London, May 15 (IANS): Lightning on earth is triggered not only by cosmic rays from space but also by energetic particles from the Sun, scientists have discovered.
The researchers found a link between increased thunderstorm activity on earth and streams of high-energy particles accelerated by the solar wind - offering compelling evidence that particles from space help trigger lightning bolts.
“We have found evidence that high-speed solar wind streams can increase lightning rates. This may be an actual increase in lightning or an increase in the magnitude of lightning, lifting it above the detection threshold of measurement instruments,” explained lead author Chris Scott from University of Reading.
Scott and his team from department of meteorology found a substantial and significant increase in lightning rates across Europe for up to 40 days after the arrival of high-speed solar winds.
After the arrival of a solar wind at the earth, the researchers showed there was an average of 422 lightning strikes across Europe in the following 40 days, compared to an average of 321 lightning strikes in the 40 days prior the arrival of the solar wind.
The rate of lightning strikes peaked between 12 and 18 days after the arrival of the solar wind.
These solar winds can travel at more than a million miles per hour into the earth's atmosphere.
The electrical properties of the air are somehow altered as the incoming charged particles from the solar wind collide with the atmosphere, the researchers proposed.
“The results could prove useful for weather forecasters, since these solar wind streams rotate with the sun, sweeping past the earth at regular intervals, accelerating particles into earth's atmosphere,” Scott noted.
As these streams can be tracked by spacecraft, this offers the potential for predicting the severity of hazardous weather events many weeks in advance, said the study published in the journal Environmental Research Letters.