Vertical conveyor driving the integration of moisture transported by the westerlies to the Asian water towers’ atmospheric water cycle
Abstract
The westerlies moisture transport underpins water security for over two billion people dependent on the Asian water towers (AWTs). However, the mechanisms by which large-scale westerlies-advected moisture is integrated into the AWTs’ atmospheric water budget remain poorly understood due to observational gaps. Here, we combine three-dimensional observations of atmospheric water vapor stable isotopes with isotope-enabled modeling. We identify the conveyor mechanism that regulates the vertical moisture transport under calm conditions during the winter-spring period when the westerlies are dominant. Sharp vertical isotopic gradients show that large-scale westerlies-advected moisture is predominantly confined aloft, while local residual moisture persists near the surface. Our results show the interplay of the westerlies’ subsidence at night with thermodynamically distinct local residual air, yielding thermal inversions and condensation that suppresses vertical mixing and decouples moisture between the free troposphere and the atmospheric boundary layer. This process constitutes a primary pathway for integrating westerlies-advected moisture into the local moisture budget without precipitation, sustaining near-surface moisture accumulation. Our results provide critical benchmarks for improving atmospheric models, refining climate projections of the intensifying water cycle over the AWTs, and advancing interpretations of isotopic records in regional climatic archives.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (19)
Jing Gao
Tandong Yao
State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences
Valérie Masson-Delmotte
Laboratoire des Sciences du Climat et de l’Environnement (LSCE), CEA–CNRS–UVSQ–Paris-Saclay–IPSL, UMR8212, Université Paris Saclay
Martin Werner
Jean Jouzel
Laboratoire des Sciences du Climat et de l’Environnement (LSCE), CEA–CNRS–UVSQ–Paris-Saclay–IPSL, UMR8212, Université Paris Saclay
Lonnie Thompson
Byrd Polar and Climate Research Center and School of Earth Sciences, Ohio State University
Mathieu Casado
Laboratoire des Sciences du Climat et de l’Environnement (LSCE), CEA–CNRS–UVSQ–Paris-Saclay–IPSL, UMR8212, Université Paris Saclay
Hans Christian Steen-Larsen
Geophysical Institute, University of Bergen
Alexandre Cauquoin
Institute of Industrial Science, The University of Tokyo
Ellen Mosley-Thompson
Byrd Polar and Climate Research Center and Department of Geography, Ohio State University
Zeqing He
Aerospace Information Research Institute, Chinese Academy of Sciences
Rong Cai
New Cornerstone Science Laboratory, CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety & CAS Center for Excellence in Nanoscience
Taihua Zhang
Aerospace Information Research Institute, Chinese Academy of Sciences
Yigang Liu
Gebanruo Chen
State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences
Baiqing Xu
State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences
Guangjian Wu
State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences
Hongxi Pang
Key Laboratory of Coast and Island Development of Ministry of Education, School of Geography and Ocean Science, Nanjing University
Maosheng He
National Space Science Center, Chinese Academy of Sciences