Atmospheric dust dynamics in southern Central Asia: Implications for buildup of Tajikistan loess sediments

Yue, Lili; Song, Yougui; Kaskaoutis, Dimitris G.; Chen, Xiuling; Mamadjanov, Yunus; Tan, Liangcheng

doi:10.1016/j.atmosres.2019.06.013

Cited by 52 publications

(27 citation statements)

References 77 publications

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“…Similar characteristics are also observed in Chinese loess/paleosol couplets. Recent studies further demonstrate that eolian dusts entrained from the foothills in northern Afghanistan and several large deserts in the Asian interior make a dominant contribution to the Tajikistan loess (Li, Song, et al, ). Accelerator mass spectrometry 14 C and optically‐stimulated luminescence dating of several 1–2 m loess sequences from southern Tajikistan demonstrates that continuous Holocene eolian deposits are well preserved in the western Pamir Plateau (e.g., Dodonov et al, ; Gao et al, ; Wang et al, ).…”

Section: Study Areamentioning

confidence: 99%

Critical Altitudinal Shift From Detrital to Pedogenic Origin of the Magnetic Properties of Surface Soils in the Western Pamir Plateau, Tajikistan

Kang

Zan

Bai

et al. 2020

Geochem Geophys Geosyst

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Sedimentary archives of the westerlies‐influenced Pamir Plateau in Tajikistan, a climatically sensitive region in arid central Asia, provide information on past climatic changes and the tectonic evolution of the northern Tibetan Plateau. However, due to the scarcity of meteorological stations, knowledge of the recent precipitation history of the region is limited. We conducted a detailed rock magnetic investigation of 34 surface loess samples from the western Pamir Plateau. The results show that on the windward side, below an altitude of 2,000–2,200 m above sea level, the concentration of magnetic minerals initially decreases and then begins to increase with increasing altitude. Below 2,000–2,200 m above sea level, the surface soils are enriched in multidomain magnetite particles, suggesting a detrital origin of the magnetic minerals, whereas above this altitude the samples are enriched in fine superparamagnetic magnetite/maghemite grains of pedogenic origin. The inferred variations in pedogenic intensity, combined with analysis of the available meteorological data and the content of organic matter and clay, support the occurrence of an altitudinal threshold separating a predominantly detrital control on surface soil magnetic mineral assemblages from a predominantly pedogenic control. Within the plateau interior, the surface loess samples exhibit low and uniform values of magnetic concentration parameters and organic matter and clay content, which is attributed to the decreased supply of moisture from westerly sources because of the rain shadow effect. Our results indicate that rock magnetic investigations can be used to define a critical climatic boundary in arid central Asia.

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Section: Study Areamentioning

confidence: 99%

Critical Altitudinal Shift From Detrital to Pedogenic Origin of the Magnetic Properties of Surface Soils in the Western Pamir Plateau, Tajikistan

Kang

Zan

Bai

et al. 2020

Geochem Geophys Geosyst

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“…The internal and external studies that have been done so far have been solely on the size of river sediments or only on sediment pollution. For example [11] , they dealt with the physical properties and granulation-sediments of the Sarbaz River in southern Iran. Also [12] have studied the chemical properties of sediments for Jajroud River and reuse of sediments for agricultural operations [13] .…”

Section: Introductionmentioning

confidence: 99%

Examining the association between dust and sediment and evaluating the impact of climate change on dust and providing adaptation

Javadinejad

Dara

Jafary

2020

Resour Environ Inf Eng

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In this research, the catchment area of the Karkheh River has been investigated in order to investigate the relationship between the sediment and the effect of climate change on the phenomenon of microstrip. In the first step, to determine the relationship between the grains and sediments, it is necessary to determine the origin of sedimentation and its gradation. Accordingly, some sediment samples were taken from the river bed. Sediment aggregate size measurement is an important tool for studying its origin. Currently, for statistical purposes, many samples are used, but these methods are time-consuming and difficult. The size of the sediment in the study of origin, and its relationship with the micro-organisms, is an important factor. Therefore, the use of modern methods is essential. In the present study, the data of the sediment samples were introduced into the acetate gradient (statistical analysis program) to determine the texture and granulation of the sediment. The results showed that sand gravel texture is. Then sampling and testing on the microscopes showed that they are also of sandy origin, so it can be assumed that abrupt grafting of microspheres after sediment can cause sediment in the river. In addition, in order to investigate the effect of climate change on the micrographs, the relationship between three climatic parameters including rainfall, minima and relative humidity with the number of days with a rigorous refreshment for two years of 2015 and 2016 were analyzed. The results showed that, with increasing temperature and decreasing precipitation and relative humidity, the number of days with the coarse cutter increases, and as a result, it can be caused by sedimentation as part of sedimentation in the river.

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“…However, this viewpoint is the lack of strong evidence. Recent studies found that the foothills in northern Afghanistan were the most likely dust sources, while the southeastern part of the Karakum Desert may also have a minor contribution by analyzing loess trace elements and meterological reanalysis data (Li et al, 2019). This implies that the moisture variations in loess deposit regions would be consistent or synchronously with that in the dust source area because the main dust source of the loess is closed to the research site.…”

Section: Discussionmentioning

confidence: 99%

“…In addition, recent studies have shown that the strong Levar winds in eastern Iran modulate dust activity over southwestern Asia (Alizadeh Chooobari et al, 2014). Moreover, near‐surface northerly and/or northwesterly winds in south central Asia are responsible for loess formation; the local sources within foothills in northern Afghanistan are the most likely dust sources (Li et al, 2019). Since eolian dust transported by these airflows is blocked by the high‐altitude Pamirs and then deposited, forming thick and extensive loess deposits in the Afghan‐Tajik Basin (Li et al, 2019).…”

Section: Discussionmentioning

confidence: 99%

Atmospheric Dynamics Patterns in Southern Central Asia Since 800 ka Revealed by Loess‐Paleosol Sequences in Tajikistan

Jia

Yin

et al. 2020

Geophysical Research Letters

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The atmospheric mechanisms responsible for the loess grain‐size variations in central Asia are less clear, and an increasing number of studies have found that the coarse‐grained component is likely supplied by the surface circulation rather than by the westerlies (westerlies circulation). In this study, we attempt to determine the atmospheric dynamics patterns in the Afghan‐Tajik Basin during the past 800 kyr, based on the coarse grain‐size fraction of loess, combined with a study of modern dust transport processes. We suggest that the coarse grain‐size fraction can be used to indicate the intensity of near‐surface winds, while on glacial‐interglacial time scales, the variations of loess grain size in Tajikistan are dominated by Northern Hemisphere ice volume via its effect on the strength of the Siberian High. In addition, we suggest that atmospheric greenhouse gases concentration affected the loess grain size during interglacials via their influence on the temperature of southern high latitudes.

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Atmospheric dust dynamics in southern Central Asia: Implications for buildup of Tajikistan loess sediments

Cited by 52 publications

References 77 publications

Critical Altitudinal Shift From Detrital to Pedogenic Origin of the Magnetic Properties of Surface Soils in the Western Pamir Plateau, Tajikistan

Critical Altitudinal Shift From Detrital to Pedogenic Origin of the Magnetic Properties of Surface Soils in the Western Pamir Plateau, Tajikistan

Examining the association between dust and sediment and evaluating the impact of climate change on dust and providing adaptation

Atmospheric Dynamics Patterns in Southern Central Asia Since 800 ka Revealed by Loess‐Paleosol Sequences in Tajikistan

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