Melting of the Greenland Ice Sheet: insights from past dynamics

Over the past million years, ice sheets hundreds to thousands of meters thick have waxed and waned over the Northern Hemisphere, at times covering North America, Scandinavia, and the British Isles. Despite decades of research, we do not yet understand how an ice age starts or terminates, nor how the dynamics of ice ages are influenced by feedbacks with other elements of the earth system, such as the ocean and atmosphere. Furthermore, most climate modeling has focused only on the peak of the last ice age - the last glacial maximum. Yet this time slice is not representative of our warmer future climate. We will therefore focus on intervals of rapid ice sheet decay.  

You will work to unravel the dynamics of ice ages by investigating the growth and decay of major Northern Hemisphere ice sheets. For example, the terrestrial environment around the Laurentide Ice Sheet was highly asymmetric during its growth and decay. Large proglacial lakes formed around the margins of the Laurentide during the last deglaciation. The impact of these lakes on the surface mass balance and ice streams of the Laurentide is still debated, making it a first topic of investigation. You will also examine how atmosphere and ocean circulation responded to growing and receding ice sheet topography.  

We will apply insights from the above-mentioned research to understanding the dynamics of the Fennoscandian ice sheets and the Greenland ice sheet using existing and novel climate simulations. Lastly, we will examine the long-term fate of Greenland in future warm climates. Much of Greenland's bedrock lies below sea level, so a significant melting could allow seawater to penetrate its present-day margins, analogous to the formation of proglacial lakes during the last deglaciation. This work will have important implications for understanding sea level rise in the coming decades to centuries.  

 For this project, you will also be supervised Minmin FU (lead supervisor).