Geological and Environmental Engineering | Article | Published 2022-05-04
Different origins of loess deposits in northern and southern Central Asia are not only associated with Central Asian topography, but also with aeolian dust dynamics. However, the latter has received far less attention so far. This review focuses on atmospheric dust dynamics for loess deposition in Central Asia, aiming to heal this knowledge gap. Comparisons of loess grain size data from the Chinese Loess Plateau, and the northern and southern Central Asia suggested that the Siberian High-pressure system largely controlled dust mobilization and loess accumulation in northern Central Asia, instead of southern Central Asia. The North Atlantic Oscillation (NAO) mode also provided an additional promising solution to trigger of loess accumulation in the North Tianshan Mountains. In southern Central Asia, intensity of dust activity was majorly determined by the Caspian Sea-Hindu Kush Index (CasHKI), with stronger dust dynamics under higher CasHKI modes. However, the causes of variations in the CasHKI intensity represent a future challenge. The CasHKI values also influenced the wind dynamics controlling dust mobilization in the Fergana Valley. Therefore, the Central Asia can be divided into two parts regarding the aeolian dust dynamics, with a boundary located in the North Tianshan Mountains and the south of Aral Sea. The Siberian High and NAO phase appeared to affect the dust activity and loess accumulation in the northern part; while dust entrainment and deposition were mostly determined by the CasHKI mode in the southern part. However, precisely determining the boundary highlights the necessity of investigations on loess deposits in the Tashkent region. In addition, we further recommend that the dynamic linkages between the mid-latitude Westerlies and aeolian loess deposition constitute a future critical research topic in Central Asia.