Movie Caption: A spectrum of waves from lower atmosphere drives wind, temperature, and composition variability in the thermosphere and ionosphere. Waves originating in the lower atmosphere affect the background atmosphere on which solar storm-driven variability is superimposed. WAVE research will determine if and when lower atmosphere waves trigger ionospheric irregularities.
Model Description: The Whole Atmosphere Model (WAM) is an extension of the National Weather Service (NWS) operational Global Forecast System (GFS) model for medium-range weather forecasts. The model extends from the ground to the top of the thermosphere (~600 km depending on solar activity) (Akmaev and Huang, 2008; Akmaev et al., 2008). WAM calculates fields of winds, temperature, and molecular and atomic atmospheric composition. Additional upper atmospheric physics and chemistry, including electrodynamics and ion-neutral interactions, are included. WAM has a spectral hydrostatic dynamical core.
The Ionosphere-Plasmasphere-Electrodynamics (IPE) model (Maruyama et al., 2016) provides the plasma (ionized gas) component of the Earth’s upper atmosphere. IPE is a time-dependent, global three-dimensional model of the ionosphere and plasmasphere from 90 km to approximately 10,000 km. It provides global electron and ion densities, electron and ion temperatures, and plasma flow. The parallel plasma transport is based on the Field Line Interhemispheric Plasma (FLIP) model (Richards et al., 2010). International Geomagnetic Reference Field (IGRF) has been used to determine the model grid. The current version of the IPE simulations uses ~3.5 million grid points, a total of 13,600 flux tubes spaced to yield spatial resolution of 0.34° in latitude and 4.5° in longitude.
WAM has been coupled to IPE to enable the plasma to respond to changes driven by the neutral atmosphere and further study the connection between terrestrial and space weather. The coupling is based on time-dependent 3D re-gridding in the Earth System Modeling Framework in the NOAA Environment Modeling System architecture (Theurich, 2016). The WAM-IPE model ingests solar wind and geomagnetic inputs, provided both by direct observation and as forecasts from NOAA Space Weather Prediction Center (SWPC) from operational runs. The WAM-IPE Forecast System provides products out to two days using these drivers as initialized by the data assimilation (DA) system (Wang et al., 2011). Using DA improves the initial conditions by ingesting meteorological data every six hours based on the existing National Weather Service (NWS) forecasts. The coupled WAM-IPE model has been officially transitioned to the NWS National Centers for Environmental Prediction Central Operations in June 2021, providing space weather operational products at NOAA’s SWPC.
During Phase II of the WAVE DRIVE Science Center, we will implement multi-step vertical coupling (derived from the HIAMCM and tested in WACCMX) into WAM-IPE to evaluate the improvement in the space weather operational forecasts associated with gravity wave-induced Ionosphere-Thermosphere-Mesosphere variability.
A spectrum of waves from lower atmosphere drives wind, temperature, and composition variability in the thermosphere and ionosphere. Waves originating in the lower atmosphere affect the background atmosphere on which solar storm-driven variability is superimposed. WAVE research will determine if and when lower atmosphere waves trigger ionospheric irregularities.
See the Operational WAM-IPE page at SWPC: https://www.swpc.noaa.gov/products/wam-ipe
References: Akmaev, R. A., and H.-M. H. Juang (2008), Using enthalpy as a prognostic variable in atmospheric modelling with variable composition, Q. J. R. Meteorol. Soc., 134(637), 2193–2197, doi:10.1002/qj.345.
Akmaev, R. A., T. J. Fuller-Rowell, F. Wu, J. M. Forbes, X. Zhang, A. F. Anghel, M. D. Iredell, S. Moorthi, and H.-M. Juang (2008), Tidal variability in the lower thermosphere: Comparison of Whole Atmosphere Model (WAM) simulations with observations from TIMED, Geophys. Res. Lett., 35, L03810, doi:10.1029/2007GL032584.
Maruyama, N., Y.-Y. Sun, P. G. Richards, J. Middlecoff, T.-W. Fang, T. J. Fuller-Rowell, R. A. Akmaev, J.-Y. Liu, and C. E. Valladares (2016a), A new source of the midlatitude ionospheric peak density structure revealed by a new Ionosphere-Plasmasphere model, Geophys. Res. Lett., 43, 2429–2435, doi:10.1002/2015GL067312.
Richards, P. G., R. R. Meier, and P. J. Wilkinson (2010), On the consistency of satellite measurements of thermospheric composition and solar EUV irradiance with Australian ionosonde electron density data, J. Geophys. Res., 115, A10309, doi:10.1029/2010JA015368
Theurich, G., et al. (2016), The Earth System Prediction Suite: Toward a coordinated U.S. modeling capability, Bull. Amer. Meteorol. Soc., 97(7), 1229–1247, doi:10.1175/BAMS-D-14-00164.1.
Wang, H., Fuller-Rowell, T. J., Akmaev, R. A., Hu, M., Kleist, D. T., & Iredell, M. (2011). First simulations with a whole atmosphere data assimilation and forecast system: The January 2009 major sudden stratospheric warming. Journal of Geophysical Research,116, A12321. https://doi.org/10.1029/2011JA017081.
