LAUSR

Abstract As one of the typical underlying surfaces on the Qinghai-Tibetan Plateau (QTP), alpine wetlands play a very important role in runoff regulation and affect climate change in downstream regions. However, the mechanisms of the latent heat transfer and coupling processes between the alpine wetland and atmosphere have rarely been investigated with a combination of land surface models. In this paper, the hydrometeorological factors are analyzed, the coupling degree is quantified, and the controlling factors are discussed. Alpine wetland has a hysteretic response to the net radiation, and the dominant factor controlling the latent heat flux is downward shortwave radiation (Rs), which intensely promoting the exchange of latent heat flux in the daytime. Biological control exercised by Rs is positive and decreasing with the increasing of Rs, while biological control exercised by water vapor pressure deficit (D) is negative and increasing with the increasing of D. The coupling degree is low from 9:00–17:00 when latent heat flux is mainly controlled by Rs and high in the early morning and 19:00 when D is the dominant factor. This study contributes to understanding land surface processes and protecting alpine wetland ecosystems on the QTP.