Sunburn in the Polar Vortex - by Tre

    In many ways, New Zealand is a lot like Alaska. It has mountains, friendly people, and the climate is pretty similar. It's a bit warmer, but overall the mountainous terrain, cold ocean, glaciers, and windy conditions make it seem a lot like home. Right now it's summer here, and the temperature is about seventeen degrees Celsius, or 63 degrees Fahrenheit. Which is nice and cool compared to the scorching temperatures in French Polynesia. 

    But what I didn't expect is how easily I burn here. It's not crazy, but definitely not what you expect from a place that's cloudy and sixty degrees. In high summer you can burn within minutes of stepping outside if you don't wear the proper protection. This is due to an interesting atmospheric phenomenon.

    Above Antarctica, the ozone layer, which protects us from ultraviolet radiation, thins due to a complex chain of meteorological events. And, as is the case with many other destructive weather events, it's all the fault of humans. 

    Certain human-made chemicals, the most notorious being chlorofluorocarbons, halons, carbon tetrachloride, and methyl chloroform deplete ozone when they break down. These ozone depleting substances (ODS's) were once common in aerosols, solvents, and refrigerator coolants. While we have been successful in fazing some of these chemicals out of use, we are still feeling their effects today. 

    After ODS's are used, these chemicals slowly move through the atmosphere. ODS's are stable, and they don't break down easily, but eventually they make their way to the stratosphere where they are broken down by ultraviolet radiation. When they break down, they release chlorine and bromine atoms, which react with the ozone and break it apart, decreasing the ozone density in that area.

    Now, this might be less of a problem if the destruction was spread out across the world, and it is possible that the lessening in ozone density would not be very noticeable. however, during the Southern Hemisphere's spring, Antarctica experiences a phenomenon called the Polar Vortex. This is basically a giant cyclone that traps cold air over the continent. It draws more of the chemicals into itself, and the ODS's are activated by the ultraviolet rays, breaking down the ozone. The ozone thins inside the vortex, creating a sort of "hole" that hangs out over Antarctica due to the isolation caused by the polar vortex. 

    You may have heard of this "ozone hole" before, but many people make the mistake of thinking that it is a constant thing. In truth, the ozone hole comes and goes, reforming every spring with the Polar Vortex, then slowly dissipating through the fall and winter. 

    When the ozone hole does exist, it tends to stay above Antarctica. However, atmospheric circulation can cause it to affect places like New Zealand. Because of this, ultraviolet radiation from the sun can get to our skin easier since it isn't being blocked by ozone. This is why New Zealand has some of the highest skin cancer rates in the world, and why you burn easier here. 

Luckily, international efforts such as the Montreal Protocol have been successful in fazing out ozone depleting chemicals from use, and a recent United Nation's report shows the ozone layer slowly but surely healing itself. We should be able to expect the ozone hole to mend in about 43 years.