Staff information

Biography

Dr. Steve Ghan is a climate scientist in the Atmospheric Sciences and Global Change Division at the Pacific Northwest National Laboratory. The mission of the division is to understand the atmospheric processes that drive regional and global earth systems, with a primary focus on climate, aerosol and cloud physics; global and regional scale modeling; integrated assessment; and complex regional meteorology and chemistry. Dr. Ghan's work involves a combination of development, evaluation, and application of parameterizations for climate models. He has focused on parameterizations that represent cloud-aerosol interactions and the subgrid influence of orography on atmospheric and land surface processes. He has worked closely with atmospheric chemists to produce self-consistent treatments of not only the influence of aerosols on clouds, but also the influence of clouds on aerosols. He leads the Aerosol Climate Initiative for PNNL.

For the last fifteen years, Dr. Ghan's second research passion has been the representation of the subgrid influence of orography on atmospheric and land surface processes. By treating land as well as atmospheric processes in a consistent framework, the scheme produces high-resolution distributions of not only temperature and precipitation but also snow water, soil moisture, and runoff. His colleague, Dr. Ruby Leung, and he first developed the scheme in 1994, using a regional climate model as a testbed. They evaluated it by comparing with station measurements in a region with complex terrain, and then used it to simulate the impact of global warming on the climate of the Pacific Northwest. He subsequently applied the scheme to a global climate model, and in 2005 used it to produce global 5-km simulations of climate change for a 125-year IPCC scenario.

Research Interests

• Cloud-aerosol interactions
• Cloud microphysics parameterization
• Aerosol-climate interactions
• Chemistry-climate interactions
• Global and regional climate modeling
• Subgrid orography parameterization

Education and Credentials

• Ph.D., Meteorology, Massachusetts Institute of Technology
• M.S., Meteorology, Massachusetts Institute of Technology
• B.S., in Atmospheric Science (cum laude), University of Washington

Affiliations and Professional Service

• Member of American Geophysical Union

Awards and Recognitions

• Science Steering Committee, Community Climate System Model
• Science Steering Committee, DOE Atmospheric Science Program
• Editor, J. Geophysical Research - Atmospheres

PNNL Publications

2009

• Fast JD, SJ Ghan, and SE Schwartz. 2009. Modeling Activities in the Department of Energy's Atmospheric Sciences Program. PNNL-18752, Pacific Northwest National Laboratory, Richland, WA. 
• Qian Y, WI Gustafson, Jr, LYR Leung, and SJ Ghan. 2009. "Effects of soot-induced snow albedo change on snowpack and hydrological cycle in western United States based on Weather Research and Forecasting chemistry and regional climate simulations." Journal of Geophysical Research. D. (Atmospheres) 114:D03108.  doi:10.1029/2008JD011039
• Chapman EG, WI Gustafson, Jr, RC Easter, JC Barnard, SJ Ghan, MS Pekour, and JD Fast. 2009. "Coupling Aerosol-Cloud-Radiative Processes in the WRF-Chem Model: Investigating the Radiative Impact of Elevated Point Sources." Atmospheric Chemistry and Physics 9(3):945-964. 
• Fan J, T Yuan, JM Comstock, SJ Ghan, A Khain, LYR Leung, Z Li, VJ Martins, and M Ovchinnikov. 2009. "Dominant Role by Vertical Wind Shear in Regulating Aerosol Effects on Deep Convective Clouds." Journal of Geophysical Research. D. (Atmospheres) 114(D22206):, doi:10.1029/2009JD012352
• Khain A, LYR Leung, BH Lynn, and SJ Ghan. 2009. "Effects of aerosols on the dynamics and microphysics of squall lines simulated by WRF with spectral bin and bulk parameterization schemes." Journal of Geophysical Research. D. (Atmospheres) 114(D22203):, doi:10.1029/2009JD011902

2008

• Gustafson WI, Jr, LK Berg, RC Easter, and SJ Ghan. 2008. "The Explicit-Cloud Parameterized-Pollutant Hybrid Approach for Aerosol-Cloud Interactions in Multiscale Modelling Framework Models: Tracer Transport Results." Environmental Research Letters 3(2):Art. No. 025005.  doi:10.1088/1748-9326/3/2/025005
• Gettelman A, H Morrison, and SJ Ghan. 2008. "A New Two-Moment Bulk Stratiform Cloud Microphysics Scheme in the Community Atmosphere Model, Version 3 (CAM3). Part II: Single-Column and Global Results." Journal of Climate 21(15):3660-3679.  doi:10.1175/2008JCLI2116.1
• 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

