Field Scientific Experiment Base of Akdala Atmospheric Background, China Meteorological Administration, located in Fuhai County, Altay Prefecture, Xinjiang, lies within a typical continental temperate arid to semi-arid climate zone. The regional representativeness of the Akdala Station differs significantly from other atmospheric background stations in China. Its observed greenhouse gas concentration levels and variation patterns exhibit distinct regional characteristics compared to observations from background stations in eastern China.

These atmospheric background parameters effectively represent background conditions not only for the Xinjiang region but also for Central Asia and southern Russia. In 2002, Akdala was selected by the China Meteorological Administration (CMA) as a regional atmospheric background station due to its excellent air quality and unique location within China's upwind regions. It became one of China's newly established regional background stations following the Waliguan (Qinghai), Shangdianzi (Beijing), Longfengshan (Heilongjiang), and Lin'an (Zhejiang) stations. Akdala is also China's only plain-based atmospheric background station.

ⅠDisciplinary Focus

The disciplinary focus of the base is proposed to be Atmospheric Environmental Chemistry, with primary research directions in Regional Atmospheric Chemistry and Regional Climate Change.Building upon operational observations of atmospheric composition, the base ensures the integrity, accuracy, and timeliness of original observational data from the Akdala Regional Atmospheric Background Station.Research data processing and quality control methods.Establish long-term standardized observational datasets.Concurrently, the base undertakes comprehensive atmospheric environmental field experiments for the meteorological sector, universities, and research institutes.Research on multi-instrument coordinated observation techniques for atmospheric environments.

II Representativeness

1. Typical Meteorological and Ecological Environment

The base is situated 50 km from the nearest town, Fuhai County. This significant distance minimizes interference from human production and living activities, ensuring the regional representativeness of its meteorological elements. Secondly, Akdala is located on alluvial plains and Gobi desert, characterized by semi-desert steppe vegetation. The nature of this surface cover is representative of northern Xinjiang and even the heartland of Eurasia. Due to the absence of significant anthropogenic disturbance, the station can effectively reflect changes in the desert ecological environment.

2. Key Corridor for Cross-Border Atmospheric Pollutant Transport

The base lies within the interior of Central Asia. Its remote geographical location, sparse local population, weak local emission sources, and distance from significant pollution sources mean that Akdala's observational data provide crucial information on the current state and long-term trends of atmospheric composition and related physical properties in northern Xinjiang, China. Furthermore, backward trajectory analyses indicate that Akdala is positioned along a major pathway for air mass movement. Pollutants characteristic of regional transport are less likely to be masked by local pollution, making this site particularly valuable for investigating the impacts of long-range transport of pollutants from neighboring regions such as western Kazakhstan, Russia, and Mongolia.

3. Prime Candidate Site for Ground-Based Satellite Validation

The base site features open, flat terrain in all directions. Within a 50 km radius, the land consists of river valley alluvial plains and Gobi desert, with sparse and homogeneous semi-desert steppe vegetation. The site is not directly impacted by local anthropogenic emissions but can receive the influence of transported polluted air masses from specific regions. Consequently, its observations represent the average, well-mixed atmospheric state of the broader region to a significant degree. Research demonstrates a strong correlation between surface observations at Akdala and satellite retrievals. This high degree of regional representativeness establishes Akdala as an ideal site for validating satellite products.

III Research Achievements

Building upon its core mission of conducting atmospheric composition observations, the base has served as a key platform, facilitating the execution of numerous national-level and provincial/ministerial-level research projects. To date, the station has participated in the completion of 8 funded research projects, with a total funding amount of 3.27 million CNY (Chinese Yuan Renminbi). This portfolio includes 2 national-level projects and 6 provincial/ministerial-level projects. Research conducted at or utilizing data from Akdala has resulted in the publication of 16 academic papers. Among these, 6 are indexed in SCI/SCIE (Science Citation Index / Science Citation Index Expanded) journals, and 5 were published in top-tier Chinese core journals. The high-quality observational datasets generated by the Akdala station have been extensively utilized in a wide range of scientific outputs, including peer-reviewed journal articles, academic collections, technical reports, and scientific presentations. This widespread application underscores the significant scientific value of the data acquired at this unique site.

IV Open Collaboration and Talent Development

Since the establishment of the experimental base, the station has fostered active scientific partnerships. Key collaborative activities include: 1. Joint Observational Campaigns: Conducted with leading institutions such as the Chinese Academy of Meteorological Sciences (CAMS) and the School of Marine Environments, Ocean University of China. 2. Postgraduate Training: We have jointly supervised Master's students in collaboration with Xinjiang University.

Beyond serving the operational and research activities of the Xinjiang Meteorological Department, the high-quality datasets generated by the base are actively shared with multiple entities under the China Meteorological Administration (CMA) and its partner institutions. This open data policy facilitates broader scientific advancement within the meteorological community.