The highest levels of ultraviolet radiation ever recorded on Earth have been detected by a team of U.S. and German researchers. Oddly enough, the high levels of radiation were not recorded in Antarctica, where scientists have been researching the recurring problem of holes in the ozone layer for decades. The UV fluxes were recorded 1,500 miles from the equator in the Bolivian Andes near small villages and towns. The radiation levels are far above the ones that are often considered dangerous for terrestrial and aquatic life.
According to a recent press release by Frontiers in Environmental Science, measurements were made in the summer of 2003 and 2004 in the southern hemisphere with instruments that were developed for the European Light Dosimeter Network. As part of an astrobiology study looking for atmospheres similar to Mars, the team of researchers investigated lakes at high altitudes in the Andes. The dosimeters were placed at the Licancabur volcano summit and close by at the Laguna Bianca. In December of 2003, they found that ultraviolet radiation levels were indexed at 43.3 near Licancabur in Bolivia. A combination of the midday sun as well as the high elevation, produced higher ultraviolet radiation levels because of the naturally low ozone in these areas. At a beach during the summer in the United States, one might experienced a UV index of eight or nine, which is intense enough to authorize protection. A UV index of 11 is usually considered extreme.
The high ultraviolet radiation levels coincided with other circumstances which occurred around the same time that may have had an effect on the UV index reading as well. Increased aerosols from fires and seasonal storms in the area could have played a role in ozone depletion. In addition, just before the highest radiation fluxes were registered, a very large solar flare took place.
Even though they were at a lower intensity, radiation spikes continued to be recorded throughout the entirety of solar activity, and stopped soon after. Although the evidence linking the solar flare to the highest ultraviolet radiation levels ever recorded is circumstantial, particles from the sun have been known to alter atmospheric chemistry and possibly increase depletion of the ozone. These events are not linked directly to climate change, however, if the ozone layer thins across the globe, people will become more prone to radiation.
It is extremely important to closely monitor ultraviolet flux levels around the world. UV-B exposure at high levels can negatively alter the entire biosphere. It can affect photosynthesis, damage DNA, as well as decrease the viability of larvae and eggs. The increase in radiation levels is a contemporary example of the similarities in the atmosphere of other planets and Earth’s. The fluxes are comparable to that of which happened on early Mars but are occurring in populated areas.
The highest ultraviolet radiation levels ever recorded seem as though they happened due to bunch of rare events such as the storms, fires and solar flare in combination with the high altitude area. However, all of these factors by themselves are not rare at all. Radiation levels this high could happen again in largely populated places. Monitoring index levels and looking for increases or changes in UV radiation could be the first step in warning at-risk areas.
By Addi Simmons