Australian cloudiness from a high resolution satellite archive

The distribution of total cloudiness over Australia is examined using data from the United States Air Force 3D Nephanalysis dataset. Data for the First GARP (Global Atmospheric Research Programme) Global Experiment (FGGE) period (December 1978 to November 1979) are examined and the results compared with available conventional descriptions of cloud cover distribution over Australia. The data for 1979 are found to be in general agreement with the few previous studies, although the high resolution. dataset reveals the influence of particular synoptic and smaller scale features (e.g. northwestern cloudbands (NWCBs)) which are not evident in the large-scale conventional analyses. Although the nature of the atmospheric circulation in the Australian region was somewhat anomalous during the FGGE year, the high resolution data do provide a useful view of the cloudiness regime in the Australian region. The cloud data are analysed to clarify the influence of surface station data on archive quality by examining mean cloud-free interval and a normalised standard deviation of cloudiness. The cloud distributions derived in this study and presented here provide the first high resolution cloud study over Australia. Although the data are for a single year only, they provide a valuable summary of the typical pattern of cloud distribution over the Australian region.