• Ghan SJ, and RC Easter. 2007. "Corrigendum to "Impact of cloud-borne aerosol representation on aerosol direct and indirect effects" published in Atmos. Chem. Phys., 6, 4163-4174, 2006 ." Atmospheric Chemistry and Physics 7:293-294. 
• Ghan SJ, and SE Schwartz. 2007. "Aerosol Properties and Processes: A Path from Field and Laboratory Measurements to Global Climate Models." Bulletin of the American Meteorological Society 88(7):1059-1083.  doi:10.1175/BAMS-88-7-1059
• Gustafson WI, Jr, EG Chapman, SJ Ghan, RC Easter, and JD Fast. 2007. "Impact on Modeled Cloud Characteristics Due to Simplified Treatment of Uniform Cloud Condensation Nuclei During NEAQS 2004." Geophysical Research Letters 34(19):L19809.  doi:10.1029/2007GL030021
• 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
• Ghan SJ, and RA Zaveri. 2007. "Parameterization of Optical Properties for Hydrated Internally Mixed Aerosol." Journal of Geophysical Research. D. (Atmospheres) 112(D10):D10201.  doi:10.1029/2006JD007927

2006

• Ghan SJ, and RC Easter. 2006. "Impact of Cloud-Borne Aerosol Representation on Aerosol Direct and Indirect Effects." Atmospheric Chemistry and Physics 6:4163-4174. 
• Ghan SJ, and TR Shippert. 2006. "Physically-Based Global Downscaling: Climate Change Projections for a Full Century." Journal of Climate 19(9):1589-1604.  doi:10.1175/JCL13701.1
• Ghan SJ, TR Shippert, and J Fox. 2006. "Physically Based Global Downscaling: Regional Evaluation." Journal of Climate 19(3):429-445. 
• Ferrare R, G Feingold, SJ Ghan, JA Ogren, B Schmid, SE Schwartz, and P Sheridan. 2006. "Preface to Special Section: Atmospheric Radiation Measurement Program May 2003 Intensive Operations Period Examining Aerosol Properties and Radiative Influences." Journal of Geophysical Research. D. (Atmospheres) 111(D5):D05S01, doi: 10.1029/2005JD006908. 
• Ghan SJ, TA Rissman, R Elleman, R Ferrare, DD Turner, CJ Flynn, J Wang, JA Ogren, J Hudson, H Jonsson, T VanReken, RC Flagan, and JH Seinfeld. 2006. "Use of in situ cloud condensation nuclei, extinction, and aerosol size distribution Measurements to test a method for retrieving cloud condensation nuclei profiles from surface measurements." Journal of Geophysical Research. D. (Atmospheres) 111(D05S10):, doi:10.1029/2004JD005752
• Ghan SJ, TA Rissman, R Elleman, R Ferrare, DD Turner, CJ Flynn, J Wang, JA Ogren, J Hudson, H Jonsson, T VanReken, RC Flagan, and JH Seinfeld. 2006. "Use of In Situ Cloud Condensation Nuclei, Extinction, and Aerosol Size Distribution Measurements to Test a Method for Retrieving Cloud Condensation Nuclei Profiles from Surface Measurements." Journal of Geophysical Research. D. (Atmospheres) 111(D5):D05S10, doi: 10.1029/2004JD005752. 
• Kinne S, M Schulz, C Textor, S Guibert, Y Balkanski, S Bauer, T Berntsen, T Berglen, O Boucher, M Chin, W Collins, F Dentener, T Diehl, RC Easter, H Feichter, D Fillmore, SJ Ghan, P Ginoux, S Gong, A Grini, J Hendricks, M Herzog, L Horrowitz, I Isaksen, T Iversen, A Kirkevag, S Kloster, D Koch, JE Kristjansson, M Krol, A Lauer, JF Lamarque, G Lesins, X Liu, U Lohmann, V Montanaro, G Myhre, JE Penner, G Pitari, S Reddy, O Seland, P Stier, T Takemura, and X Tie. 2006. "An AeroCom Initial Assessment - Optical Properties in Aerosol Component Modules of Global Models." Atmospheric Chemistry and Physics 6(7):1815-1834. 
• Storelvmo T, JE Kristjansson, SJ Ghan, A Kirkevag, O Seland, and T Iversen. 2006. "Predicting Cloud Droplet Number Concentration in Community Atmosphere Model (CAM)-Oslo." Journal of Geophysical Research. D. (Atmospheres) 111(D24):D24208.  doi:10.1029/2005JD006300
• Textor C, M Schulz, S Guibert, S Kinne, Y Balkanski, S Bauer, T Berntsen, T Berglen, O Boucher, M Chin, F Dentener, T Diehl, RC Easter, H Feichter, D Fillmore, SJ Ghan, P Ginoux, S Gong, A Grini, J Hendricks, L Horrowitz, 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, JE Penner, G Pitari, S Reddy, O Seland, P Stier, T Takemura, and X Tie. 2006. "Analysis and Quantification of the Diversities of Aerosol Life Cycles within AeroCom." Atmospheric Chemistry and Physics 6(7):1777-1813. 

