Australia is near the equator so we experience high UV levels. time of year: our elliptical orbit around the sun and our axial tilt combine to ensure that we are closer to the sun in our summer than the northern hemisphere e.g. in summer the UK has UV Index 6–8, while Australia has UV Index 10–14.
Australia has some of the highest levels of UV radiation in the world – in fact, UV radiation is strong enough to cause sunburn in as little as 11 minutes on a fine summer day. UV radiation from the sun is also one of the best natural sources for vitamin D so a balance is important.
The southern hemisphere tends to have more UV exposure because of the ozone hole, a seasonal depletion of the ozone layer centered on the South Pole. There are also fewer particles of air pollution — which help block UV — due to the comparatively small numbers of people who live in the southern hemisphere.
Basically, through migration, our two countries have been populated by many people with fair skin whose ancestors come from much less sunny climates. Lack of protective pigmentation leaves skin cells especially vulnerable to the DNA-damaging rays from the sun.
Map of peak UVI, using a modified colour scale to highlight the absolute peaks. Figure 2 uses a modified colour scale and shows that the highest values of UVI occur in the Peruvian Andes and throughout the Altiplano region. The maximum UVI of 25 is for the grid cell at 13.5° S, 172° W, centred on Cuzco in Peru.
UV problem of another kind
"Tasmania is unique with the fact that in summer it gets to extreme level, and in winter it doesn't even get to moderate," Mr Carr said.
Australia is near the equator so we experience high UV levels. time of year: our elliptical orbit around the sun and our axial tilt combine to ensure that we are closer to the sun in our summer than the northern hemisphere e.g. in summer the UK has UV Index 6–8, while Australia has UV Index 10–14.
Students learn that the atmosphere above Australia has less ozone than the atmosphere above Brazil, and use the Light Waves Modeling Tool to show how this allows more ultraviolet light to reach Australia.
Australia gets more ultraviolet light from sunlight than many other places do. Melanin in cells absorbs ultraviolet light and prevents it from being absorbed by other parts of the cell which can be damaged.
As the ozone hole over the south pole breaks up in spring, pockets of ozone depleted air drift across Tasmania, southern Victoria and the southern part of New Zealand's south island.
New Zealand's rather cool and temperate temperatures can easily hide the harmful effects of the sun. Yet in any season and any weather, the New Zealand sun can burn. Many people say they get more sunburned in New Zealand than anywhere else in the world, even Australia!
Massive wildfires that raged across southeast Australia in 2019–20 unleashed chemicals that chewed through the ozone layer, expanding and prolonging the ozone hole.
More about ozone layer depletion
Firstly, the ozone layer in the mid-latitude (e.g. over Australia) is thinned, leading to more UV radiation reaching the earth.
It is illegal under the Radiation Act 2005 to conduct a commercial tanning practice (also known as a solarium). The Department of Health has successfully prosecuted for offences related to commercial tanning operations.
Australia gets more sunlight during the summer primarily because it is closer to the equator than the landmass of other English-speaking countries like the U.S. and the U.K. Also, the Earth is closer to the Sun in January (summer in the southern hemisphere) than it is in July (summer in the northern hemisphere).
Australian sunscreens are among the best in the world, with stringent requirements for what can be classed as sunscreen down under. In Australia, sunscreen is classified as a therapeutic good, with higher manufacturing requirements than anywhere else in the world.
The stratospheric ozone layer absorbs the biologically damaging wavelengths of ultraviolet (UV) rays but in the 1970s, Australia's ozone layer was severely thinned as a consequence of heavy use of ozone-depleting, substances such as chloroflurocarbons (CFCs) and hydro-chloroflurocarbons (HCFCs).
Their dark skin reflects an African origin and a migration and residence in latitudes near the equator, unlike Europeans and Asians whose ancestors gained the paler skin necessary for living in northern latitudes.
In contrast, the safest countries are found in Scandinavia, with Finland boasting the lowest average (2.17) and Sweden (2.25), Norway (2.25) and Denmark (2.67) not far behind.
UV levels are higher closer to the equator. Closer to the equator the sun's rays have a shorter distance to travel through the atmosphere and therefore less of the harmful UV radiation can be absorbed. With increasing altitude less atmosphere is available to absorb UV radiation.
The safest countries are found in Scandinavia, with Finland boasting the lowest average (2.17) and Sweden, Norway and Denmark not far behind.
The lowest values occur in June-July where the UV Index averages less than 2 over Tasmania, increasing to almost 8-9 in far northern Australia.
The sun's rays are strongest at the equator where the sun is most directly overhead and where UV rays must travel the shortest distance through the atmosphere.
When it comes to tanning, the UV index is a very important factor. The lower the UV index scale number, the less ultraviolet radiation from the sun reaches your skin. A reading of 0-2 indicates low risk; 3-5 is moderate risk; 6-7 is high risk; 8-10 is a very high risk, and 11+ is very dangerous.