Document Type

Article

Publication Date

5-16-2021

Journal Title

Journal of Geophysical Research: Atmospheres

Volume Number

126

Issue Number

9

Version

Publisher PDF: the final published version of the article, with professional formatting and typesetting

Abstract

The El Niño-Southern Oscillation (ENSO) has been found to be closely related to dust aerosol activities in many parts of the world. However, previous studies have rarely explored the ENSO’s impacts in the global context. In this study, the responses of the interannual variability of global atmospheric dust content to the ENSO cycle (including the eastern Pacific and central Pacific types) are examined using the MERRA-2 atmospheric aerosol reanalysis data. The ENSO-related tropical eastern Pacific sea surface temperature (SST) anomalies in the antecedent winter (November to January) have the most significant effect on the airborne dust content in a region from the Arabian Peninsula to Central Asia during the following spring and summer (April to July), which is identified as the key region (KR) of the ENSO’s impacts. The positive (negative) tropical eastern Pacific SST anomalies in the preceding winter during the El Niño (La Niña) years correspond to significantly reduced (increased) dust column content in the following spring and summer over the KR, which was confirmed using singular value decomposition. With the above (below)-normal winter SST anomalies in the tropical eastern Pacific, the Walker Circulation weakens (strengthens), and the divergence (convergence) over the western tropical Pacific and the convergence (divergence) over the southern tropical Indian Ocean in the lower troposphere are strengthened, which facilitate (restrain) the southward diffusion of airborne dust in the KR. Meanwhile, the increased (decreased) precipitation and soil moisture and the corresponding vegetation conditions help limit (promote) the dust emission in the KR during the El Niño (La Niña) years.

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