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

• Editor, Journal "Atmospheric Chemistry and Physics" (ACP), 2013.01-
• Guest Professor, Nanjing University, China, 2010/12-
• Guest Professor, Institute of Atmospheric Physics, Chinese Academy of Science, 2010/06-
• Exceptional Contribution Program Award, Pacific Northwest National Laboratory, 2012
• 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

2013

• Jiang Y, X Liu, X Yang, and M Wang. 2013. "A numerical study of the effect of different aerosol types on East Asian summer clouds and precipitation." Atmospheric Environment 70:51-63.  doi:10.1016/j.atmosenv.2012.12.039
• Long MS, WC Keene, RC Easter, Jr, R Sander, A Kergweg, D Erickson, X Liu, and SJ Ghan. 2013. "Implementation of the chemistry module MECCA (v2.5) in the modal aerosol version of the Community Atmosphere Model component (v3.6.33) of the Community Earth System Model." Geoscientific Model Development 6(1):255-262.  doi:10.5194/gmd-6-255-2013
• Myhre G, BH Samset, M Schulz, Y Balkanski, S Bauer, T Berntsen, H Bian, N Bellouin, M Chin, T Diehl, RC Easter, Jr, J Feichter, SJ Ghan, D Hauglustaine, T Iversen, S Kinne, A Kirkevag, JF Lamarque, G Lin, X Liu, MT Lund, G Luo, X Ma, T van Noije, JE Penner, PJ Rasch, A Ruiz, O Seland, RB Skeie, P Stier, T Takemura, K Tsigaridis, P Wang, Z Wang, L Xu, H Yu, F Yu, JH Yoon, K Zhang, H Zhang, and C Zhou. 2013. "Radiative Forcing of the Direct Aerosol Effect from AeroCom Phase II Simulations." Atmospheric Chemistry and Physics 13(4):1853-1877.  doi:10.5194/acp-13-1853-2013
• Samset BH, G Myhre, M Schulz, Y Balkanski, SE Bauer, T Berntsen, H Bian, N Bellouin, T Diehl, RC Easter, Jr, SJ Ghan, T Iversen, S Kinne, A Kirkevag, JF Lamarque, G Lin, X Liu, JE Penner, O Seland, RB Skeie, P Stier, T Takemura, K Tsigaridis, and K Zhang. 2013. "Black Carbon Vertical Profiles Strongly Affect its Radiative Forcing Uncertainty." Atmospheric Chemistry and Physics 13(5):2423-2434.  doi:10.5194/acp-13-2423-2013
• Shindell D, JF Lamarque, M Schulz, MG Flanner, C Jiao, M Chin, PJ Young, YH Lee, L Rotstayn, NM Mahowald, G Milly, G Faluvegi, Y Balkanski, WJ Collins, A Conley, S Dalsoren, RC Easter, Jr, SJ Ghan, L Horowitz, X Liu, G Myhre, T Nagashima, V Naik, S Rumbold, RB Skeie, K Sudo, S Szopa, T Takemura, A Voulgarakis, JH Yoon, and F Lo. 2013. "Radiative forcing in the ACCMIP historical and future climate simulations." Atmospheric Chemistry and Physics 13(6):2939-2974.  doi:10.5194/acp-13-2939-2013
• Yang B, Y Qian, G Lin, LYR Leung, PJ Rasch, GJ Zhang, SA McFarlane, C Zhao, Y Zhang, H Wang, M Wang, and X Liu. 2013. "Uncertainty Quantification and Parameter Tuning in the CAM5 Zhang-McFarlane Convection Scheme and Impact of Improved Convection on the Global Circulation and Climate." Journal of Geophysical Research. D. (Atmospheres) 118(2):395-415.  doi:10.1029/2012JD018213

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
• Liu X, X Shi, K Zhang, E Jensen, A Gettelman, D Barahona, A Nenes, and P Lawson. 2012. "Sensitivity Studies of Dust Ice Nuclei Effect on Cirrus Clouds with the Community Atmosphere Model CAM5." Atmospheric Chemistry and Physics 12(24):12061-12079.  doi:10.5194/acp-12-12061-2012
• 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. 
• Gettelman A, X Liu, D Barahona, U Lohmann, and CC Chen. 2012. "Climate Impacts of Ice Nucleation." Journal of Geophysical Research. D. (Atmospheres) 117:D20201.  doi:10.1029/2012JD017950
• Ghan SJ, X Liu, RC Easter, Jr, RA Zaveri, PJ Rasch, JH Yoon, and B Eaton. 2012. "Toward a Minimal Representation of Aerosols in Climate Models: Comparative Decomposition of Aerosol Direct, Semidirect, and Indirect Radiative Forcing." Journal of Climate 25(19):6461-6476.  doi:10.1175/JCLI-D-11-00650.1
• 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
• Yu F, G Luo, X Liu, RC Easter, Jr, X Ma, and SJ Ghan. 2012. "Indirect radiative forcing by ion-mediated nucleation of aerosol." Atmospheric Chemistry and Physics 12(23):11451-11463.  doi:10.5194/acp-12-11451-2012
• 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.