5.5
Towards weather prediction in the whole atmosphere-ionosphere system: A coupled model of Integrated Dynamics through Earth's Atmosphere (IDEA)
Rashid A. Akmaev, NOAA SWPC, Boulder, CO; and T. J. Fuller-Rowell, F. Wu, A. Anghel, H. Wang, M. Iredell, S. Moorthi, H. -. M. Juang, Y. -. T. Hou, G. H. Millward, A. D. Richmond, and A. Maute
The upper atmosphere and ionosphere exhibit spatial and temporal variability on global scales with periods from several hours to several days, characteristic of lower-atmospheric planetary waves and tides. To study the origin, vertical propagation, and effects of these planetary-scale perturbations on the coupled thermosphere-ionosphere-electrodynamics system, a new model of Integrated Dynamics through Earth's Atmosphere (IDEA) is being developed under a NASA sponsored collaborative project between the University of Colorado and National Weather Service's (NWS) Environmental Modeling and Space Environment Centers. IDEA interactively couples a Whole Atmosphere Model (WAM) with Global Ionosphere-Plasmasphere (GIP) and electrodynamics models. WAM is a 150-layer general circulation model (GCM) based on NWS's operational weather prediction Global Forecast System (GFS), extended from its nominal top altitude of about 60 km to over 600 km. It incorporates relevant physical processes in the extended domain, ranging from the hydrological cycle, cloud physics, and atmosphere-surface exchanges in the troposphere, to solar and Joule heating and mutual diffusion of major species in the thermosphere. The model extension into a domain of highly variable composition, high temperatures, and very low density requires certain generalization of the standard GCM framework. First simulations reveal the presence of realistic tidal waves modulated at planetary wave periods with a substantial contribution from non-migrating modes, recently implicated in the observed spatial morphology of the ionosphere. The structure and variability of tides in WAM will be presented and discussed.
Session 5, New Developments with Physics-Based Forecast Models Part I
Tuesday, 22 January 2008, 8:30 AM-9:45 AM, 221
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