James H. Ruppert, Jr.

James H. Ruppert, Jr.

  • Assistant Research Professor
624 Walker Building
University Park, PA 16802
Email: james.ruppert@psu.edu


Google Scholar

I am an Assistant Research Professor in the Department of Meteorology and Atmospheric Science at Penn State University. My primary fascination is on how clouds and moist convection affect and interact with weather and climate systems at much larger space and time scales than that of any individual thunderstorm or cloud. My research relies heavily on both theory and cloud-resolving/permitting numerical models. 


  • Postdoc: 2015–2018, Max Planck Institute for Meteorology, Hamburg, Germany, funded through NSF-AGS Postdoctoral Research Fellowship and Alexander von Humboldt Foundation Postdoctoral Fellowship
  • Ph.D., 2015, Atmospheric Science, Colorado State University
  • M.S., 2012, Atmospheric Science, Colorado State University
  • B.S. 2009, Atmospheric Science, University at Albany


  • Diurnal time-scale feedbacks.  I am greatly fascinated by how clouds and moist convection create links across scales, both in space and time. A particular example of "time-scale feedback" is the effects in slowly varying weather and climate caused by 24-hr diurnal cyclic processes. The many potential avenues through which diurnal time scale feedback may manifest has consumed much of my thoughts since I began my Ph.D. at Colorado State University.
  • Convectively coupled gravity waves.  I am currently investigating the links between diurnally generated deep convection in the Maritime Continent and long-lived gravity waves. A fascinating finding thus far is that gravity waves of a scale ~ 1500 km phase-lock with the diurnal cycle, connecting one diurnal burst of convection over one island with another the subsequent day. Namely, we see this link between Sumatra and Borneo.


  • Ruppert, J. H., Jr., and F. Zhang, 2019: Diurnal forcing and phase locking of gravity waves in the Maritime Continent, J. Atmos. Sci., doi:10.1175/JAS-D-19-0061.1.
  • Ruppert, J. H., Jr., and D. Klocke, 2019: The two diurnal modes of tropical upward motion, Geophysical Research Letters, doi:10.1029/2018GL081806.
  • Chen, X, F. Zhang, and J. H. Ruppert, Jr., 2019: Modulations of Coastal Rainfall Diurnal Cycle Over South China by the Boreal Summer Intraseasonal Oscillation, J. Climate, doi:10.1175/JCLI-D-18-0786.1.
  • Ruppert, J. H., Jr., and M. E O’Neill, 2019*: Diurnal cloud and circulation changes in tropical cyclones, Geophysical Research Letters, doi:10.1029/2018GL081302.
    * Eos Research Spotlight: Underwood, E., 2019: A better understanding of tropical cyclones, Eos, 100. DOI: 10.1029/2019EO118381.
  • Ruppert, J. H., Jr., and C. Hohenegger, 2018: Diurnal circulation adjustment and organized deep convection, J. Climatedoi:10.1175/JCLI-D-17-0693.1.
  • Ciesielski, P. E., R. H. Johnson, W. H. Schubert, and J. H. Ruppert, Jr., 2018: Diurnal cycle of the ITCZ in DYNAMO, J. Climatedoi:10.1175/JCLI-D-17-0670.1.
  • Bony, S., B. Stevens, F. Ament, S. Crewel, J. Delanoé, D. Farrell, C. Flamant, S. Gross, L. Hirsch, B. Mayer, J. H. Ruppert, Jr., S. Speich, R. Vogel, M. Wendisch, 2017: EUREC4A: a field campaign to elucidate the couplings between clouds, convection and circulation, Surveys in Geophysics, doi:10.1007/s10712-017-9428-0.
  • Ruppert, J. H., Jr., 2016: Diurnal timescale feedbacks in the tropical cumulus regime. Journal of Advances in Modeling Earth Systems, doi:10.1002/2016MS000713.
  • Ruppert, J. H., Jr., and R. H. Johnson, 2016: On the cumulus diurnal cycle over the tropical warm pool. Journal of Advances in Modeling Earth Systems, doi:10.1002/2015MS000610.
  • Ruppert, J. H., Jr., and R. H. Johnson, 2015: Diurnally modulated cumulus moistening in the pre-onset stage of the Madden–Julian oscillation during DYNAMO, Journal of the Atmospheric Sciences, 72, 1622–1647. doi:10.1175/JAS-D-14-0218.1.
  • Johnson, R. H., P. E. Ciesielski, J. H. Ruppert, Jr., and M. Katsumata, 2015: Sounding-based thermodynamic budgets for DYNAMO, Journal of the Atmospheric Sciences, 72, 598–622. doi:10.1175/JAS-D-14-0202.1.
  • Ruppert, J. H., Jr., and L. F. Bosart, 2014: A case study of the interaction of a mesoscale gravity wave with a mesoscale convective system. Monthly Weather Review, 142, 1403–1429. doi:10.1175/MWR-D-13-00274.1.
  • Johnson, R. H., R. S. Schumacher, J. H. Ruppert, Jr., D. T. Lindsey, J. E. Ruthford, and L. Kriederman, 2014: The role of convective outflow in the Waldo Canyon Fire, Monthly Weather Review, 142, 3061–3080. doi:10.1175/MWR-D-13-00361.1.
  • Ruppert, J. H., Jr., R. H. Johnson, and A. K. Rowe, 2013: Diurnal circulations and rainfall in Taiwan during SoWMEX/TiMREX (2008). Monthly Weather Review, 141, 3851–3872. doi:10.1175/JAS-D-14-0218.1.