2005

• Ghan SJ, and TR Shippert. 2005. "Load Balancing and Scalability of a Subgrid Orography Scheme in a Global Climate Model." International Journal of High Performance Computing Applications 19(3):237-245. 
• Ghan SJ, and TR Shippert. 2005. "Physically-Based Global Downscaling Climate Change Projections for a Full Century." Journal of Physics: Conference Series 16:343-347.  doi:10.1088/1742-6596/16/1/047
• Gustafson WI, Jr, JD Fast, RC Easter, and SJ Ghan. 2005. "Triumphs and Tribulations of WRF-Chem Development and Use." In 2005 Joint WRF/MM5 User's Workshop, June 27-30, 2005, Boulder, Colorado, p. Paper No. 8.4.  National Center for Atmospheric Research, Boulder, CO. 
• Ovtchinnikov M, and SJ Ghan. 2005. "Parallel Simulations of Aerosol Influence on Clouds Using Cloud-Resolving and Single-Column Models." Journal of Geophysical Research. D. (Atmospheres) 110(D15):D15S10.  doi:10.1029/2004JD005088
• Abdul-Razzak H, and SJ Ghan. 2005. "Influence of Slightly Soluble Organics on Aerosol Activation." Journal of Geophysical Research. D. (Atmospheres) 110:D06206 -1-6.  doi:10.1029/2004JD005324
• Xie S, M Zhang, M Branson, RT Cederwall, AD Del Genio, ZA Eitzen, SJ Ghan, SF Iacobellis, KL Johnson, M Khairoutdinov, SA Klein, SK Krueger, W Lin, U Lohmann, MA Miller, DA Randall, RC Somerville, YC Sud, GK Walker, A Wolf, X Wu, KM Xu, JJ Yio, GJ Zhang, and J Zhang. 2005. "Simulations of Midlatitude Frontal Clouds by Single-Column and Cloud-Resolving Models during the Atmospheric Radiation Measurement March 2000 Cloud Intensive Operational Period." Journal of Geophysical Research. D. (Atmospheres) 110(D15):D15S03 - 1-25.  doi:10.1029/2004JD005119
• Xu KM, M Zhang, ZA Eitzen, SJ Ghan, SA Klein, X Wu, S Xie, M Branson, AD Del Genio, SF Iacobellis, M Khairoutdinov, W Lin, U Lohmann, DA Randall, RC Somerville, YC Sud, GK Walker, A Wolf, JJ Yio, and J Zhang. 2005. "Modeling Springtime Shallow Frontal Clouds with Cloud-Resolving and Single-Column Models." Journal of Geophysical Research. D. (Atmospheres) 110(D15):D15S04, doi: 10.1029/2004JD005153. 

