Intensified Atmospheric Branch of the Hydrological Cycle Over the Tibetan Plateau During the Last Interglacial From a Dynamical Downscaling Perspective

Abstract

Investigation of the variations of hydrological cycles during the Last Interglacial (130–115 ka; LIG) may deepen our understanding of climate change in a warmer‐than‐present world induced by Earth's orbit. Here we revealed an intensified atmospheric branch of the hydrological cycle over the Tibetan Plateau (TP) in summer during the LIG relative to the preindustrial period, using the mesoscale Weather Research and Forecasting model driven by the Community Earth System Model. Our results showed that precipitation over the TP increased by 5.65 × 107 kg s−1, with 63.2% of the increase contributed by advected moisture transports, and the remaining 36.8% caused by local moisture recycling processes. As for advected moisture transports, the inflow increased by 1.93 × 107 kg s−1 and the outflow decreased by 0.87 × 107 kg s−1, respectively. Variations of the moisture transport were more profound at the eastern and northern edges, which were linked with changes in Indian summer monsoon and westerly jets. Regarding local moisture recycling processes, evaporation enhanced by 2.85 × 107 kg s−1 over the TP, influenced by variations in surface air temperature, surface net radiation flux, surface relative humidity, and surface wind fields. Increased evaporation accompanied by enhanced moisture inflow resulted in an enriched precipitation recycling ratio of ∼1% over the TP during the LIG relative to the preindustrial in summer. Our results aid in understanding the atmospheric branch of the hydrological cycle over the TP in an orbit‐induced warmer world and shed light on the future evolution of the hydrological cycle over the TP at multi‐millennial and orbital timescale.

Analyzing the Contribution of Moisture Sources to Precipitation Changes Under 1.5/2.0°C Stabilized Warming Scenarios: A Study Over Northwest China

“…Zhang & Gao, 2021). Current work on the PRR through RCM-GCM has mostly focused on the Tibetan Plateau region (N. Jiang et al, 2022;H. Zhang & Gao, 2021).…”

“…Compared with observational diagnostics, numerical climate models are also a powerful tool to investigate precipitation dynamics (N. Jiang et al., 2022; Tang et al., 2019). At the global scale, coarse‐resolution global climate models (GCMs) are reliable in providing the large‐scale circulation patterns and moisture distributions, but simulating the meso‐ to local‐scale physical processes associated with precipitation evolution remains a challenge.…”

“…Consequently, the coupling of RCMs and GCMs (RCM‐GCM) has been widely used in recent years to study the characteristics of regional precipitation variability and future climate change projections (X. Yang et al., 2023; Yao et al., 2019; H. Zhang & Gao, 2021). Current work on the PRR through RCM‐GCM has mostly focused on the Tibetan Plateau region (N. Jiang et al., 2022; H. Zhang & Gao, 2021). Existing studies showed that the RCM‐GCM can significantly improve performance of regional climate and produce more reliable future climate change projections (Bai et al., 2022; Tang et al., 2019; H. Zhang & Gao, 2021).…”