Contribution of Tibetan Plateau ecosystems to local and remote precipitation through moisture recycling

Abstract

The ecosystems of the Tibetan Plateau (TP) provide multiple important ecosystem services that benefit both local populations and those beyond, such as through climate regulation services on precipitation for East Asia and China. However, the precipitation regulation service of the TP ecosystems for supplying moisture and maintaining precipitation is yet to be evaluated. In this study, we used the moisture recycling framework and a moisture tracking model to quantify the precipitation regulation services of TP ecosystems for their contribution to precipitation. We found TP ecosystems contributed substantially to local and downwind precipitation, with a contribution of 221 mm/year for the TP and neighboring areas through evapotranspiration (ET) (104 mm/year through transpiration), declined to <10 mm/year for eastern China and other surrounding countries. Among ecosystem types, grassland contributed most to precipitation, followed by barren and snow lands, forests, and shrublands. In terms of seasonality, precipitation contribution from TP ecosystems was greater in summer months than in non‐summer months for western China, while the opposite was true for eastern China—although the magnitude was much smaller. Over the past two decades, the significant ET increases in TP translated to a widespread increase in precipitation contribution for TP and downwind beneficiary regions from 2000 to 2020. Our study provides a quantitative way to understand the precipitation regulation services of TP ecosystems through moisture recycling, substantiating their key role to maintain precipitation and the water cycle for downwind regions—effectively acting as an ecological safeguard that could be perceived by the public.

Fate and Changes in Moisture Evaporated From the Tibetan Plateau (2000–2020)

“…According to Li et al. (2023), the TP ERR using UTrack with ERA5 data is about 76.2% (their Table 2), slightly different from our estimate of 79.7% due to possible differences in the exact study region, grid size, and other factors. Based on the evaluation of the two models in simulating the fate of TP evaporation, we cautiously suggest that WAM2Layers may be a better model for this region.…”

Recycling and transport of evapotranspiration over the Tibetan Plateau: Detected by a water vapour tracer method embedded in regional climate model

“…ET in dominates the ET moisture over the TP, especially in summer the ET in ratio reaches up to 73.1%. Recently, based on EAR5, Li et al (2022b) also found the same seasonality of the contribution of ET to the TP itself and eastern China, although the uncertainty of ERA5 precipitation might exert uncertainty on results than regional climate simulations (Xu & Gao, 2019). The similarities of 2014 and multiyear average in our study, as well as our findings and results of other groups demonstrate the representative of the normal year 2014 in the spatial distribution and seasonal variation of ET for multiyears average.…”

Contribution of Recycled and External Advected Moisture to Precipitation and Its Inter‐Annual Variation Over the Tibetan Plateau

“…These can be interpreted in the way that, grasslands could enhance the precipitation contribution directly through evaporation (Y. Li et al, 2023). Since evaporation from grassland is probably driven by energy availability as proposed by Jansen et al (2023), net radiation as indication of energy availability is compared between different land-use categories, and it turns out to be the possible drivers of stronger evaporation in grasslands as expected.…”