Long-term trend of dust event duration over Northwest China

Abstract

Dust events in Northwest China have become more variable under regional climate change. Prior research has largely overlooked the spatial-temporal distribution of dust event duration (DED) and its long-term trend. This study systematically analyzed the spatial and temporal variations of DED in Northwest China and explored their associated factors using satellite-derived air quality datasets during 2000–2021. We find that dust event frequency (DEF) and DED generally showed a significant decreasing trend since 2000, but in 2013, DEF and DED started to rebound, with DED in particular, showing a more pronounced rebound in most parts of Northwest China. Correlation analysis with many factors suggests that the rise in near-surface wind speed since 2013 may primarily account for the increase in DEF and DED by enhancing dust generation and suppressing dust dry deposition processes. Further projections reveal that regions close to dust sources are likely to have more frequent and prolonged dust events, while areas far from dust sources will experience a decrease in DEF and DED in the future. These findings are crucial for understanding dust event variations and for guiding local dust management strategies.