Arctic Getting Closer to Ozone Depletion Record
16.03.2011 - Atmosphere & Space, Arctic
The recent unusually low temperatures in the ozone (O3) layer over the Arctic have triggered massive ozone depletion, putting the Arctic on track for a record loss. This conclusion was reached following measurements carried out by an international network of over 30 ozone sounding stations spread all over the Arctic and Sub-Arctic and led by the Alfred Wegener Institute. The measurements show that half of the ozone above the Arctic at the relevant altitudes was destroyed over the past few weeks. As conditions remain the same, the scientists say, the unusually rapid ozone depletion is bound to continue.
The connection between ozone loss and climate change is not new, and scientists showed that the colder winters have led to increased ozone depletion in the stratosphere (about 20,000 metres altitude). In fact, there is a paradoxical relation between the two phenomena, as increasing greenhouse gas concentrations retain the Earth’s thermal radiation at lower layers of the atmosphere, heating up these layers. Yet as less of the heat radiation reaches the stratosphere, the cooling becomes more intense in the stratosphere, contributing to the loss of ozone – which protects life on the Earth’s surface from harmful ultraviolet rays.
Scientists say that in the long term, the ozone layer should be able to recover thanks to extensive environmental policy measures enacted for its protection, most notably the Montreal Protocol. Despite this year’s record ozone loss, the long-term effect of the Montreal Protocol will prevent significant ozone destruction during the second half of this century, according to scientists. Until then, ozone depletion over the Arctic will depend on the temperature in the stratosphere and is therefore linked to the development of Earth’s climate.
