The ozone layer above Sweden was much denser this February than usual following years of dire warnings of dangerously low levels in the stratosphere. Just one year after recording the second-thinnest ozone layer in its history for a February, Swedish meteorologists have now discovered the ozone layer is thicker than it’s been in decades.
Ozone is depleted by extremely cold temperatures in the stratosphere; but the Circumpolar Whirl (an ultra-cold wind generated during the polar winter darkness) disappeared much more suddenly than usual this year at the end of January. Consequently less ozone was destroyed than usual.
Measurements taken in February by the Swedish meteorological institute SMHI’s station in Norrkoeping show that the ozone layer over Sweden is experiencing its thickest levels since records began there in 1988. At the older Vindeln station in the north of the country, readings for February were even higher at 426 Dobson Units (DU), another record.
“We have to go as far back to the measurements taken in Uppsala between 1951 and 1966 to find levels that high,” SMHI said in a statement reported by the AFP. Sweden’s ozone layer is traditionally thickest during spring. It then thins out over the summer months before reaching its minimum levels in the winter, according to the SMHI.
Ozone provides the natural filter against dangerous UV rays from the sun. These rays, when unfiltered, can cause problems from minor sunburn to skin cancer and vegetation damage.