2004

• Ghan SJ, and DR Collins. 2004. "Use of In Situ Data to Test a Raman Lidar-Based Cloud Condensation Nuclei Remote Sensing Method." Journal of Atmospheric and Oceanic Technology 21(2):387-394. 
• Abdul-Razzak H, and SJ Ghan. 2004. "Parameterization of the Influence of Organic Surfactants on Aerosol Activation." Journal of Geophysical Research. D. (Atmospheres) 109(D3):D03205.  doi:10.1029/2003JD004043
• Easter RC, SJ Ghan, Y Zhang, RD Saylor, EG Chapman, NS Laulainen, H Abdul-Razzak, LR Leung, X Bian, and RA Zaveri. 2004. "MIRAGE: Model Description and Evaluation of Aerosols and Trace Gases." Journal of Geophysical Research. D. (Atmospheres) 109(D20):D20210.  doi:10.1029/2004JD004571
• Fox JB, and SJ Ghan. 2004. "Combining Weather Data for a Dataset Sufficient for Generating High-Resolution Weather Prediction Models." Journal of Young Investigators 10(3):na. 
• Ghan SJ, X Bian, EG Chapman, RC Easter, GI Fann, SC Kothari, RA Zaveri, and Y Zhang. 2004. Simulation of Climate Forcing by Aerosols. PNNL-14634, Pacific Northwest National Laboratory, Richland, WA. 
• Henning S, S Bojinski, K Diehl, SJ Ghan, S Nyeki, E Weingartner, S Wurzler, and U Baltensperger. 2004. "Aerosol Partitioning in Natural Mixed-Phase Clouds." Geophysical Research Letters 31(6):L06101.  doi:10.1029/2003GL019025

2003

• Qian Y, LR Leung, SJ Ghan, and F Giorgi. 2003. "Regional Climate Effects of Aerosols Over China: Modeling and Observation." Tellus Series B, Chemical and Physical Meteorology 55(4):914-934. 
• Kinne S, U Lohmann, J Feichter, M Schulz, C Timmreck, SJ Ghan, RC Easter, M Chin, P Ginoux, T Takemura, I Tegen, D Koch, M Herzog, J Penner, G Pitari, BN Holben, T Eck, A Smirnov, O Dubovik, I Slutsker, D Tanre, O Torres, M Mishchenko, I Geogdzhayev, DA Chu, and YJ Kaufman. 2003. "Monthly Averages of Aerosol Properties: A Global Comparison Among Models, Satellite Data, and AERONET Ground Data." Journal of Geophysical Research. D. (Atmospheres) 108(D20):4634.  doi:10.1029/2001JD001253
• Menon S, JL Brenguier, O Boucher, P Davison, AD Del Genio, J Feichter, SJ Ghan, S Guibert, X Liu, U Lohmann, H Pawlowska, JE Penner, J Quaas, DL Roberts, L Schuller, and J Snider. 2003. "Evaluating Aerosol/Cloud/Radiation Process Parameterizations with Single- Column Models and Second Aerosol Characterization Experiment (ACE-2) Cloudy Column Observations." Journal of Geophysical Research. D. (Atmospheres) 108(D24):Art. no. 4762. 

2002

• Chapman EG, WJ Shaw, RC Easter, X Bian, and SJ Ghan. 2002. "The Influence of Wind Speed Averaging on Estimates of Dimethylsulfide Emission Fluxes." Journal of Geophysical Research. D. (Atmospheres) 107(D23: art. no.4672):, doi:10.1029/2001JD001564
• Ghan SJ, X Bian, AG Hunt, and AM Coleman. 2002. "The Thermodynamic Influence of Subgrid Orography in a Global Climate Model." Climate Dynamics 20(1):31-44. 
• Thomson AM, RA Brown, SJ Ghan, RCC Izaurralde, NJ Rosenberg, and LR Leung. 2002. "Elevation dependence of winter wheat production in eastern Washington state with climate change: A methodological study." Climatic Change 54:141-164. 
• Abdul-Razzak H, and SJ Ghan. 2002. "A Parameterization of Aerosol Activation. Part 3: Sectional Representation." Journal of Geophysical Research. D. (Atmospheres) 107(D3):AAC 1-1 - 1-6. 
• Remer LA, YJ Kaufman, Z Levin, and SJ Ghan. 2002. "Model Assessment of the Ability of MODIS to Measure Top-of-Atmosphere Direct Radiative Forcing from Smoke Aerosols." Journal of the Atmospheric Sciences 59(3, Part 2):657-667. 
• Xie S, KM Xu, RT Cederwall, P Bechtold, AD Del Genio, SA Klein, DG Cripe, SJ Ghan, D Gregory, SF Iacobellis, SK Krueger, U Lohmann, JC Petch, DA Randall, LD Rotstayn, RC Somerville, YC Sud, K Von Salzen, GK Walker, A Wolf, JJ Yio, GJ Zhang, and M Zhang. 2002. "Intercomparison and Evaluation of Cumulus Parameterizations under Summertime Midlatitude Continental Conditions." Quarterly Journal of the Royal Meteorological Society 128(582 Pt. B):1095-1136. 
• Zhang Y, RC Easter, SJ Ghan, and H Abdul-Razzak. 2002. "Impact of Aerosol Size Representation on Modeling Aerosol-Cloud Interactions." Journal of Geophysical Research. D. (Atmospheres) 107(D21 art.no.4558):, doi:10.1029/2001JD001549

