Quantifying the Contribution of Multiple Processes to the Dust Decreasing Trend in the Guliya Ice Core Over the Past 50 Years

• Published in: Geophysical research letters 2024-09, Vol.51 (17), p.n/a
• Main Authors: Huang, Ju, Wu, Guangjian, Zhao, Huabiao, Xu, Baiqing
• Format: Article
• Language: English
• Subjects: Atmospheric particulates; Climate change; Climatic evolution; Cores; Deposition; Desertification; Deserts; Dust; Dust emission; Emission; Emissions; Evolution; Glaciers; Ice; Ice caps; Ice cores; Plateaus; Reconstruction; Records; Surface wind; Wind speed
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2024GL110429

Dust records extracted from ice cores can facilitate the reconstruction of historical atmospheric dust levels and climate change. However, interpreting dust variations in ice cores is intricate because of the compounded influence of emission, transport, and deposition processes. This study investigated dust records retrieved from the Guliya ice cap drilled in 2015 on the West Tibetan Plateau using a mean trajectory transport and deposition model. Results showed that the Guliya dust concentration has exhibited a declining trend since the 1960s (−751 μg kg−1 yr−1). Applying an attribution approach, we discovered that low dust emission (80.3%) was the main cause of the drop in dust concentration, with changes related to transportation (5.2%) and deposition (14.5%) making only minor contributions. The weakening of surface wind speed in the desert and increasing precipitation in both the desert and glacier were the primary factors driving the decrease in Guliya dust concentration. Plain Language Summary Dust emission, transport, and deposition processes are the key factors influencing the dust record in an ice core. Consequently, relying solely on ice core records may not be sufficient for the accurate reconstruction of past desertification processes and the evolution of the climate and environment. In this study, we endeavored to separate these complex processes from the Guliya ice core records on the Tibetan Plateau by integrating a transport model, thereby quantifying the impact of these processes on ice core records over the past 50 years. We found that the dust concentration changes in the Guliya ice core were primarily attributed to changes in dust emission strength, with a secondary influence of deposition and transport changes. This study can enhance the scientific interpretation of dust records preserved in ice cores, providing novel insights for a deeper comprehension of the climate and environmental evolution of the Tibetan Plateau. Key Points The dust concentration in the Guliya ice core has decreased over the past 50 years The decreasing trend of Guliya dust is primarily controlled by the emission process in the Taklimakan Desert The principal drivers behind the reduction in Guliya dust were decreased surface wind speed and increased precipitation