Staff information

Research Interests

• Regional and global modeling of atmospheric aerosols, and their direct and indirect effects on global climate
• Sub-scale parameterizations of cloud microphysics, cloud-aerosol interactions, and their applications in the global models

Affiliations and Professional Service

• Member of American Geophysical Union (AGU)
• Member of American Meteorological Society (AMS)
• Member, Sigma Xi, The Scientific Research Society

Awards and Recognitions

• Guest Professor, Nanjing University, China, 2010/12-
• Guest Professor, Institute of Atmospheric Physics, Chinese Academy of Science, 2010/06-
• Outstanding Performance Award, Fundamental and Computational Science Directorate, Pacific Northwest National Laboratory, 2010
• World Meteorology Organization (WMO) Young Scientist Award, 2001
• World Meteorological Organization (WMO) Mariolopoulos-Kanaginis Award (Honorable Mention), for papers in the Atmospheric Environmental researches, 1998
• Alexander von Humboldt Research Fellow, 1996
• Elected into “100 Talent Program” of the Chinese Academy of Sciences, 1995

PNNL Publications

2012

• Liu X, RC Easter, Jr, SJ Ghan, RA Zaveri, PJ Rasch, X Shi, JF Lamarque, A Gettelman, H Morrison, F Vitt, A Conley, S Park, R Neale, C Hannay, AM Ekman, P Hess, N Mahowald, WD Collins, MJ Iacono, CS Bretherton, MG Flanner, and D Mitchell. 2012. "Toward a Minimal Representation of Aerosols in Climate Models: Description and Evaluation in the Community Atmosphere Model CAM5." Geoscientific Model Development 5(3):709-739.  doi:10.5194/gmd-5-709-2012
• Flanner MG, X Liu, C Zhou, JE Penner, and C Jiao. 2012. "Enhanced Solar Energy Absorption by Internally-mixed Black Carbon in Snow Grains." Atmospheric Chemistry and Physics 12(10):4699-4721.  doi:10.5194/acp-12-4699-2012
• Gantt B, J Xu, N Meskhidze, Y Zhang, A Nenes, SJ Ghan, X Liu, RC Easter, Jr, and RA Zaveri. 2012. "Global Distribution and Climate Forcing of Marine Organic Aerosol - Part 2: Effects on Cloud Properties and Radiative Forcing." Atmospheric Chemistry and Physics 12(14):6555-6563.  doi:10.5194/acp-12-6555-2012
• Gao Y, M Zhang, X Liu, and C Zhao. 2012. "Model analysis of the anthropogenic aerosol effect on clouds over East Asia." Atmospheric and Oceanic Science Letters, 5(1):1-7. 
• Gu Y, KN Liou, J Jiang, H Su, and X Liu. 2012. "Dust Aerosol Impact on North Africa Climate: A GCM Investigation of Aerosol-Cloud-Radiation Interactions Using A-Train Satellite Data." Atmospheric Chemistry and Physics 12(4):1667-1679.  doi:10.5194/acp-12-1667-2012
• Kulkarni GR, J Fan, JM Comstock, X Liu, and M Ovchinnikov. 2012. "Laboratory Measurements and Model Sensitivity Studies of Dust Deposition Ice Nucleation." Atmospheric Chemistry and Physics 12(16):7295-7308.  doi:10.5194/acp-12-7295-2012
• Wang M, SJ Ghan, X Liu, TL Ecuyer, K Zhang, H Morrison, M Ovchinnikov, RC Easter, Jr, R Marchand, D Chand, Y Qian, and JE Penner. 2012. "Constraining cloud lifetime effects of aerosols using A-Train satellite observations ." Geophysical Research Letters 39:L15709.  doi:10.1029/2012GL052204
• Zhao C, X Liu, and LYR Leung. 2012. "Impact of the Desert Dust on the Summer Monsoon System over Southwestern North America ." Atmospheric Chemistry and Physics 12(8):3717-3731.  doi:10.5194/acp-12-3717-2012
• Zhao C, SA Klein, S Xie, X Liu, J Boyle, and Y Zhang. 2012. "Aerosol First Indirect Effects on Non-Precipitating Low-Level Liquid Cloud Properties as Simulated by CAM5 at ARM Sites." Geophysical Research Letters 39:Article No. L08806.  doi:10.1029/2012GL051213

