Extreme Dust Intensity is Decoupled from Spring Dust Intensity in the Taklamakan Desert due to Different Low-level Winds
Abstract. Extreme dust events (EDEs) are intensifying under climate change, causing serious environmental and ecological issues. However, the relationship between EDE intensity and seasonal dust intensity remains unclear, limiting the possibility of using seasonal dust activities to estimate EDE strength. Using two satellite observation datasets, we investigate the relationship between interannual variations of spring dust intensity and EDE intensity in North Africa (NA), the Middle East (ME), and the Taklamakan Desert (TD). Results reveal that EDE intensity strongly correlates with spring dust intensity on an interannual basis in NA and ME, whereas no significant correlation exists between them in TD. The discrepancy in TD arises because spring dust and EDEs are driven by different atmospheric circulations: spring dust responds to a “positive-negative-positive” geopotential pattern over Europe, Central Asia, and East Asia which caused by European precipitation anomalies; conversely, EDEs are linked to a negative geopotential height pattern over East Asia which is originated from the diabatic heating/cooling due to the western/eastern North Atlantic precipitation anomalies. A composite index, integrating spring and EDE circulations, can effectively characterize the dust intensity variation difference in TD. In the future, the inconsistency between the interannual variability of EDE intensity and that of spring dust intensity will persist under high-emission scenarios. Our study demonstrates EDEs in TD are relatively independent of spring dust activities, providing a novel framework for improving EDE predictability.