ionospheric electrodynamics & low-earth orbiting satellites (leos)
DESCRIPTION
Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS). J-M No ë l, A. Russell, D. Burrell & S. Thorsteinson Royal Military College of Canada October 7 th , 2009 Ubatuba, Brazil. Outline. An extreme example of space weather - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/1.jpg)
Ionospheric Electrodynamics
&Low-Earth Orbiting
Satellites (LEOS)J-M Noël, A. Russell, D. Burrell
& S. Thorsteinson
Royal Military College of CanadaOctober 7th, 2009Ubatuba, Brazil
![Page 2: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/2.jpg)
Outline
• An extreme example of space weather– Halloween 2003 Event and it’s effect on LEOs orbits.
• Numerical models– Neutral atmosphere – HLTIM– Electrodynamic – Electro– Ionospheric – Transcar
• Some numerical Results• Implications for satellite orbits
– predictions• Concluding remarks
![Page 3: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/3.jpg)
Most Powerful Solar Flares Ever Recorded
Ranking Date X-Ray Class
1 November 4th, 2003 X28+ (est. closer to X45 (Thomson et. al, 2004)
2 April 2nd, 2001 X20.0 2 August 16th, 1989 X20.0 3 October 28th, 2003 X17.2 4 September 7th, 2005 X17 5 March 6th, 1989 X15.0 5 July 11th, 1978 X15.0 6 April 15th, 2001 X14.4 7 April 24th, 2004 X13.0 7 October 19th, 1989 X13.0
![Page 4: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/4.jpg)
![Page 5: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/5.jpg)
CHAMP
Altitude from the surface
![Page 6: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/6.jpg)
SCISAT 1
Altitude from the surface
Drop of ~300 m in a few days
![Page 7: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/7.jpg)
Altitude ~ 390 km
Nov 9-11 2004 ??
May 28 2003 ??
July 29 2004 ??
![Page 8: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/8.jpg)
Altitude ~ 710 km
![Page 9: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/9.jpg)
Satellite Drag
2
2
1nsatDdrag vvACa
•adrag is the in-track acceleration (m/s2)•CD is the drag coefficient•vsat is the satellite velocity (m/s)•vn is the neutral wind (m/s)•A is the cross-sectional area (m2)•ρ is the neutral number density (m-3)
![Page 10: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/10.jpg)
Drag Coefficient, CD
Moe and Moe, 2005Average value that is used for most satellites
![Page 11: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/11.jpg)
What we want to study
• Thermospheric responses to ionospheric electric fields.– Electric fields can vary substantially in both
space and time.
• How does the thermospheric responses affect satellite orbits?– Variation in CD, ρ and v (not just only ρ)
– In this talk we will concentrate on ρ.
![Page 12: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/12.jpg)
Tools
![Page 13: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/13.jpg)
High Resolution High Latitude Thermospheric Model
• Thermospheric Model – A. T. Russell– based on the 2-D model of Chang and St.-
Maurice (1991)– solves the Navier-Stokes equations – several upgrades have been incorporated into
the model e.g. new cooling rates, stretched vertical grid, more realistic initial conditions.
![Page 14: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/14.jpg)
Some Numerical Results
![Page 15: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/15.jpg)
Thermospheric Response
A. T. Russell (2007), Russell et. al. (2007)vertical transport
horizontal transport
![Page 16: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/16.jpg)
Satellite Observations
Schlegel et al, Ann. Geophys., 2005
![Page 17: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/17.jpg)
CHAMP Observations
Schlegel et al, Ann. Geophys., 2005
![Page 18: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/18.jpg)
The End
Liu et al., JGR 2005
![Page 19: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/19.jpg)
FAC and Neutral Densities
Neubert & Christiansen, GRL, 2003 Liu et al., JGR 2005
![Page 20: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/20.jpg)
STK Simulations of CHAMP OrbitThe Halloween Event
![Page 21: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/21.jpg)
Basic Assumptions
• Severe space weather simulation– large ambient electric field in the ionosphere-
thermosphere, 100 mV/m, 0.5° half-width centered at 70°, ramped from 0 to 100 linearly in 1000 seconds.
• Use MSIS as a base neutral atmosphere– Add density perturbations obtained from the
thermospheric model (HLTIM – Russell)
![Page 22: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/22.jpg)
• Assumed that the thermosphere is symmetric.– i.e. no variation in the East-West direction.
• The latitudinal distribution is the same for the southern hemisphere as it is for the northern hemisphere.
Basic Assumptions – Continued
![Page 23: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/23.jpg)
STK Modeling of CHAMP Orbit October 26th, 2003
1200 to 1430, separation between sats ~ 20 meters
![Page 24: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/24.jpg)
Modeling of CHAMP Orbit November 4th, 2003
1000 to 1330 separation of sats is ~250 km
![Page 25: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/25.jpg)
CHAMP accelerations
![Page 26: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/26.jpg)
Concluding Remarks
• Space weather plays a important role in the decay rates of satellite orbits via:→ increases in the electrodynamical response
→ increases frictional heating
→ increases the thermospheric densities in the vicinity of orbiting satellites.
![Page 27: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/27.jpg)
Concluding Remarks
• Small-scale auroral structures having intense electrodynamics should not be neglected when simulating satellite orbits to determine their projected lifetimes.
• We have made an attempt to simulate the effects of the small-scale structures on satellites for the first time.
![Page 28: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/28.jpg)
What’s Next?
• Complete the coupling of the thermospheric model:– Transcar – ionospheric model
• Blelly et al., 1996
– Electro – electrodynamic model • Noel et al., 2001, 2005
• Comprehensive Coupled 2 – D Model– De Boer et al., 2009 submitted
![Page 29: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/29.jpg)
Thank YouObrigado
![Page 30: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/30.jpg)
Steep Precipitation Pattern
arctan2
arctanarctan)(
xxxf
![Page 31: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/31.jpg)
Electrodynamical response
Noël, 2006
![Page 32: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/32.jpg)
Ionospheric Response
Noël, 2006
![Page 33: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/33.jpg)
More observations from CHAMP
![Page 34: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/34.jpg)
Thermospheric Response
A. T. Russell (2005)
![Page 35: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/35.jpg)
![Page 36: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/36.jpg)
![Page 37: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/37.jpg)
Halloween 2003
Halloween 2003 Event
![Page 38: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/38.jpg)
Halloween 2003 EventSOHO
![Page 39: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/39.jpg)
What we want to study
• Current systems and electric fields in the vicinity and inside auroral arcs– There are 2 kinds of FAC
• FAC driven by the magnetosphere.
• FAC associated with divergences in Pedersen currents.– They are known to produce FACs on the edges of arcs.
• Electric Fields• Ionospheric and thermospheric responses.• How these responses affect satellite orbits.
![Page 40: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/40.jpg)
CHAMP accelerations
![Page 41: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/41.jpg)
CHAMP accelerations
![Page 42: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/42.jpg)
Electrodynamic Model (Electro)
• 2-dimensional model based on divergence-free current density.
• computes the electric potential, electric fields and current densities.
Noël, (1999), Noël et al. (2001, 2005)
![Page 43: Ionospheric Electrodynamics & Low-Earth Orbiting Satellites (LEOS)](https://reader033.vdocuments.mx/reader033/viewer/2022051517/5681585a550346895dc5b5c2/html5/thumbnails/43.jpg)
• Transcar – transport (Blelly et al., 1996)– computes the time evolution of the ionosphere
(composition, energetics and transport).– 1-dimensional along the magnetic field line. – electron energy spectrum – electron heating due to waves (Dimant and
Milikh, (2003), Noel et al. (2005))
Ionospheric Model