2011

• Fan J, SJ Ghan, M Ovchinnikov, X Liu, PJ Rasch, and A Korolev. 2011. "Representation of Arctic Mixed-Phase clouds and the Wegener-Bergeron-Findeisen Process in Climate Models: Perspectives from a Cloud-Resolving Study." Journal of Geophysical Research. D. (Atmospheres) 116:Article No. D00T07.  doi:10.1029/2010JD015375
• Gao Y, X Liu, C Zhao, and M Zhang. 2011. "Emission Controls Versus Meteorological Conditions in Determining Aerosol Concentrations in Beijing during the 2008 Olympic Games." Atmospheric Chemistry and Physics 11(23):12437-12451.  doi:10.5194/acp-11-12437-2011
• Ghan SJ, H Abdul-Razzak, A Nenes, Y Ming, X Liu, M Ovchinnikov, B Shipway, N Meskhidze, J Xu, and X Shi. 2011. "Droplet Nucleation: Physically-Based Parameterization and Comparative Evaluation." Journal of Advances in Modeling Earth Systems 3:Article No. M10001.  doi:10.1029/2011MS000074
• Han X, M Zhang, Z Han, JY Xin, and X Liu. 2011. "Simulation of aerosol direct radiative forcing with RAMS-CMAQ in East Asia." Atmospheric Environment 45(36):6576-6592.  doi:10.1016/j.atmosenv.2011.08.006
• Huneeus N, M Schulz, Y Balkanski, J Griesfeller, J Prospero, S Kinne, S Bauer, O Boucher, M Chin, F Dentener, T Diehl, RC Easter, Jr, D Fillmore, SJ Ghan, P Ginnoux, A Grini, L Horowitz, D Koch, M Krol, W Landing, X Liu, N Mahowald, R Miller, JJ Morcrette, G Myhre, J Penner, J Perlwitz, P Stier, T Takemura, and CS Zender. 2011. "Global dust model intercomparison in AeroCom phase I." Atmospheric Chemistry and Physics 11(15):7781-7816.  doi:10.5194/acp-11-7781-2011
• Koch D, Y Balkanski, S Bauer, RC Easter, Jr, S Ferrachat, SJ Ghan, C Hoose, T Iversen, A Kirkevag, JE Kristjansson, X Liu, U Lohmann, S Menon, J Quaas, M Schulz, O Seland, T Takemura, and N Yan. 2011. "Soot microphysical effects on liquid clouds, a multi-model investigation." Atmospheric Chemistry and Physics 11(3):1051-1064.  doi:10.5194/acp-11-1051-2011
• Liu X, S Xie, J Boyle, SA Klein, X Shi, Z Wang, W Lin, SJ Ghan, M Earle, P Liu, and A Zelenyuk. 2011. "Testing Cloud Microphysics Parameterizations in NCAR CAM5 with ISDAC and M-PACE Observations." Journal of Geophysical Research. D. (Atmospheres) 116:Article No: D00T11.  doi:10.1029/2011JD015889
• McFarquhar G, SJ Ghan, J Verlinde, A Korolev, JW Strapp, B Schmid, JM Tomlinson, M Wolde, SD Brooks, DJ Cziczo, MK Dubey, PhD, J Fan, CJ Flynn, I Gultepe, JM Hubbe, MK Gilles, A Laskin, P Lawson, WR Leaitch, PS Liu, X Liu, D Lubin, C Mazzoleni, AM Macdonald, RC Moffet, H Morrison, M Ovchinnikov, MD Shupe, DD Turner, S Xie, A Zelenyuk, K Bae, M Freer, and A Glen. 2011. "Indirect and Semi-Direct Aerosol Campaign: The Impact of Arctic Aerosols on Clouds ." Bulletin of the American Meteorological Society 92(2):183 - 201.  doi:10.1175/2010BAMS2935.1
• Meskhidze N, J Xu, B Gantt, Y Zhang, A Nenes, SJ Ghan, X Liu, RC Easter, Jr, and RA Zaveri. 2011. "Global distribution and climate forcing of marine organic aerosol: 1. Model improvements and evaluation." Atmospheric Chemistry and Physics 11(22):11689-11705.  doi:10.5194/acp-11-11689-2011
• Su H, J Jiang, X Liu, J Penner, WG Read, ST Massie, MR Schoeberl, P Colarco, NJ Livesey, and ML Santee. 2011. "Observed Increase of TTL Temperature and Water Vapor in Polluted Couds over Asia." Journal of Climate 24(11):2728-2736.  doi:10.1175/2010JCLI3749.1
• Wang M, SJ Ghan, M Ovchinnikov, X Liu, RC Easter, Jr, EI Kassianov, Y Qian, and H Morrison. 2011. "Aerosol Indirect effects in a multi-scale aerosol-climate model PNNL-MMF." Atmospheric Chemistry and Physics 11(11):5431-5455.  doi:10.5194/acp-11-5431-2011
• Wang M, SJ Ghan, RC Easter, Jr, M Ovchinnikov, X Liu, EI Kassianov, Y Qian, WI Gustafson, Jr, VE Larson, D Schanen, M Khairoutdinov, and H Morrison. 2011. "The multi-scale aerosol-climate model PNNL-MMF: model description and evaluation." Geoscientific Model Development 4(1):137-168.  doi:10.5194/gmd-4-137-2011
• Zhao C, X Liu, LYR Leung, and SM Hagos. 2011. "Radiative impact of mineral dust on monsoon precipitation variability over West Africa ." Atmospheric Chemistry and Physics 11(5):1879-1893.  doi:10.5194/acp-11-1879-2011

