Record Radiation in South America
Astrobiologists from the United States and Germany recorded the highest known level of solar UV radiation to reach Earth's surface. This was around 10 years ago.
On December 29, 2003, the UV Index (UVI) peaked, reaching the blistering number of 43.3 over the Andes Mountains in Bolivia. To put this in context, a beachgoer in the United States would expect a UVI of 8 or 9 on a summer day. Even with those numbers, one may not escape the day without sunburn.
Nonetheless, it has taken scientists 10 years to detail a report of this data while taking into account of the variables and anomalies monitored from an international network of dosimeters — or Eldonets (European Light Dosimeter Network) — that measure UV radiation worldwide. This system is comprised of more than 100 stations across 5 continents to account for variation in the atmosphere above each station.
In fact, around 35% of the peak data from the station at the summit of Licancabur volcano in the Andes was lost — it was only through the wide scope of Eldonets that the data could be placed.
And the reason behind a staggering UVI of 43.3 — a list of uncertainties:
- Ozone depletion in a region where column ozone is naturally the thinnest
- NOAs (negative ozone anomalies), which has to do with air circulation
- A solar flare on November 4, 2003 that increased solar irradiance
Unlike the sky on that December day in 2003, the explanation behind the "perfect storm" of conditions is clouded.
But, what does this mean for us? 10 years removed from these dangerous conditions, CFCs and some other harmful aerosols have been phased out of every day use, but they still persist in the atmosphere. Ozone depletion means that we are running out of our natural sunscreen.
Short-wave ultraviolet radiation damages DNA and causes cancer, affects reproduction in all organisms, and prevents photosynthesis. Some plants that we rely on for food and entire food chains (phytoplankton) are even more sensitive to short-wave UV rays than humans. This is especially concerning to the future of food security in a world of rapid population growth. After all, plants can't reapply every 2 hours.
This report — 10 years in the making — attempts to shine light on the harsh reality of ozone depletion.
For more information visit frontiers.
Licancabur volcano image via Shutterstock.