Cloud and Climate System Modeling
Dept. of Geological and Atmospheric Sciences
Iowa State University
Ames, IA 50011
Ph.D. UCLA , 1992
M.S. Institute of Atmospheric Physics, Chinese Academy of Sciences, 1986
B.S. Hangzhou University, 1983
My research interests include numerical modeling, diagnostic,and theoretical studies to understand convection, cloud, radiation and precipitation processes and to improve their representation in general circulation models (GCMs) for predicting future climate. Studying and modeling of cloud systems are motivated by their profound effects on the global circulation, radiation budget and surface temperature, and the need for improved climate models and data for policy makers to determine safe levels of greenhouse gases for the Earth system. Cloud, radiation and precipitation processes are key components of the global water and energy cycle and operate on a wide range of time and space scales. Convection and clouds affect atmospheric temperature, moisture and wind fields through the release of latent heat; the redistributions of heat, moisture and momentum; and the precipitation. Clouds strongly affect the planetary energy budget and surface temperature through the reflection of sunlight, the absorption of infrared radiation from the surface and the emission of radiation to the surface as part of greenhouse effect. Since individual clouds have a spatial scale of less than 10 km that is much smaller than the conventional grid size of several hundred kilometers in climate and weather prediction models, they must be quantitatively formulated in terms of resolved variables in the prognostic equations of temperature, moisture and wind. Deriving such formulations for convection and clouds has been a major challenge for the climate modeling community due to the lack of observations of cloud and microphysical properties. To address this problem, my collaborators at NCAR and I have developed a cloud-resolving model (CRM) which resolves individual clouds but covers a large horizontal domain to generate cloud-scale datasets. The diagnostic and theoretical studies applying the high-resolution datasets generated by the CRM have lead to the improved representation of convection and cloud-radiation interaction in the climate models, and the improved simulations of global climate mean state and variability.
Wu, X., and X.-Z. Liang (Co-PI), 2002-2006: Application of Seasonal CRM Integrations to Develop Statistics and Improved GCM Parameterization of Subgrid Cloud-Radiation Interactions. DOE/ARM.
Wu, X., G.J. Zhang (Co-PI), and R.W. Arritt (Co-I), 2004-2008: Evaluating the representation and impact of convective momentum transport in CCSM atmosphere model. DOE/CCPP.
Wu, X., and Qilong Min (Co-I), 2008-2011: Understanding and Improving CRM and GCM Simulations of Cloud Systems with ARM Observations. DOE/ARM.
Wu, X., 2009-2012: Effects of Cloud and Radiation Processes on the Global Water and Energy Cycle. NSF.
Atmosperic Physics I (Mteor 341, 3 credits)
Atmosperic Physics II (Mteor 342, 3 credits )
Atmosperic Physics (Mteor 542, 3 credits)
Recent Refereed Papers
Park, S., and X. Wu, 2010: Effects of Surface Albedo on Cloud and Radiation Processes in Cloud-Resolving Model Simulations. J. Atmos. Sci., in press.
Deng, L., and X. Wu, 2010: Effects of Convective Processes on GCM Simulations of the Madden-Julian Oscillation. J. Climate, 352–377.
Song, X., X. Wu, G.J. Zhang, and R. Arritt, 2008: Understanding the effects of convective momentum transport on climate simulations: The role of convective heating. J. Climate., 21, 5034-5047.
Wu, X., S. Park, Q. Min, 2008: Seasonal variation of cloud systems over ARM SGP. J. Atmos. Sci., 65, 2107-2129.
Wu, X., and X. Li, 2008: A review of cloud-resolving model studies of convective processes. Advances in Atmospheric Sciences, 25, 202-212.
Song, X., X. Wu, G.J. Zhang, and R. Arritt, 2008: Dynamical effects of convective momentum transports on global climate simulations. J. Climate, 21, 180-194.
Wu, X., L. Deng, X. Song, G. Vettoretti, W. R. Peltier, and G. J. Zhang, 2007: Impact of a modified convective scheme on the MJO and ENSO in a coupled climate model. Geophys. Res. Lett. 34, L16823, doi:10.1029/2007GL030637.
Wu, X., L. Deng, X. Song, and G.-J. Zhang, 2007: Coupling of convective momentum transport with convective heating in global climate simulations. J. Atmos. Sci., 64, 1334-1349.
Wu, X., and X.-Z. Liang, and S. Park, 2007: Cloud-resolving model simulations over the ARM SGP. Mon. Wea. Rev., 135, 2841-2853.
Grabowski, W.W., X. Wu, and Co-authors, 2006: Daytime convective development over land: A model intercomparison based on LBA observations. Quart. J. Roy. Meteor. Soc., 132, 317-344.
Wu, X., and S. Guimond, 2006: Two- and three-dimensional cloud-resolving model simulations of the mesoscale enhancement of surface heat fluxes by precipitating deep convection. J. Climate, 19, 139-149.
Wu, X., and X.-Z. Liang, 2005: Radiative effects of cloud horizontal inhomogeneity and vertical overlap identified from a month-long cloud-resolving simulation. J. Atmos. Sci., 62, 4105-4112.
Wu, X., and X. Liang, 2005: Effect of subgrid cloud-radiation interaction on climate simulations. Geophys. Res. Lett., 32, L24806, doi:10.1029/2005GL024432.
Liang, X.-Z., and X. Wu, 2005: Evaluation of a GCM subgrid cloud-radiation interaction parameterization using cloud-resolving model simulations. Geophys. Res. Lett., 32, L06801, doi:10.1029/2004GL022301.
Xu, K.-M., X. Wu, and Co-authors, 2005: Modeling springtime shallow frontal clouds with cloud-resolving and single-column models, J. Geophys. Res., 110, D15S04,doi:10.1029/2004JD005153.
Xie, S., X. Wu, and Co-authors, 2005: Simulations of midlatitude frontal clouds by SCMs and CRMs during the ARM March 2000 cloud IOP. J. Geophys. Res., 110, D15S03, doi:10.1029/2004JD005119.