Observed trend drivers of West African storms and implications for rainfall intensification in climate projections

Séminaire de C. Klein le mardi 18 mai à 14h en visio

Title : Observed trend drivers of West African storms and implications for rainfall intensification in climate projections

Séminar by Cornelia Klein,University of Innsbruck
Link to the Zoom : here

Abstract : Organised convective storm clusters, known as mesoscale convective systems (MCSs), dominate rainfall and its extremes in most parts of West Africa. Yet, projected changes in future convective rainfall characteristics and intensities remain highly uncertain. This is in part because traditional coarse-scale climate models we rely on, such as those in the Climate Model Intercomparison Project (CMIP) ensembles, cannot explicitly capture convective processes, rendering their representation of extreme precipitation questionable.

In this context, convection-permitting (CP) simulations have been found to simulate a more realistic MCS interaction with atmospheric and land surface states, hence are useful tools to obtain improved rainfall predictions, though not without limitations. Based on our recent studies on observed historical MCS trend drivers, I will present why the land surface may play an important role for future storm trends, why CMIP models lack a key feedback linking global warming to more extreme rainfall, and why CP models still aren’t the solution to everything. Finally, I will illustrate how changes in atmospheric MCS drivers can be used as proxies to infer future change in extreme rainfall by combining the strengths of observations, CMIP and CP models.

Conni Klein is an atmospheric scientist at the UK Centre for Ecology and Hydrology and the University of Innsbruck, Austria. She received her PhD in 2016 on the topic of West African monsoon dynamics and land-atmosphere interactions (WASCAL) at the University of Augsburg / Karlsruhe Institute of Technology, Germany. Her research focuses on organised convective storms and how their characteristics are affected by changing atmospheric conditions and land surface states. Her current projects are targeting tropical regions, in particular Africa and tropical South America, using a combination of remote sensing and atmospheric models to better understand processes that drive convective rainfall predictability and change, and to benchmark convection-permitting models for weather forecasts and climate projections.