Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 7 13 2007 10.5194/acp-7-3497-2007 http://www.atmos-chem-phys.net/7/3497/2007/ http://www.atmos-chem-phys.net/7/3497/2007/acp-7-3497-2007.html http://www.atmos-chem-phys.net/7/3497/2007/acp-7-3497-2007.pdf 3497 3505 2007-07-03 The effects of heating by transported dust layers on cloud and precipitation: a numerical study Y. Yin yyatnuist@yahoo.co.uk L. Chen Nanjing University of Information Science and Technology, Nanjing 210044, China There have been numerous recent publications showing that mineral dust might be a good absorber for solar radiation in addition to its capability to act as cloud condensation nuclei (CCN) and ice forming nuclei (IFN), and could lead to reduced cloud cover and precipitation in the region where it is present. This effect is investigated using a dynamic cloud model with detailed microphysics of both warm and ice phase processes. The model is initialized using measured size distributions and concentrations of mineral dust particles. Our results show that when dust appears at the cloud-base height and below 3 km, where the temperature is warmer than −5°C, the heating induced by the presence of dust layers can inhibit the formation of cloud droplets and suppresses the development of precipitation, leading to lower cloud optical depth and albedo. On the other hand, when the dust layers are located at altitudes with temperature colder than −5°C, or above the −5°C level, mineral aerosols can act as effective ice nuclei, intensify the ice-forming processes, and may enhance the development of cloud and precipitation. It is also found that the heating effect is more pronounced in continental clouds than in maritime clouds. Andreae, M. O., Charlson, R. J., Bruynseels, F., Storms, H., van Grieken, R., and Maenhaut, W.: Internal mixtures of sea salt, silicates and excess sulfate in marine aerosols, Science, 232, 1620–1623, 1986. Bauer, S. E., Mishchenko, M. I., Lacis, A. A., Zhang, S., Perlwitz, J., and Metzger, S. M.: Do sulfate and nitrate coatings on mineral dust have important effects on radiative properties and climate modeling?, J. Geophys. Res., 112, D06307, doi:10.1029/2005JD006977, 2007. Cheng, T. and Shen, Z.: The radiative forcing of atmospheric dust in northwest China (in Chinese with English abstract), Plateau Meteorol., 21(5), 473–478, 2002. Cooper, W. A. and Lawson, R. P.: Physical interpretation of results from the HIPLEX-1 experiment, J. Clim. Appl. Meteor., 23, 523–540, 1984. Costa, M. J., Sohn, B.-J., Levizzani, V., and Silva, A. M.: Radiative forcing of Asian dust determined from the synergized GOME and GMS satellite data – A case study, J. Meteorol. Soc. Jpn., 84, 85–95, 2006. DeMott, P. J., Sassen, K., Poellot, M. R., et al.: African dust aerosols as atmospheric ice nuclei, Geophys. Res. Lett., 30(14), 1732, doi:10.1029/2003GL017410, 2003. Dubovik, O., Holben, B., Eck, T. F., et al.: Variability of absorption and optical properties of key aerosol types observed in worldwide locations, J. Atmos. Sci, 59, 590–608, 2002. Huang, J., Minnis, P., Lin, B., et al.: Possible influences of Asian dust aerosols on cloud properties and radiative forcing observed from MODIS and CERES, Geophys. Res. Lett., 33, L06824, doi:10.1029/2005GL024724, 2006a. Huang, J., Lin, B., Minnis, P., et al.: Satellite-based assessment of possible dust aerosols semi-direct effect on cloud water path over East Asia, Geophys. Res. Lett., 33, L19802, doi:10.1029/2006GL026561, 2006b. Intergovernmental Panel on Climate Change (IPCC), World Meteorological Office, United Nations Environmental Programme: Summary for Policymakers, 2001. Israelevich, P. L., Levin, Z., Joseph, J. H., and Ganor, E.: Desert aerosol transport in the Mediterranean region as inferred from the TOMS aerosol index, J. Geophys. Res., 107(D21), 4572, doi:10.1029/2001JD002011, 2002. Jaenicke, R.: Aerosol physics and chemistry, in: Ladolt-Boernstein: Zahlenwerte und Funktionen aus Naturwissenschaften und Technik, Vol 4b, edited by: Fischer, G., Springer-Verlag, New York, 391–457, 1988. Krauss, T. W., Bruintjes, R. T., Verlinde, J., and Kahn, A.: Microphysical and radar observations of