en http://www.sunearthplan.net/ The Sun Earth Plan aims to learn more about the region of space dominated by our sun. EISCAT (European Incoherent SCATter) radars beam pulses of radio waves into space and detect the echoes. Built in the late 1970s, the radar have helped European scientists understand the aurorae, the magnetosphere, and to monitor micrometeorites and space debris orbiting the Earth.Unlike the traditional dish-antennas, EISCAT-3D will comprise several fields of small antennas scattered across northern Scandinavia. By collecting radio echoes over a ... http://www.sunearthplan.net/5/947/More-eyes-on-the-skies The upper atmosphere lies between forty and ninety kilometres above the Earth’s surface, and is traditionally hard to monitor since it is too low for satellites and too high for balloons. It is where high-speed electrons, protons, and X-rays from our solar system and beyond deposit their energy, which ultimately affects the Earth’s climate. Radio waves with very low frequency, known as VLF waves, get trapped between the Earth and ab ... http://www.sunearthplan.net/5/581/Radio-AARDDVARK If you look at a distant thunderstorm at night, you may be lucky enough to see a flash of red light above the clouds known as a sprite. These enormous flares appear above the cloud tops and reach 80 kilometres high and several tens of kilometres wide, yet the whole scene lasts just a few milliseconds. They belong to a family of elusive electrical discharges that includes elves, sprite haloes, blue jets, blue starters and gigantic jets.First scien ... http://www.sunearthplan.net/5/564/In-search-of-sprites Typically, aurorae are observed within crown-like ovals that surround the northern and southern geomagnetic poles. During intervals of high geomagnetic activity the ovals expand equatorward, while quiescent periods cause them to shrink poleward. Consequently, the likelihood of observing an aurora at mid-latitudes varies widely, depending on the current state of the 11-year solar cycle. But we can expect to see visible aurora over the UK a couple ... http://www.sunearthplan.net/5/101/Aurora-alert British researchers are at the forefront of ground-based investigations into the Earth’s ionosphere and magnetosphere. These can be built and operated reliably for a tiny fraction of the cost of satellites. Measurements of the ionosphere made by instruments on terra-firma can be mapped out thousands of kilometres into the magnetosphere to reveal the structure and motion of near-Earth space.The Space Plasma Exploration by Active Radar (SPEA ... http://www.sunearthplan.net/5/27/The-bottom-up-approach Radio waves travelling through a plasma can accelerate electrons to high energies. This is partly how the aurorae are created naturally in the ionosphere in the first place. However, the interactions are extremely complex. They depend on many factors, such as the radio wave frequency and power, the electron’s initial energy, and the magnetic field strength and direction. At the Department of Communication Systems, Lancaster University, the ... http://www.sunearthplan.net/5/26/Man-made-aurorae What if tomographic images could be made of the sky . . .? The University of Bath’s Department of Electronic and Electrical Engineering has pioneered a technique that makes tomographic measurements of the high atmosphere, just like x-ray beams scanning a patient; only in this case the beams are radio waves, and the patient under observation is the Earth’s ionosphere. Radio signals passing between overhead space satellites and the gro ... http://www.sunearthplan.net/5/25/3D-movies-of-the-ionosphere Particles from the Sun spiral along the magnetic field lines, and lose energy when they collide with atmospheric oxygen and nitrogen. But this 'lost' energy doesn't simply vanish. It is converted partly into electromagnetic ‘light’ of different colours. The exact colour (or wavelength of the light) depends on how much energy the incoming particle started with, and what kind of atmospheric molecule or atom it hits. The ASK cameras he ... http://www.sunearthplan.net/5/24/ASK-the-auroral-experts