record low ozone over the Arctic have reached southern Scandinavia, where large ozone-depleted air masses have produced higher ultraviolet radiation levels in Finland this week, scientists say. While ozone levels above Finland in the spring are usually 420 Dobson units, levels have dropped to 250 to 270 Dobson units, said Markus Rex, a researcher at the Alfred Wegener Institute in Germany. Those ozone-depleted masses could move east over Russia in the next few days, and could travel as far south as the Chinese border, he said. Ozone, which protects life from harmful ultraviolet rays, has long been depleted over the Antarctic because of ozone-destroying chemicals. The destruction of ozone is exacerbated by cold winter temperatures in the stratosphere, which the Arctic has been experiencing this year, in part because greenhouse gases are trapping warmth closer to Earth’s surface.