About average UV Index maps

How were the maps created?

The UV Index is calculated by a computer model which takes into account ozone concentrations, altitude, latitude, day and time of year, solar irradiance (incoming energy from the sun) and UV surface albedo (reflectivity of the surface). These values are then converted to a regular grid over Australia and the ocean.

Monthly, seasonal and annual average values of the UV Index were calculated from these daily grids.

Finally, the gridded data were visualised in a geographic information system and the colour maps created through this process.

The values derived from the model have been compared to those measured by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) and found to be accurate to within ±10 percent of the observed UV.

Data used in the analysis

Ozone concentration data was measured by the Total Ozone Mapping Spectrometer (TOMS) and the Ozone Monitoring Instrument (OMI) run by NASAs Goddard Space Flight Center (GSFC).

The TOMS and OMI devices are carried on satellites orbiting the earth. Data used for this set of maps were taken from the following satellites:

  • Nimbus - 7 TOMS from 1979 to 05/1993
  • Meteor - 3 TOMS from 09/1992 to 11/1994
  • Earth Probe TOMS from 08/1996 to 12/2005
  • Aura satellite OMI from 10/2004 to present

These data were input into a computer model to calculate UV Index.

UV Index metadata

The following metadata summary, and detailed metadata file, provide information about the monthly, seasonal and annual gridded UV Index datasets. For example, information is provided about the format, spatial extents and analysis techniques used to generate the grids.

TITLE: Mean monthly, seasonal and annual UV Index data.
DESCRIPTION: Mean monthly, seasonal and annual UV Index grids. The grids show the UV Index values across Australia in the form of a two-dimensional array. The mean data are based on the period 1979-2007.
CUSTODIAN: Bureau of Meteorology
GEOGRAPHIC EXTENT NAMES(s): Australia
AVAILABLE FORMAT TYPE(S): ASCII row major, Arc/InfoTM grid export(.e00), Shapefiles.
SCALE/RESOLUTION The resolution of the data is 1.5 degrees (approximately 150km)