A PDF from the university of Florida / 2013
While naturally occurring events can have a pronounced and long-lasting effect on the ionosphere, the term “ionospheric modification” specifically refers to changes in the ambient properties of the ionosphere that are produced by humans. Our working definition of “ionospheric modification” applies only to effects that can be repeated and controlled. Ionospheric heating facilities broadcast high power radio waves typically in the HF band in order to modify the ionosphere in a controlled manner.
HF heaters have been able to successfully reproduce several types of naturally occurring events: scintillation, electron density channels and layers, and airglow, among others. These HF heaters thus provide a controlled environment in which to study naturally occurring events. A number of HF heating facilities exist around the world: HAARP (Alaska), EISCAT (Norway), Sura (Russia), Jicamarca (Peru), and the once-and-future ionospheric heater at Arecibo (Puerto Rico).
Our work centers on experiments performed at HAARP. … One primary focus of our work at HAARP is to quantify the HAARP-modified HF radio wave absorption that occurs within the D-region ionosphere. We make use of a process known as HF cross-modulation, wherein a high power radio wave modifies the rate of absorption experienced by other HF waves propagating through the same volume. This phenomenon was first observed by Tellegen , and explained appropriately by Bailey and Martyn . Figure 1 shows a cartoon diagram for a typical HF cross-modulation experiment, wherein the HAARP HF heating array radiates two distinct waves: a high-power radio wave that modifies D-region absorption, and a lower-power CW probing pulse that is used to quantify changes in absorption.
Article & images here:
Guadalupe Island off Baja CA (below)
Guadalupe Island off Baja CA /various
The Prince Edward Islands (below) are two small islands in the sub-antarctic Indian Ocean that are part of South Africa. The islands are named Marion Island (named after Marc-Joseph Marion du Fresne) and Prince Edward Island (named after Prince Edward, Duke of Kent and Strathearn).
The islands in the group have been declared Special Nature Reserves under the South African Environmental Management: Protected Areas Act, No. 57 of 2003, and activities on the islands are therefore restricted to research and conservation management. Further protection was granted when the area was declared a “Marine Protected Area” in 2013. The only human inhabitants of the islands are the staff of a meteorological and biological research station run by the South African National Antarctic Programme on Marion Island.
The Prince Edward Islands (above & one below) are two small islands in the sub-antarctic Indian Ocean that are part of South Africa. http://go.nasa.gov/2fYKeFJ
Marion Island (above) http://go.nasa.gov/2fWSK5E
The island of Paramushir (above) http://go.nasa.gov/2fWO0gi
Severo-Kurilsk (Russian: Се́веро-Кури́льск; Japanese: 柏原, Kashiwabara) is a town and the administrative center of Severo-Kurilsky District of Sakhalin Oblast, Russia, located in the northern part of the Kuril Islands, on the island of Paramushir. (above)
Guadalupe Island (above) off Baja CA. Crazy spirals, right angles, and … Big transmitter?