Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 


Low ozone air forecast over New Zealand

Media Release 22 September 2006

Low ozone air forecast over New Zealand

New Zealand is expected to experience a ‘low ozone event’ on Sunday (24 September). The Royal Dutch Meteorological Institute and the European Space Agency are forecasting that a filament of low ozone air currently circulating in the stratosphere around Antarctica will spin off and pass over much of New Zealand.

The agencies are forecasting about 23% less ozone over New Zealand than the average for this time of year. ‘Ozone values of about 275 Dobson Units are possible, whereas the September average at Lauder, Central Otago, is 358 Dobson Units,’ says Dr Greg Bodeker of the National Institute of Water & Atmospheric Research (NIWA).

‘The forecast suggests that the ozone values around noon on Sunday are likely to be a record low for this time of the year,’ says Dr Bodeker. The New Zealand ozone records began in 1970.

The forecast low ozone will push UV levels higher than usual for this time of year. Wendy Billingsley, SunSmart spokesperson, says if the day is clear or partly cloudy, SunSmart protection will be essential. ‘When UV levels are 6 or above we all need to follow the Slip, Slop, Slap, and Wrap rules,’ she says.

According to NIWA, if the skies are clear, the forecast low ozone means that UV levels in the south of New Zealand are likely to increase from a typical September noon-time UV index of 4 to 5.5. In the north of the country, the noon UV index could be as high as 8 compared to the usual September value of around 6.5. At southern ski fields, where the snow covered surface enhances UV levels, the reduced ozone could cause noon-time UV levels to increase from 6 to close to 8.

A UV index of 8 is not extreme by standards of New Zealand’s mid-summer but it still represents very high UV levels. ‘If the sun is hidden by cloud, the risks are not as high, but when the weather is partly cloudy but people can still see the sun, the UV levels may go even higher than for clear skies,’ says Dr Bodeker.

--

Background

What causes such a low ozone event?
Dr Greg Bodeker of NIWA explains:

‘During spring, the air in the stratosphere at about 60 °S whirls strongly around Antarctica in a westerly direction. This is called the Antarctic Vortex. These strong westerly winds keep the ozone-depleted air concentrated over Antarctica during spring (the ‘ozone hole’).

‘Occasionally, waves in the stratosphere scrape air off the edge of the vortex and a filament of this ozone-depleted air peels off and flicks into the mid-latitudes.

‘Imagine mixing two fluids of different colours together in a cup. You can sometimes see long, stringy bits stretching out from the main mass of a fluid. In this case, that filament is ozone-depleted stratospheric air, and it operates much like a weather front does at lower altitude.’

The UV Index
UV levels Recommended behaviour
Levels 1 & 2: The UV level is low. Low protection is needed and people can stay safely outside. Low – Low protection required. You can safely stay outside.

Levels 3 to 5: This indicates moderate UV levels. Moderate – Protection required when spending long periods in the sun.

Levels 6 & 7: Protection is essential. High – Protection essential. ‘Slip, slop, slap, and wrap.’

Levels 8 to 10: People should take great precaution. Very high – Seek shade between 11am and 4pm. ‘Slip, slop, slap, and wrap.’ Reapply sunscreen regularly.

Level 11+: This is regarded as extreme and full protection is essential. Extreme – Reschedule outdoor activities for early morning/evening. Shade is essential between 11am and 4pm. Reapply sunscreen regularly.

People should remember that you can get sun burnt even on cool days. Temperature is caused by the sun's infrared radiation, while sunburn is caused by UV radiation that cannot be felt.


ENDS

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

Watch This Space: Mahia Rocket Lab Launch Site Officially Opened

Economic Development Minster Steven Joyce today opened New Zealand’s first orbital launch site, Rocket Lab Launch Complex 1, on the Mahia Peninsula on the North Island’s east coast. More>>

Earlier:

Marketing Rocks!
Ig Nobel Award Winners Assess The Personality Of Rocks

A Massey University marketing lecturer has received the 2016 Ig Nobel Prize for economics for a research project that asked university students to describe the “brand personalities” of three rocks. More>>

ALSO:

Nurofen Promotion: Reckitt Benckiser To Plead Guilty To Misleading Ads

Reckitt Benckiser (New Zealand) intends to plead guilty to charges of misleading consumers over the way it promoted a range of Nurofen products, the Commerce Commission says. More>>

ALSO:

Half A Billion Accounts, Including Xtra: Yahoo Confirms Huge Data Breach

The account information may have included names, email addresses, telephone numbers, dates of birth, hashed passwords (the vast majority with bcrypt) and, in some cases, encrypted or unencrypted security questions and answers. More>>

ALSO:

Rural Branches: Westpac To Close 19 Branches, ANZ Looks At 7

Westpac confirms it will close nineteen branches across the country; ANZ closes its Ngaruawahia branch and is consulting on plans to close six more branches; The bank workers union says many of its members are nervous about their futures and asking ... More>>

Interest Rates: RBNZ's Wheeler Keeps OCR At 2%

Reserve Bank governor Graeme Wheeler kept the official cash rate at 2 percent and said more easing will be needed to get inflation back within the target band. More>>

ALSO:

Get More From Scoop

 
 
 
 
 
 
 
 
 
Sci-Tech
Search Scoop  
 
 
Powered by Vodafone
NZ independent news