Xihui Gu, Qiang Zhang, Jianfeng Li, Vijay P. Singh, Jianyu Liu, Peng Sun, Chunyang He, Jianjun Wu
[Xihui Gu]. Department of Atmospheric Science, School of Environmental Studies, China University of Geosciences, Wuhan, China.
[Qiang Zhang]. Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing Normal University, Beijing 100875, China.
[Qiang Zhang]. Faculty of Geographical Science, Academy of Disaster Reduction and Emergency Management, Beijing Normal University, Beijing 100875, China.
[Qiang Zhang]. State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China.
[Jianfeng Li]. Department of Geography, Hong Kong Baptist University, Hong Kong.
[Vijay P. Singh]. Department of Biological and Agricultural Engineering and Department of Civil and Environmental Engineering, Texas A&M University, College Station, TX, USA.
[Jianyu Liu]. Laboratory of Critical Zone Evolution, School of Earth Sciences, China University of Geosciences, Wuhan, China.
[Peng Sun]. College of Territory Resources and Tourism, Anhui Normal University, Anhui 241000, China.
[Chunyang He]. Center for Human-Environment System Sustainability, State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China.
[Jianjun Wu]. Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing Normal University, Beijing, China.
Abstract: Soil moisture (SM) is a key hydrological component regulating the net ecosystem energy exchange at the land‐atmosphere boundary layer over the continents via heat fluxes and relevant feedback on precipitation. Due to its ecological and meteor‐hydrological implications, SM change is of great significance in Eurasia that has the highest population density and fragile ecological environment. Using monthly data from the Global Land Data Assimilation System, this study investigated SM changes over Eurasia during the warm season (May–September). It was found that recent 63 years witnessed widespread decreasing SM across Eurasia during the warm season. Regions with a drying SM tendency kept expanding till the 1990s. Specifically, the largest decreasing magnitude of SM with the aridity index ranging 0.5–0.6 and 1.0–1.1 was found along the semi‐arid and dry‐humid transition regions, respectively. In addition, more significant drying SM was observed in Sahel, northern Asia, northeastern Asia, and western Europe. Weakening West African monsoon (WAM)/East Asia summer monsoon did not benefit the propagation of water vapor flux to the Sahel regions/northeastern and northern Asia, and hence decreased SM in these regions. Besides, results by the maximum covariance analysis highlighted the roles of warming climate in SM variations over Eurasia during the warm season. Global climate models also indicate decreased SM due to global warming and projects continuously decreasing SM in the warm season over the 21st century under Representative Concentration Pathway (RCP) 2.6, RCP4.5, RCP6.0, and RCP8.5 scenarios. Decreasing SM across the Eurasia and related ecological and environmental implications should cause international concern.
Published in Journal of Geophysical Research, 2019, 124, https://doi.org/10.1029/2018JD029776.
