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The worldwide solar-driven wind results in the so-called Sq (solar quiet) current system in the E region of the Earth's ionosphere (ionospheric dynamo region) (100–130 km (60–80 mi) altitude). [citation needed] Resulting from this current is an electrostatic field directed west–east (dawn–dusk) in the equatorial day side of the ionosphere.
In the height region between about 85 and 200 km altitude on Earth, the ionospheric plasma is electrically conducting. Atmospheric tidal winds due to differential solar heating or due to gravitational lunar forcing move the ionospheric plasma against the geomagnetic field lines thus generating electric fields and currents just like a dynamo coil moving against magnetic field lines.
The autoignition temperature or self-ignition temperature, often called spontaneous ignition temperature or minimum ignition temperature (or shortly ignition temperature) and formerly also known as kindling point, of a substance is the lowest temperature at which it spontaneously ignites in a normal atmosphere without an external source of ignition, such as a flame or spark. [1]
For a specified geographic location, time, and date, IRI provides average monthly values for electron density, electron temperature and ion temperature, and the molecular composition of the ions in the range of altitudes from 50 km to 2000 km. [1] The latest standard is IRI-2012. [1] [2] A new version, IRI-2016, has since been released. [3]
The ionosphere is where space weather manifests, creating unexpected conditions; electric currents can cause electrical charging of satellites, changing density can affect satellite orbits, and shifting magnetic fields can induce current in power systems, causing strain, disrupting communications and navigation or even triggering blackouts. [3]
Rate-of-Rise (ROR) heat detectors operate on a rapid rise in element temperature of 6.7 to 8.3°C (12.1 to 14.9°F) increase per minute, irrespective of the starting temperature. This type of heat detector can operate at a lower temperature fire condition than would be possible if the threshold were fixed.
The reaction is initiated by heat, typically supplied by electric current pulse. The reaction begins at 600 °C, the melting point of aluminium, and proceeds violently to temperature of 2200–2800 °C. The reaction does not need presence of oxygen, and the wire is consumed. [10]
The F-region is the highest region of the ionosphere. Consisting of the F1 and F2 layers, its distance above the Earth's surface is approximately 200–500 km. [7] The duration of these storms are around a day and reoccur every approximately 27.3 days. [6] Most ionospheric abnormalities occur in the F2 and E layers of the ionosphere.