Nature - Images

Interesting Images:

New Map Charts Every Lightning Bolt

Every second, as many as 100 lightning bolts strike the Earth. Now, a new map reveals a tally of those flashes over the last two decades, tracing where they strike the planet each year.

Westward on the map, lightning flashes run down Mexico and Central America, before reaching their peak in Colombia and Venezuela; eastward, they peak in Singapore and Malaysia. But neither region compares to the dramatic strikes in the Democratic Republic of the Congo in Central Africa.

The data reveal that lightning is more likely to strike land than water, and these flashes occur more on land close to the equator. But the different intensities also reveal subtle differences in the storms themselves.

Lighting results from processes occurring within clouds. As ice particles within a cloud collide and break apart, the smaller particles acquire positive charge and the larger particles acquire negative charge. Updrafts of wind then push the small particles upward, until the top of the cloud is positively charged, while the bottom of the cloud is negatively charged. This separation of charge creates a huge electric potential within the cloud, and between the cloud and the ground.

Eventually, the electric potential grows strong enough to overcome the air's resistance to electrical flow. Negative charges venture toward the ground from the bottom of the cloud, causing positive charges to surge up toward the cloud from the ground. This electrical discharge is a surge of lightning.