Lightning’s Secrets Revealed March 31, 2008Posted by tkcollier in Enviroment.
Tags: Cool photos, Lightning, Science, storms, weather
Researchers unravel mystery of lightning diversity | NetworkWorld.com Community
For example, most people don’t see lightning see lightning strikes that go from clouds to the ground, but some lightning goes upward, forming blue jets and gigantic jets. Perhaps the most dangerous lightning appears as “bolts from the blue” – lightning that begins upward, but then moves sideways and then downward to hit the ground as much as three miles from a thunderstorm.
About 90% of lightning occurs inside clouds and is not visible to the casual observer, researchers said.
Lightning that strikes the ground does so because precipitation or the storm’s progression creates an excess of net negative charge in the mid-levels of the cloud. This results in either a direct ground strike or a bolt from the blue, researchers saidAn alternative way to discharge a middle negative charge is through a gigantic jet, which propagates upward. The height of the clouds somewhat controls whether a gigantic jet or bolt from the blue propagates. The higher the top of the cloud, the more likely a gigantic jet will appear, researchers said. However, large positive charge in the upper levels of the storm causes blue jets.
In run-of-the-mill thunderstorms, blue jets are positive, originate in the uppermost part of the cloud and propagate continuously upward; while gigantic jets are negative, begin like a normal intracloud flash and propagate stepwise upward. Inverted polarity storms do exist and the charges of the various lightning types would then reverse, researchers said.The higher the cloud, the more likely either type of jet becomes.
Thunderstorms in the tropics form with very high clouds increasing the chances of jets forming. Thunderstorms in the temperate United States do not have clouds quite so high, allowing a great number of bolts from the blue to occur. Bolts from the blue are very common in continental mid-latitude storms, researchers said. More Storm Pictures.
Caught on Camera -40 mile long vertical Lightning bolt.
Click on the picture below to learn more about the different kinds-of lightning bolts.