Subjective visual interpretation of MODIS Quick-Look imagery has proven useful in characterising dust source geomorphology and dust event frequency over diverse areas, but is limited by the small temporal sampling window of polar orbiting platforms, and obscuration by cloud. In this paper we seek to quantify the inevitable under-reporting of dust events in Quick-Look imagery, via a three-year case study over the Lake Eyre Basin (LEB), the largest dust source in Australia and the southern hemisphere. Dust event identification from MODIS imagery is compared with the level of dust mobilization inferred from measurements of near-surface aerosol made by a continuously-operating integrating nephelometer, located at the AeroSpan/AERONET station at Tinga Tingana in the Strzelecki Desert, adjacent to major dust sources in the LEB. The analysis indicates a major upward revision in the overall dust event frequency by ~ 72%, including a doubling of the incidence of major dust outbreaks. The intensity of missed events increases toward late afternoon and evening, although without a net day-night bias. These factors suggest the potential of new geostationary sensors and the analysis of night-time polar orbiting imagery in improving the reporting of dust mobilization over active dust-source regions. For the LEB, the corrections are crucial in understanding not only the seasonal distribution of dust mobilization, but its interannual variability and climatology.
- Dust storm
- Remote sensing