and the Laboratoire de Meteorologie Dynamique-Zoom (LMDZ) general circulation model, J. Geophys. Res., 109, D08205, <a href="http://dx.doi.org/10.1029/2003JD004317">https://doi.org/10.1029/2003JD004317</a>, 2004.

Rayner, N. A., Parker, D. E., Horton, E. B., Folland, C. K., Alexander, L. V., Rowell, D. P., Kent, E. C., and Kaplan, A.: Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century, J. Geophys. Res., 108, 4407, <a href="http://dx.doi.org/10.1029/2002JD002670">https://doi.org/10.1029/2002JD002670</a>, 2003.

Reddy, M. S., Boucher, O., Balkanski, Y., and Schulz, M.: Aerosol optical depths and direct radiative perturbations by species and source type, Geophys. Res. Lett., 32, L12803, <a href="http://dx.doi.org/10.1029/2004GL021743">https://doi.org/10.1029/2004GL021743</a>, 2005.

Samset, B. H. and Myhre, G.: Vertical dependence of black carbon, sulphate and biomass burning aerosol radiative forcing, Geophys. Res. Lett., 38, L24802, <a href="http://dx.doi.org/10.1029/2011gl049697">https://doi.org/10.1029/2011gl049697</a>, 2011.

Samset, B. H., Myhre, G., Schulz, M., Balkanski, Y., Bauer, S., Berntsen, T. K., Bian, H., Bellouin, N., Diehl, T., Easter, R. C., Ghan, S. J., Iversen, T., Kinne, S., Kirkevåg, A., Lamarque, J.-F., Lin, G., Liu, X., Penner, J. E., Seland, Ø., Skeie, R. B., Stier, P., Takemura, T., Tsigaridis, K., and Zhang, K.: Black carbon vertical profiles strongly affect its radiative forcing uncertainty, Atmos. Chem. Phys., 13, 2423–2434, <a href="http://dx.doi.org/10.5194/acp-13-2423-2013">https://doi.org/10.5194/acp-13-2423-2013</a>, 2013.

Satheesh, S. K., Ramanathan, V., Jones, X., Lobert, J. M., Podgorny, I. H., Prospero, J. M., Holben, B. N., and Loeb, N. G.: A model for the natural and anthropogenic aerosols over the tropical Indian Ocean derived from Indian Ocean Experiment data, J. Geophys. Res., 104, 27421–27440, 1999.

Schulz, M., Textor, C., Kinne, S., Balkanski, Y., Bauer, S., Berntsen, T., Berglen, T., Boucher, O., Dentener, F., Guibert, S., Isaksen, I. S. A., Iversen, T., Koch, D., Kirkevåg, A., Liu, X., Montanaro, V., Myhre, G., Penner, J. E., Pitari, G., Reddy, S., Seland, Ø., Stier, P., and Takemura, T.: Radiative forcing by aerosols as derived from the AeroCom present-day and pre-industrial simulations, Atmos. Chem. Phys., 6, 5225–5246, <a href="http://dx.doi.org/10.5194/acp-6-5225-2006">https://doi.org/10.5194/acp-6-5225-2006</a>, 2006.

Simmons, A., Uppala, S., Dee, D., and Kobayashi, S.: ERA-Interim: new ECMWF reanalysis products from 1989 onwards, ECMWF Newsletter articles, 110, 25–35, 2006.

Takemura, T., Nakajima, T., Dubovik,O., Holben, B. N., and Kinne, S.: Single scattering albedo and radiative forcing of various aerosol species with a global three-dimensional model, J. Climate, 15, 333–352, 2002.

Takemura, T., Nozawa, T., Emori, S., Nakajima, T., and Nakajima, T.: Simulation of climate response to aerosol direct and indirect effects with aerosol transport-radiation model, J. Geophys. Res., 110, D02202, <a href="http://dx.doi.org/10.1029/2004JD005029">https://doi.org/10.1029/2004JD005029</a>, 2005.

Turpin, B. J. and Lim, H. J.: Species contributions to PM<sub>2.5</sub> mass concentrations: Revisiting common assumptions for estimating organic mass, Aerosol Sci. Tech., 35, 602–610, 2001.

Twomey, S.: Pollution and the planetary albedo, Atmos. Environ., 8, 1251–1256, 1974.

Twomey, S.: Aerosols, clouds, and radiation, Atmos. Environ., 25, 2435–2442, 1991.

Visser, H., Folkert, R. J. M., Hoekstra, J., and de Wolff, J. J.: Identifying Key Sources of Uncertainty in Climate Change Projections, Clim. Change, 45, 421–457, 2000.

Vuolo, M. R., Chepfer, H., Menut, L., and Cesana, G.: Comparison of mineral dust layers vertical structures modelled with Chimere-Dust and observed with the Caliop lidar, J. Geophys. Res., 114, 1984–2012, <a href="http://dx.doi.org/10.1029/2008JD011219">https://doi.org/10.1029/2008JD011219</a>, 2009.

Zarzycki, C. M. and Bond, T. C.: How much can the vertical distribution of black carbon affect its global direct radiative forcing?, Geophys. Res. Lett., 37, L20807, <a href="http://dx.doi.org/10.1029/2010gl044555">https://doi.org/10.1029/2010gl044555</a>, 2010.