2001

• Ghan SJ, RC Easter, JD Hudson, and F Breon. 2001. "Evaluation of Aerosol Indirect Radiative Forcing in MIRAGE." Journal of Geophysical Research. D. (Atmospheres) 106(D6):5317-5334. 
• Ghan SJ, NS Laulainen, RC Easter, R Wagener, S Nemesure, EG Chapman, Y Zhang, and LR Leung. 2001. "Evaluation of Aerosol Direct Radiative Forcing in MIRAGE." Journal of Geophysical Research. D. (Atmospheres) 106(D6):5295-5316. 
• Ghan SJ, RC Easter, EG Chapman, H Abdul-Razzak, Y Zhang, LR Leung, NS Laulainen, RD Saylor, and RA Zaveri. 2001. "A Physically-Based Estimate of Radiative Forcing by Anthropogenic Sulfate Aerosol." Journal of Geophysical Research. D. (Atmospheres) 106(D6):5279-5293. 
• Nenes A, SJ Ghan, H Abdul-Razzak, P Chuang, and J Seinfeld. 2001. "Kinetic Limitations on Droplet Formation." Tellus Series B, Chemical and Physical Meteorology 53:133-149. 
• Ramaswamy V, O Boucher, J Haigh, D Hauglustaine, J Haywood, G Myhre, T Nakajima, G Shi, S Solomon, RE Betts, R Charlson, CC Chuang, JS Daniel, AD Del Genio, J Feichter, J Fuglestvedt, PM Forster, SJ Ghan, A Jones, JT Kiehl, D Koch, C Land, J Lean, U Lohmann, K Minschwaner, JE Penner, DL Roberts, H Rodhe, GJ Roelofs, LD Rotstayn, TL Schneider, U Schumann, SE Schwartz, MD Schwartzkopf, KP Shine, SJ Smith, DS Stevenson, F Stordal, I Tegen, R van Dorland, Y Zhang, J Srinivasan, and F Joos. 2001. "Radiative Forcing of Climate Change ." Chapter 6 in Climate Change 2001: The Scientific Basis, ed. Houghton, J. T. et al.  Cambridge University Press, New York, NY. 

2000

• Ghan SJ, D Randall, KM Xu, R Cederwall, D Cripe, J Hack, S Iacobellis, S Klein, S Krueger, U Lohmann, J Pedretti, A Robock, L Rotstayn, R Somerville, G Stenchikov, Y Sud, G Walker, S Xie, J Yio, and M Zhang. 2000. "A Comparison of Single Column Model Simulations of Summertime Midlatitude Continental Convection ." Journal of Geophysical Research. D. (Atmospheres) 105(D2):2091-2124. 
• Abdul-Razzak H, and SJ Ghan. 2000. "A Parameterization of Aerosol Activation. Part 2: Multiple Aerosol Types." Journal of Geophysical Research. D. (Atmospheres) 105:6,837-6,844. 

1999

• Leung LR, and SJ Ghan. 1999. "Pacific Northwest Sensitivity Simulated by a Regional Climate Model Driven by a GCM. Part I: Control Simulations." Journal of Climate 12(7):2010-2030. 
• Leung LR, and SJ Ghan. 1999. "Pacific Northwest Sensitivity Simulated by a Regional Climate Model Driven by a GCM. Part II: 2XCO2 Simulations." Journal of Climate 12(7):2031-2053. 
• Leung LR, SJ Ghan, Z Zhao, Y Luo, WC Wang, and HL Wei. 1999. "Intercomparison of Regional Climate Simulations of the 1991 Summer Monsoon in Eastern Asia." Journal of Geophysical Research. D. (Atmospheres) 104:6425-6454. 
• Ghan SJ, LR Leung, and J McCaa. 1999. "A Comparison of Three Different Modeling Strategies for Evaluating Cloud and Radiation Parameterizations." Monthly Weather Review 127(9):1967-1984. 

1998

• Leung LR, and SJ Ghan. 1998. "Parameterizing Subgrid Orographic Precipitation and Surface Cover in Climate Models." Monthly Weather Review 126(12):3271-3291.