Solar wind periscope
Space weather, mainly in form of the solar wind or heliosphere, constantly affects earth’s atmosphere. A solar flux of particles collides with atmospheric gas atoms creating an ionized layer at the border between earth and space. Depending on the solar wind and the ionization caused by it, this layer can both reflect or absorb high frequency (HF) electromagnetic waves. Radio signals may use this reflecting layer in order to reach places normally occluded by the curvature of the earth – a process named skywave propagation. In turn, the range of a HF radio signal is determined by the reflection and absorption of this layer and thus becomes a correlate of the ionization by the solar wind. Because of this, by measuring radio signal range an earth-bound radio station can serve as a weather station for extraterrestrial weather.
The „solar wind periscope“ is a periscope connecting the visible surroundings of the Weather Tunnel with invisible space weather which becomes accessible through an antenna. It is accompanied by an antenna connected to a radio receiver. The receiver constantly monitors low-power HF radio signals stemming from a global network of radio transmitters known as wsprnet (pron.: whisper net). Through wsprnet, the radio receiver monitors which nodes of the global transmitter network currently are reaching the Weather Tunnel, indicating their respective range and thus ionospheric conditions.
Looking through the periscope, the surroundings of the Weather Tunnel can be seen. This image is augmented by a direction-dependent visualization of radio signal range and therewith the solar wind and its current effect on the ionosphere of the earth.