The record-breaking 2020 Antarctic ozone hole lastly closed in ~ the end of December after an outstanding season as result of naturally developing meteorological conditions and the continued presence of ozone depleting substances in the atmosphere.

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The 2020 Antarctic ozone hole grew rapidly from mid-August and peaked at around 24.8 million square kilometres on 20 September 2020, spreading over many of the Antarctic continent.


It was the longest-lasting and one that the largest and deepest holes since the ozone layer monitoring began 40 year ago. It was thrust by a strong, stable and also cold polar vortex and an extremely cold temperature in the stratosphere (the class of the setting between approximately 10 km and also round 50 km altitude). The exact same meteorological factors likewise contributed come the record 2020 Arctic ozone hole.

This is in contrast to the unusually little and short-lived Antarctic ozone feet in 2019.

“The last two ozone hole seasons demonstrate the year-to-year variability of the ozone hole and improve our knowledge of the components responsible for its formation, extent and also severity,” claimed Oksana Tarasova, head the Atmospheric environment Research Division, which monitor global Atmosphere watch network of monitoring stations. “We need ongoing international action to obtrude the Montreal Protocol top top ozone depleting chemicals. There is still enough ozone depleting substances in the environment to reason ozone depletion on an yearly basis,” said Dr Tarasova.’s an international Atmosphere watch programme works closely with Copernicus Atmospheric surveillance Service, NASA, Environment and Climate adjust Canada and other partner to screen the earth ozone layer, i m sorry protects us from the harmful ultraviolet light ray of the sun.

Strong Polar Vortex

Ozone depletion is straight related come the temperature in the stratosphere, i beg your pardon is the layer of the setting between approximately 10 km and round 50 kilometres altitude. This is due to the fact that polar stratospheric clouds, i m sorry have crucial role in the chemical destruction of ozone, only kind at temperatures below -78°C.

These polar stratospheric clouds contain ice crystals that can turn non-reactive compounds right into reactive ones, which have the right to then rapidly damage ozone as quickly as irradiate from the sun becomes available to start the chemical reactions. This suspended on polar stratospheric clouds and also solar radiation is the key reason the ozone feet is just seen in so late winter/early spring.

During the southern Hemisphere spring season (August - October) the ozone hole over the Antarctic rises in size, reaching a maximum between mid-September and also mid-October (NASA Ozone Watch image of 2020 ozone feet at that September height pictured left). Once temperatures high increase in the atmosphere (stratosphere) begin to climb in late southerly Hemisphere spring, ozone depletion slows, the polar vortex weakens and also finally breaks down, and by the finish of December ozone levels have returned to normal.

However, in 2020, a strong, stable and cold polar vortex retained the temperature the the ozone layer end Antarctica repeatedly cold, avoiding the mixing of ozone depleted air over Antarctica with ozone rich air from higher latitudes. 

For lot of the 2020 season, stratospheric ozone concentrations approximately 20 to 25 kilometres of altitude (50-100hPa) got to near-zero values with the ozone great depth as low together 94 Dobson devices (a unit the measurement), or around one 3rd of its regular value.

The EU Copernicus Atmospheric Monitoring company reported the ozone analyses confirmed the ozone hole had closed ~ above 28 December.

Every season, the appearance of the ozone hole and its development is monitored by means of satellites and a variety of ground-based observing stations. Attributes of the ozone hole, interactive maps, timeseries, existing state and forecast are being prepared and also monitored through the huge ozone community through the solutions of various organizations such as the Copernicus atmosphere Monitoring company (CAMS), NASA ozonewatch programme, NOAA, KNMI, ECCC and also others.

Montreal Protocol

The Montreal Protocol on substances that deplete the Ozone class is the landmark multilateral environmental agreement that regulates the production and consumption of nearly 100 chemicals referred to as ozone depleting substances (ODS). Due to the fact that the ban on halocarbons, the ozone great has slowly been recovering and also the data plainly show a tendency in to decrease area that the ozone hole – subject to annual variations.

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The recent /UN environment Programme scientific Assessment of Ozone Depletion, issued in 2018, concluded the the ozone layer on the course of recovery and to potential return of the ozone values over Antarctica to pre-1980 level by 2060. This is due to the fact that of the long life time of the chemicals in the atmosphere.