About annual, monthly and seasonal cloud maps
How were the maps created?
Total cloud amount data is recorded at a network of weather stations across Australia. The data from these weather stations are stored electronically in the Bureau of Meteorology's database called ADAM (Australian Data Archive for Meteorology).
The average TCA maps were based on daily 9 am and 3 pm cloud amount data from about 365 weather stations, where estimates of TCA are made by observers. The daily data were extracted from ADAM and a number of quality control checks were then applied to the data. For example, the data were checked for missing values over the length of the data record.
After the quality checks were applied to the data, monthly and annual 9 am and 3 pm averages were calculated for each of the weather stations. An objective analysis technique was then applied to these station averages to produce regular gridded datasets (each month and annual) covering Australia
Finally, the gridded data were visualised in a geographic information system and the colour maps created through this process.
Stations used in the analysis
Daily cloud data from about 365 weather stations across Australia were used to create the average cloud maps. These stations are shown in the map below.
Cloud metadata
The following metadata summary, and detailed metadata file, provide information about the monthly, annual and seasonal gridded cloud datasets. For example, information is provided about the format, spatial extents and analysis techniques used to generate the grids.
| TITLE: | Mean monthly, mean annual & mean seasonal cloud gridded datasets. |
| DESCRIPTION: | Mean monthly, mean annual & mean seasonal cloud grids. The grids show average cloud across Australia in the form of a two-dimensional array. The mean data are based on the period 1976-2005. |
| 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 0.1 degrees (approximately 10km) |