Deployment of the ARM Mobile Facility (AMF) and the ARM Ancillary Facility (AAF) to Study Aerosol Indirect Effect in China 2008 Zhanqing Li 1 , Graeme L. Stephens 2 , Si-Chee Tsay 3 , Mark Miller 4 , Yangang Liu 4 , Hongbin Chen 5 , Jianping Huang 6 , Daren Lu 5 , Guangyu Shi 5 , Guoxiong Wu 5 1. Department of Atmospheric and Oceanic Science/ESSIC, University of Maryland, College Park, MD 2. Dept of Atmospheric Sciences, Colorado State University, Fort Collins, CO 3. Radiation and Climate Branch, NASA Goddard Space Flight Center, Greenbelt, MD 4. Brookhaven National Lab, Long Island, NY 5. Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China 6. School of Atmospheric Sciences, Lanzhou University, Lanzhou, China Introduction Aerosols in China have exceptionally high loading and diverse properties whose influence has been detected across the Pacific Rim. The rapid pace of changes in the atmospheric environment over China provides a natural testbed for identifying and quantifying the climatic effects of aerosols. Preliminary analyses of multiple satellite datasets (MODIS, TMI, TRMM) indicate more complex and unique aerosol indirect effects than what is found in relatively cleaner environments. Unfortunately, China is one of the least observed regions, especially in terms of aerosol and cloud properties. To verify the satellite findings and gain a deeper understanding requires either in-situ measurements or independent ground-based remote sensing data or ideally both. To this end, the AMF and AAF will be deployed to southern and northern China to study the climatic effects of both anthropogenic (pollutants) and natural aerosols (primarily dust) from March to December 2008 References (selected from EAST-AIRE special issue) Li, Z., X., Xia, M. Cribb, M. Wen, B. Holben, H. Chen, P. Wang, S.-C. Tsay, T.F. Eck, F. Zhao, E.G. Dutton, R.E. Dickerson, 2006, Aerosol optical properties and its radaitive effects in northern China, J. Geophy. Res., EAST-AIRE special section, in press. Li, C., L.T. Marufu, R. R. Dickerson, Z. Li, T. Wen, Y. Wang, P. Wang, H. Chen, J. W. Stehr, In-situ measurements of trace gases and aerosol optical properties at a rural site in northern China during EAST-AIRE IOP 2005. J. Geophy. Res. Special Issue on EAST-AIRE, in press. Xin, J., Y. Wang, Z. Li, P. Wang, W.-M. Hao, B.L. Nordgren, S. Wang, G. Liu, L. Wang, Y. Sun, B. Hu, AOD and Angstrom exponent of aerosols observed by the Chinese Sun Hazemeter Network from August 2004 to September 2005, J. Geophy. Res. Special Issue on EAST-AIRE, in press. Zhao, Z., and Z. Li, 2006, Estimation of aerosol single scattering albedo from solar direct spectral radiance and total broadband irradiances. J. Geophy. Res. Special Issue on EAST-AIRE, in press. Xia, X., H. Chen, Z. Li, P. Wang, J. Wang, Significant reduction of surface solar irradiance induced by aerools in a suburban region in northeastern China, J. Geophy. Res. Special Issue on EAST-AIRE, in press. Dickerson, R.R., C. Li, Z. Li, J.W. Stehr, H. Chen, P. Wang, X. Xia, X. Ban, F. Gong, J. Yuan, J. Yang, Aircraft observations of dust and pollutants over NE China: Insight into the meteorological mechanisms of long-range transport, J. Geophy. Res. Special Issue on EAST-AIRE, under revision. Instruments deployed in the past and ongoing experiments Goals 1. Acquisition of essential cloud, aerosol and meteorological parameters using the ARM mobile facility to validate satellite-based findings; 2. Use of AMF measurements together with validated satellite retrievals and in-situ data to understand the mechanisms of the aerosol indirect effects in the region; 3. Examination of the roles of aerosols in affecting regional climate and atmospheric circulation with a special focus on the impact of the East Asian monsoon system. Key Science Questions to Address  How different are the cloud microphysics over heavily polluted How different are the cloud microphysics over heavily polluted regions in regions in China from those found in clean regions elsewhere with similar China from those found in clean regions elsewhere with similar meteorological meteorological conditions? conditions?  Are the clouds embedded in severely polluted regions less effi Are the clouds embedded in severely polluted regions less efficient in producing cient in producing rainfall than clouds in clean regions? rainfall than clouds in clean regions?  What are the major mechanisms for aerosols in China to affect pr What are the major mechanisms for aerosols in China to affect precipitation, ecipitation, cloud microphysics, water content and cloud lifetimes ? cloud microphysics, water content and cloud lifetimes ?  What are the impacts of aerosols emitted in China on the East As What are the impacts of aerosols emitted in China on the East Asian monsoon ian monsoon system, and regional and global climate? system, and regional and global climate?  To what extent do changes in aerosol emissions in China contribu To what extent do changes in aerosol emissions in China contribute to the te to the observed changes in cloud and precipitation, especially with reg observed changes in cloud and precipitation, especially with regards to the trend of ards to the trend of the northern drought and southern flooding? the northern drought and southern flooding? Observations and Objectives  Deployment of the AMF in China for one year to acquire extensive measurements of aerosols, cloud, precipitation and radiation in northern and southern China, which are characterized by distinct climates and aerosol emissions;  Enhancement of existing baseline ground observation stations and nation-wide aerosol survey stations so that the major types of aerosols are characterized and their temporal and spatial variations across China are quantified;  Use of US airborne instruments onboard Chinese aircraft to measure the profiles of aerosol properties and cloud microphysics  Acquisition, validation & improvement of remote sensing data sets from various sensors over the region in order to identify, reduce or remove any systematic errors. Taihu Site - Lake Deployment: March – December 2008 (AMF) Location: 31.702ºN, 120.358ºE Elevation: 10 m Cities nearby: Wuxi, Suzhou, Shanghai, Hangzhu, Nanjing Annual Rainfall: 1184.4 mm Annual Cloud Amount: 62% Mean aerosol optical depth: 0.78 Mean aerosol single scattering albedo: 0.93 Mean aerosol Angstrom exponent: 1.21 b wRH a RH R − ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ > < − ⋅ = 100 1 ) ( Beijing (75 km) Tianjin (130 km) Xianghe Zhangye Lanzhou (350 km) Xianghe Site - Plain Deployment: February – May 2008 (AAF) Location: 39 o 45’14”N, 116 o 57’43”E Elevation: 36 m Cities Nearby: Wuxi, Suzhou, Shanghai, Hangzhu, Nanjing Annual Rainfall: 571.9 Annual Cloud Amount: 45% Mean aerosol optical depth: 0.82 Mean aerosol single scattering albedo: 0.90 Mean aerosol Angstrom exponent: ? Zhangye Site - Desert Deployment: June – December 2008 (AAF) Location: 31.702ºN, 120.358ºE, Elevation: 1477.2 m Cities nearby: Lanzhou, Jiayuguan, Jiuquan Annual Rainfall: 87.7 mm Annual Cloud Amount: 45% Annual mean aerosol optical depth: ? Annual mean aerosol single scattering albedo: ?