• Adiabatic nonlinear normal mode initialization for a grid point global model

    • Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/jess/100/01/0079-0104

    • Keywords

       

      C-grid; enstrophy; general circulation; gravity waves; initialization; normal modes; Rossby waves

    • Abstract

       

      The baroclinic primitive equation model used for short and medium range forecasting admits high frequency as well as desirable Rossby modes. These high frequency oscillations are excited by initial imbalances between the observed mass and wind fields. In this paper we determine and describe the normal modes of the linearized version of the general circulation model of Laboratoire de Meteorologie Dynamique, Paris. These normal modes are then used to initialize the model through Machenhauer’s nonlinear correction scheme. The adiabatic nonlinear normal mode initialization technique is shown to be superior to dynamic initialization in terms of elimination of high-frequency oscillations in the forecast. Normal modes of a particular model depend on the finite difference scheme chosen to approximate the governing system of model equations. The results presented correspond to enstrophy-conserving finite difference scheme.

    • Author Affiliations

       

      H C Upadhyaya1 A Mokssit2

      1. Centre Tor Atmospheric Sciences, Indian Institute of Technology, New Delhi - 110016, India
      2. LMD du CNRS, 24 Rue Lhomond, Paris - 75231, France
    • Dates

       
  • Journal of Earth System Science | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2021-2022 Indian Academy of Sciences, Bengaluru.