Dust deposition and ambient PM&amp;lt;sub&amp;gt;10&amp;lt;/sub&amp;gt; concentration in northwest China: spatial and temporal variability

Xiao-Xiao Zhang,Brenton Sharratt,Huan-Sheng Chen,Jie Li,Zi-Fa Wang,Yu-Hong Guo,Wen-Yi Yang,Lian-You Liu,Xi Chen

doi:10.5194/acp-17-1699-2017

Abstract

Abstract. Eolian dust transport and deposition are important geophysical processes which influence global bio-geochemical cycles. Currently, reliable deposition data are scarce in central and east Asia. Located at the boundary of central and east Asia, Xinjiang Province of northwestern China has long played a strategic role in cultural and economic trade between Asia and Europe. In this paper, we investigated the spatial distribution and temporal variation in dust deposition and ambient PM10 (particulate matter in aerodynamic diameter ≤ 10 µm) concentration from 2000 to 2013 in Xinjiang Province. This variation was assessed using environmental monitoring records from 14 stations in the province. Over the 14 years, annual average dust deposition across stations in the province ranged from 255.7 to 421.4 t km−2. Annual dust deposition was greater in southern Xinjiang (663.6 t km−2) than northern (147.8 t km−2) and eastern Xinjiang (194.9 t km−2). Annual average PM10 concentration across stations in the province varied from 100 to 196 µg m−3 and was 70, 115 and 239 µg m−3 in northern, eastern and southern Xinjiang, respectively. The highest annual dust deposition (1394.1 t km−2) and ambient PM10 concentration (352 µg m−3) were observed in Hotan, which is located in southern Xinjiang and at the southern boundary of the Taklamakan Desert. Dust deposition was more intense during the spring and summer than other seasons. PM10 was the main air pollutant that significantly influenced regional air quality. Annual average dust deposition increased logarithmically with ambient PM10 concentration (R2 ≥ 0.81). While the annual average dust storm frequency remained unchanged from 2000 to 2013, there was a positive relationship between dust storm days and dust deposition and PM10 concentration across stations. This study suggests that sand storms are a major factor affecting the temporal variability and spatial distribution of dust deposition in northwest China.

Highlights

Airborne dust generated by eolian activity is an environmental concern in central and east Asia (Huang et al, 2011; Chen et al, 2014)
Dust deposition was relatively low (< 150 t km−2) for the majority of stations in northern Xinjiang Province, dust deposition was at least 50 % higher for stations within the industrial belt on the northern slope of the Tianshan Mountains
The atmospheric environment of central and east Asia is severely affected by the airborne dust; this study was undertaken to quantify dust deposition and ambient PM10 concentration in east Asia

Summary

Introduction

Airborne dust generated by eolian activity is an environmental concern in central and east Asia (Huang et al, 2011; Chen et al, 2014). Eolian activity and airborne dust influenced civilization along the ancient Silk Road which connected Asia and Europe (Zhang, 1984; Dong et al, 2012; Groll et al, 2013). Airborne dust is recognized as a factor affecting global radiation and warming (Stanhill, 2005; Carslaw et al, 2013; IPCC, 2013; Huang et al, 2009; Chen et al, 2013; Huang et al, 2014) and air quality in distant lands (Tsoar and Pye, 1987; Xu et al, 2007; Uno et al, 2009; Li et al, 2012).

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