PAST, PRESENT AND FUTURE OF ACTIVE EXPERIMENTS IN SPACE
A. V. Streltsov1,2, J.-J. Berthelier3, A. A. Chernyshov4, V. L. Frolov5,6, F. Honary7,
J. Kosch7,8,9, R. P. McCoy10, E. V. Mishin2, M. T. Rietveld11,12
1Embry-Riddle Aeronautical University, Daytona Beach, Florida, USA;
2Air Force Research Laboratory, Space Vehicles Directorate, Albuquerque, New Mexico, USA;
3LATMOS/IPSL, CNRS-UPMC-UVSQ, UPMC, Paris, France;
4Space Research Institute, Moscow, Russia;
5Nizhny Novgorod State University, Nizhny Novgorod, Russia;
6Kazan Federal University, Kazan, Russia;
7Lancaster University, Lancaster, United Kingdom;
8South African National Space Agency, Hermanus, South Africa;
9University of the Western Cape, Bellville, South Africa;
10Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska, USA;
11EISCAT, Ramfjordbotn, Norway;
12UiT The Arctic University of Norway, Tromsø, Norway.
Abstract. Active ionospheric experiments using high-power, high-frequency transmitters, “heaters”, to study plasma processes in the ionosphere and magnetosphere continue to provide new insights into understanding plasma and geophysical proceses. This review describes the heating facilities, past and present, and discusses scientific results from these facilities and associated space missions. Phenomena that have been observed with these facilities are reviewed along with theoretical explanations that have been proposed or are commonly accepted. Gaps or uncertainties in understanding of heating initiated phenomena are discussed together with proposed science questions to be addressed in the future. Suggestions for improvements and additions to existing facilities are presented including important satellite missions which are necessary to answer the outstanding questions in this field.
Table of Contents
2.2.2 Defense Meteorological Satellite Program (DMSP) 20
2.2.3 The Demonstration and Science Experiments (DSX) Satellite. 22
3 Theory of the HF Ionospheric Modification. 29
3.1 Propagation of O-Mode Waves. 30
3.2 Electrostatic Plasma Waves. 31
3.2.1 Wave-Particle Analogy. 33
3.3 Ponderomotive Parametric Instability (PPI) 33
3.3.1 PPI in Isotropic Plasma (PPIL) 35
3.3.2 Parametric Decay Instability (PDIL) 36
3.3.3 Modulational Instability (MI) 36
3.4 PPI in the Plasma Resonance Layer 37
3.4.1 Strong Langmuir Turbulence (SLT) 38
3.4.2 Coexistence of WT and SLT Regimes. 40
3.4.3 Full-Wave Simulations of SLT at HAARP. 41
3.5 PPI in the Upper Hybrid Layer (PPI ) 42
3.5.2 Langmuir Turbulence in the UH Layer 45
3.6 Nonlinear Thermal Effects. 46
3.6.1 Electron Heating and Thermal Flux. 47
3.6.2 Thermal Self-Focusing Instability (TSFI) 48
3.6.3 Thermal Parametric Instability (TPI) 48
4.1 Stimulated Electromagnetic Emissions (SEEs) 53
4.2 Artificial Field-Aligned Irregularities (FAIs) 60
4.2.1 Amplitude-Time History of the Pump Wave Reflected from the Ionosphere. 64
4.2.2 Temporal Development of FAIs. 66
4.2.4 Temporal Evolution of Short-Pulse Pumped FAIs. 67
4.2.5 Spectral Characteristics of SSIs. 68
4.2.6 Dependence of FAI Intensity on the Pump Power 70
4.2.7 Magnetic Zenith Effects. 70
4.2.8 Unexplained UHF Radar Backscatter at the Magnetic Zenith. 72
4.2.9 Gyroharmonic Effects Associated with FAIs. 73
4.3.1 DEMETER Observations over SURA.. 78
4.3.2 DMSP and DEMETER Observations over HAARP. 80
4.3.3 Numerical Modeling of Artificial Ducts. 81
4.4.2 Electron Temperature Effects. 85
4.4.3 Magnetic Aspect Angle Effects. 87
4.4.4 Electron Energy Spectrum.. 87
4.4.5 Small-Scale Optical Structures. 88
4.4.6 X-Mode Optical Phenomena. 89
4.4.7 Optical Phenomena in the E Region. 90
4.5.1 Generation of ULF/ELF/VLF Waves. 91
4.5.3 ULF Waves in the Global Magnetospheric Resonator 99
4.5.4 ULF Waves in the Ionospheric Alfvén Resonator 102
4.5.5 ULF Waves in the Earth-Ionosphere Waveguide (Schumann Resonator) 103
4.5.6 ELF/VLF Waves in the Magnetosphere. 105
4.6 Descending Artificial Ionization Layers (DLs) 107
4.6.2 Observations of DLs. 109
4.7 Other Active Experiments. 121
4.7.1 Artificial Ionospheric Horizontal Periodic Irregularities (APIs) 121
4.7.2 E Region Ionospheric Perturbations. 122
4.7.3 D Region and Mesospheric Perturbations. 122