Global map of characterized dust sources using multisource remote sensing data

Area of Science:

• Atmospheric Science
• Remote Sensing
• Environmental Science

Background:

• Existing global dust emission maps, like Ginoux et al. (2012) using MODIS Aerosol Optical Depth (AOD), require updates due to advancements in remote sensing.
• Accurate and current dust source maps are essential for understanding dust phenomena and informing management strategies.

Purpose of the Study:

• To create an updated, high-resolution global map of dust emission sources.
• To identify and characterize major dust emission regions worldwide using recent satellite data.

Main Methods:

• Calculated the global mean Sentinel-5P Absorbing Aerosol Index (AAI) from 2018-2024.
• Identified potential dust sources using AAI values > 0.25, validated with ground truth data.
• Applied a multi-stage masking process excluding non-dust emission areas (e.g., water bodies, built-up areas) based on land surface characteristics.

Main Results:

• Developed a reliable global dust source map with 84.7% precision, 80.7% recall, and 82.6% F1-score.
• Dust emission sources cover approximately 5% of global land, predominantly in North Africa (67%) and Asia (30%).
• Deserts (65%), vegetation (26%), and hydrological features (9%) constitute the primary land cover types of dust sources; natural factors (65%) dominate over human factors (35%).

Conclusions:

• The study provides a new global dust atlas, essential for climate modeling and disaster risk reduction.
• Dust event frequency from desert sources shows an increasing global trend, while non-desert sources exhibit regional decreases.
• The updated map enhances our understanding of dust emission dynamics and their drivers.