2010

• Liu X, and J Wang. 2010. "How Important Is Organic Aerosol Hygroscopicity to Aerosol Indirect Forcing?" Environmental Research Letters 5(4):Article No. 044010.  doi:10.1088/1748-9326/5/4/044010
• Bhattacharjee PS, YC Sud, X Liu, GK Walker, R Yang, and J Wang. 2010. "Importance of including ammonium sulfate ((NH4)2SO4) aerosols for ice cloud parameterization in GCMs." Annales Geophysicae 28(2):621-631. 
• DeMott PJ, AJ Prenni, X Liu, SM Kreidenweis, MD Petters, CH Twohy, MS Richardson, T Eidhammer, and DC Rogers. 2010. "Predicting global atmospheric ice nuclei distributions and their impacts on climate." Proceedings of the National Academy of Sciences of the United States of America 107(25):11217-11222.  doi:10.1073/pnas.0910818107
• Gettelman A, X Liu, SJ Ghan, H Morrison, S Park, A Conley, SA Klein, J Boyle, D Mitchell, and JLF Li. 2010. "Global Simulations of Ice nucleation and Ice Supersaturation with an Improved Cloud Scheme in the Community Atmosphere Model." Journal of Geophysical Research. D. (Atmospheres) 115:Article No. D18216.  doi:10.1029/2009JD013797
• Zhang K, H Wan, B Wang, M Zhang, J Feichter, and X Liu. 2010. "Tropospheric aerosol size distributions simulated by three online global aerosol models using the M7 microphysics module." Atmospheric Chemistry and Physics 10(13):6409-6434.  doi:10.5194/acp-10-6409-2010
• Zhao C, X Liu, LYR Leung, B Johnson, SA McFarlane, WI Gustafson, Jr, JD Fast, and RC Easter, Jr. 2010. "The spatial distribution of mineral dust and its shortwave radiative forcing over North Africa: Modeling sensitivities to dust emissions and aerosol size treatments ." Atmospheric Chemistry and Physics 10(18):8821-8838.  doi:10.5194/acp-10-8821-2010

