Aerosol Microphysical and Macrophysical Effects on Deep Convective Clouds

Friday, 19 December 2014
Tianle Yuan1,2, Zhanqing Li3, Eric M Wilcox4, Lazaros Oreopoulos2, Lorraine Ann Remer5, Hongbin Yu6, Steven E Platnick7, Derek J Posselt8, Zhibo Zhang9 and Jose-Vanderlei Martins5, (1)Joint Center for Earth Systems Technology, Baltimore, MD, United States, (2)NASA GSFC, Greenbelt, MD, United States, (3)Univ of Maryland College Park, College Park, MD, United States, (4)Desert Research Institute Reno, Reno, NV, United States, (5)University of MD Baltimore County, Baltimore, MD, United States, (6)University of Maryland College Park, College Park, MD, United States, (7)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (8)University of Michigan Ann Arbor, Ann Arbor, MI, United States, (9)University of Maryland Baltimore County, Baltimore, MD, United States
We illustrate a conceptual model of hydrometeor vertical development inside a convective cloud and its utility in studying of aerosol-DCC interactions. Both case studies and ensemble means are used to investigate aerosol-DCC interactions. We identify a few scenarios where possible signal of aerosol effect on DCC may be extracted. The results show a consistent and physically sound picture of aerosols affecting DCC microphysics as well as macrophysical properties. Specifically, pollutions and smokes are shown to consistently decrease ice particle size. On the contrary, dust particles close to source regions are shown to make cloud ice particle size more maritime like. We postulate that dust may achieve this by acting as either heterogeneous ice nuclei or giant cloud condensation nuclei. This contrast between smoke or pollution and dust also exists for their effects on cloud glaciation temperature. Smoke and pollution aerosols are shown to decrease glaciation temperature while dust particles do the opposite. Possible Implications of our results for studying aerosol indirect forcing, cirrus cloud properties, troposphere-stratosphere water vapor exchange and cloud latent heating are discussed.