ionospheric research at usu r.w. schunk, l. scherliess, j.j. sojka, d.c. thompson & l. zhu...
TRANSCRIPT
Ionospheric Research at USU
R.W. Schunk, L. Scherliess, J.J. Sojka, D.C. Thompson & L. Zhu
Center for Atmospheric & Space SciencesUtah State UniversityLogan, Utah 84322
Presented at:University of New Mexico
May 16, 2006
OUTLINE
1. Current Ionosphere Data Assimilation Models
2. Thermosphere Modeling
3. Tracking a TID
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
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
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
GAIM Basic ApproachWe 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 Regional Local
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
GAIM Assimilates Multiple Data Sources
• Data Assimilated Exactly as They Are Measured
o Bottomside Ne Profiles from Digisondes (20)
o Slant TEC from up to 1000 Ground GPS Receivers
o Ne Along Satellite Tracks (4 DMSP satellites)
o Integrated UV Emissions
o Occultation Data (CHAMP, SAC-C, IOX)Global Assimilation of Ionospheric Measurements
Utah State University, (435)797-2962, [email protected];Universities of Colorado (Boulder), Texas (Dallas), and Washington
“Bringing the pieces together”
Gauss-Markov Kalman Filter Model
Specification of the Global Ionosphere
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Ionosphere Forecast Model (IFM)
• Provides background ionosphere• Global physics-based model• 90 - 1400 km• 15 - minute output cadence
• O+, H+, NO+, N2+, O2
+, Te, Ti
– Only use Ne
• Kalman solves for deviations from background
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Gauss-Markov Kalman Filter Model
• Operational Version Delivered July 15, 2004.o NRL
o AFWA
o Northrop Grumman
o AFRL
o CCMC
o CISM, BEI, UCAR-ESMF
o NOAA
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Full Physics Kalman Filter Model
Ionosphere Specification with Middle & Low Latitude Drivers
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Global Ionosphere-Plasmasphere-Polar Wind Model
• 3-D Time-Dependent Parameters– NO+, O2
+, N2+, O+, H+, He+
– Te, Ti
– u||, u
• Auxiliary Parameters– NmF2
– hmF2
– NmE
– hmE
– 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
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Full Physics GAIM Output
• Continuous Reconstruction of Global Ne Distribution
o Ionosphere-Plasmasphere-Polar Wind
o 90-30,000 km
• Quantitative Estimates of the Accuracy of Reconstruction
• Auxiliary Parameterso NmF2, hmF2, NmE, hmE
o Slant and vertical TEC
• Model Driverso High-Latitude Convection and Precipitation
o Low-Latitude Electric Fields
o Global Neutral Winds
o Global Neutral Composition
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Ensemble Kalman Filter for High-Latitude Electrodynamics
High-Resolution Specification of Convection & Precipitation Drivers
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 Model0 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 Model0 Calculates B Perturbations in Space & on Ground
0 Includes Earth’s Induction Effect
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
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
We obtain the entire High Latitude Electrodynamic Environment
Kalman Filter Climate (No Data) ‘Truth’
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)
Thermosphere Model Inputs
• Global Ionosphereo Densities
o Velocities
o Temperatures
• Tidal and Gravity Wave Forcing from Below
Global Thermosphere Response to Ionospheric Structures
• Propagating Plasma Patcheso Ma & Schunk (1995, 1997a, 1997b, 2001)
• Sun-Aligned Polar Cap Arcso Ma & Schunk (1997)
• Theta Aurorao Demars & Schunk (2005)
• Equatorial Plasma Bubbleso Schunk & Demars (2003, 2005)
• Cusp Neutral Gas Upwellingo Demars & Schunk (2006)
• Supersonic Neutral Windso Schunk & Demars (2006)
Qaanaaq, Greenland, October 29, 1989
All-Sky Images (630 nm)
2 - Minute Interval
Equatorial Spread-F and Bubbles
JULIA Coherent Scatter Radar
Hysell and Burcham (1998)
3. Tracking a TID
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
• 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
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
1-D TID/TAD
1-D Propagation Propagation along meridian Density Perturbations Network of ~10 observatories
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
1-D TID/TAD
1-D Propagation Propagation along meridian Density Perturbations Network of ~10 observatories
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
1-D TID/TAD
1-D Propagation Propagation along meridian Density Perturbations Network of ~10 observatories
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
1-D TID/TAD
1-D Propagation Propagation along meridian Density Perturbations Network of ~10 observatories
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
The Observations
10 Stations Density Perturbations 100% Noise
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Kalman Filter Reconstruction
# of Stations = 10 100% Noise True Velocity = 2
Reconstruction of TID Density Perturbations
T=1
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Kalman Filter Reconstruction
# of Stations = 10 100% Noise True Velocity = 2
Reconstruction of TID Density Perturbations
T=2
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Kalman Filter Reconstruction
# of Stations = 10 100% Noise True Velocity = 2
Reconstruction of TID Density Perturbations
T=3
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Kalman Filter Reconstruction
# of Stations = 10 100% Noise True Velocity = 2
Reconstruction of TID Density Perturbations
T=4
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Kalman Filter Reconstruction
# of Stations = 10 100% Noise True Velocity = 2
Reconstruction of TID Density Perturbations
T=5
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Kalman Filter Reconstruction
# of Stations = 10 100% Noise True Velocity = 2
Reconstruction of TID Density Perturbations
T=6
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Kalman Filter Reconstruction
# of Stations = 10 100% Noise True Velocity = 2
Reconstruction of TID Density Perturbations
T=10
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Kalman Filter Reconstruction
# of Stations = 10 100% Noise True Velocity = 2
Reconstruction of TID Density Perturbations
T=15
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Kalman Filter Reconstruction
# of Stations = 10 100% Noise True Velocity = 2
Reconstruction of TID Density Perturbations
T=20
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Kalman Filter Reconstruction
# of Stations = 10 100% Noise True Velocity = 2 Guessed Velocity 50% Off
Reconstruction of TID Density Perturbations
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Kalman Filter Reconstruction
Reconstruction of TID Density Perturbations
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# of Stations = 10 100% Noise True Velocity = 2 Guessed Velocity 50% Off
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”
Kalman Filter Reconstruction
# of Stations = 10 100% Noise True Velocity = 2
Reconstruction of TID Density Perturbations Determination of TID Velocity
T=150
Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];
Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”