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Ionospheric Research at USU R.W. Schunk, L. Scherliess, J.J. Sojka, D.C. Thompson & L. Zhu Center for Atmospheric & Space Sciences Utah State University Logan, Utah 84322 Presented at: University of New Mexico May 16, 2006
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OUTLINE 1.Current Ionosphere Data Assimilation Models 2.Thermosphere Modeling 3.Tracking a TID
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1. Current Ionosphere Data Assimilation Models Gauss-Markov Kalman Filter Model of the Ionosphere Full Physics Kalman Filter Model of the Ionosphere Ensemble Kalman Filter Model of High-Latitude Electrodynamics
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GAIM Basic Approach We use a physics-based ionosphere-plasmasphere-polar wind model and a Kalman Filter as a basis for assimilating a diverse set of real-time (or near real-time) measurements. GAIM provides both specifications and forecasts on a global, regional, or local grid. Global RegionalLocal
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GAIM Assimilates Multiple Data Sources Data Assimilated Exactly as They Are Measured o Bottomside N e Profiles from Digisondes (20) o Slant TEC from up to 1000 Ground GPS Receivers o N e Along Satellite Tracks (4 DMSP satellites) o Integrated UV Emissions o Occultation Data (CHAMP, SAC-C, IOX)
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Gauss-Markov Kalman Filter Model Specification of the Global Ionosphere
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Ionosphere Forecast Model (IFM) Provides background ionosphere Global physics-based model 90 - 1400 km 15 - minute output cadence O +, H +, NO +, N 2 +, O 2 +, T e, T i –Only use N e Kalman solves for deviations from background
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Gauss-Markov Kalman Filter Model Operational Version Delivered July 15, 2004. oNRL oAFWA oNorthrop Grumman oAFRL oCCMC oCISM, BEI, UCAR-ESMF oNOAA
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Full Physics Kalman Filter Model Ionosphere Specification with Middle & Low Latitude Drivers
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Global Ionosphere-Plasmasphere-Polar Wind Model 3-D Time-Dependent Parameters –NO +, O 2 +, N 2 +, O +, H +, He + –T e, T i –u ||, u Auxiliary Parameters –N m F 2 –h m F 2 –N m E –h m E –TEC Grid System –Global –Regional –Localized –90-30,000 km –Realistic Magnetic Field (IGRF) Spatial Resolution Along B –0.9 km in E-Region –1.3 km in F-Region –3.8 km in Topside –240 km at 17,000 km
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Full Physics GAIM Output Continuous Reconstruction of Global N e Distribution oIonosphere-Plasmasphere-Polar Wind o90-30,000 km Quantitative Estimates of the Accuracy of Reconstruction Auxiliary Parameters oN m F 2, h m F 2, N m E, h m E oSlant and vertical TEC Model Drivers oHigh-Latitude Convection and Precipitation oLow-Latitude Electric Fields oGlobal Neutral Winds oGlobal Neutral Composition
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Ensemble Kalman Filter for High- Latitude Electrodynamics High-Resolution Specification of Convection & Precipitation Drivers
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Physics-Based Model of High-Latitude Electrodynamics Time-Dependent Ionosphere Model 0 3-D Density Distributions (NO+,O2+,N2+,O+,H+,He+) 0 3-D Te and Ti Distributions 0 Ion Drifts Parallel & Perpendicular to B 0 Hall & Pedersen Conductances M-I Electrodynamics Model 0 MHD Transport Equations & Ohm’s Law 0 Alfven Wave Propagation 0 Active Ionosphere 0 10 km & 5 sec Resolutions 0 Potential, E-field, Currents, Joule Heating Magnetic Induction Model 0 Calculates B Perturbations in Space & on Ground 0 Includes Earth’s Induction Effect
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Data Assimilated Ground Magnetic Data from 100 Sites Cross-Track Velocities from 4 DMSP Satellites Line-of-Sight Velocities from the SuperDARN Radars In-situ Magnetic Perturbations from the 66 IRIDIUM Satellites
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Output of the Electrodynamics Model (High Resolution) Electric Potential Convection Electric Field Energy Flux and Average Energy of Precipitation Field-Aligned and Horizontal Currents Hall and Pedersen Conductances Joule Heating Rates 3-D Electron and Ion Densities 3-D Electron and Ion Temperatures TEC Ground and Space Magnetic Disturbances
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We obtain the entire High Latitude Electrodynamic Environment Kalman FilterClimate (No Data)‘Truth’
