Photosynthetically Active Radiation (PAR) is the portion of the solar spectrum - from approximately 400 to 700 nanometres - which is utilised in the process of photosynthesis. This spectral band is a subset of the spectral band measured by the Bureau's pyranometers, and can be determined from observations using special instruments. Alternatively, when expressed as an energy, PAR may be estimated using an empirical relationship such as: PAR=0.45 * Global solar exposure (MJm-2). For further information refer to, for example:
Illuminance is the total luminous flux incident on a surface per unit area, where the luminous flux is the power of light weighted to correspond to the sensitivity of the human eye. The Bureau of Meteorology does not have illuminance data.
The Bureau of Meteorology does not provide Leaf Area Index data. These data, along with the Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) can be obtained in a research-oriented spatial data format from the National Computational Infrastructure website.
The Bureau of Meteorology has a UV forecast service, but it does not provide observations of UV radiation. UV data from a number of locations are available from the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA).
Not at this time. The solar data available from the Bureau of Meteorology are from its own ground observation network and from the Bureau's model which processes satellite images.
The Bureau's model to estimate solar exposure from satellite images currently does not process imagery over large bodies of water. However, during the processing of the imagery over land, the solar exposure is extrapolated approximately 50km from the coastline to include narrow peninsulas and small islands close to the mainland.
Large salt lakes can sometimes appear to have a lower solar exposure than the surrounding land. The computer model processes the whitish salt areas as if they were cloud, which would block some of the sunlight reaching the ground.
Daily solar data for locations via Climate Data Online, and daily gridded solar data and maps are nominally updated shortly after midnight each day.
Hourly solar grids and one minute solar data are updated at various times during the year. Please visit (or subscribe to) our Updates to One Minute Solar Data and Changes to Solar Data pages to keep informed of updates.