Studies of Electromagnetic Radiation in Space
Highlights
Atmosphere-Ionosphere Mission - AIM
Response to the Swedish National Space Board “Call for Ideas”
“The processes in this transition region connect the solar and magnetospheric effects with the atmospheric response which, in fact, determine space weather in the Earth’s environment. This region is also the part of the Earth’s atmosphere where electromagnetic radiation from natural sources such as lightnings, and artificial sources such as radio, TV and radar transmitters, exhibit resonance and other interaction phenomena. The impact of these natural and man-made effects on the Earth’s space environment are of major public concern.”
“Controlled experiments using purpose-built radio transmitters have shown that non-linear interactions in the ionosphere give rise to noise-like secondary EM radiation [29]. This radiation is particularly strongly excited when the frequency of the injected radio wave is near a harmonic of the ionospheric electron cyclotron frequency [3]; see Figure 3. Similar sideband structures are expected when radio waves from powerful broadcast stations propagate in the ionosphere.”
“Studies of radiation-turbulence interactions above geographical regions with a high density of very powerful broadcast and TV stations (e.g., central Europe and the Far East).”
“The spectra measured in the HF frequency range onboard the Intercosmos-19, Cosmos-1809, ACTIVE, APEX and CORONAS-I satellites revealed unusual features suggesting a strong modification of the electron plasma in the topside ionosphere over densely populated areas of Europe and Asia. The location of broadband enhancements of about 20 dB relative to the cosmic noise over these areas is evident.”
“2.1.4 Mechanisms for outflow of ionospheric ions
What is the initial mechanism that pre-heats the ionospheric ions (mainly oxygen) which then are ejected upward by the mirror force and parallel electric fields, is a widely debated problem. The postulated mechanisms include lower hybrid waves, ion-cyclotron waves, and dispersive Alfv´en waves via a stochastic acceleration [13, 23]. Since the proposed wave instrumentation cover all the possible ion plasma frequencies, we should be able to determine the dominant transverse heating mechanism that operates at the topside ionosphere. For this purpose a Langmuir probe operating in the ion current mode would be appropriate complement of the AIM instrumentation.”
“Experiments show that ion outflows can be caused by radio waves from powerful radio transmitters.”
“Our research has demonstrated that not only natural perturbations but also radio waves from modern high-power radio stations can have such a "modifying" effect.” from 5 earth radii away and from conjugate hemispheres. The signals that bounce off the polar cusp are clearer than those that bounce off the magnetosphere.
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