The Ozone Layer Might Not Be Recovering Properly

  • The Ozone Layer Might Not Be Recovering Properly

The Ozone Layer Might Not Be Recovering Properly

The new research, published in the journal Atmospheric Chemistry and Physics, carefully combined measurements of atmospheric ozone from 11 different datasets to produce a record of the last 30 years.

Almost three decades later, the "ozone hole" over the South Pole and the upper reaches of the stratosphere are showing clear signs of recovery. London is at 51N.

The stratosphere stretches from 10km above the Earth to 50km and ozone is slowly rising in the upper stratosphere, back towards the levels seen before CFC chemicals caused their damage.

Prof Joanna Haigh at Imperial College London and a member of the global research team stated, "The study is in lower to mid-latitudes, where the sunshine is more intense, so that is not a good signal for skin cancer".

TAKE OFF! What is the SpaceX Falcon Heavy and when is it launching to Mars? She said ozone had been declining seriously since the 1980s, but while the banning of CFCs was leading to a recovery at the poles, this did not appear to be true for the lower latitudes. It's vital to determine what's eating away at ozone in the mid-latitudes, where the majority of the world's population resides. It is a matter of worry as the Montreal protocol no doubt has helped to reduce damage level at the poles but there are other things going on. Overall, the effects balance out but this means the ozone layer over the area studied is remaining in its depleted state. But new findings suggest that at mid-latitudes, where most people live, the ozone layer in the lower stratosphere is growing more tenuous-for reasons that scientists are struggling to fathom.

The Ozone layer is situated in the Stratosphere, it is the area of the Atmosphere between 10 to 5 Km above the troposphere. One suggestion by the authors of the paper include the use of chlorine and bromine-containing chemicals known as very short-lived substances (VSLSs), used in paint strippers and solvents. Dr. William Ball from ETH Zurich and PMOD/WRC Davos, who led the analysis, said that their team was surprised to find out that the lower latitude ozone is declining since their current best atmospheric circulation models do not predict this effect.

Scientists had thought that VSLSs would not persist long enough in the atmosphere to reach the stratosphere and affect ozone. "But we have to keep an eye on the ozone layer and its function as a UV filter in the heavily populated mid-latitudes and tropics". They found that from 1998 to 2016, ozone in the lower stratosphere ebbed by 2.2 Dobson units-a measure of ozone thickness-even as concentrations in the upper stratosphere rose by about 0.8 Dobson units. "What matters most for UV at Earth's surface is the total column amount of ozone overhead", says co-author Sean Davis, a research scientist with NOAA's Earth System Research Laboratory in Boulder, Colorado.

Dr Justin Alsing from the Flatiron Institute in NY, who took on a major role in developing and implementing the statistical technique used to combine the data, said: "This research was only possible because of a great deal of cross-disciplinary collaboration".

The study was conducted by researchers from institutions in Switzerland, the United Kingdom, the USA, Sweden, Canada and Finland, and included data gathered by satellite missions including those by NASA.