The Stratosphere as a Key Uncertainty of the Hydrological Response to Global Warming

Our understanding of climate change, especially future projections, depends heavily on climate models, which have become the primary tool in the climate change study on mechanisms, prediction and adaptation. The authenticity of climate models is diminished by the fact that some key physical and chemical processes are not complete in some models. Here, we compared two groups of climate models from the CMIP5 with and without the full stratosphere. The models with the full stratosphere simulated a stronger hydrological cycle with higher precipitation sensitivity to the global temperature change, leading to a stronger precipitation change pattern of wet-get-wetter and dry-get-drier. We also reported significant discrepancies in the circulation parameters such as the height of the tropopause, the strength and position of the subtropical jet and the strength of the meridional circulation between two groups, suggesting the necessity of updating climate change assessment using models with better descriptions of the stratosphere.