16 November 2005
Ozone Hole Intense For Summer
While not at record levels, NIWA scientists report the ozone hole over Antarctica this year is “relatively large” and
certainly more intense than last year.
According to Dr Richard McKenzie, Principal Scientist and leader of NIWA’s Ultraviolet Radiation Programme, there has
been a lot of year to year variability in the size of the ozone hole. It was weak in 2002 and 2004 but this year the
hole is almost as large and intense as in 2003, which was close to the all-time maximum.
It has also persisted later than in recent years increasing the probability of ozone-poor air in the summer ahead, which
is predicted by MetService to be a period of “settled weather”.
Dr McKenzie says people need to be especially careful about exposure to the sun during the middle of the day (solar
noon, which during daylight saving is about 1:30 pm) when the sun is at its highest.
NIWA has measured UV radiation levels since the late 1980s. The earliest full recovery of the hole is not expected until
the middle of the century.
SunSmart spokesperson Wendy Billingsley says media attention often focuses on the ozone hole during SunSmart Week – this
year from November 13 -19.
“Ozone is important because it acts like a giant shield against the sun’s harmful rays. With less ozone in the upper
atmosphere, the amount of harmful UVR reaching the earth’s surface will increase, so people have to take extra care to
use sunscreen, cover up with clothes and hats and take shade where possible.”
The further north in New Zealand, the greater the risk, Dr McKenzie says.
“Even though the ozone hole is south of New Zealand, the further north you go the greater the risk because the sun is
higher in the sky, and the summertime ozone amounts are lower.
Looking forward, MetService Weather Ambassador Bob McDavitt says heading in to summer, with neutral conditions – neither
El Nino or La Nina – we can expect an increased variety of weather patterns and a possible widening of the extremes.
ENDS