A hydroclimatological perspective of tropical cyclone activity and the uncertainty in climate sensitivity: the role of extratropical transition and ocean salinity
Predicting weather and climate extremes such as tropical cyclones and constraining climate sensitivity are two grand challenges facing the climate community. In this talk, I will discuss my work towards addressing these two challenges. In the first part of my talk, I will focus on the Extratropical Transition (ET) of tropical cyclones. I will first highlight the role of ET in shaping flood hazards in the Northeastern US at both the individual event scale and the climatological scale. I will then discuss the seasonal prediction and predictability of ET of tropical cyclones. I will show the long-term change in ET activity under a warming climate in the North Atlantic and how this change influences future flood risks in the Northeastern US.
In the second part of my talk, I will discuss the often overlooked role of ocean salinity in affecting climate sensitivity. I will demonstrate how changes in salinity due to changes in the water cycle enhance ocean heat uptake (OHU) and moderate transient warming. The importance of ocean salinity is further highlighted by its dominant role, relative to ocean temperature, in determining the inter-model spread in OHU efficiency in Coupled Model Intercomparison Project Phase 6 (CMIP6) models. Lastly, I will show that the model spread of cloud feedback from CMIP6 models, one of the most important sources of uncertainty in climate sensitivity, largely depends on the pre-conditioning salinity in the extratropical Southern Ocean. This opens the door to constrain OHU efficiency, cloud feedback, and climate sensitivity using salinity observations.
Zoom link: https://illinois.zoom.us/j/88283770092?pwd=bHB0WjM2Znc1cUdvYnY3dVREbWxGUT09