Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

Benjamin Green

Dr. Green is collaborating with Dr. Stan Benjamin and Dr. Chris Fairall (both of whom are also CIRES fellows associated with the Weather and Climate Dynamics division) and their colleagues at NOAA’s Earth System Research Laboratories (ESRL) to investigate numerical simulations of the Madden-Julian Oscillation (MJO). Specifically, the simulations couple the atmospheric Flow-following finite-volume Icosahedral Model (FIM) developed at ESRL to an icosahedral version of the HYbrid Coordinate Ocean Model (iHYCOM). The MJO is the primary cause of intraseasonal (30-60 day) variability in the tropical troposphere, and has been found to have impacts on weather across the globe on similar timescales. Therefore, it is believed that numerical weather prediction (NWP) models capable of adequately simulating the MJO will yield more accurate forecasts at longer lead times. This research will investigate the ability of the coupled FIM-iHYCOM model (hereafter “FIM”) to simulate the MJO by comparing month-long FIM hindcasts with observations taken during the Dynamics of the Madden-Julian Oscillation (DYNAMO) field campaign. Preliminary results indicate that FIM struggles to propagate the MJO signal eastward across the equatorial Indian Ocean and Maritime Continent. This deficiency is likely a consequence of the model inadequately resolving the thin layer of warm water in the top few meters of the ocean, as suggested by recent studies. The next step of the project will be to improve FIM’s representation of this so-called “diurnal warm layer” and thus hopefully yield more realistic MJO simulations. Concurrent research will also examine the sensitivity of the MJO to FIM’s parameterization of convection. Finally, we will determine if better MJO representation in FIM leads to more skillful forecasts globally – which if so would be of great significance, especially because the non-hydrostatic version of FIM (NIM) is being considered as a candidate for NOAA’s new operational global model.

View Publications

  • Merryfield, WJ; Baehr, J; Batte, L; Becker, EJ; Butler, AH; Coelho, CAS; Danabasoglu, G; Dirmeyer, PA; Doblas-Reyes, FJ; Domeisen, DIV; Ferranti, L; Ilynia, T; Kumar, A; Muller, WA; Rixen, M; Robertson, AW; Smith, DM; Takaya, Y; Tuma, M; Vitart, F; White, CJ; Alvarez, MS; Ardilouze, C; Attard, H; Baggett, C; Balmaseda, MA; Beraki, AF; Bhattacharjee, PS; Bilbao, R; de Andrade, FM; DeFlorio, MJ; Diaz, LB; Ehsan, MA; Fragkoulidis, G; Grainger, S; Green, BW; Hell, MC; Infanti, JM; Isensee, K; Kataoka, T; Kirtman, BP; Klingaman, NP; Lee, JY; Mayer, K; McKay, R; Mecking, JV; Miller, DE; Neddermann, N; Ng, CHJ; Osso, A; Pankatz, K; Peatman, S; Pegion, K; Perlwitz, J; Recalde-Coronel, GC; Reintges, A; Renkl, C; Solaraju-Murali, B; Spring, A; Stan, C; Sun, YQ; Tozer, CR; Vigaud, N; Woolnough, S; Yeager, S. (Jun 2020). Current and Emerging Developments in Subseasonal to Decadal Prediction. BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY , 101(6). 10.1175/BAMS-D-19-0037.1
  • Pegion, K; Kirtman, B; Becker, E; Collins, DC; LaJoie, E; Burgman, R; Bell, R; DelSole, T; Min, D; Zhu, YJ; Li, W; Sinsky, E; Guan, H; Gottschalck, J; Metzger, EJ; Barton, NP; Achuthavarier, D; Marshak, J; Koster, RD; Lin, H; Gagnon, N; Bell, M; Tippett, MK; Robertson, AW; Sun, S; Benjamin, SG; Green, BW; Bleck, R; Kim, H. (Oct 2019). The Subseasonal Experiment (SubX): A Multimodel Subseasonal Prediction Experiment. BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY , 100(10). 10.1175/BAMS-D-18-0270.1
  • Sun, S, R Bleck, SG Benjamin, BW Green and GA Grell. (May 2018). Subseasonal Forecasting with an Icosahedral, Vertically Quasi-Lagrangian Coupled Model. Part I: Model Overview and Evaluation of Systematic Errors. MONTHLY WEATHER REVIEW , 146(5). 10.1175/MWR-D-18-0006.1
  • Sun, S, BW Green, R Bleck and SG Benjamin. (May 2018). Subseasonal Forecasting with an Icosahedral, Vertically Quasi-Lagrangian Coupled Model. Part II: Probabilistic and Deterministic Forecast Skill. MONTHLY WEATHER REVIEW , 146(5). 10.1175/MWR-D-18-0007.1
  • Chen, YJ, FQ Zhang, BW Green and XP Yu. (Jan 2018). Impacts of Ocean Cooling and Reduced Wind Drag on Hurricane Katrina (2005) Based on Numerical Simulations. MONTHLY WEATHER REVIEW , 146(1). 10.1175/MWR-D-17-0170.1
  • Green, BW, S Sun, R Bleck, SG Benjamin and GA Grell. (Jul 2017). Evaluation of MJO Predictive Skill in Multiphysics and Multimodel Global Ensembles. MONTHLY WEATHER REVIEW , 145(7). 10.1175/MWR-D-16-0419.1
  • Green BW; Zhang F. (May 2015). Idealized Large-Eddy Simulations of a Tropical Cyclone-like Boundary Layer. Journal of the Atmospheric Sciences , 72(5), 1743-1764. 10.1175/JAS-D-14-0244.1
  • Green BW; Zhang F. (Mar 2015). Numerical simulations of Hurricane Katrina (2005) in the turbulent gray zone. Journal of Advances in Modeling Earth Systems , 7(1), 142-161. 10.1002/2014MS000399
  • Yun Y; Zeng Q; Green BW; Zhang F. (Jan 2015). Mitigating atmospheric effects in InSAR measurements through high-resolution data assimilation and numerical simulations with a weather prediction model. International Journal of Remote Sensing , 36(8), 2129-2147. 10.1080/01431161.2015.1034894
  • Green BW; Zhang F. (Jun 2014). Sensitivity of Tropical Cyclone Simulations to Parametric Uncertainties in Air-Sea Fluxes and Implications for Parameter Estimation. Monthly Weather Review , 142(6), 2290-2308. 10.1175/MWR-D-13-00208.1
  • Qian C; Zhang F; Green BW; Zhang J; Zhou X. (Dec 2013). Probabilistic Evaluation of the Dynamics and Prediction of Supertyphoon Megi (2010). Weather and Forecasting , 28(6), 1562-1577. 10.1175/WAF-D-12-00121.1
  • Green BW; Zhang F. (Jul 2013). Impacts of Air-Sea Flux Parameterizations on the Intensity and Structure of Tropical Cyclones. Monthly Weather Review , 141(7), 2308-2324. 10.1175/MWR-D-12-00274.1
  • Green BW; Zhang F; Markowski P. (Dec 2011). Multiscale Processes Leading to Supercells in the Landfalling Outer Rainbands of Hurricane Katrina (2005). Weather and Forecasting , 26(6), 828-847. 10.1175/WAF-D-10-05049.1