2009

• Liu X, JE Penner, and M Wang. 2009. "Influence of Anthropogenic Sulfate and Black Carbon on Upper Tropospheric Clouds in the NCAR CAM3 Model Coupled to the IMPACT Global Aerosol Model." Journal of Geophysical Research. D. (Atmospheres) 114:Article number: D03204.  doi:10.1029/2008JD010492
• Wang W, and X Liu. 2009. "Evaluating Deep Updraft Formulation in NCAR CAM3 with High-Resolution WRF Simulations During ARM TWP-ICE." Geophysical Research Letters 36:Art. No. L04701.  doi:10.1029/2008GL036692
• Wang W, X Liu, S Xie, J Boyle, and SA McFarlane. 2009. "Testing ice microphysics parameterizations in the NCAR Community Atmospheric Model Version 3 using Tropical Warm Pool-International Cloud Experiment data." Journal of Geophysical Research. D. (Atmospheres) 114:Art. No. D14107.  doi:10.1029/2008JD011220
• Han X, M Zhang, X Liu, SJ Ghan, JY Xin, and LL Wang. 2009. "Development of RAMS-CMAQ to Simulate Aerosol Optical Depth and Aerosol Direct Radiative Forcing and Its Application to East Asia." Atmospheric and Oceanic Science Letters, 2(6):368 - 375. 
• Klein SA, R McCoy, H Morrison, A Ackerman, A Avramov, GIJS DeBoer, M Chen, JN Cole, AD DelGenio, M Falk, M Foster, A Fridlind, JC Golaz, T Hashino, JY Harrington, C Hoose, M Khairoutdinov, V Larson, X Liu, Y Luo, G McFarquhar, S Menon, R Neggers, S Park, MR Poellot, JM Schmidt, I Sednev, B Shipway, MD Shupe, D Spangenberg, Y Sud, DD Turner, D Veron, K Von Salzen, GK Walker, Z Wang, A Wolf, S Xie, KM Xu, F Yang, and G Zhang. 2009. "Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. I: Single layer cloud." Quarterly Journal of the Royal Meteorological Society 135(641 (Pt. B)):979-1002.  doi:10.1002/qj.416
• Koch D, M Schulz, S Kinne, CS McNaughton, JR Spackman, Y Balkanski, S Bauer, T Berntsen, TC Bond, O Boucher, M Chin, AD Clarke, N De Luca, F Dentener, T Diehl, O Dubovik, RC Easter, Jr, DW Fahey, J Feichter, D Fillmore, S Freitag, SJ Ghan, P Ginoux, S Gong, L Horowitz, T Iversen, A Kirkevag, Z Klimont, Y Kondo, M Krol, X Liu, R Miller, V Montanaro, N Moteki, G Myhre, J Penner, J Perlwitz, G Pitari, S Reddy, L Sahu, H Sakamoto, G Schuster, JP Schwarz, O Seland, P Stier, N Takegawa, T Takemura, C Textor, J van Aardenne, and Y Zhao. 2009. "Evaluation of Black Carbon Estimations in Global Aerosol Models." Atmospheric Chemistry and Physics 9:9001-9026. 
• Morrison H, R McCoy, SA Klein, S Xie, Y Luo, A Avramov, M Chen, JN Cole, M Falk, M Foster, AD Del Genio, JY Harrington, C Hoose, M Khrairoutdinov, V Larson, X Liu, G McFarquhar, MR Poellot, K Von Salzen, B Shipway, MD Shupe, YC Sud, DD Turner, D Veron, GK Walker, Z Wang, A Wolf, KM Xu, F Yang, and G Zhang. 2009. "Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. II: Multi layered cloud." Quarterly Journal of the Royal Meteorological Society 135(641 Pt. B):1003-1019.  doi:10.1002/qj.415
• Penner JE, Y Chen, M Wang, and X Liu. 2009. "Possible Influence of Anthropogenic Aerosols on Cirrus Clouds and Anthropogenic Forcing." Atmospheric Chemistry and Physics 9(3):879-896. 
• Quaas J, Y Ming, S Menon, T Takemura, M Wang, JE Penner, A Gettelman, U Lohmann, N Bellouin, O Boucher, AM Sayer, GE Thomas, A McComiskey, G Feingold, C Hoose, JE Kristjansson, X Liu, Y Balkanski, LJ Donner, P Ginoux, P Stier, B Grandey, J Feichter, I Sednev, SE Bauer, D Koch, RG Grainger, A Kirkevag, T Iversen, O Seland, RC Easter, Jr, SJ Ghan, PJ Rasch, H Morrison, JF Lamarque, MJ Iacono, S Kinne, and M Schulz. 2009. "Aerosol indirect effects - general circulation model intercomparison and evaluation with satellite data." Atmospheric Chemistry and Physics 9(22):8697-8717 . 
• Sud YC, E Wilcox, WK Lau, GK Walker, X Liu, A Nenes, D Lee , KM Kim, Y Zhou, and PS Bhattacharjee. 2009. "Sensitivity of Boreal-Summer Circulation and Precipitation to Atmospheric Aerosols in Selected Regions: Part I Africa and India ." Annales Geophysicae 27(10):3989-4007. 
• Wang M, JE Penner, and X Liu. 2009. "The Coupled IMPACT Aerosol and NCAR CAM3 Model: Evaluation of Predicted Aerosol Number and Size Distribution." Journal of Geophysical Research. D. (Atmospheres) 114:Art. No. D06302.  doi:10.1029/2008JD010459

