Upward Lightning Recorded in Brazil

Hello reader!

It follows one note published on the day (02/28) in the website of the National Institute for Space Research (INPE) noting that upward lightning recorded in Brazil.

Duda Falcão

Upward Lightning Recorded in Brazil

Tuesday, February 28, 2012

The Group for Atmospheric Electricity (ELAT) of the National Institute for Space Research (Instituto Nacional de Pesquisas Espaciais - INPE) captured the first images of upward lightning in Brazil.

Four upward lightning which started from one of the towers based on Pico do Jaraguá, in São Paulo, were recorded at intervals of twenty minutes. They were recorded with a fast camera (4000 frames per second). These observations may contribute to improve standards of lightning protection in Brazil.

"This is the first evidence of this kind of lightning in Brazil," said Marcelo Saba, researcher at ELAT/INPE and responsible for the observations.

The record of four upward lightning was something that drew attention of the researchers. This is a very high number, even when considering the short time interval. To get a comparative sense, in the Empire State Building in New York City, which has over 100 meters high, upward lightning happen about 26 times per year.

Most of the lightning (99%) are cloud-to-ground, or lightning that originate in the clouds and hit the ground, and only 1% is upward - leave from the surface. These percentages are different only at specific places, like very tall buildings, where the number of upward lightning might overcome the cloud-to-ground lightning.

The upward lightning are usually artificial, as a result of the environmental changes caused by human activity. They arise due to high-rise buildings, such as telecommunication towers, lightning rods or skyscrapers.

The experts say that studies could estimate frequency and conditions of the phenomenon occurrence (such as the height of structures and types of clouds and storms). The research may also improve the detection systems that monitor lightning incidence in Brazil.

In some countries, like Japan, upward lightning have brought great losses when they reach wind generation turbines. Therefore, it becomes relevant to intensify research in the country which has the highest lightning incidence in the world, especially because Brazil is likely to expand this type of power generation.

Few countries have images of this phenomenon, including the United States, Canada, Japan and Austria. Nevertheless, little is known about the physics and characteristics of upward lightning, which makes this record even more important for research.

Source: WebSite of the National Institute for Space Research (INPE)