Haarp, a Powerful Active Ionospheric Laboratory Open for International Research

The High-frequency Active Auroral Research Program (HAARP) is the most powerful and capableionospheric heater in the world. High-power, high-frequency (HF) transmitters provide a means tostudy the ionosphere, upper atmosphere, and magnetosphere in ways not possible with traditional insituor remote sensing observations. With an HF "heater" an overhead region of the ionosphere can bemodified briefly to create a desired effect and then observe the ionosphere as it relaxes to its originalstate. By varying the frequency, amplitude, or on/off transmit time, the ionosphere can be used as anantenna to generate low frequency waves (ULF, ELF, VLF, Whistler, etc.) which propagate alongmagnetic field lines into the magnetosphere or are injected into the earth-atmosphere waveguide. Highpower HF energy can be used to create artificial airglow, perform radio science experiments and drive avariety of plasma instabilities, irregularities and turbulence.HAARP is powered by four 3600 HP diesel engines and can transmit 3.6 MW at multiple frequencies andmultiple beams anywhere in the interval 2.8 - 10 MHz. HAARP has been used to create artificial airglow,long-lived artificial ionospheric layers, instabilities, irregularities and turbulence; and various forms oflow frequency waves. The Geophysical Institute of the University of Alaska Fairbanks (UAF/GI) recentlytook ownership of HAARP from the Air Force Research Laboratory, restored the facility to operationalstatus and has been conducting scientific campaigns for outside investigators. The HAARP facility isopen to international researchers. The status and future plans for HAARP and a summary of recentexperiments will be presented.