sciencetech-blog

comments

A mixture of thunderstorms, fires, chemicals and solar flares are thought to have been the catalyst for record levels of radiation detected over Bolivia in 2003.

Researchers from Germany believe this combination of events created the 'perfect storm' of damage to the ozone layer, and caused levels to soar to 43.3 at the region's Licancabur volcano.

The report continued that data collected across the Andes show UV anomalies such as this could increase - and if they do it could lead to more radiation entering our atmosphere.

In December 2003, a record UV index of 43.3 was detected at Bolivia's Licancabur volcano. Researchers believe thunderstorms, fires in the Amazon, chemicals from Antarctica and a solar flare combined to deplete the ozone layer and let harmful rays through. This spike is pictured in white around the Andes

On 29 December 2003, a radiation detector, known as a dosimeter, fitted to the top of the volcano recorded UV-B radiation level of 43.3. 

Although this spike was initially put down to detection error, two dosimeters placed more than 6 miles (10 km) apart saw the same peaks at the same time.

The high for the volcano, and the Andes region in general across Peru, Bolivia and Chile is 25.

By comparison, the average UV levels in New York reach only nine during the summer, with a high of 13 being spotted in Kenya and Australia.

A high of 12 is seen as dangerous to people's skin and eyes, according to the World Health Organisation.

The Andes receives higher levels because of its elevation, naturally lower ozone levels and tropical sun.

But this latest research claims these levels soared due to a rare combination of factors that destroyed the Earth's protective layer, which typically blocks the sun's radiation.

This included seasonal thunderstorms over the Andes, fires in the Amazon, ozone-depleting chemicals from Antarctica and a large solar flare that was emitted the month before the spike.

The Andes and the Licancabur volcano (pictured) receives higher levels because of its elevation, naturally lower ozone levels and tropical sun. But, the latest research claims these levels soared due to a rare combination of factors that destroyed the Earth's protective layer, which typically blocks the sun's radiation

This chart reveals the different radiation levels spotted on Bolivia's Licancabur volcano in January 2004 - two weeks after the spike. Before the solar flare in November, levels were around 20. The high is 25. By January 17 it reached 30 and researchers state this is evidence that the solar flare made an impact on radiation

'The solar flare is the big question mark here,' researcher Nathalie Cabrol, a planetary scientist at the SETI Institute in Mountain View, California, told Live Science.

These images plot total ozone layer levels on 10, 15 and 17 January. Purple areas show where the column amount decreased

'The major spikes in UV pretty much match exactly with this major solar activity.'

The discovery was made as the researchers were trying to identify environments in the Andes that were similar to those found on Mars.

Other contributing factors may also include elevated levels of water transported from the troposphere into the stratosphere at very low temperatures.

'Although the evidence is circumstantial, an X45 class solar flare also took place on November 4, 2003, becoming the largest event ever recorded with instruments,' explained the researchers.

'Solar particle events have been shown to affect atmospheric chemistry and foster ozone depletion.

'Our instruments were deployed two weeks after the X45 flares and showed the most extreme UV variability between the time of their deployment and the end of March 2004.

'The coincidental timing of the historical solar activity with seasonal UV maximum, and weather pattern that brings atmospheric instability over the Andes may have been additional factors that could have contributed to the generation of these unprecedented record values.'

The results were published in the journal Frontiers in Environmental Science.

Recent models suggest that tropical stratospheric ozone will slightly decrease in the coming decades, potentially resulting in more UV anomalies.

If they become more common, the researchers explained that events of this magnitude may have societal and ecological implications.

The spike was so extreme, it was initially put down to detection error. But two dosimeters placed more than 6 miles (10 km) apart saw the same peaks at the same time. This image shows the location of the dosimeter on the volcano, and one on the nearby Laguna Blanca