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The vertical distribution and transport properties of dust aerosols play a key role in regional and even global climate and environmental changes. However, there are still gaps in understanding the optical properties, transport mechanisms, and topographic effects on dust in the dust-prone area-southern margin of the Tarim Basin. In this study, we use the Ground-Based Aerosol Lidar (GBQL-01) installed in Hotan and Minfeng in cooperation with the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) to synthesize and analyze the dust formation process at the southern margin of the basin once, and to test the reliability of the ground-based aerosol lidar. The variability characteristics of meteorological elements during this dust process will be discussed. Furthermore, the Weather Research and Forecasting Model with Chemistry (WRF-Chem) was used to reproduce this dust process. The results show that the vertical transport of dust particles reaches about 4 km and 3 km in Hotan and Minfeng, respectively, and the dust aerosol stratification intensity is obvious within 1 km height in both places, and there is a dust aerosol layer at 3 km height in both places. The high winds are blocked by the large topography of the Tianshan Mountains and the northern slopes of the Tibet Plateau, and they change to northeasterly winds, triggering dusty weather outbreaks at the southern margin of the Tarim Basin. When the dusty weather subsided, dust aerosols with concentrations of 300–400 μg m−3 were still present at an altitude of 4 km, and a clear suspended dust phenomenon was formed. Meanwhile, the increase of wind speed and relative humidity, as well as the decrease of temperature, easily contribute to the occurrence of dusty weather and the transport of particulate matter. This work provides a useful reference for the study of regional climate change, topographic effects and "suspended dust". • The evaluation of the ground-based aerosol lidar's performance was conducted in an integrated manner using CALIPSO and particulate matter data. This assessment is essential for future studies. • Data on the height of dust stratification in the southern margin of the Tarim Basin (Hotan and Minfeng) was collected, confirming the presence of a stable aerosol layer at an altitude of 3 km. • The analysis using the WRF-Chem model clearly demonstrates the influence of topographic effects on dust aerosols. Additionally, this study confirms the occurrence of a unique phenomenon known as "suspended dust.". [ABSTRACT FROM AUTHOR]

The global carbon balance is a core issue in climate change research and a focus of international policy concern [[1]]. Through the close relationships between CO SB 2 sb flux and soil temperature, combined with historical soil temperature data in the study area at 0 and 10 cm every hour between 2004 and 2017, we estimated the total amount of CO SB 2 sb exchange per year in the TD shifting sand (Fig. An average of 6.71 × 10 SP 6 sp t of CO SB 2 sb per year was released to the atmosphere through the physical process of thermal expansion of soil air containing CO SB 2 sb in the TD shifting sand during 2004-2017. Besides, the combined action of the remaining components (salt/alkali + moisture + microbes) led the TD shifting sand to absorb atmospheric CO SB 2 sb , with an average absorption rate of 8.31 × 10 SP 6 sp t a SP -1 sp during 2004-2017. [Extracted from the article]

• Shifting sand in the Taklimakan Desert can sequester CO 2 at an uptake rate of 7.11 g m−2·a−1. • Soil respiration in the desert is dominated by soil air expansion/contraction and salt/alkali effects. • The carbon sink rate of shifting sand in Taklimakan Desert will decrease in the future. An understanding of the global terrestrial carbon cycle is crucial to predict future climate change. Deserts are an important part of the terrestrial ecosystem, but their role in the terrestrial carbon cycle has long been neglected. Recent studies have shown that deserts may sequester enormous volumes of CO 2 and play a pivotal role as a carbon sink. As the world's second-largest shifting desert, the Taklimakan Desert (TD) contributes substantially to the global desert carbon sink. However, the contributions of the internal processes of the TD to its carbon sink and the long-term trend of the carbon sink under climate change are still unclear. Based on an observational study, we determined that both the expansion/contraction of soil air containing CO 2 caused by heat fluctuation in shifting sand and the salt/alkali chemistry control the release/absorption processes of soil respiration in shifting sand. Besides, the mutual offset of these processes indicates that the shifting sand in the TD acts as a stable carbon sink at present, with an annual average CO 2 uptake rate of 7.11 g m−2. However, an increase in soil temperature difference will stimulate soil air expansion and release more CO 2 into the atmosphere under climate change, gradually lessening the carbon sink rate of shifting sand in TD in the future. These processes will be accelerated by a positive feedback loop, where this effect triggered by climate change will enhance regional warming. Our results highlight the status of deserts in the global carbon cycle and provide crucial information regarding the world's missing carbon sink. [ABSTRACT FROM AUTHOR]