1 of 2 | NASA and NOAA scientists say Earth's average Antarctica ozone hole is slightly smaller -- 8.91 million square miles in 2022 compared with 2021. But satellite observations determined the ozone hole reached its annual one day maximum area of 10.2 million square miles Oct. 5, 2022. Photo courtesy of NOAA
Oct. 26 (UPI) -- The Earth's ozone layer hole over Antarctica is slightly smaller in 2022, according to NASA and the National Oceanic and Atmospheric Administration. Ozone protects Earth from ultraviolet rays from the sun.
The ozone hole covers an average area of 8.91 million square miles compared with an average of 8.99 million square miles last year.
That's well below the 2006 peak size of the ozone hole, according to NOAA.
"Over time, steady progress is being made and the hole is getting smaller," said Paul Newman, chief scientist for Earth Sciences at NASA's Goddard Space Flight Center, in a statement.
"We see some wavering as weather changes and other factors make the numbers wiggle slightly from day to day and week to week. But overall, we see it decreasing through the last two decades. Eliminating ozone-depleting substances through the Montreal Protocol is shrinking the hole."
The ozone hole happens every September above the South Pole.
According to NOAA, chlorine and bromine derived from human-produced compounds are released through chemical reactions in high-altitude polar clouds. Those reactions deplete the ozone layer, with the strongest depletion over Antarctica.
Measurements in recent years show the ozone hole smaller in recent years than it was during the late 1990s and early 2000s, according to NASA and NOAA scientists.
NASA and NOAA use instruments aboard the Aura, Suomi NPP and NOAA-20 satellites to measure the growth and breakup of the ozone hole.
Despite the average size of the ozone hole becoming slightly smaller, the satellites detected a single-day maximum ozone hole of 10.2 million square miles -- slightly larger than last year.
NOAA scientists also use a Dobson Spectrophotometer to take ozone hole measurements. That's an optical instrument that records the total amount of ozone between the Earth's surface and the edge of space -- known as the total column ozone value.
A study of the ozone hole in 2018 by the United Nations and World Meteorological Organization said scientists expect the northern atmosphere's ozone hole to recover completely by 2030.