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Environmental Science

Drivers of recent decline in dust activity over East Asia

Profile image of Yaping ShaoYaping Shao

Nature Communications

https://doi.org/10.1038/S41467-022-34823-3
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Abstract

It is essential to understand the factors driving the recent decline of dust activity in East Asia for future dust projections. Using a physically-based dust emission model, here we show that the weakening of surface wind and the increasing of vegetation cover and soil moisture have all contributed to the decline in dust activity during 2001 to 2017. The relative contributions of these three factors to the dust emission reduction during 2010–2017 relative to 2001 are 46%, 30%, and 24%, respectively. Much (78%) of the dust emission reduction is from barren lands, and a small fraction (4.6%) of the reduction is attributed to grassland vegetation increase that is partly ascribed to the ecological restoration. This suggests that the ecological restoration plays a minor role in the decline of dust activity. Rather, the decline is mainly driven by climatic factors, with the weakening of surface wind playing the dominant role.

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Yaping Shao

Meteorologische Zeitschrift, 2003

In this paper, the synoptic features of Northeast Asian dust events in spring are studied. Using surface meteorological records for March, April and May of 2000, 2001 and 2002, the distribution of dust-event frequencies, possible dust-source regions and the synoptic conditions responsible for dust activities are examined. Four regions of frequent dust events are found in the domain of analysis. These are the Tarim Basin, the southern Mongolia and the Inner Mongolia Autonomous Region of China, the Hexi (Yellow River West) Corridor and the northern part of the Indian Subcontinent. The Tarim Basin has the highest dust-event frequency, with most of the events being weak ones (classi ed as dust-in-suspension). Dust events occur less frequently in the Gobi Desert, but they are often severe and widespread. Dust concentrations in the Tarim and the Gobi regions are found to be of similar order of magnitude with (averaged) maximum values reaching 1 mg m 3. In different regions, dust events are generated by different synoptic systems. Over the Gobi, almost all dust events arise from the strong northwesterly winds associated with low-pressure systems. In the Tarim Basin, dust events are mostly associated with light winds. Strong northeasterly winds may affect the eastern and southeastern parts of the basin, generating dust storms. It is shown that topography plays a signi cant role in the transport of dust particles. A preferred route of dust transport is found to exist along the northeastern boundary, and another along the southern boundary, of the Tibetan Plateau. It is suggested that the mechanisms for dust emission in the Tarim Basin requires further investigation. Zusammenfassung In diesem Artikel werden die synoptischen Merkmale von nordostasiatischen Staubereignissen untersucht. Aus meteorologischen Bodenbeobachtungen der Monate März, April und Mai der Jahre 2000 bis 2002 werden die Häu gkeitsverteilung solcher Staubereignisse, mögliche Herkunftsregionen des Staubes, sowie die synoptischen Bedingungen für deren Auftreten untersucht. Man ndet vier Regionen mit häu gen Staubereignissen im Untersuchungsgebiet: das Tarim Becken, die südliche Mongolei und die Autonome Region Innere Mongolei in China, der Hexi Korridor (Westlicher Gelber Fluss) und der nördliche Teil des Indischen Subkontinents. Das Tarim Becken zeigt die höchste Zahl von Staubereignissen, wobei die meisten davon leicht sind (klassiert als Staubtrübung). In der Wüste Gobi treten Staubereignisse weniger häu g auf, sind dann aber kräftiger und groß ächiger. Die Staubkonzentrationen im Tarim Becken und in der Wüste Gobi sind von derselben Größenordnung mit (gemittelten) Maximalwerten von 1 mg m 3. In den verschiedenen Gegenden werden die Staubereignisse durch unterschiedliche synoptische Systeme erzeugt.Über der Wüste Gobi entstehen fast alle Staubereignisse durch kräftige nordwestliche Winde in Verbindung mit Tiefdrucksystemen. Im Tarim Becken treten die Ereignisse in Verbindung mit schwachen Winden auf. Starke Nordostwinde können in denöstlichen und südöstlichen Teilen des Beckens zu Staubstürmen führen. Es wird gezeigt, dass die Topographie eine wichtige Rolle beim Transport von Staubteilchen spielt. Als zwei bevorzugte Routen für Staubtransport zeichnen sich die Gebiete entlang des nordöstlichen und des südöstlichen Rands des Hochlands von Tibet aus. Es zeigt sich, dass der Mechanismus für die Staubemission im Tarim Becken weiterer Untersuchungen bedarf.

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