Vertical Structure of Dust Aerosols Observed by a Ground-Based Raman Lidar with Polarization Capabilities in the Center of the Taklimakan Desert

Abstract

The vertical structure of dust properties in desert sources is crucial for evaluating their long-range transportation and radiative forcing. To investigate vertical profiles of dust optical properties in the Taklimakan Desert, we conducted ground-based polarization Raman lidar measurements in Tazhong (83.39°E, 38.58°N, 1103 m above sea level), located at the center of the Taklimakan Desert in the summer of 2019. The lidar system developed by Lanzhou University for continuous network observation is capable of measuring polarization at 532 and 355 nm and detecting Raman signals at 387, 407, and 607 nm. The results indicate that dust aerosols in the central Taklimakan Desert were regularly lifted over 6 km during the summer with a mass concentration of 400–1000 µg m−3, while the majority of the dust remained restricted within 2 km. Moreover, the height of the boundary layer can reach 5–6 km in the afternoon under the strong convention. Above 3 km, dust is composed of finer particles with an effective radius (Reff.) less than 3 μm and a Ångström exponent (AE) related to the extinction coefficient (AEE)532,355 greater than 4; below 3 km, however, dust is dominated by coarser particles. In addition, the particle depolarization ratios (PDR) of Taklimakan dust are 0.32 ± 0.06 at 532 nm and 0.27 ± 0.04 at 355 nm, while the lidar ratios (LRs) are 49 ± 19 sr at 532 nm and 43 ± 12 sr at 355 nm. This study firstly provides information on dust vertical structure and its optical properties in the center of the desert, which may aid in further evaluating their associated impacts on the climate and ecosystem.

Optical Properties and Vertical Distribution of Aerosols Using Polarization Lidar and Sun Photometer over Lanzhou Suburb in Northwest China

“…The maximum value of AOD in the Taklimakan Desert was in April and the coarse-sized particles were the main component of aerosols in this region [61]. Zhang et al [62] found that the depolarization ratio of Taklimakan dust was 0.32 ± 0.06 at 532 nm, which did not change significantly compared with the depolarization ratio of dust aerosol transported to SACOL.…”

The Lower Atmospheric Characteristics of Dust Storms Using Ground-Based Sensor Data: A Comparative Analysis of Two Cases in Jinan, China

“…The vertical structure plays a crucial role in facilitating the mixing of dust aerosols [21]. By using the ground-based polarization Raman lidar, Zhang et al [22] demonstrated that dust aerosols in the central Taklimakan Desert were regularly lifted over 6 km during the summer, while the majority of the dust remained restricted within 2 km. Based on the CALIPSO data analysis conducted in March 2021, Ye et al [23] revealed that the dust conveyance height was mostly concentrated at 1-3 km and 3-10 km.…”

Long‐Term Variation of Dust Devils in East Asia During 1959–2021

“…The mineral dust that has been lifted in the air can, directly and indirectly, affect climate, which can in turn alter radiation balance in the atmosphere and act as cloud condensation nuclei to influence precipitation (Ginoux et al., 2001; Z. Huang et al., 2010; Zhang et al., 2022). Direct effect of dust aerosols on radiation balance (through absorption and scattering) influences the energy balance of the earth system (E‐cycle), while the organic matters carried by dust is associated with the carbon cycle (C‐cycle) (Dong et al., 2022; Z. Huang et al., 2022; J. Liu et al., 2022; Shao et al., 2011).…”

“…A typical dust devil can bring approximately 20 kg of dust into the atmosphere, while a very large one with a radius of over 100 m can carry about 15,000 kg of dust during its life span (Koch & Renno, 2005;Renno et al, 2004).The mineral dust that has been lifted in the air can, directly and indirectly, affect climate, which can in turn alter radiation balance in the atmosphere and act as cloud condensation nuclei to influence precipitation (Ginoux et al, 2001;Z. Huang et al, 2010;Zhang et al, 2022). Direct effect of dust aerosols on radiation balance (through absorption and scattering) influences the energy balance of the earth system (E-cycle), while the organic matters…”