page_title: Lightning strike
section_title: Lightning protection systems
hierarchical_section_title: Lightning strike / Prevention and mitigations / Lightning protection systems
caption_attribution_description: English: Pointed tip en:Lightning rod in Illinois, USA I, Dual Freq, took this photo and release it as GFDL.
context_page_description: A lightning strike or lightning bolt is an electric discharge between the atmosphere and the ground. They mostly originate in a cumulonimbus cloud and terminate on the ground, called cloud to ground lightning. A less common type of strike, called ground to cloud, is upward propagating lightning initiated from a tall grounded object and reaches into the clouds. About 25% of all lightning events worldwide are strikes between the atmosphere and earth-bound objects. The bulk of lightning events are intra-cloud or cloud to cloud, where discharges only occur high in the atmosphere. Lightning strikes the average commercial aircraft at least once a year, but modern engineering and design means this is rarely a problem. The movement of aircraft through clouds can even cause lightning strikes.
  A single lightning event is a "flash", which is a complex, multi-stage process, some parts of which are not fully understood. Most cloud to ground flashes only "strike" one physical location, referred to as a "termination".
context_section_description: Hundreds of devices, including lightning rods and charge transfer systems, are used to mitigate lightning damage and influence the path of a lightning flash.
  A lightning rod (or lightning protector) is a metal strip or rod connected to earth through conductors and a grounding system, used to provide a preferred pathway to ground if lightning terminates on a structure.  The class of these products are often called a "finial" or "air terminal".  A lightning rod or "Franklin rod" in honor of its famous inventor, Benjamin Franklin, is simply a metal rod, and without being connected to the lightning protection system, as was sometimes the case in the old days, will provide no added protection to a structure.  Other names include "lightning conductor", "arrester", and "discharger"; however, over the years these names have been incorporated into other products or industries with a stake in lightning protection.  Lightning arrester, for example, often refers to fused links that explode when a strike occurs to a high voltage overhead power line to protect the more expensive transformers down the line by opening the circuit.  In reality, it was an early form of a heavy duty surge protection device (SPD). Modern arresters, constructed with metal oxides, are capable of safely shunting abnormally high voltage surges to ground while preventing normal system voltages from being shorted to ground.
  In 1962, the USAF placed protective lightning strike-diversion tower arrays at all of the Italian and Turkish Jupiter MRBM nuclear armed missiles sites after two strikes partially arming the missiles.
caption: An example of a standard, pointed-tip, air terminal.
exif: {}