Climate scientist Dr Olaf Morgenstern.
An early and long-lasting ozone hole in the atmosphere is being predicted by NIWA (the National Institute of Water and Atmospheric Research) this year.
Principal atmosphere and climate scientist Dr Olaf Morgenstern said he had a hunch the ozone season would be longer than usual, due to a combination of climate change and last year’s volcanic eruption in Tonga.
“There’s a cooling trend in the stratosphere that has resulted in the ozone hole decaying later in its seasonal cycle and lasting a bit longer than we would otherwise have.
The Antarctic ozone hole typically reaches its greatest extent in September or October and disappears in November or December.
Ozone molecules absorb ultraviolet radiation from the sun, acting like sunscreen for life on Earth.
Morgenstern said the Hunga-Tonga-Hunga Ha’apai sent an astonishing amount of water vapour into the atmosphere, which caused the stratosphere to cool and enhanced the depletion of ozone by forming clouds above Antarctica.
He said the stratosphere was very sensitive to changes in temperature, with climate change causing a long-term cooling trend, which could be contributing to the cold and stable conditions seen at present.
New Zealand would see the effects of ozone depletion in December through January, which coincided with the sun being at its highest point on the horizon, he said.
Morgenstern said it was likely to be mid-2060 before the hole in the ozone layer started disappearing.
Credit: radionz.co.nz
