Divergent impacts of snow cover and vegetation on albedo in drylands Central Asia from 2000 to 2023

Surface shortwave albedo (SW albedo) plays a critical role in regulating land-atmosphere energy exchange and influencing regional climate feedback. Over recent decades, the surface conditions in drylands Central Asia have undergone significant transformations. However, the impacts of these surface changes on SW albedo dynamics remain poorly understood. In this study, based on remote sensing data, we systematically investigated the spatial and temporal characteristics of SW albedo in Central Asia from 2000 to 2023, and quantified the driving roles of snow cover fraction (SCF), normalized difference vegetation index (NDVI), and soil moisture (SM) on the changes of SW albedo. The results showed an overall upward trend in SW albedo in Central Asia, with 67% of the regional albedo showing an upward trend, mainly concentrated in the central and western parts of Kazakhstan, whereas the area of SW albedo decline is mainly distributed over most of Xinjiang, China, Uzbekistan and Kyrgyzstan. The results of multiple linear regression and structural equation modeling indicate that SCF is the dominant factor of SW, visible (VIS) and near-infrared (NIR) albedo changes, especially in autumn and winter. NDVI is the second major driving factor, with the most significant influence in summer; SM has a relatively small influence on SW albedo. It is noteworthy that the decrease of SW albedo in Xinjiang was mainly driven by the combined effect of the continuous decrease of SCF and the increase of NDVI. This study contributes to the understanding of key processes of land-atmosphere interactions in drylands and provides an important basis for assessing regional climate feedback mechanisms. • Shortwave albedo (SW albedo) in Central Asian shows a growth trend from 2000 to 2023. • SW albedo shows a broad increase in Kazakhstan and a decrease in Xinjiang. • Snow cover and vegetation together increased SW albedo in Kazakhstan but decreased it in Xinjiang.