These secondary return strokes often make a lightning strike seem to 'pulse' or 'flicker' on and off.
The positive charge from the ground connects with the negative charge from the clouds and a spark of lightning strikes. during lightning formation, so that we may model them. When it occurs between two separate clouds it is known as Intra-cloud lightning most commonly occurs between the upper Another term used for cloud–cloud or cloud–cloud–ground lightning is "Anvil Crawler", due to the habit of charge, typically originating beneath or within the anvil and scrambling through the upper cloud layers of a thunderstorm, often generating dramatic multiple branch strokes. Phys. The overall discharge, termed a flash, is composed of a number of processes such as preliminary breakdown, stepped leaders, connecting leaders, return strokes, dart leaders and subsequent return strokes.Cloud-to-ground (CG) lightning is either positive or negative, as defined by the direction of the There are six different mechanisms theorized to result in the formation of downward positive lightning.Contrary to popular belief, positive lightning flashes do Positive lightning strikes tend to be much more intense than their negative counterparts. But what causes such a huge electrical current to form in the first place?After moist air has risen high enough to cool down and takes place, cloud formation takes place. Uman, Positive and bipolar lightning discharges to ground, in: Light. The lightning channel is an example of terrestrial plasma in action. Lightning can also cause the surrounding air to heat up to 27,700 degrees Celsius (almost 50,000 degrees Fahrenheit), often setting nearby objects on fire. Anecdotally, there are many examples of people saying 'the storm was directly overhead or all-around and yet there was no thunder'. The most vivid crawler behavior occurs in well developed thunderstorms that feature extensive rear anvil shearing. Lightning Stroke Definition: Lightning stroke is the direct discharge of an electrical charge between the atmosphere and the object of earth.It is a sudden flow of electric charge between the electrical charge area of a cloud also called intra-cloud and another cloud called (CC lightning) or between the charged cloud and the ground (CG lightning). Lightning strikes on people, though comparatively rare, can cause conditions ranging from amnesia to cardiac arrest. There are about 70–100 lightning flashes/s world wide (Israel, 1973; Rennie, 1999) resulting in (assuming 100 flashes) the generation of 10 11 J/s or 100 Gigawatts of power. See lightning strikes in real time across the planet. A Division of Autumn Skies Online (Pty) Ltd Most of us have experienced a lightning strike or thunderstorm. Feel free to leave me any comments, questions or suggestions, and I will get back to you as soon as possible. Fig. This simply means that when we talk about thunderstorms or a thunder cloud, technically we are referring to a byproduct of a lightning bolt. These discharges normally originate from the tops of very tall structures, such as communications antennas. The idea behind a lightning rod is that it serves as the highest object around and so it intercepts the stepped leader on its way to the ground. Estimates of Lightning NOx Production Per Flash from OMI NO2 and Lightning Observations. The rate at which the return stroke current travels has been found to be around 100,000 km/s.The massive flow of electric current occurring during the return stroke combined with the rate at which it occurs (measured in microseconds) rapidly High-speed videos (examined frame-by-frame) show that most negative CG lightning flashes are made up of 3 or 4 individual strokes, though there may be as many as 30.Each re-strike is separated by a relatively large amount of time, typically 40 to 50 milliseconds, as other charged regions in the cloud are discharged in subsequent strokes. Positive lightning has also been shown to trigger the occurrence of upward lightning flashes from the tops of tall structures and is largely responsible for the initiation of A unique form of cloud-to-ground lightning exists where lightning appears to exit from the cumulonimbus cloud and propagate a considerable distance through clear air before veering towards, and striking, the ground. It will make a flash of lightning.