About daily global solar exposure data

Introduction

Historical daily global solar exposure data are provided from this product in a variety of formats - web (HTML), data (CSV), graphical, and print (PDF). There is a tool to change between megajoule per square metre (MJ m -2) and kilowatt-hour per square metre (kwh m-2). 1 kwh m-2 = 3.6 MJ m -2.

The table of daily global solar exposure data

Above the table of data

Metadata about the Bureau station
Information about the Bureau station used to retrieve data in the table.

Near the top of the data table page are links to Help Pages, including this information page. Also at the same location are links to download one or all years of solar exposure data in text file format (CSV files) suitable for importing into spreadsheets, and in PDF format for printing. The text formatted data are available both as one file containing all years of available observations, and one file containing data for only the year being displayed (to reduce download time). These files are created at the same time as the HTML page and automatically removed from the web site after a short time. Thus a stored link to one of these files (such as a Bookmark or Favorite in your browser) may not work for very long after it was created.

Global solar exposure is not measured by equipment at the Bureau station selected in the Climate Data Online menu. The data are obtained from satellite images. The process of displaying the data uses the latitude and longitude of the Bureau's ground observation stations to retrieve the data for a point within Australia. A basic site summary and topographic map of the area around the Bureau station are provided by clicking on the map icon.

Information and display options for data in the table
Key information and display options at the top of the data table.

A control to change the units of measurement is provided on the right, directly above the table. There is also an option to highlight in the table data which are above or below the mean values calculated from all available observations.

The table of data

Structure of the data table
Structure of the data table.

In the top left of the table is the year in which the data were measured. Another year of data can be selected from the drop-down list of years for which there are data available. The row below contains links to graphs of the daily global solar exposure for each month of the year. Following this are the solar exposure observations, with the day of the month in the left column. For each day of the year a table cell may contain:

  • A number in normal black text - solar exposure for the day. These solar exposure data, being derived from satellite observations, do not go through the conventional quality control process of ground-based observations. Thus there is no indicator of the status of quality control (such as the red italic text 12.3 used for other elements such as rainfall).
  • A blank cell - no solar exposure is available for that day.

The bottom of the table of data

Content at the bottom of the table
Information at the bottom of the data table.

The highest and lowest solar exposure for each month are provided at the bottom of the data table, along with the mean exposure for each month of the year being displayed. Mean values are only calculated if there are more than 20 observations within the month.

The mean daily global solar exposure for the year is provided directly below the table of data. It is listed as being not available if there are missing monthly data. A progressive mean to the end of the last complete month is provided if the table being displayed is for the current year. Next to the annual mean is a link to the full record of monthly data, and a link to a graph of the year of daily solar exposure.

Summary solar exposure statistics

Summary statistics at the bottom of the table
Summary statistics are provided beneath the data table.

Below the main table of data is a summary table of daily solar exposure statistics related to the data in the main table, and a link to plot these statistics against the data for the year being displayed. These statistics are calculated over all available years of data. The statistics are not provided if there are less than 10 years of data available.

Finally, at the bottom of the page is the Bureau's product code for this page, and a unique reference number. Please record this number if you need to contact the Bureau about any aspect of the data you have retrieved. Further information is available from the Bureau, and there may be a charge associated with this service.

Graphical display of data

monthly graph of rainfall
A graph of one month of daily global solar exposure.

If you click on the graph icon within the main data table a graph of the corresponding month of data will be generated. Above the graph is a menu which will re-plot the graph for a newly selected time period. Missing data are represented by a cross on the x axis (time axis) of the graph.

yearly graph of rainfall
A graph of one year of daily global solar exposure.

If you click on the yearly graph icon at the bottom of the main data table, or the annual menu button on the graph page, a graph of the corresponding year of data will be generated.

graph of rainfall statistics
Monthly global solar exposure statistics graph.

The final type of graph, accessible via a link at the bottom of the summary statistics table, plots the mean for each month of the year being displayed and the long-term mean. Also included in the table are the highest and lowest means for any individual month over the period for which observations were made. The plot is not available if there are less than 10 years of data.

Using these data

Satellite-derived global solar exposure estimates are based on images from the Geostationary Meteorological Satellite GMS-5, Geostationary Operational Environmental Satellite (GOES-9), MTSAT-1R, MTSAT-2 and Himawari-8 satellites, which are provided with permission of the Japan Meteorological Agency (JMA) and the United States National Oceanic & Atmospheric Administration (NOAA). Any use of products from this imagery requires acknowledgement of the satellites of JMA and NOAA as the original source of the satellite data, and acknowledgement of the Commonwealth of Australia (Bureau of Meteorology) which received and processed the images.

Acknowledgement should be in the form: "Solar exposure data derived from satellite imagery processed by the Bureau of Meteorology from the Himawari series operated by Japan Meteorological Agency and from GOES-9 operated by the National Oceanographic & Atmospheric Administration (NOAA) for the Japan Meteorological Agency".

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Page updated: 28 April 2011