Abstract:
The Tibetan Plateau (TP) is a key area affecting extreme weather and climate events and related weather and climate forecasting in China. The China Meteorological Administration (CMA), the National Natural Scientific Foundation of China, and the Chinese Academy of Sciences jointly initiated the Third Tibetan Plateau Atmospheric Scientific Experiment (TIPEX-Ⅲ). Since the preliminary experiment conducted in 2013, routine automatic sounding systems have been newly deployed at Shiquanhe, Gaize and Shenzha stations during the TIPEX-Ⅲ, which fills the gap of routine operational sounding stations lacked over the western TP. Observational networks for soil temperature and moisture in the central and western TP have also been established. Meanwhile, the TIPEX-Ⅲ also conducted plateau- and regional-scale boundary-layer observations, measured cloud-precipitation microphysical characteristics by multiple radars and aircraft campaigns, and collected tropospheric-stratospheric atmospheric composition at multiple sites. The research results of the TIPEX-Ⅲ show that the surface turbulent heat exchange coefficient and sensible heat flux are remarkably lower than the earlier estimations at grassland, meadow and bare soil surfaces of the central and western TP. Climatologically, cumulus clouds over the main body of the TP might develop locally instead of originating from cumulus clouds that propagate northward from South Asia. The TIPEX-Ⅲ reveals diurnal variations of cumulus cloud, macro- and micro-physical characteristics of cloud and mechanisms for the transition between different water phases in clouds, proposes a maintenance mechanism responsible for the Asian "atmospheric water tower", and explores the effects of the TP heating anomalies on Asian, African, and North American climates. In the numerical forecast models, it is found that the Γ raindrop size distribution is more suitable for the TP characteristics compared to the M-P distribution, and modifying the parametrization scheme of heat transfer processes over the TP can reduce the overestimation of simulated sensible heat, which may further improve the skill for rain belt simulation in central and eastern parts of China. Considering climatic signals in some key areas of the TP can also improve the skill for rainfall forecast in the central and eastern parts of China. Moreover, the TIPEX-Ⅲ promotes the development of operational technology in processing surface observations, soundings, and radar observations, improves the quality of satellite remote sensing soil moisture and atmospheric water vapor content products as well as high-resolution gauge-radar-satellite merged rainfall products, and promotes the development of meteorological monitoring, forecast, and data sharing operations.
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