FIGURE S.1 Overhead photo of the High Frequency Active Auroral Research Program Gakona Facility. SOURCE: McCarrick, M., et. al., Marsh Creek LLC, “HAARP Facility Status,” presentation to the Committee on the Role of High-Power, High-Frequency-Band Transmitters in Advancing Ionospheric/Thermospheric Research: A Workshop, April 2013. Courtesy of M. McCarrick. Available at

According to experts at the workshop, the combination of extremely high power and the capability to be rapidly reconfigured to create a variety of spatial and temporal antenna patterns is unique in the world to “HAARP,” or more properly its ionospheric research instrument (IRI).5 Further, in presentations at the workshop, participants learned how the ability to produce such large and patterned energy into the ionosphere is being used for exploring many aspects of the upper atmosphere, including the mesosphere and lower thermosphere (MLT) region, the ionosphere, and the magnetosphere. These regions form a coupled system whose nonlinear response to variable and wide-ranging energy and momentum sources have important influences on those of us living on the surface of Earth; for example, radio and satellite communications, global navigation, and the lifetime of space assets limited by atmospheric drag. Many participants in the workshop, even some who were familiar with experiments at heater facilities, said they came away with an increased appreciation for the breadth of phenomena that are addressed by the HAARP facility.


5 Throughout this report “HAARP” is used interchangeably with IRI except in those instances when reference is made to the HAARP facility, which includes the IRI, various diagnostic instrumentation, and other associated operational elements, or the “HAARP program,” which strictly speaking is not correct, because the “P” in HAARP refers to “Program,” but is common usage.

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