2008

• Xie S, J Boyle, SA Klein, X Liu, and SJ Ghan. 2008. "Simulations of Arctic Mixed-Phase Clouds in Forecasts with CAM3 and AM2 for M-PACE." Journal of Geophysical Research. D. (Atmospheres) 113:Art. No. D04211.  doi:10.1029/2007JD009225

2007

• Liu X, JE Penner, B Das, D Bergmann, JM Rodriguez, S Strahan, and M Wang. 2007. "Uncertainties in global aerosol simulations: Assessment using three meteorological data sets ." Journal of Geophysical Research. D. (Atmospheres) 112:paper no.: D11212.  doi:10.1029/2006JD008216
• Liu X, JE Penner, SJ Ghan, and M Wang. 2007. "Inclusion of Ice Microphysics in the NCAR Community Atmospheric Model Version 3 (CAM3)." Journal of Climate 20(18):4526-4547.  doi:10.1175/JCLI4264.1
• Liu X, S Xie, and SJ Ghan. 2007. "Evaluation of a New Mixed-Phase Cloud Microphysics Parameterization with CAM3 Single-Column Model and M-PACE Observations." Geophysical Research Letters 34:Art. no. L23712.  doi:10.1029/2007GL031446
• Textor C, M Schulz, S Guibert, S Kinne, Y Balkanski, S Bauer, T Berntsen, T Berglen, O Boucher, M Chin, F Dentener, T Diehl, J Feichter, D Fillmore, P Ginoux, S Gong, A Grini, J Hendricks, L Horowitz, P Huang, I Isaksen, T Iversen, S Kloster, D Koch, A Kirkevag, JE Kristjansson, M Krol, A Lauer, JF Lamarque, X Liu, V Montanaro, G Myhre, J Penner, G Pitari, S Reddy, O Seland, P Stier, T Takemura, and X Tie. 2007. "The effect of harmonized emissions on aerosol properties in global models - an AeroCom experiment." Atmospheric Chemistry and Physics 17(17):4489-4501. 
• Weisenstein DK, JE Penner, M Herzog, and X Liu. 2007. "Global 2-D intercomparison of sectional and modal aerosol modules ." Atmospheric Chemistry and Physics 7(9):2339-2355. 

2006

• Schulz M, C Textor, S Kinne, Y Balkanski, S Bauer, T Berntsen, T Berglen, O Boucher, F Dentener, S Guibert, I Isaksen, T Iversen, D Koch, A Kirkevag, X Liu, V Montanaro, G Myhre, J Penner, G Pitari, O Seland, P Stier, and T Takemura. 2006. "Radiative forcing by aerosols as derived from the AeroCom present-day and pre-industrial simulations ." Atmospheric Chemistry and Physics 6(12):5225-5246.