seeded and unseeded continental cumulus clouds, J. Clim. Appl. Meteor., 26, 585–606, 1987. Levin, Z., Ganor, E., and Gladstein, V.: The effects of desert particles coated with sulfate on rain formation in the eastern Mediterranean, J. Appl. Meteorol., 35, 1511–1523, 1996. Levin, Z., Teller, A., Ganor, E., and Yin, Y.: On the interactions of mineral dust, sea salt particles and clouds – Measurements and modeling study from the MEIDEX campaign, J. Geophys. Res., 110, D20202, doi:10.1029/2005JD005810, 2005. Lohmann, U. and Diehl, K.: Sensitivity Studies of the Importance of Dust Ice Nuclei for the Indirect Aerosol Effect on Stratiform Mixed-Phase Clouds, J. Atmos. Sci., 63, 968–982, 2006. Niu, S., Zhang, C., and Sun, J.: A observational study of the particle spectra of dust aerosol over the Helan Mts. Region, Chinese J. Atmos. Sci., 25, 2, 243–252, 2001. Prospero, J. M.: Long range transport of mineral dust in the global atmosphere: Impact of African dust on the environment of the southeastern United States, Proc. Nat. Acad. Sci., 96, 3396–3403, 1999. Pruppacher, H. R. and Klett, J. D.: Microphysics of Clouds and Precipitation, D Reidel, 714~pp., 1997. Reisin, T., Levin, Z., and Tzivion, S.: Rain production in convective clouds as simulated in an axisymmetric model with detailed microphysics, Part I: Description of the model, J. Atmos. Sci., 53, 497–519, 1996. Rosenfeld, D., Rudich, Y., and Lahav, R.: Desert dust suppressing precipitation: A possible desertification feedback loop, Proc. Natl. Acad. Sci. USA, 98, 11, 5975–5980, 2001. Rudich Y., Khersonsky, O., and Rosenfeld, D.: Treating clouds with a grain of salt, Geophys. Res. Lett., 29, 22, 2060, doi:10.1029/2002GL016055, 2002. Teller, A. and Levin, Z.: The effects of aerosols on precipitation and dimensions of subtropical clouds: a sensitivity study using a numerical cloud model, Atmos. Chem. Phys., 6, 67–80, 2006. Trochkine, D., Iwasaka, Y., Matsuki A., et al.: Mineral aerosol particles collected in Dunhuang, China, and their comparison with chemically modified particles collected over Japan, J. Geophys. Res., 108(D23), 8642, doi:10.1029/2002JD003268, 2003. Tzivion, S., Feingold, G., and Levin, Z.: A efficient numerical solution to the stochastic collection equation, J. Atmos. Sci., 44, 3139–3149, 1987. Tzivion, S., Feingold, G., and Levin, Z.: The evolution of raindrop spectra. Part II: Collisional collection/breakup and evaporation in a rainshaft, J. Atmos. Sci., 46, 3312–3327, 1989. Tzivion, S., Reisin, T., and Levin, Z.: A numerical solution of the kinetic collection equation using high spectral grid resolution: A proposed reference, J. Comput. Phys., 148, 527–544, 1999. Wurzler, S., Reisin, T. G., and Levin, Z.: Modification of mineral dust particles by cloud processing and subsequent effects on drop size distributions, J. Geophys. Res., 105(D4), 4501–4512, 2000. Yin, Y., Levin, Z., Reisin, T. G., et al.: The effect of giant cloud condensation nuclei on the development of precipitation in convective clouds – A numerical study, Atmos. Res., 53, 91–116, 2000. Yin, Y., Wurzler, S., Levin, Z., et al.: Effects on precipitation and cloud optical properties, J. Geophys. Res., 107(D23), 4724, doi:10.1029/2001JD001544, 2002. Yin, Y., Carslaw, K. S., and Feingold, G.: Vertical transport and processing of aerosols in a mixed-phase convective cloud and the feedback on cloud development, Q. J. Roy. Meteor. Soc., 131, 221–246, 2005. Zhang, X. Y., Gong, S. L., Shen, Z. X., et al.: Characterization of soil dust aerosol in China and its transport and distribution during 2001 ACE-Asia: 1. Network observations, J. Geophys. Res., 108(D9), 4261, doi:10.1029/2002JD002632, 2003. Zhao, T. L., Gong, S. L., Zhang, X. Y., and McKendry, I. G.: Modeled size-segregated wet and dry deposition budgets of soil dust aerosol during ACE-Asia 2001: Implications for trans-Pacific transport, J. Geophys. Res., 108(D23), 8665, doi:10.1029/2002JD003363, 2003. Zhao, T. L., Gong, S. L., Zhang, X. Y., Blanchet, J. P., McKendry, I. G., and Zhou, Z. J.: A simulated climatology of Asian dust aerosol and its trans-Pacific transport. Part I: Mean climate and validation, J. Clim, 19, 88–103, 2006.