Contribution of Recycled Moisture to Precipitation in an Inland River Basin Over Temperate Grasslands: Considering Cold‐Warm Air Mass Convergences

Abstract Vegetation‐air mass interactions play a critical role in regulating recycled moisture dynamics in temperate grasslands. This study focused on a representative inland river basin, primarily including typical, meadow, and sparse wood grasslands. To account for the impacts of cold and warm air mass convergence, we improved the isotope‐based estimation framework by incorporating the tracer signals from multiple advected vapor sources, identified using a trajectory model. The results indicate that the contribution of recycled moisture to precipitation was suppressed under cold‐cold air mass convergence, but enhanced under cold‐warm air mass convergence; meadow grasslands showed the largest contribution of recycled moisture to precipitation (43.1%), followed by sparse wood grasslands (41.3%) and typical grasslands (17.6%). The contribution of plant transpiration to precipitation ( f tr ) was significantly greater than that of surface evaporation ( f ev ). Specifically, the f tr in meadow grasslands was estimated at 38%, much larger than those in sparse wood grasslands (25.3%) and typical grasslands (9.2%). This highlights that under cold‐warm air mass convergence, the intense plant transpiration in meadow grasslands plays a crucial role in regional precipitation formation. The results are important for evaluating the water balance of inland grassland ecosystems.