What is solar ultraviolet radiation (UVR)?

Solar radiation is electromagnetic radiation emitted by the sun. At the earth's surface it consists mainly of visible light and infrared radiation (IR). Our eyes respond to visible light and IR can be felt on the skin as heat. Ultraviolet radiation (UVR) is also present and is invisible, high-energy radiation, which is capable of causing damage to living organisms.

Ultraviolet radiation is classified by wavelength into three regions:

UVA - Ultraviolet radiation in the range 315 nanometers (nm) to 400 nm is thought to contribute to premature aging and wrinkling of the skin and has recently been implicated as a cause of skin cancer.

UVB - Ultraviolet radiation in the range 280 nm to 315 nm is more dangerous than UVA and has been implicated as the major cause of skin cancers, sunburning and cataracts.

UVC - Ultraviolet radiation in the range 100 nm to 280 nm is extremely dangerous but does not reach the earth's surface due to absorption in the atmosphere.

Why is there so much solar UVR in Australia?

Due to its geographical position and close proximity to the equator, Australia experiences some of the highest levels of solar ultraviolet radiation in the world. The earth's elliptical orbit brings the earth closer to the sun in January, during summer in the southern hemisphere, resulting in higher levels of UVR in that region. Relatively clear atmospheric conditions and the influence of ozone depletion over Antarctica contribute to higher levels of solar UVR in the southern hemisphere than at similar latitudes in the northern hemisphere.