haarp-induced ionospheric ducts gennady milikh, university of maryland in collaboration with: dennis...
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HAARP-induced HAARP-induced Ionospheric DuctsIonospheric DuctsGennady Milikh, Gennady Milikh, University of University of
Maryland Maryland
in collaboration with: Dennis Papadopoulos, in collaboration with: Dennis Papadopoulos, Chia-Lee Chang, Chia-Lee Chang, BAEBAE systems systems
Evgeny Mishin,Evgeny Mishin, AFRL/RVBXI, AFRL/RVBXI, Hanscom AFBHanscom AFBMichel ParrotMichel Parrot, LPCE/CNRS, France, LPCE/CNRS, France
Joe HubaJoe Huba, NRL, NRLAndrei DemekhovAndrei Demekhov, IAP, N-Novgorod, Russia, IAP, N-Novgorod, Russia
Conference on Dynamical Processes in Space Plasma, Israel, April, 2010
MotivationMotivation
• Naturally induced field aligned irregularities of the plasma density exhibit enhanced refractive indices and act as ducts that guide waves in the whistler range between the two hemispheres.
• HF heating of the ionosphere creates density perturbations that may propagate into the plasmasphere, thus produce artificial ducts.
ObjectivesObjectives
•To present the observations of the density perturbations caused by the HF-heating of the ionosphere by HAARP and detected by Demeter and DMSP satellites.
•To check the observations against a model of the artificial ducts due to HF-heating of the ionosphere.
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04/24/07f=3.2 MHzO-mode0.1 HzMagn. Zen.No electrojet
Demeter observations of the daytime artificial ducts
10/16/09f=5.1 MHz, O-modeCW, Magn. Zen.
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Kodiak radar diagnostics
HF-heating
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Daytime Measurements (summarizing)
Daytime artificial ducts are narrow (the width in N-S direction is under 100 km), and relatively weak (Ni,e and Ti,e perturbations are under 10%). Thus they can be detected only from a close overfly.
The artificial ducts required a strong HF-heating which produces the ionospheric perturbations, such as observed by Kodiak. To generate such perturbations the heating frequency should be close to MUF.
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04/24/07f=3.2 MHzO-mode0.1 HzMagn. Zen.No electrojet
Demeter observations of the nighttime artificial ducts
10/21/09f=2.8 MHz, O-modeCW, Magn. Zen.
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Nighttime Measurements (summarizing)
• Nighttime artificial ducts broader than daytime (the width reaches 200 km), and Ni,e and Ti,e perturbations reach 80%. Detectable even at few hundred km distances from the HAARP MZ.
• Outflow of O+ ions pushes H+ and He+ upward – artificial polar wind.
The model of artificial ducts in the The model of artificial ducts in the ionosphereionosphere
•It is based on the SAMI2 model of the ionosphere [Huba, et al., 2000] which describes evolution of the ionospheric plasma confined by a bunch of the geomagnetic field lines.
•The SAMI2 model was modified, namely a flexible local source of the electron HF-heating was introduced in the form of the localized heating rate per electron:
4/ 2 10 ( / )eq P Vn K s
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Model Validation
Validation of the numerical model of ductsby comparison with two well documented experiments:
The first experiment was conducted at the EISCAT facility and diagnosed by the EISCAT Incoherent Scatter Radar, which measured the vertical profiles of the electron and ion temperature between 150 - 600 km.
The second experiment was conducted at the SURA facility, and used DEMETER satellite as a diagnostic tool to measure the ion density along the overflying satellite orbit close to the magnetic zenith of the HF-heater.
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EISCAT EXPERIMENT
EISCAT HF facility is located near Tromso, Norway (69ooN, 19oE)
Experiments conducted on 10/7/99 [Rietveld et al., JGR, 2003]
Heater operated at 4.5 MHz, ERP=205 MW under quiet ionospheric conditions.
Major diagnostic tool: UHF ISR.
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Comparison with the EISCAT experiment (model has been adjusted)
The absorption efficiencies=0.16, 0.32 and 0.64.
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SURA EXPERIMENT
SURA HF facility located near Nizny Novgorod, Russia (56ooN, 46oE).
Experiment conducted on 05/01/06 [Frolov et al., Radiophys. @ Quantum Electronics, 2008] under quiet ionospheric conditions.
The heater operated at 4.3 MHz, O-mode, magnetic zenith, ERP=80 MW.
Ground-based diagnostics was provided by ionosonde.
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Comparison with the SURA experiment
Absorption efficiencies=0.14 (blue) and 0.25 (red), crosses - observations.
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In summary, the modified model of ducts reproduces observations with high accuracy, which establishes it as a key tool for the study of the artificial ionospheric modifications.
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Demeter observations of the nighttime artificial ducts
02/12/10 f=2.8 MHz, O-mode, CW, MZ
Focusing of HF waves by ducts
The strong signal was detected between 6:30:37 – 6:30:47 shown by arrows
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Theory of focusing of HF waves by ducts
0oNeΔN
2ω
2eω
21Δn
rρ2drdznΔc
ωiexpc2π
ωoiφAeE
i
i.e. forming a focusing lens
Expanding n and r by powers of 2 we obtain the focusing distance
km50~ ifkm400300~o/NeΔNΔz
2ρoz
1
dzoNeΔN
2ρ
22ω
2eω
oz
1000~2
oNeΔN
2cΔz f2
E/A
Lens
Magnification:
ConclusionsConclusions• Artificial ducts due to the ionospheric heating was
detected by the Demeter satellite during daytime & nighttime.
• Modified SAMI2 model provides quantitative predictions of the ducts.
• HF focusing by ducts propagation was detected. A HF focusing by ducts propagation was detected. A theoretical model of HF-focusing was developed.theoretical model of HF-focusing was developed.