Temporal and spatial variations in dust activity in Australia based on remote sensing and reanalysis data sets

• Main Authors: Che, Yahui, Yu, Bofu, Bracco, Katherine
• Format: Text
• Language: English
• Published: 2024
• Subjects: Merra; Aerosol Robotic Network
• Online Access: https://doi.org/10.5194/egusphere-2023-1710; https://egusphere.copernicus.org/preprints/2023/egusphere-2023-1710/

Spatial and temporal variations in the level of dust activity can provide valuable information for policymaking and climate research. Recently, Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol products have been successfully used for retrieving dust aerosol optical depth (DAOD), especially over bright dust source areas, and Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) aerosol reanalysis provides DAOD and additionally other dust-aerosol-related parameters. In this study, spatial and temporal variations in dust activity in Australia were analyzed using MODIS and MERRA-2 combined (M&amp;M) DAOD and MERRA-2 near-surface dust concentrations and estimated PM 10 for the period 1980–2020. Validation results show that M&amp;M DAOD has an expected error of ± ( 0.016 + 0.15 τ ) <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="83pt" height="12pt" class="svg-formula" dspmath="mathimg" md5hash="2538cbe72e568c427dc10f21f8db66bc"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-24-4105-2024-ie00001.svg" width="83pt" height="12pt" src="acp-24-4105-2024-ie00001.png"/> </svg:svg> compared to the ground observations at the AErosol RObotic NETwork (AERONET) dust storms on populated areas sites. MERRA-2 near-surface dust concentrations show a power-law relationship with visibility data collected at meteorological stations with an r 2 value from 0.18 to 0.44, and the estimated MERRA-2 PM 10 shows similar temporal variations and correlates with ground-based PM 10 data with an r 2 value from 0.14 to 0.44 at six selected stations in Australia. Moreover, MERRA-2 horizontal dust flux shows the same major dust pathways as those in previous studies and similar dust emissions and deposition areas identified using ground-based observations. Dust events based on DAOD over eastern Australia are concentrated in the north in December, are concentrated in the south in February, and can occur anywhere in January. Near-surface dust concentration ...