讲座简介：
Despite continuous improvements in climate models, uncertainties persist regarding the amplitude of the projected global warming and the associated hydrological changes. Better evaluating the representation of physical processes such as clouds, water vapor transport, atmospheric convection and land surface-atmosphere interactions is necessary to assess the credibility in climate change projections. Because of fractionation during phase changes, the water vapor isotopic composition reflects the history of phase changes during the water cycle. A growing number of water isotopic observations are becoming available: in situ measurements in atmospheric water vapor, precipitation, land surface and biosphere components, in-situ and remote sensing measurements in atmospheric water vapor. To what extent could these water isotopic measurements, combined with meteorological measurements, provide process-oriented diagnostics to evaluate the representation of
hydrological processes in models? We explore this question using the LMDZ atmospheric general circulation model and the ORCHIDEE land surface model in which we have implemented water isotopes. First, we will present how remote-sensing atmospheric water vapor measurements in the tropics and subtropics can be used to better evaluate the representation of vertical transport and of the convective processes, and the interplay between the different parameterizations producing clouds and rain. Second, we will investigate the use of water isotopic measurements in soil and river water to better evaluate the representation of the infiltration of rain, the partitioning of evapo-transpiration into evaporation and transpiration, and the pathways of water from the soil to rivers. Third, we will discuss the use of atmospheric water vapor measurements to evaluate the role of continental recycling in atmospheric moisture variability.