Ionosphere-Thermosphere Modeling
Tim Killeen, Stan Solomon,
and the CISM Ionosphere-Thermosphere Team
CISM Advisory Council Meeting
4 March 2003
1
Ionosphere-Thermosphere Overview
CISM Advisory Council Meeting
4 March 2003
2
Perturbations in the Ionosphere-Thermosphere System
Positive & Negative ionospheric
storm effects (TIE-GCM simulation,
R. Roble, B. Foster)
Changes in neutral density following geomagnetic
disturbances alters satellite orbits due to
atmospheric drag, resulting in tracking anomalies
CISM Advisory Council Meeting
4 March 2003
3
Magnetosphere - Ionosphere Coupling
LFM Model
Jll, np,Tp
E
Magnetosphere Ionosphere Coupler
Particle precipitation: Fe, E0
(SH+SP)F = Jll
Conductivities: Sp, Sh
Electric potential: F
TING Model
One Way Coupling
Two Way Coupling
CISM Advisory Council Meeting
4 March 2003
4
Comparison of Coupled Models — Energy Flux & Ion Drift
One Way Coupling
CISM Advisory Council Meeting
Two Way Coupling
4 March 2003
5
Comparison of Coupled Models — Conductivities
One Way Coupling
CISM Advisory Council Meeting
Two Way Coupling
4 March 2003
6
Current Research: High-Resolution Polar Cap Model
with Multiple Levels of Nested Grids
Regular Grid (5°)
Nested Grid (~1°)
Electron Densities at F2 Peak (pressure level 2.0)
CISM Advisory Council Meeting
4 March 2003
7
Ionosphere-Thermosphere Validation Matrix
ISRs
Digisondes
SuperDarn
Imagers
Accelerometers ‡
Satellite Drag ‡
DE 2‡
AE ‡
GPS systems
DMSP/NOAA
TIMED
SNOE
Ground FPI
Ground Imager
Arc hivedRocket†
Tn U V O2 N2 O NO N nn ne O+ NO+ O2+ Te Ti ui
x1 x1 x1
x
x x x
x
x
x
2
2
2
x x
x
x
x
x
x x x
x x
x x x
x x x
x
x x x
x x x x
x
x
x x
x
x
x x x3
x
x x
x x x
x
x
x x
x
x
x
x
x
x
vi
x
x
x
x
x3
x
1
Below ~130 km
O/N2 during the day, electron densities at night, also coupling parameters. Useful composition data could
not be obtained from POLAR and IMAGE
‡ In situ or mainly in situ measurements, DE 2 and AE were multi-instrumented missions
† Only some of these variables were available on any particular rocket flight. Generally sporadic.
3 Derived quantities with assumptions
2
CISM Advisory Council Meeting
4 March 2003
8
M-I Coupling Validation Matrix
B
AMIE
ISRs
NOAA ‡
DMSP‡
x
GBMagnetometers x
Iridium ‡
x
‡
DirectParticle*
SuperDARN
Imagers†
E
x3
x3
V
x1
x3
x3
ui,vi E0
x3
x
x3
F
Precip J_
JH
SP
x1
x2,3
SH
x1
x2,3
x3
x3
x3
x3
x3
x
x
x3
x3
Jp
x3
x3
x3
x3
x3
3
x
3
x
x3
x
x
x3
1
AMIE uses measurements of B by ground-based magnetometers and of E and B from DMSP and NOAA
satellites. The resulting conductivities and potential pattern are reconciled, so the errors in potential are not
large. However, the original estimates of conductivies come from ISR measurements that were developed
using a Bates profile to describe the neutral atmosphere to derive the collision frequency. A Bates profile is
not an accurate description of the thermosphere, especially in regions of auroral precipitation. Low latitude
conductivities should not be used at all (see validation document).
2 See 1 for the difficulties with ISR conductivities.
3 Derived quantities with assumptions.
* Archived DE 2, UARS data
† Imagers provide measures of brightnesses in the UV. E and F can be derived from these brightnesses
0
‡ In situ
CISM Advisory Council Meeting
4 March 2003
9
Metrics
Rationale
• A robust set of metrics are needed that will be available for the foreseeable
future.
• The data used for these metrics should not be subject to uncorrectable
instrument drift and should be measured in the same way all the time.
• These metrics should reflect those developed by the Space Weather
Programs metrics panel as closely as possible.
Plan
• Proposed metrics for the ionosphere: the maximum electron density at the
F2 peak; the height of the F2 peak; and as a secondary product the maximum
electron density at the E-region peak.
• Densities will come from ionosondes and height from incoherent scatter
radars, although GPS measurements should also be considered when they
become routine.
• Proposed metrics for the thermosphere: satellite drag and accelerometer
densities; FPI red line temperatures; and O/N2 from satellite imaging when it
becomes regularly available.
CISM Advisory Council Meeting
4 March 2003
10
Research Plan Outline
Year 1
Complete preliminary coupling of the TING model to the Dartmouth MHD model. (70%)
Test magnetosphere/ionosphere model with observations with and AMIE analysis. (10%)
Begin transition to nested-grid version of the TIE-GCM coupled with the MHD model. (50%)
Participate in development of model coupling framework design and specifications. (90%)
Year 2
Couple MHD model and Rice convection model with the TIE-GCM.
Implement multi-processor version of coupled model, using coupling framework.
Initiate observational validation of magnetosphere/ionosphere coupled model.
Initiate development of graphical interfaces for output analysis.
Year 3
Initiate development of algorithms to assimilate observational data into the TIE-GCM.
Continue observational validation of magnetosphere/ionosphere coupled model.
Continue development of graphical interfaces for output analysis.
Support coupling of solar wind model to magnetospheric model to create CISM model.
Year 4
Extend TIE-GCM altitude range to include the plasmasphere.
Integrate new TIE-GCM with magnetosphere MHD model and Rice convection model.
Support validation of CISM model with observations.
Support installation of CISM model on NCAR computational facilities.
Year 5
Transition to pre-operational model on special-purpose NCAR computational facility.
Implement data assimilation system with CISM model.
Conclude observational validation activities.
Conclude graphical interface development activities.
CISM Advisory Council Meeting
4 March 2003
11
Meetings & Activities
• Magnetosphere-Ionosphere coupling meeting
Monthly, Access Grid
• NCAR-wide general CISM meeting
Monthly, HAO
• Ionosphere-Thermosphere model development meeting
Bi-Weekly, HAO
• CISM executive committee
Bi-Weekly, Telecon
• CISM general meetings
May kickoff, September retreat, March advisory council
• Space Weather Summer School
Lectures & Labs, BU
CISM Advisory Council Meeting
4 March 2003
12
Issues and Challenges
• Auroral energy flux and conductivity feedback (including solar ionization)
— parameterization of auroral acceleration
• Three-way coupling with the LFM and RCM
— unified solution to potential fields?
• Plasmasphere - ionosphere interactions
— incorporation of plasmasphere model into TIE-GCM
• Ion outflow
• Sub-grid-scale phenomena and model resolution
• Lower and middle atmosphere effects
• Validation & metrics
• Approach to data assimilation
CISM Advisory Council Meeting
4 March 2003
13