Opportunities for High-Power, High-Frequency Transmitters to Advance Ionospheric/Thermospheric Research Report of a Workshop (2014) / Chapter Skim
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1 Introduction
1 Introduction
Pages 12-20
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From page 12... ...
Studies of the nonlinear interaction of HF radio waves with the ionosphere using recently developed powerful and agile ionospheric heaters, such as the EISCAT (European Incoherent Scatter Scientific Association) heater and more recently the completed HAARP heater (Appendix E)
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He further noted that this capability enables wide-ranging studies, such as the flow of energy in matter, cascading in excited states of atoms and molecules; ionizing matter to probe aspects of the very nature of particle, collective gas, and wave-particle energy exchange; and exploring fundamental plasma processes, which bear directly on attempts to realize controlled plasma fusion. All of the above is also highly relevant to understanding the geospace response to solar storms and the development of space weather near Earth.
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One workshop participant noted that recent observations of PMSE modulations created using the EISCAT heating facility could help to deduce mean grain size, dust density, and photoemission rates from PMSE temporal variations. • Some participants discussed using HF-induced optical emissions to measure neutral densities at altitudes between 200 and 350 km (F-region)
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Congress followed the recommendation of several scientific panels that there was an urgent need for a U.S.-based "worldleading" experimental facility with a heater based on modern electronic phased-array beam steering with wide transmitter frequency coverage and power exceeding theoretical thresholds for triggering strongly nonlinear processes, which was supported by an extensive complement of diagnostic instruments. The facility was completed and achieved its full design power in 2007 and has produced, according to several participants, a number of scientific firsts and breakthrough physics, in addition to being instrumental in training future workers in radio science and space-related disciplines.
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AMISR's novel modular configuration allows it be relocated with relative ease, thus enabling the study of upper atmospheric activity around the globe. In addition, remote operation and electronic beam steering allow researchers to operate and position the radar beam instantaneously.
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Papadopoulos, University of Maryland. In addition to the IRI, the HAARP site has a number of diagnostic instruments and facilities to support additional instruments.
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Table 1.1 and Figure 1.2 make clear that HAARP represents the culmination of achievement in HF ionospheric heaters. It has already been noted that as the HF power delivered to the ionosphere increases, the response of the geophysical environment changes discontinuously, 3 thus indicating the 3 See Joint Services Program Plans and Activities, Air Force Geophysics Laboratory, and Navy Office of Naval Research (1990)
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Journal of Geophysical Research 105:10657-10672. Joint Services Program Plans and Activities, Air Force Geophysics Laboratory, and Navy Office of Naval Research.
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2009. Mesospheric ice clouds as indicators of upper atmosphere climate change: Workshop on Modeling Polar Mesospheric Cloud Trends, Boulder, Colo., December 10-11, 2009.
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