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2. Thermosphere General Circulation Model Numerical Solution of Neutral Gas Continuity, Momentum, and Energy Equations Time-Dependent, High-Resolution, Global Model 25 Non-Uniform Altitude Layers from 97-500 km 0.5 deg in latitude, 3 deg in longitude 50 km resolution in polar region Flux-Corrected-Transport (FCT) Numerical Method Rotating Coordinate System fixed to Earth Ma and Schunk (1995)
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Thermosphere Model Inputs Global Ionosphere oDensities oVelocities oTemperatures Tidal and Gravity Wave Forcing from Below
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Global Thermosphere Response to Ionospheric Structures Propagating Plasma Patches oMa & Schunk (1995, 1997a, 1997b, 2001) Sun-Aligned Polar Cap Arcs oMa & Schunk (1997) Theta Aurora oDemars & Schunk (2005) Equatorial Plasma Bubbles oSchunk & Demars (2003, 2005) Cusp Neutral Gas Upwelling oDemars & Schunk (2006) Supersonic Neutral Winds oSchunk & Demars (2006)
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Qaanaaq, Greenland, October 29, 1989 All-Sky Images (630 nm) 2 - Minute Interval
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Equatorial Spread-F and Bubbles JULIA Coherent Scatter Radar Hysell and Burcham (1998)
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3. Tracking a TID
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In this “test,” the following are variables –TID Equatorward Speed –TID Width in Latitude –TID Amplitude History In this “test,” the assumptions are –TID is a perturbation on the background ionosphere. –TID perturbed densities are very noisy –TID moves along a meridian. –Observations lie along the meridian. Propagation with simple advective model A Model TID
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1-D TID/TAD 1-D Propagation Propagation along meridian Density Perturbations Network of ~10 observatories
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1-D TID/TAD 1-D Propagation Propagation along meridian Density Perturbations Network of ~10 observatories
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1-D TID/TAD 1-D Propagation Propagation along meridian Density Perturbations Network of ~10 observatories
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1-D TID/TAD 1-D Propagation Propagation along meridian Density Perturbations Network of ~10 observatories
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The Observations 10 Stations Density Perturbations 100% Noise
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Kalman Filter Reconstruction # of Stations = 10 100% Noise True Velocity = 2 Reconstruction of TID Density Perturbations T=1
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Kalman Filter Reconstruction # of Stations = 10 100% Noise True Velocity = 2 Reconstruction of TID Density Perturbations T=2
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Kalman Filter Reconstruction # of Stations = 10 100% Noise True Velocity = 2 Reconstruction of TID Density Perturbations T=3
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Kalman Filter Reconstruction # of Stations = 10 100% Noise True Velocity = 2 Reconstruction of TID Density Perturbations T=4
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Kalman Filter Reconstruction # of Stations = 10 100% Noise True Velocity = 2 Reconstruction of TID Density Perturbations T=5
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Kalman Filter Reconstruction # of Stations = 10 100% Noise True Velocity = 2 Reconstruction of TID Density Perturbations T=6
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Kalman Filter Reconstruction # of Stations = 10 100% Noise True Velocity = 2 Reconstruction of TID Density Perturbations T=10
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Kalman Filter Reconstruction # of Stations = 10 100% Noise True Velocity = 2 Reconstruction of TID Density Perturbations T=15
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Kalman Filter Reconstruction # of Stations = 10 100% Noise True Velocity = 2 Reconstruction of TID Density Perturbations T=20
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Kalman Filter Reconstruction # of Stations = 10 100% Noise True Velocity = 2 Guessed Velocity 50% Off Reconstruction of TID Density Perturbations
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Kalman Filter Reconstruction Reconstruction of TID Density Perturbations # of Stations = 10 100% Noise True Velocity = 2 Guessed Velocity 50% Off
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Kalman Filter Reconstruction # of Stations = 10 100% Noise True Velocity = 2 Reconstruction of TID Density Perturbations Determination of TID Velocity T=150
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